Merge pull request #880 from mapbox/version-1.36.0

Forgot to increment the version number

.dockerignore

@@ -0,0 +1,5 @@
+# Don't copy Dockerfile or git items
+.gitignore
+.git
+Dockerfile
+Dockerfile.centos7

.gitignore

@@ -4,6 +4,9 @@
 *.o
 *.obj
 
+# Autogenerated dependencies
+*.d
+
 # Precompiled Headers
 *.gch
 *.pch
@@ -27,3 +30,23 @@
 *.exe
 *.out
 *.app
+tippecanoe
+tile-join
+tippecanoe-decode
+tippecanoe-enumerate
+tippecanoe-json-tool
+unit
+
+# Tests
+tests/**/*.mbtiles
+tests/**/*.check
+tests/**/*.geobuf
+
+# Vim
+*.swp
+
+# Mac
+.DS_Store
+
+# Nodejs
+node_modules

.travis.yml

@@ -1,9 +1,37 @@
-language: generic
+language: node_js
+node_js:
+  - "6"
 
 sudo: false
 
 matrix:
   include:
+    # test on docker+centos7
+    - os: linux
+      compiler: clang
+      services:
+       - docker
+      sudo: true
+      dist: trusty
+      env: DOCKERFILE=Dockerfile.centos7
+      before_install: []
+      install:
+        - docker build -t tippecanoe-image -f ${DOCKERFILE} .
+      script:
+        - docker run -it tippecanoe-image
+    # test on docker+ubuntu
+    - os: linux
+      compiler: clang
+      services:
+       - docker
+      sudo: true
+      dist: trusty
+      env: DOCKERFILE=Dockerfile
+      before_install: []
+      install:
+        - docker build -t tippecanoe-image -f ${DOCKERFILE} .
+      script:
+        - docker run -it tippecanoe-image
     # debug+integer-santizer build
     - os: linux
       compiler: clang
@@ -15,7 +43,7 @@ matrix:
     # debug+leak+address-sanitizer build
     - os: linux
       compiler: clang
-      env: CLANG_VERSION='3.8.0' BUILDTYPE=Debug ASAN_OPTIONS=detect_leaks=1 CC="clang-3.8" CXX="clang++-3.8" CXXFLAGS="-fsanitize=address" CFLAGS="-fsanitize=address" LDFLAGS="-fsanitize=address"
+      env: CLANG_VERSION='3.8.0' BUILDTYPE=Debug ASAN_OPTIONS=detect_leaks=1 CC="clang-3.8" CXX="clang++-3.8" CXXFLAGS="-fsanitize=address,undefined" CFLAGS="-fsanitize=address,undefined" LDFLAGS="-fsanitize=address,undefined" FEWER=true
       addons:
         apt:
           sources: ['ubuntu-toolchain-r-test' ]
@@ -24,6 +52,13 @@ matrix:
     - os: linux
       compiler: clang
       env: CLANG_VERSION='3.8.0' BUILDTYPE=Debug CC="clang-3.8" CXX="clang++-3.8" CXXFLAGS="--coverage" CFLAGS="--coverage" LDFLAGS="--coverage"
+      after_script:
+        - mason install llvm-cov 3.9.1
+        - mason link llvm-cov 3.9.1
+        - which llvm-cov
+        - curl -S -f https://codecov.io/bash -o codecov
+        - chmod +x codecov
+        - ./codecov -x "llvm-cov gcov" -Z
       addons:
         apt:
           sources: ['ubuntu-toolchain-r-test' ]
@@ -68,9 +103,8 @@ install:
  - BUILDTYPE=${BUILDTYPE} make -j
 
 script:
- - BUILDTYPE=${BUILDTYPE} make test
- - if [ -n "${COVERAGE}" ]; then
-       /usr/bin/llvm-cov-3.5 -lp *.o;
-       pip install --user cpp-coveralls;
-       ~/.local/bin/coveralls --no-gcov -i ./ --exclude clipper;
+ - npm install geobuf
+ - if [ -n "${FEWER}" ]; then
+       BUILDTYPE=${BUILDTYPE} make fewer-tests; else
+       BUILDTYPE=${BUILDTYPE} make test geobuf-test;
    fi

CHANGELOG.md

@@ -1,3 +1,504 @@
+## 1.36.0
+
+* Update Wagyu to version 0.5.0
+
+## 1.35.0
+
+* Fix calculation of mean when accumulating attributes in clusters
+
+## 1.34.6
+
+* Fix crash when there are null entries in the metadata table
+
+## 1.34.5
+
+* Fix line numbers in GeoJSON feature parsing error messages
+
+## 1.34.4
+
+* Be careful to avoid undefined behavior from shifting negative numbers
+
+## 1.34.3
+
+* Add an option to keep intersection nodes from being simplified away
+
+## 1.34.2
+
+* Be more consistent about when longitudes beyond 180 are allowed.
+  Now if the entire feature is beyond 180, it will still appear.
+
+## 1.34.1
+
+* Don't run shell filters if the current zoom is below the minzoom
+* Fix -Z and -z for tile directories in tile-join and tippecanoe-decode
+* Return a successful error status for --help and --version
+
+## 1.34.0
+
+* Record the command line options in the tileset metadata
+
+## 1.33.0
+
+* MultiLineStrings were previously ignored in Geobuf input
+
+## 1.32.12
+
+* Accept .mvt as well as .pbf in directories of tiles
+* Allow tippecanoe-decode and tile-join of directories with no metadata
+
+## 1.32.11
+* Don't let attribute exclusion apply to the attribute that has been specified
+  to become the feature ID
+
+## 1.32.10
+
+* Fix a bug that disallowed a per-feature minzoom of 0
+
+## 1.32.9
+
+* Limit tile detail to 30 and buffer size to 127 to prevent coordinate
+  delta overflow in vector tiles.
+
+## 1.32.8
+
+* Better error message if the output tileset already exists
+
+## 1.32.7
+
+* Point features may now be coalesced into MultiPoint features with --coalesce.
+* Add --hilbert option to put features in Hilbert Curve sequence
+
+## 1.32.6
+
+* Make it an error, not a warning, to have missing coordinates for a point
+
+## 1.32.5
+
+* Use less memory on lines and polygons that are too small for the tile
+* Fix coordinate rounding problem that was causing --grid-low-zooms grids
+  to be lost at low zooms if the original polygons were not aligned to
+  tile boundaries
+
+## 1.32.4
+
+* Ignore leading zeroes when converting string attributes to feature IDs
+
+## 1.32.3
+
+* Add an option to convert stringified number feature IDs to numbers
+* Add an option to use a specified feature attribute as the feature ID
+
+## 1.32.2
+
+* Warn in tile-join if tilesets being joined have inconsistent maxzooms
+
+## 1.32.1
+
+* Fix null pointer crash when reading filter output that does not
+  tag features with their extent
+* Add `--clip-bounding-box` option to clip input geometry
+
+## 1.32.0
+
+* Fix a bug that allowed coalescing of features with mismatched attributes
+  if they had been passed through a shell prefilter
+
+## 1.31.7
+
+* Create the output tile directory even if there are no valid features
+
+## 1.31.6
+
+* Issue an error message in tile-join if minzoom is greater than maxzoom
+
+## 1.31.5
+
+* Add options to change the tilestats limits
+
+## 1.31.4
+
+* Keep tile-join from generating a tileset name longer than 255 characters
+
+## 1.31.3
+
+* Fix the missing filename in JSON parsing warning messages
+
+## 1.31.2
+
+* Don't accept anything inside another JSON object's properties as a
+  feature or geometry of its own.
+
+## 1.31.1
+
+* Add --exclude-all to tile-join
+
+## 1.31.0
+
+* Upgrade Wagyu to version 0.4.3
+
+## 1.30.6
+
+* Take cluster distance into account when guessing a maxzoom
+
+## 1.30.4
+
+* Features within the z0 tile buffer of the antimeridian (not only
+  those that cross it) are duplicated on both sides.
+
+## 1.30.3
+
+* Add an option to automatically assign ids to features
+
+## 1.30.2
+
+* Don't guess a higher maxzoom than is allowed for manual selection
+
+## 1.30.1
+
+* Ensure that per-feature minzoom and maxzoom are integers
+* Report compression errors in tippecanoe-decode
+* Add the ability to specify the file format with -L{"format":"…"}
+* Add an option to treat empty CSV columns as nulls, not empty strings
+
+## 1.30.0
+
+* Add a filter extension to allow filtering individual attributes
+
+## 1.29.3
+
+* Include a generator field in tileset metadata with the Tippecanoe version
+
+## 1.29.2
+
+* Be careful to remove null attributes from prefilter/postfilter output
+
+## 1.29.1
+
+* Add --use-source-polygon-winding and --reverse-source-polygon-winding
+
+## 1.29.0
+
+* Add the option to specify layer file, name, and description as JSON
+* Add the option to specify the description for attributes in the
+  tileset metadata
+* In CSV input, a trailing comma now counts as a trailing empty field
+* In tippecanoe-json-tool, an empty CSV field is now an empty string,
+  not null (for consistency with tile-join)
+
+## 1.28.1
+
+* Explicitly check for infinite and not-a-number input coordinates
+
+## 1.28.0
+
+* Directly support gzipped GeoJSON as input files
+
+## 1.27.16
+
+* Fix thread safety issues related to the out-of-disk-space checker
+
+## 1.27.15
+
+* --extend-zooms-if-still-dropping now also extends zooms if features
+  are dropped by --force-feature-limit
+
+## 1.27.14
+
+* Use an exit status of 100 if some zoom levels were successfully
+  written but not all zoom levels could be tiled.
+
+## 1.27.13
+
+* Allow filtering features by zoom level in conditional expressions
+* Lines in CSV input with empty geometry columns will be ignored
+
+## 1.27.12
+
+* Check integrity of sqlite3 file before decoding or tile-joining
+
+## 1.27.11
+
+* Always include tile and layer in tippecanoe-decode, fixing corrupt JSON.
+* Clean up writing of JSON in general.
+
+## 1.27.10
+
+* Add --progress-interval setting to reduce progress indicator frequency
+
+## 1.27.9
+
+* Make clusters look better by averaging locations of clustered points
+
+## 1.27.8
+
+* Add --accumulate-attribute to keep attributes of dropped, coalesced,
+  or clustered features
+* Make sure numeric command line arguments are actually numbers
+* Don't coalesce features whose non-string-pool attributes don't match
+
+## 1.27.7
+
+* Add an option to produce only a single tile
+* Retain non-ASCII characters in layernames generated from filenames
+* Remember to close input files after reading them
+* Add --coalesce-fraction-as-needed and --coalesce-densest-as-needed
+* Report distances in both feet and meters
+
+## 1.27.6
+
+* Fix opportunities for integer overflow and out-of-bounds references
+
+## 1.27.5
+
+* Add --cluster-densest-as-needed to cluster features
+* Add --maximum-tile-features to set the maximum number of features in a tile
+
+## 1.27.4
+
+* Support CSV point input
+* Don't coalesce features that have different IDs but are otherwise identical
+* Remove the 700-point limit on coalesced features, since polygon merging
+  is no longer a performance problem
+
+## 1.27.3
+
+* Clean up duplicated code for reading tiles from a directory
+
+## 1.27.2
+
+* Tippecanoe-decode can decode directories of tiles, not just mbtiles
+* The --allow-existing option works on directories of tiles
+* Trim .geojson, not just .json, when making layer names from filenames
+
+## 1.27.1
+
+* Fix a potential null pointer when parsing GeoJSON with bare geometries
+* Fix a bug that could cause the wrong features to be coalesced when
+  input was parsed in parallel
+
+## 1.27.0
+
+* Add tippecanoe-json-tool for sorting and joining GeoJSON files
+* Fix problem where --detect-shared-borders could simplify polygons away
+* Attach --coalesce-smallest-as-needed leftovers to the last feature, not the first
+* Fix overflow when iterating through 0-length lists backwards
+
+## 1.26.7
+
+* Add an option to quiet the progress indicator but not warnings
+* Enable more compiler warnings and fix related problems
+
+## 1.26.6
+
+* Be more careful about checking for overflow when parsing numbers
+
+## 1.26.5
+
+* Support UTF-16 surrogate pairs in JSON strings
+* Support arbitrarily long lines in CSV files.
+* Treat CSV fields as numbers only if they follow JSON number syntax
+
+## 1.26.4
+
+* Array bounds bug fix in binary to decimal conversion library
+
+## 1.26.3
+
+* Guard against impossible coordinates when decoding tilesets
+
+## 1.26.2
+
+* Make sure to encode tile-joined integers as ints, not doubles
+
+## 1.26.1
+
+* Add tile-join option to rename layers
+
+## 1.26.0
+
+Fix error when parsing attributes with empty-string keys
+
+## 1.25.0
+
+* Add --coalesce-smallest-as-needed strategy for reducing tile sizes
+* Add --stats option to tipppecanoe-decode
+
+## 1.24.1
+
+* Limit the size and depth of the string pool for better performance
+
+## 1.24.0
+
+* Add feature filters using the Mapbox GL Style Specification filter syntax
+
+## 1.23.0
+
+* Add input support for Geobuf file format
+
+## 1.22.2
+
+* Add better diagnostics for NaN or Infinity in input JSON
+
+## 1.22.1
+
+* Fix tilestats generation when long string attribute values are elided
+* Add option not to produce tilestats
+* Add tile-join options to select zoom levels to copy
+
+## 1.22.0
+
+* Add options to filter each tile's contents through a shell pipeline
+
+## 1.21.0
+
+* Generate layer, feature, and attribute statistics as part of tileset metadata
+
+## 1.20.1
+
+* Close mbtiles file properly when there are no valid features in the input
+
+## 1.20.0
+
+* Add long options to tippecanoe-decode and tile-join. Add --quiet to tile-join.
+
+## 1.19.3
+
+* Upgrade protozero to version 1.5.2
+
+## 1.19.2
+
+* Ignore UTF-8 byte order mark if present
+
+## 1.19.1
+
+* Add an option to increase maxzoom if features are still being dropped
+
+## 1.19.0
+
+* Tile-join can merge and create directories, not only mbtiles
+* Maxzoom guessing (-zg) takes into account resolution within each feature
+
+## 1.18.2
+
+* Fix crash with very long (>128K) attribute values
+
+## 1.18.1
+
+* Only warn once about invalid polygons in tippecanoe-decode
+
+## 1.18.0
+
+* Fix compression of tiles in tile-join
+* Calculate the tileset bounding box in tile-join from the tile boundaries
+
+## 1.17.7
+
+* Enforce polygon winding and closure rules in tippecanoe-decode
+
+## 1.17.6
+
+* Add tile-join options to set name, attribution, description
+
+## 1.17.5
+
+* Preserve the tileset names from the source mbtiles in tile-join
+
+## 1.17.4
+
+* Fix RFC 8142 support: Don't try to split *all* memory mapped files
+
+## 1.17.3
+
+* Support RFC 8142 GeoJSON text sequences
+
+## 1.17.2
+
+* Organize usage output the same way as in the README
+
+## 1.17.1
+
+* Add -T option to coerce the types of feature attributes
+
+## 1.17.0
+
+* Add -zg option to guess an appropriate maxzoom
+
+## 1.16.17
+
+* Clean up JSON parsing at the end of each FeatureCollection
+  to avoid running out of memory
+
+## 1.16.16
+
+* Add tile-join options to include or exclude specific layers
+
+## 1.16.15
+
+* Add --output-to-directory and --no-tile-compression options
+
+## 1.16.14
+
+* Add --description option for mbtiles metadata
+* Clean up some utility functions
+
+## 1.16.13
+
+* Add --detect-longitude-wraparound option
+
+## 1.16.12
+
+* Stop processing higher zooms when a feature reaches its explicit maxzoom tag
+
+## 1.16.11
+
+* Remove polygon splitting, since polygon cleaning is now fast enough
+
+## 1.16.10
+
+* Add a tippecanoe-decode option to specify layer names
+
+## 1.16.9
+
+* Clean up layer name handling to fix layer merging crash
+
+## 1.16.8
+
+* Fix some code that could sometimes try to divide by zero
+* Add check for $TIPPECANOE_MAX_THREADS environmental variable
+
+## 1.16.7
+
+* Fix area of placeholders for degenerate multipolygons
+
+## 1.16.6
+
+* Upgrade Wagyu to 0.3.0; downgrade C++ requirement to C++ 11
+
+## 1.16.5
+
+* Add -z and -Z options to tippecanoe-decode
+
+## 1.16.4
+
+* Use Wagyu's quick_lr_clip() instead of a separate implementation
+
+## 1.16.3
+
+* Upgrade Wagyu to bfbf2893
+
+## 1.16.2
+
+* Associate attributes with the right layer when explicitly tagged
+
+## 1.16.1
+
+* Choose a deeper starting tile than 0/0/0 if there is one that contains
+  all the features
+
+## 1.16.0
+
+* Switch from Clipper to Wagyu for polygon topology correction
+
 ## 1.15.4
 
 * Dot-dropping with -r/-B doesn't apply if there is a per-feature minzoom tag

Dockerfile

@@ -0,0 +1,19 @@
+# Start from ubuntu
+FROM ubuntu:16.04
+
+# Update repos and install dependencies
+RUN apt-get update \
+  && apt-get -y upgrade \
+  && apt-get -y install build-essential libsqlite3-dev zlib1g-dev
+
+# Create a directory and copy in all files
+RUN mkdir -p /tmp/tippecanoe-src
+WORKDIR /tmp/tippecanoe-src
+COPY . /tmp/tippecanoe-src
+
+# Build tippecanoe
+RUN make \
+  && make install
+
+# Run the tests
+CMD make test

Dockerfile.centos7

@@ -0,0 +1,15 @@
+FROM centos:7
+
+RUN yum install -y make sqlite-devel zlib-devel bash git gcc-c++
+
+# Create a directory and copy in all files
+RUN mkdir -p /tmp/tippecanoe-src
+WORKDIR /tmp/tippecanoe-src
+COPY . /tmp/tippecanoe-src
+
+# Build tippecanoe
+RUN make \
+  && make install
+
+# Run the tests
+CMD make test

MADE_WITH.md

@@ -1,4 +1,4 @@
-## [Visualizing a Month of Lightning](http://rousseau.io/2015/03/23/visualizing-a-month-of-lightning/) by Jordan Rousseau
+## [Visualizing a Month of Lightning](http://rousseau.io/2015/03/23/visualizing-a-month-of-lightning) by Jordan Rousseau
 
 ![](http://rousseau.io/assets/img/ltg-studio-style.png)
 

Makefile

@@ -7,9 +7,9 @@ SHELL = /bin/bash
 CC := $(CC)
 CXX := $(CXX)
 CFLAGS := $(CFLAGS)
-CXXFLAGS := $(CXXFLAGS) -std=c++14
+CXXFLAGS := $(CXXFLAGS) -std=c++11
 LDFLAGS := $(LDFLAGS)
-WARNING_FLAGS := -Wall -Wshadow -Wsign-compare
+WARNING_FLAGS := -Wall -Wshadow -Wsign-compare -Wextra -Wunreachable-code -Wuninitialized -Wshadow
 RELEASE_FLAGS := -O3 -DNDEBUG
 DEBUG_FLAGS := -O0 -DDEBUG -fno-inline-functions -fno-omit-frame-pointer
 
@@ -19,19 +19,23 @@ else
 	FINAL_FLAGS := -g $(WARNING_FLAGS) $(DEBUG_FLAGS)
 endif
 
-all: tippecanoe tippecanoe-enumerate tippecanoe-decode tile-join unit
+all: tippecanoe tippecanoe-enumerate tippecanoe-decode tile-join unit tippecanoe-json-tool
 
 docs: man/tippecanoe.1
 
-install: tippecanoe tippecanoe-enumerate tippecanoe-decode tile-join
+install: tippecanoe tippecanoe-enumerate tippecanoe-decode tile-join tippecanoe-json-tool
 	mkdir -p $(PREFIX)/bin
 	mkdir -p $(MANDIR)
 	cp tippecanoe $(PREFIX)/bin/tippecanoe
 	cp tippecanoe-enumerate $(PREFIX)/bin/tippecanoe-enumerate
 	cp tippecanoe-decode $(PREFIX)/bin/tippecanoe-decode
+	cp tippecanoe-json-tool $(PREFIX)/bin/tippecanoe-json-tool
 	cp tile-join $(PREFIX)/bin/tile-join
 	cp man/tippecanoe.1 $(MANDIR)/tippecanoe.1
 
+uninstall:
+	rm $(PREFIX)/bin/tippecanoe $(PREFIX)/bin/tippecanoe-enumerate $(PREFIX)/bin/tippecanoe-decode $(PREFIX)/bin/tile-join $(MANDIR)/tippecanoe.1 $(PREFIX)/bin/tippecanoe-json-tool
+
 man/tippecanoe.1: README.md
 	md2man-roff README.md > man/tippecanoe.1
 
@@ -40,19 +44,22 @@ PG=
 H = $(wildcard *.h) $(wildcard *.hpp)
 C = $(wildcard *.c) $(wildcard *.cpp)
 
-INCLUDES = -I/usr/local/include -I. -I../geometry.hpp/include -I../variant/include -I../wagyu/include
+INCLUDES = -I/usr/local/include -I.
 LIBS = -L/usr/local/lib
 
-tippecanoe: geojson.o jsonpull/jsonpull.o tile.o pool.o mbtiles.o geometry.o projection.o memfile.o mvt.o serial.o main.o text.o
+tippecanoe: geojson.o jsonpull/jsonpull.o tile.o pool.o mbtiles.o geometry.o projection.o memfile.o mvt.o serial.o main.o text.o dirtiles.o plugin.o read_json.o write_json.o geobuf.o evaluator.o geocsv.o csv.o geojson-loop.o
 	$(CXX) $(PG) $(LIBS) $(FINAL_FLAGS) $(CXXFLAGS) -o $@ $^ $(LDFLAGS) -lm -lz -lsqlite3 -lpthread
 
 tippecanoe-enumerate: enumerate.o
-	$(CXX) $(PG) $(LIBS) $(FINAL_FLAGS) $(CFLAGS) -o $@ $^ $(LDFLAGS) -lsqlite3
+	$(CXX) $(PG) $(LIBS) $(FINAL_FLAGS) $(CXXFLAGS) -o $@ $^ $(LDFLAGS) -lsqlite3
 
-tippecanoe-decode: decode.o projection.o mvt.o
+tippecanoe-decode: decode.o projection.o mvt.o write_json.o text.o jsonpull/jsonpull.o dirtiles.o
 	$(CXX) $(PG) $(LIBS) $(FINAL_FLAGS) $(CXXFLAGS) -o $@ $^ $(LDFLAGS) -lm -lz -lsqlite3
 
-tile-join: tile-join.o projection.o pool.o mbtiles.o mvt.o memfile.o
+tile-join: tile-join.o projection.o pool.o mbtiles.o mvt.o memfile.o dirtiles.o jsonpull/jsonpull.o text.o evaluator.o csv.o write_json.o
+	$(CXX) $(PG) $(LIBS) $(FINAL_FLAGS) $(CXXFLAGS) -o $@ $^ $(LDFLAGS) -lm -lz -lsqlite3 -lpthread
+
+tippecanoe-json-tool: jsontool.o jsonpull/jsonpull.o csv.o text.o geojson-loop.o
 	$(CXX) $(PG) $(LIBS) $(FINAL_FLAGS) $(CXXFLAGS) -o $@ $^ $(LDFLAGS) -lm -lz -lsqlite3 -lpthread
 
 unit: unit.o text.o
@@ -67,7 +74,7 @@ unit: unit.o text.o
 	$(CXX) -MMD $(PG) $(INCLUDES) $(FINAL_FLAGS) $(CXXFLAGS) -c -o $@ $<
 
 clean:
-	rm -f ./tippecanoe ./tippecanoe-* ./tile-join ./unit *.o *.d */*.o */*.d
+	rm -f ./tippecanoe ./tippecanoe-* ./tile-join ./unit *.o *.d */*.o */*.d tests/**/*.mbtiles tests/**/*.check
 
 indent:
 	clang-format -i -style="{BasedOnStyle: Google, IndentWidth: 8, UseTab: Always, AllowShortIfStatementsOnASingleLine: false, ColumnLimit: 0, ContinuationIndentWidth: 8, SpaceAfterCStyleCast: true, IndentCaseLabels: false, AllowShortBlocksOnASingleLine: false, AllowShortFunctionsOnASingleLine: false, SortIncludes: false}" $(C) $(H)
@@ -75,68 +82,259 @@ indent:
 TESTS = $(wildcard tests/*/out/*.json)
 SPACE = $(NULL) $(NULL)
 
-test: tippecanoe tippecanoe-decode $(addsuffix .check,$(TESTS)) parallel-test pbf-test join-test enumerate-test unit
+test: tippecanoe tippecanoe-decode $(addsuffix .check,$(TESTS)) raw-tiles-test parallel-test pbf-test join-test enumerate-test decode-test join-filter-test unit json-tool-test allow-existing-test csv-test layer-json-test
 	./unit
 
+suffixes = json json.gz
+
 # Work around Makefile and filename punctuation limits: _ for space, @ for :, % for /
 %.json.check:
-	./tippecanoe -aD -f -o $@.mbtiles $(subst @,:,$(subst %,/,$(subst _, ,$(patsubst %.json.check,%,$(word 4,$(subst /, ,$@)))))) $(wildcard $(subst $(SPACE),/,$(wordlist 1,2,$(subst /, ,$@)))/*.json) < /dev/null
-	./tippecanoe-decode $@.mbtiles > $@.out
-	cmp $(patsubst %.check,%,$@) $@.out
+	./tippecanoe -q -a@ -f -o $@.mbtiles $(subst @,:,$(subst %,/,$(subst _, ,$(patsubst %.json.check,%,$(word 4,$(subst /, ,$@)))))) $(foreach suffix,$(suffixes),$(sort $(wildcard $(subst $(SPACE),/,$(wordlist 1,2,$(subst /, ,$@)))/*.$(suffix)))) < /dev/null
+	./tippecanoe-decode -x generator $@.mbtiles > $@.out
+	cmp $@.out $(patsubst %.check,%,$@)
+	rm $@.out $@.mbtiles
+
+# Don't test overflow with geobuf, because it fails (https://github.com/mapbox/geobuf/issues/87)
+# Don't test stringids with geobuf, because it fails
+nogeobuf = tests/overflow/out/-z0.json $(wildcard tests/stringid/out/*.json)
+geobuf-test: tippecanoe-json-tool $(addsuffix .checkbuf,$(filter-out $(nogeobuf),$(TESTS)))
+
+# For quicker address sanitizer build, hope that regular JSON parsing is tested enough by parallel and join tests
+fewer-tests: tippecanoe tippecanoe-decode geobuf-test raw-tiles-test parallel-test pbf-test join-test enumerate-test decode-test join-filter-test unit
+
+# XXX Use proper makefile rules instead of a for loop
+%.json.checkbuf:
+	for i in $(wildcard $(subst $(SPACE),/,$(wordlist 1,2,$(subst /, ,$@)))/*.json); do ./tippecanoe-json-tool -w $$i | ./node_modules/geobuf/bin/json2geobuf > $$i.geobuf; done
+	for i in $(wildcard $(subst $(SPACE),/,$(wordlist 1,2,$(subst /, ,$@)))/*.json.gz); do gzip -dc $$i | ./tippecanoe-json-tool -w | ./node_modules/geobuf/bin/json2geobuf > $$i.geobuf; done
+	./tippecanoe -q -a@ -f -o $@.mbtiles $(subst @,:,$(subst %,/,$(subst _, ,$(patsubst %.json.checkbuf,%,$(word 4,$(subst /, ,$@)))))) $(foreach suffix,$(suffixes),$(addsuffix .geobuf,$(sort $(wildcard $(subst $(SPACE),/,$(wordlist 1,2,$(subst /, ,$@)))/*.$(suffix))))) < /dev/null
+	./tippecanoe-decode -x generator $@.mbtiles | sed 's/checkbuf/check/g' | sed 's/\.geobuf//g' > $@.out
+	cmp $@.out $(patsubst %.checkbuf,%,$@)
 	rm $@.out $@.mbtiles
 
 parallel-test:
 	mkdir -p tests/parallel
-	perl -e 'for ($$i = 0; $$i < 20; $$i++) { $$lon = rand(360) - 180; $$lat = rand(180) - 90; print "{ \"type\": \"Feature\", \"properties\": { \"yes\": \"no\", \"who\": 1 }, \"geometry\": { \"type\": \"Point\", \"coordinates\": [ $$lon, $$lat ] } }\n"; }' > tests/parallel/in1.json
+	perl -e 'for ($$i = 0; $$i < 20; $$i++) { $$lon = rand(360) - 180; $$lat = rand(180) - 90; $$k = rand(1); $$v = rand(1); print "{ \"type\": \"Feature\", \"properties\": { \"yes\": \"no\", \"who\": 1, \"$$k\": \"$$v\" }, \"geometry\": { \"type\": \"Point\", \"coordinates\": [ $$lon, $$lat ] } }\n"; }' > tests/parallel/in1.json
 	perl -e 'for ($$i = 0; $$i < 300000; $$i++) { $$lon = rand(360) - 180; $$lat = rand(180) - 90; print "{ \"type\": \"Feature\", \"properties\": { }, \"geometry\": { \"type\": \"Point\", \"coordinates\": [ $$lon, $$lat ] } }\n"; }' > tests/parallel/in2.json
 	perl -e 'for ($$i = 0; $$i < 20; $$i++) { $$lon = rand(360) - 180; $$lat = rand(180) - 90; print "{ \"type\": \"Feature\", \"properties\": { }, \"geometry\": { \"type\": \"Point\", \"coordinates\": [ $$lon, $$lat ] } }\n"; }' > tests/parallel/in3.json
+	perl -e 'for ($$i = 0; $$i < 20; $$i++) { $$lon = rand(360) - 180; $$lat = rand(180) - 90; $$v = rand(1); print "{ \"type\": \"Feature\", \"properties\": { }, \"tippecanoe\": { \"layer\": \"$$v\" }, \"geometry\": { \"type\": \"Point\", \"coordinates\": [ $$lon, $$lat ] } }\n"; }' > tests/parallel/in4.json
 	echo -n "" > tests/parallel/empty1.json
 	echo "" > tests/parallel/empty2.json
-	./tippecanoe -z5 -f -pi -l test -n test -o tests/parallel/linear-file.mbtiles tests/parallel/in[123].json tests/parallel/empty[12].json
-	./tippecanoe -z5 -f -pi -l test -n test -P -o tests/parallel/parallel-file.mbtiles tests/parallel/in[123].json tests/parallel/empty[12].json
-	cat tests/parallel/in[123].json | ./tippecanoe -z5 -f -pi -l test -n test -o tests/parallel/linear-pipe.mbtiles
-	cat tests/parallel/in[123].json | ./tippecanoe -z5 -f -pi -l test -n test -P -o tests/parallel/parallel-pipe.mbtiles
-	./tippecanoe -z5 -f -pi -l test -n test -P -o tests/parallel/parallel-pipes.mbtiles <(cat tests/parallel/in1.json) <(cat tests/parallel/empty1.json) <(cat tests/parallel/empty2.json) <(cat tests/parallel/in2.json) /dev/null <(cat tests/parallel/in3.json)
-	./tippecanoe-decode tests/parallel/linear-file.mbtiles > tests/parallel/linear-file.json
-	./tippecanoe-decode tests/parallel/parallel-file.mbtiles > tests/parallel/parallel-file.json
-	./tippecanoe-decode tests/parallel/linear-pipe.mbtiles > tests/parallel/linear-pipe.json
-	./tippecanoe-decode tests/parallel/parallel-pipe.mbtiles > tests/parallel/parallel-pipe.json
-	./tippecanoe-decode tests/parallel/parallel-pipes.mbtiles > tests/parallel/parallel-pipes.json
+	./tippecanoe -q -z5 -f -pi -l test -n test -o tests/parallel/linear-file.mbtiles tests/parallel/in[1234].json tests/parallel/empty[12].json
+	./tippecanoe -q -z5 -f -pi -l test -n test -P -o tests/parallel/parallel-file.mbtiles tests/parallel/in[1234].json tests/parallel/empty[12].json
+	cat tests/parallel/in[1234].json | ./tippecanoe -q -z5 -f -pi -l test -n test -o tests/parallel/linear-pipe.mbtiles
+	cat tests/parallel/in[1234].json | ./tippecanoe -q -z5 -f -pi -l test -n test -P -o tests/parallel/parallel-pipe.mbtiles
+	cat tests/parallel/in[1234].json | sed 's/^/@/' | tr '@' '\036' | ./tippecanoe -q -z5 -f -pi -l test -n test -o tests/parallel/implicit-pipe.mbtiles
+	./tippecanoe -q -z5 -f -pi -l test -n test -P -o tests/parallel/parallel-pipes.mbtiles <(cat tests/parallel/in1.json) <(cat tests/parallel/empty1.json) <(cat tests/parallel/empty2.json) <(cat tests/parallel/in2.json) /dev/null <(cat tests/parallel/in3.json) <(cat tests/parallel/in4.json)
+	./tippecanoe-decode -x generator -x generator_options tests/parallel/linear-file.mbtiles > tests/parallel/linear-file.json
+	./tippecanoe-decode -x generator -x generator_options tests/parallel/parallel-file.mbtiles > tests/parallel/parallel-file.json
+	./tippecanoe-decode -x generator -x generator_options tests/parallel/linear-pipe.mbtiles > tests/parallel/linear-pipe.json
+	./tippecanoe-decode -x generator -x generator_options tests/parallel/parallel-pipe.mbtiles > tests/parallel/parallel-pipe.json
+	./tippecanoe-decode -x generator -x generator_options tests/parallel/implicit-pipe.mbtiles > tests/parallel/implicit-pipe.json
+	./tippecanoe-decode -x generator -x generator_options tests/parallel/parallel-pipes.mbtiles > tests/parallel/parallel-pipes.json
 	cmp tests/parallel/linear-file.json tests/parallel/parallel-file.json
 	cmp tests/parallel/linear-file.json tests/parallel/linear-pipe.json
 	cmp tests/parallel/linear-file.json tests/parallel/parallel-pipe.json
+	cmp tests/parallel/linear-file.json tests/parallel/implicit-pipe.json
 	cmp tests/parallel/linear-file.json tests/parallel/parallel-pipes.json
 	rm tests/parallel/*.mbtiles tests/parallel/*.json
 
+raw-tiles-test:
+	./tippecanoe -q -f -e tests/raw-tiles/raw-tiles -r1 -pC tests/raw-tiles/hackspots.geojson
+	./tippecanoe-decode -x generator tests/raw-tiles/raw-tiles > tests/raw-tiles/raw-tiles.json.check
+	cmp tests/raw-tiles/raw-tiles.json.check tests/raw-tiles/raw-tiles.json
+	# Test that -z and -Z work in tippecanoe-decode
+	./tippecanoe-decode -x generator -Z6 -z7 tests/raw-tiles/raw-tiles > tests/raw-tiles/raw-tiles-z67.json.check
+	cmp tests/raw-tiles/raw-tiles-z67.json.check tests/raw-tiles/raw-tiles-z67.json
+	# Test that -z and -Z work in tile-join
+	./tile-join -q -f -Z6 -z7 -e tests/raw-tiles/raw-tiles-z67 tests/raw-tiles/raw-tiles
+	./tippecanoe-decode -x generator tests/raw-tiles/raw-tiles-z67 > tests/raw-tiles/raw-tiles-z67-join.json.check
+	cmp tests/raw-tiles/raw-tiles-z67-join.json.check tests/raw-tiles/raw-tiles-z67-join.json
+	rm -rf tests/raw-tiles/raw-tiles tests/raw-tiles/raw-tiles-z67 tests/raw-tiles/raw-tiles.json.check raw-tiles-z67.json.check tests/raw-tiles/raw-tiles-z67-join.json.check
+	# Test that metadata.json is created even if all features are clipped away
+	./tippecanoe -q -f -e tests/raw-tiles/nothing tests/raw-tiles/nothing.geojson
+	./tippecanoe-decode -x generator tests/raw-tiles/nothing > tests/raw-tiles/nothing.json.check
+	cmp tests/raw-tiles/nothing.json.check tests/raw-tiles/nothing.json
+	rm -r tests/raw-tiles/nothing tests/raw-tiles/nothing.json.check
+
+decode-test:
+	mkdir -p tests/muni/decode
+	./tippecanoe -q -z11 -Z11 -f -o tests/muni/decode/multi.mbtiles tests/muni/*.json
+	./tippecanoe-decode -x generator -l subway tests/muni/decode/multi.mbtiles > tests/muni/decode/multi.mbtiles.json.check
+	./tippecanoe-decode -x generator -c tests/muni/decode/multi.mbtiles > tests/muni/decode/multi.mbtiles.pipeline.json.check
+	./tippecanoe-decode -x generator tests/muni/decode/multi.mbtiles 11 327 791 > tests/muni/decode/multi.mbtiles.onetile.json.check
+	./tippecanoe-decode -x generator --stats tests/muni/decode/multi.mbtiles > tests/muni/decode/multi.mbtiles.stats.json.check
+	cmp tests/muni/decode/multi.mbtiles.json.check tests/muni/decode/multi.mbtiles.json
+	cmp tests/muni/decode/multi.mbtiles.pipeline.json.check tests/muni/decode/multi.mbtiles.pipeline.json
+	cmp tests/muni/decode/multi.mbtiles.onetile.json.check tests/muni/decode/multi.mbtiles.onetile.json
+	cmp tests/muni/decode/multi.mbtiles.stats.json.check tests/muni/decode/multi.mbtiles.stats.json
+	rm -f tests/muni/decode/multi.mbtiles.json.check tests/muni/decode/multi.mbtiles tests/muni/decode/multi.mbtiles.pipeline.json.check tests/muni/decode/multi.mbtiles.stats.json.check tests/muni/decode/multi.mbtiles.onetile.json.check
+
 pbf-test:
-	./tippecanoe-decode tests/pbf/11-328-791.vector.pbf 11 328 791 > tests/pbf/11-328-791.vector.pbf.out
+	./tippecanoe-decode -x generator tests/pbf/11-328-791.vector.pbf 11 328 791 > tests/pbf/11-328-791.vector.pbf.out
 	cmp tests/pbf/11-328-791.json tests/pbf/11-328-791.vector.pbf.out
 	rm tests/pbf/11-328-791.vector.pbf.out
-	./tippecanoe-decode -t EPSG:3857 tests/pbf/11-328-791.vector.pbf 11 328 791 > tests/pbf/11-328-791.3857.vector.pbf.out
+	./tippecanoe-decode -x generator -s EPSG:3857 tests/pbf/11-328-791.vector.pbf 11 328 791 > tests/pbf/11-328-791.3857.vector.pbf.out
 	cmp tests/pbf/11-328-791.3857.json tests/pbf/11-328-791.3857.vector.pbf.out
 	rm tests/pbf/11-328-791.3857.vector.pbf.out
 
 enumerate-test:
-	./tippecanoe -z5 -f -o tests/ne_110m_admin_0_countries/out/enum.mbtiles tests/ne_110m_admin_0_countries/in.json
+	./tippecanoe -q -z5 -f -o tests/ne_110m_admin_0_countries/out/enum.mbtiles tests/ne_110m_admin_0_countries/in.json.gz
 	./tippecanoe-enumerate tests/ne_110m_admin_0_countries/out/enum.mbtiles > tests/ne_110m_admin_0_countries/out/enum.check
 	cmp tests/ne_110m_admin_0_countries/out/enum tests/ne_110m_admin_0_countries/out/enum.check
 	rm tests/ne_110m_admin_0_countries/out/enum.mbtiles tests/ne_110m_admin_0_countries/out/enum.check
 
-join-test:
-	./tippecanoe -f -z12 -o tests/join-population/tabblock_06001420.mbtiles tests/join-population/tabblock_06001420.json
-	./tippecanoe -f -z12 -o tests/join-population/tabblock_06001420.mbtiles tests/join-population/tabblock_06001420.json
-	./tippecanoe -f -Z5 -z10 -o tests/join-population/macarthur.mbtiles -l macarthur tests/join-population/macarthur.json
-	./tippecanoe -f -d10 -D10 -Z9 -z11 -o tests/join-population/macarthur2.mbtiles -l macarthur tests/join-population/macarthur2.json
-	./tile-join -f -o tests/join-population/joined.mbtiles -x GEOID10 -c tests/join-population/population.csv tests/join-population/tabblock_06001420.mbtiles
-	./tile-join -f -i -o tests/join-population/joined-i.mbtiles -x GEOID10 -c tests/join-population/population.csv tests/join-population/tabblock_06001420.mbtiles
-	./tile-join -f -o tests/join-population/merged.mbtiles tests/join-population/tabblock_06001420.mbtiles tests/join-population/macarthur.mbtiles tests/join-population/macarthur2.mbtiles
-	./tippecanoe-decode tests/join-population/joined.mbtiles > tests/join-population/joined.mbtiles.json.check
-	./tippecanoe-decode tests/join-population/joined-i.mbtiles > tests/join-population/joined-i.mbtiles.json.check
-	./tippecanoe-decode tests/join-population/merged.mbtiles > tests/join-population/merged.mbtiles.json.check
+join-test: tile-join
+	./tippecanoe -q -f -z12 -o tests/join-population/tabblock_06001420.mbtiles -YALAND10:'Land area' -L'{"file": "tests/join-population/tabblock_06001420.json", "description": "population"}'
+	./tippecanoe -q -f -Z5 -z10 -o tests/join-population/macarthur.mbtiles -l macarthur tests/join-population/macarthur.json
+	./tile-join -q -f -Z6 -z9 -o tests/join-population/macarthur-6-9.mbtiles tests/join-population/macarthur.mbtiles
+	./tippecanoe-decode -x generator tests/join-population/macarthur-6-9.mbtiles > tests/join-population/macarthur-6-9.mbtiles.json.check
+	cmp tests/join-population/macarthur-6-9.mbtiles.json.check tests/join-population/macarthur-6-9.mbtiles.json
+	./tile-join -q -f -Z6 -z9 -X -o tests/join-population/macarthur-6-9-exclude.mbtiles tests/join-population/macarthur.mbtiles
+	./tippecanoe-decode -x generator tests/join-population/macarthur-6-9-exclude.mbtiles > tests/join-population/macarthur-6-9-exclude.mbtiles.json.check
+	cmp tests/join-population/macarthur-6-9-exclude.mbtiles.json.check tests/join-population/macarthur-6-9-exclude.mbtiles.json
+	rm -f tests/join-population/macarthur-6-9.mbtiles.json.check tests/join-population/macarthur-6-9.mbtiles tests/join-population/macarthur-6-9-exclude.mbtiles.json.check tests/join-population/macarthur-6-9-exclude.mbtiles
+	./tippecanoe -q -f -d10 -D10 -Z9 -z11 -o tests/join-population/macarthur2.mbtiles -l macarthur tests/join-population/macarthur2.json
+	./tile-join --quiet --force -o tests/join-population/joined.mbtiles -x GEOID10 -c tests/join-population/population.csv tests/join-population/tabblock_06001420.mbtiles
+	./tile-join --quiet --force -o tests/join-population/joined-null.mbtiles --empty-csv-columns-are-null -x GEOID10 -c tests/join-population/population.csv tests/join-population/tabblock_06001420.mbtiles
+	./tile-join --quiet --force --no-tile-stats -o tests/join-population/joined-no-tile-stats.mbtiles -x GEOID10 -c tests/join-population/population.csv tests/join-population/tabblock_06001420.mbtiles
+	./tile-join -q -f -i -o tests/join-population/joined-i.mbtiles -x GEOID10 -c tests/join-population/population.csv tests/join-population/tabblock_06001420.mbtiles
+	./tile-join -q -f -o tests/join-population/merged.mbtiles tests/join-population/tabblock_06001420.mbtiles tests/join-population/macarthur.mbtiles tests/join-population/macarthur2.mbtiles
+	./tile-join -q -f -c tests/join-population/windows.csv -o tests/join-population/windows.mbtiles tests/join-population/macarthur.mbtiles
+	./tippecanoe-decode -x generator --maximum-zoom=11 --minimum-zoom=4 tests/join-population/joined.mbtiles > tests/join-population/joined.mbtiles.json.check
+	./tippecanoe-decode -x generator --maximum-zoom=11 --minimum-zoom=4 tests/join-population/joined-null.mbtiles > tests/join-population/joined-null.mbtiles.json.check
+	./tippecanoe-decode -x generator --maximum-zoom=11 --minimum-zoom=4 tests/join-population/joined-no-tile-stats.mbtiles > tests/join-population/joined-no-tile-stats.mbtiles.json.check
+	./tippecanoe-decode -x generator tests/join-population/joined-i.mbtiles > tests/join-population/joined-i.mbtiles.json.check
+	./tippecanoe-decode -x generator tests/join-population/merged.mbtiles > tests/join-population/merged.mbtiles.json.check
+	./tippecanoe-decode -x generator tests/join-population/windows.mbtiles > tests/join-population/windows.mbtiles.json.check
 	cmp tests/join-population/joined.mbtiles.json.check tests/join-population/joined.mbtiles.json
+	cmp tests/join-population/joined-null.mbtiles.json.check tests/join-population/joined-null.mbtiles.json
+	cmp tests/join-population/joined-no-tile-stats.mbtiles.json.check tests/join-population/joined-no-tile-stats.mbtiles.json
 	cmp tests/join-population/joined-i.mbtiles.json.check tests/join-population/joined-i.mbtiles.json
 	cmp tests/join-population/merged.mbtiles.json.check tests/join-population/merged.mbtiles.json
-	rm tests/join-population/tabblock_06001420.mbtiles tests/join-population/joined.mbtiles tests/join-population/joined-i.mbtiles tests/join-population/joined.mbtiles.json.check tests/join-population/joined-i.mbtiles.json.check tests/join-population/macarthur.mbtiles tests/join-population/merged.mbtiles tests/join-population/merged.mbtiles.json.check tests/join-population/macarthur2.mbtiles
+	cmp tests/join-population/windows.mbtiles.json.check tests/join-population/windows.mbtiles.json
+	rm -f tests/join-population/joined-null.mbtiles tests/join-population/joined-null.mbtiles.json.check
+	./tile-join -q -f -l macarthur -n "macarthur name" -N "macarthur description" -A "macarthur's attribution" -o tests/join-population/just-macarthur.mbtiles tests/join-population/merged.mbtiles
+	./tile-join -q -f -L macarthur -o tests/join-population/no-macarthur.mbtiles tests/join-population/merged.mbtiles
+	./tippecanoe-decode -x generator tests/join-population/just-macarthur.mbtiles > tests/join-population/just-macarthur.mbtiles.json.check
+	./tippecanoe-decode -x generator tests/join-population/no-macarthur.mbtiles > tests/join-population/no-macarthur.mbtiles.json.check
+	cmp tests/join-population/just-macarthur.mbtiles.json.check tests/join-population/just-macarthur.mbtiles.json
+	cmp tests/join-population/no-macarthur.mbtiles.json.check tests/join-population/no-macarthur.mbtiles.json
+	./tile-join -q --no-tile-compression -f -e tests/join-population/raw-merged-folder tests/join-population/tabblock_06001420.mbtiles tests/join-population/macarthur.mbtiles tests/join-population/macarthur2.mbtiles
+	./tippecanoe-decode -x generator tests/join-population/raw-merged-folder > tests/join-population/raw-merged-folder.json.check
+	cmp tests/join-population/raw-merged-folder.json.check tests/join-population/raw-merged-folder.json
+	rm -f tests/join-population/raw-merged-folder.json.check
+	./tippecanoe -q -z12 -f -e tests/join-population/tabblock_06001420-folder -YALAND10:'Land area' -L'{"file": "tests/join-population/tabblock_06001420.json", "description": "population"}'
+	./tippecanoe -q -Z5 -z10 -f -e tests/join-population/macarthur-folder -l macarthur tests/join-population/macarthur.json
+	./tippecanoe -q -d10 -D10 -Z9 -z11 -f -e tests/join-population/macarthur2-folder -l macarthur tests/join-population/macarthur2.json
+	./tile-join -q -f -o tests/join-population/merged-folder.mbtiles tests/join-population/tabblock_06001420-folder tests/join-population/macarthur-folder tests/join-population/macarthur2-folder
+	./tippecanoe-decode -x generator tests/join-population/merged-folder.mbtiles > tests/join-population/merged-folder.mbtiles.json.check
+	cmp tests/join-population/merged-folder.mbtiles.json.check tests/join-population/merged-folder.mbtiles.json
+	./tile-join -q -n "merged name" -N "merged description" -f -e tests/join-population/merged-mbtiles-to-folder tests/join-population/tabblock_06001420.mbtiles tests/join-population/macarthur.mbtiles tests/join-population/macarthur2.mbtiles
+	./tile-join -q -n "merged name" -N "merged description" -f -e tests/join-population/merged-folders-to-folder tests/join-population/tabblock_06001420-folder tests/join-population/macarthur-folder tests/join-population/macarthur2-folder
+	./tippecanoe-decode -x generator -x generator_options tests/join-population/merged-mbtiles-to-folder > tests/join-population/merged-mbtiles-to-folder.json.check
+	./tippecanoe-decode -x generator -x generator_options tests/join-population/merged-folders-to-folder > tests/join-population/merged-folders-to-folder.json.check
+	cmp tests/join-population/merged-mbtiles-to-folder.json.check tests/join-population/merged-folders-to-folder.json.check
+	rm -f tests/join-population/merged-mbtiles-to-folder.json.check tests/join-population/merged-folders-to-folder.json.check
+	./tile-join -q -f -c tests/join-population/windows.csv -o tests/join-population/windows-merged.mbtiles tests/join-population/macarthur.mbtiles tests/join-population/macarthur2-folder
+	./tile-join -q -c tests/join-population/windows.csv -f -e tests/join-population/windows-merged-folder tests/join-population/macarthur.mbtiles tests/join-population/macarthur2-folder
+	./tile-join -q -f -o tests/join-population/windows-merged2.mbtiles tests/join-population/windows-merged-folder
+	./tippecanoe-decode -x generator -x generator_options tests/join-population/windows-merged.mbtiles > tests/join-population/windows-merged.mbtiles.json.check
+	./tippecanoe-decode -x generator -x generator_options tests/join-population/windows-merged2.mbtiles > tests/join-population/windows-merged2.mbtiles.json.check
+	cmp tests/join-population/windows-merged.mbtiles.json.check tests/join-population/windows-merged2.mbtiles.json.check
+	./tile-join -q -f -o tests/join-population/macarthur-and-macarthur2-merged.mbtiles tests/join-population/macarthur.mbtiles tests/join-population/macarthur2-folder
+	./tile-join -q -f -e tests/join-population/macarthur-and-macarthur2-folder tests/join-population/macarthur.mbtiles tests/join-population/macarthur2-folder
+	./tile-join -q -f -o tests/join-population/macarthur-and-macarthur2-merged2.mbtiles tests/join-population/macarthur-and-macarthur2-folder
+	./tippecanoe-decode -x generator -x generator_options tests/join-population/macarthur-and-macarthur2-merged.mbtiles > tests/join-population/macarthur-and-macarthur2-merged.mbtiles.json.check
+	./tippecanoe-decode -x generator -x generator_options tests/join-population/macarthur-and-macarthur2-merged2.mbtiles > tests/join-population/macarthur-and-macarthur2-merged2.mbtiles.json.check
+	cmp tests/join-population/macarthur-and-macarthur2-merged.mbtiles.json.check tests/join-population/macarthur-and-macarthur2-merged2.mbtiles.json.check
+	rm tests/join-population/tabblock_06001420.mbtiles tests/join-population/joined.mbtiles tests/join-population/joined-i.mbtiles tests/join-population/joined.mbtiles.json.check tests/join-population/joined-i.mbtiles.json.check tests/join-population/macarthur.mbtiles tests/join-population/merged.mbtiles tests/join-population/merged.mbtiles.json.check  tests/join-population/merged-folder.mbtiles tests/join-population/macarthur2.mbtiles tests/join-population/windows.mbtiles tests/join-population/windows-merged.mbtiles tests/join-population/windows-merged2.mbtiles tests/join-population/windows.mbtiles.json.check tests/join-population/just-macarthur.mbtiles tests/join-population/no-macarthur.mbtiles tests/join-population/just-macarthur.mbtiles.json.check tests/join-population/no-macarthur.mbtiles.json.check tests/join-population/merged-folder.mbtiles.json.check tests/join-population/windows-merged.mbtiles.json.check tests/join-population/windows-merged2.mbtiles.json.check tests/join-population/macarthur-and-macarthur2-merged.mbtiles tests/join-population/macarthur-and-macarthur2-merged2.mbtiles tests/join-population/macarthur-and-macarthur2-merged.mbtiles.json.check tests/join-population/macarthur-and-macarthur2-merged2.mbtiles.json.check
+	rm -rf tests/join-population/raw-merged-folder tests/join-population/tabblock_06001420-folder tests/join-population/macarthur-folder tests/join-population/macarthur2-folder tests/join-population/merged-mbtiles-to-folder tests/join-population/merged-folders-to-folder tests/join-population/windows-merged-folder tests/join-population/macarthur-and-macarthur2-folder
+	# Test renaming of layers
+	./tippecanoe -q -f -Z5 -z10 -o tests/join-population/macarthur.mbtiles -l macarthur1 tests/join-population/macarthur.json
+	./tippecanoe -q -f -Z5 -z10 -o tests/join-population/macarthur2.mbtiles -l macarthur2 tests/join-population/macarthur2.json
+	./tile-join -q -R macarthur1:one --rename-layer=macarthur2:two -f -o tests/join-population/renamed.mbtiles tests/join-population/macarthur.mbtiles tests/join-population/macarthur2.mbtiles
+	./tippecanoe-decode -x generator tests/join-population/renamed.mbtiles > tests/join-population/renamed.mbtiles.json.check
+	cmp tests/join-population/renamed.mbtiles.json.check tests/join-population/renamed.mbtiles.json
+	rm -f tests/join-population/renamed.mbtiles.json.check tests/join-population/renamed.mbtiles.json.check tests/join-population/macarthur.mbtiles tests/join-population/macarthur2.mbtiles
+	# Make sure the concatenated name isn't too long
+	./tippecanoe -q -f -z0 -n 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ' -o tests/join-population/macarthur.mbtiles tests/join-population/macarthur.json
+	./tile-join -f -o tests/join-population/concat.mbtiles tests/join-population/macarthur.mbtiles tests/join-population/macarthur.mbtiles tests/join-population/macarthur.mbtiles tests/join-population/macarthur.mbtiles tests/join-population/macarthur.mbtiles tests/join-population/macarthur.mbtiles
+	./tippecanoe-decode -x generator tests/join-population/concat.mbtiles > tests/join-population/concat.mbtiles.json.check
+	cmp tests/join-population/concat.mbtiles.json.check tests/join-population/concat.mbtiles.json
+	rm tests/join-population/concat.mbtiles.json.check tests/join-population/concat.mbtiles tests/join-population/macarthur.mbtiles
+
+join-filter-test:
+	# Comes out different from the direct tippecanoe run because null attributes are lost
+	./tippecanoe -q -z0 -f -o tests/feature-filter/out/all.mbtiles tests/feature-filter/in.json
+	./tile-join -q -J tests/feature-filter/filter -f -o tests/feature-filter/out/filtered.mbtiles tests/feature-filter/out/all.mbtiles
+	./tippecanoe-decode -x generator tests/feature-filter/out/filtered.mbtiles > tests/feature-filter/out/filtered.json.check
+	cmp tests/feature-filter/out/filtered.json.check tests/feature-filter/out/filtered.json.standard
+	rm -f tests/feature-filter/out/filtered.json.check tests/feature-filter/out/filtered.mbtiles tests/feature-filter/out/all.mbtiles
+	# Test zoom level filtering
+	./tippecanoe -q -r1 -z8 -f -o tests/feature-filter/out/places.mbtiles tests/ne_110m_populated_places/in.json
+	./tile-join -q -J tests/feature-filter/places-filter -f -o tests/feature-filter/out/places-filter.mbtiles tests/feature-filter/out/places.mbtiles
+	./tippecanoe-decode -x generator tests/feature-filter/out/places-filter.mbtiles > tests/feature-filter/out/places-filter.mbtiles.json.check
+	cmp tests/feature-filter/out/places-filter.mbtiles.json.check tests/feature-filter/out/places-filter.mbtiles.json.standard
+	rm -f tests/feature-filter/out/places.mbtiles tests/feature-filter/out/places-filter.mbtiles tests/feature-filter/out/places-filter.mbtiles.json.check
+
+json-tool-test: tippecanoe-json-tool
+	./tippecanoe-json-tool -e GEOID10 tests/join-population/tabblock_06001420.json | sort > tests/join-population/tabblock_06001420.json.sort
+	./tippecanoe-json-tool -c tests/join-population/population.csv tests/join-population/tabblock_06001420.json.sort > tests/join-population/tabblock_06001420.json.sort.joined
+	./tippecanoe-json-tool --empty-csv-columns-are-null -c tests/join-population/population.csv tests/join-population/tabblock_06001420.json.sort > tests/join-population/tabblock_06001420-null.json.sort.joined
+	cmp tests/join-population/tabblock_06001420.json.sort.joined tests/join-population/tabblock_06001420.json.sort.joined.standard
+	cmp tests/join-population/tabblock_06001420-null.json.sort.joined tests/join-population/tabblock_06001420-null.json.sort.joined.standard
+	rm -f tests/join-population/tabblock_06001420.json.sort tests/join-population/tabblock_06001420.json.sort.joined
+	rm -f tests/join-population/tabblock_06001420-null.json.sort.joined
+
+allow-existing-test:
+	# Make a tileset
+	./tippecanoe -q -Z0 -z0 -f -o tests/allow-existing/both.mbtiles tests/coalesce-tract/tl_2010_06001_tract10.json
+	# Writing to existing should fail
+	if ./tippecanoe -q -Z1 -z1 -o tests/allow-existing/both.mbtiles tests/coalesce-tract/tl_2010_06001_tract10.json; then exit 1; else exit 0; fi
+	# Replace existing
+	./tippecanoe -q -Z8 -z9 -f -o tests/allow-existing/both.mbtiles tests/coalesce-tract/tl_2010_06001_tract10.json
+	./tippecanoe -q -Z10 -z11 -F -o tests/allow-existing/both.mbtiles tests/coalesce-tract/tl_2010_06001_tract10.json
+	./tippecanoe-decode -x generator -x generator_options tests/allow-existing/both.mbtiles > tests/allow-existing/both.mbtiles.json.check
+	cmp tests/allow-existing/both.mbtiles.json.check tests/allow-existing/both.mbtiles.json
+	# Make a tileset
+	./tippecanoe -q -Z0 -z0 -f -e tests/allow-existing/both.dir tests/coalesce-tract/tl_2010_06001_tract10.json
+	# Writing to existing should fail
+	if ./tippecanoe -q -Z1 -z1 -e tests/allow-existing/both.dir tests/coalesce-tract/tl_2010_06001_tract10.json; then exit 1; else exit 0; fi
+	# Replace existing
+	./tippecanoe -q -Z8 -z9 -f -e tests/allow-existing/both.dir tests/coalesce-tract/tl_2010_06001_tract10.json
+	./tippecanoe -q -Z10 -z11 -F -e tests/allow-existing/both.dir tests/coalesce-tract/tl_2010_06001_tract10.json
+	./tippecanoe-decode -x generator -x generator_options tests/allow-existing/both.dir | sed 's/both\.dir/both.mbtiles/g' > tests/allow-existing/both.dir.json.check
+	cmp tests/allow-existing/both.dir.json.check tests/allow-existing/both.mbtiles.json
+	rm -r tests/allow-existing/both.dir.json.check tests/allow-existing/both.dir tests/allow-existing/both.mbtiles.json.check tests/allow-existing/both.mbtiles
+
+csv-test:
+	# Reading from named CSV
+	./tippecanoe -q -zg -f -o tests/csv/out.mbtiles tests/csv/ne_110m_populated_places_simple.csv
+	./tippecanoe-decode -x generator -x generator_options tests/csv/out.mbtiles > tests/csv/out.mbtiles.json.check
+	cmp tests/csv/out.mbtiles.json.check tests/csv/out.mbtiles.json
+	rm -f tests/csv/out.mbtiles.json.check tests/csv/out.mbtiles
+	# Reading from named CSV, with nulls
+	./tippecanoe -q --empty-csv-columns-are-null -zg -f -o tests/csv/out-null.mbtiles tests/csv/ne_110m_populated_places_simple.csv
+	./tippecanoe-decode -x generator tests/csv/out-null.mbtiles > tests/csv/out-null.mbtiles.json.check
+	cmp tests/csv/out-null.mbtiles.json.check tests/csv/out-null.mbtiles.json
+	rm -f tests/csv/out-null.mbtiles.json.check tests/csv/out-null.mbtiles
+	# Same, but specifying csv with -L format
+	./tippecanoe -q -zg -f -o tests/csv/out.mbtiles -L'{"file":"", "format":"csv", "layer":"ne_110m_populated_places_simple"}' < tests/csv/ne_110m_populated_places_simple.csv
+	./tippecanoe-decode -x generator -x generator_options tests/csv/out.mbtiles > tests/csv/out.mbtiles.json.check
+	cmp tests/csv/out.mbtiles.json.check tests/csv/out.mbtiles.json
+	rm -f tests/csv/out.mbtiles.json.check tests/csv/out.mbtiles
+
+layer-json-test:
+	# GeoJSON with description and named layer
+	./tippecanoe -q -z0 -r1 -yNAME -f -o tests/layer-json/out.mbtiles -L'{"file":"tests/ne_110m_populated_places/in.json", "description":"World cities", "layer":"places"}'
+	./tippecanoe-decode -x generator -x generator_options tests/layer-json/out.mbtiles > tests/layer-json/out.mbtiles.json.check
+	cmp tests/layer-json/out.mbtiles.json.check tests/layer-json/out.mbtiles.json
+	rm -f tests/layer-json/out.mbtiles.json.check tests/layer-json/out.mbtiles
+	# Same, but reading from the standard input
+	./tippecanoe -q -z0 -r1 -yNAME -f -o tests/layer-json/out.mbtiles -L'{"file":"", "description":"World cities", "layer":"places"}' < tests/ne_110m_populated_places/in.json
+	./tippecanoe-decode -x generator -x generator_options tests/layer-json/out.mbtiles > tests/layer-json/out.mbtiles.json.check
+	cmp tests/layer-json/out.mbtiles.json.check tests/layer-json/out.mbtiles.json
+	rm -f tests/layer-json/out.mbtiles.json.check tests/layer-json/out.mbtiles
 
 # Use this target to regenerate the standards that the tests are compared against
 # after making a change that legitimately changes their output
@@ -144,7 +342,7 @@ join-test:
 prep-test: $(TESTS)
 
 tests/%.json: Makefile tippecanoe tippecanoe-decode
-	./tippecanoe -f -o $@.check.mbtiles $(subst @,:,$(subst %,/,$(subst _, ,$(patsubst %.json,%,$(word 4,$(subst /, ,$@)))))) $(wildcard $(subst $(SPACE),/,$(wordlist 1,2,$(subst /, ,$@)))/*.json)
-	./tippecanoe-decode $@.check.mbtiles > $@
+	./tippecanoe -q -a@ -f -o $@.check.mbtiles $(subst @,:,$(subst %,/,$(subst _, ,$(patsubst %.json,%,$(word 4,$(subst /, ,$@)))))) $(foreach suffix,$(suffixes),$(sort $(wildcard $(subst $(SPACE),/,$(wordlist 1,2,$(subst /, ,$@)))/*.$(suffix))))
+	./tippecanoe-decode -x generator $@.check.mbtiles > $@
 	cmp $(patsubst %.check,%,$@) $@
 	rm $@.check.mbtiles

README.md

@@ -1,11 +1,13 @@
 tippecanoe
 ==========
 
-Builds [vector tilesets](https://www.mapbox.com/developers/vector-tiles/) from large (or small) collections of [GeoJSON](http://geojson.org/) features,
+Builds [vector tilesets](https://www.mapbox.com/developers/vector-tiles/) from large (or small) collections of [GeoJSON](http://geojson.org/), [Geobuf](https://github.com/mapbox/geobuf), or [CSV](https://en.wikipedia.org/wiki/Comma-separated_values) features,
 [like these](MADE_WITH.md).
 
+![Mapbox Tippecanoe](https://user-images.githubusercontent.com/1951835/36568734-ede27ec0-17df-11e8-8c22-ffaaebb8daf4.JPG)
+
 [![Build Status](https://travis-ci.org/mapbox/tippecanoe.svg)](https://travis-ci.org/mapbox/tippecanoe)
-[![Coverage Status](https://coveralls.io/repos/mapbox/tippecanoe/badge.svg?branch=master&service=github)](https://coveralls.io/github/mapbox/tippecanoe?branch=master)
+[![Coverage Status](https://codecov.io/gh/mapbox/tippecanoe/branch/master/graph/badge.svg)](https://codecov.io/gh/mapbox/tippecanoe)
 
 Intent
 ------
@@ -33,15 +35,28 @@ Installation
 
 The easiest way to install tippecanoe on OSX is with [Homebrew](http://brew.sh/):
 
-```js
+```sh
 $ brew install tippecanoe
 ```
 
+On Ubuntu it will usually be easiest to build from the source repository:
+
+```sh
+$ git clone https://github.com/mapbox/tippecanoe.git
+$ cd tippecanoe
+$ make -j
+$ make install
+```
+
+See [Development](#development) below for how to upgrade your
+C++ compiler or install prerequisite packages if you get
+compiler errors.
+
 Usage
 -----
 
 ```sh
-$ tippecanoe -o file.mbtiles [file.json ...]
+$ tippecanoe -o file.mbtiles [options] [file.json file.json.gz file.geobuf ...]
 ```
 
 If no files are specified, it reads GeoJSON from the standard input.
@@ -52,112 +67,525 @@ You can concatenate multiple GeoJSON features or files together,
 and it will parse out the features and ignore whatever other objects
 it encounters.
 
+Try this first
+--------------
+
+If you aren't sure what options to use, try this:
+
+```sh
+$ tippecanoe -zg -o out.mbtiles --drop-densest-as-needed in.geojson
+```
+
+The `-zg` option will make Tippecanoe choose a maximum zoom level that should be
+high enough to reflect the precision of the original data. (If it turns out still
+not to be as detailed as you want, use `-z` manually with a higher number.)
+
+If the tiles come out too big, the `--drop-densest-as-needed` option will make
+Tippecanoe try dropping what should be the least visible features at each zoom level.
+(If it drops too many features, use `-x` to leave out some feature attributes that
+you didn't really need.)
+
+Examples
+--------
+
+Create a tileset of TIGER roads for Alameda County, to zoom level 13, with a custom layer name and description:
+
+```sh
+$ tippecanoe -o alameda.mbtiles -l alameda -n "Alameda County from TIGER" -z13 tl_2014_06001_roads.json
+```
+
+Create a tileset of all TIGER roads, at only zoom level 12, but with higher detail than normal,
+with a custom layer name and description, and leaving out the `LINEARID` and `RTTYP` attributes:
+
+```
+$ cat tiger/tl_2014_*_roads.json | tippecanoe -o tiger.mbtiles -l roads -n "All TIGER roads, one zoom" -z12 -Z12 -d14 -x LINEARID -x RTTYP
+```
+
+Cookbook
+--------
+
+### Linear features (world railroads), visible at all zoom levels
+
+```
+curl -L -O https://www.naturalearthdata.com/http//www.naturalearthdata.com/download/10m/cultural/ne_10m_railroads.zip
+unzip ne_10m_railroads.zip
+ogr2ogr -f GeoJSON ne_10m_railroads.geojson ne_10m_railroads.shp
+
+tippecanoe -zg -o ne_10m_railroads.mbtiles --drop-densest-as-needed --extend-zooms-if-still-dropping ne_10m_railroads.geojson
+```
+
+* `-zg`: Automatically choose a maxzoom that should be sufficient to clearly distinguish the features and the detail within each feature
+* `--drop-densest-as-needed`: If the tiles are too big at low zoom levels, drop the least-visible features to allow tiles to be created with those features that remain
+* `--extend-zooms-if-still-dropping`: If even the tiles at high zoom levels are too big, keep adding zoom levels until one is reached that can represent all the features
+
+### Discontinuous polygon features (buildings of Rhode Island), visible at all zoom levels
+
+```
+curl -L -O https://usbuildingdata.blob.core.windows.net/usbuildings-v1-1/RhodeIsland.zip
+unzip RhodeIsland.zip
+
+tippecanoe -zg -o RhodeIsland.mbtiles --drop-densest-as-needed --extend-zooms-if-still-dropping RhodeIsland.geojson
+```
+
+* `-zg`: Automatically choose a maxzoom that should be sufficient to clearly distinguish the features and the detail within each feature
+* `--drop-densest-as-needed`: If the tiles are too big at low or medium zoom levels, drop the least-visible features to allow tiles to be created with those features that remain
+* `--extend-zooms-if-still-dropping`: If even the tiles at high zoom levels are too big, keep adding zoom levels until one is reached that can represent all the features
+
+### Continuous polygon features (states and provinces), visible at all zoom levels
+
+```
+curl -L -O https://www.naturalearthdata.com/http//www.naturalearthdata.com/download/10m/cultural/ne_10m_admin_1_states_provinces.zip
+unzip -o ne_10m_admin_1_states_provinces.zip
+ogr2ogr -f GeoJSON ne_10m_admin_1_states_provinces.geojson ne_10m_admin_1_states_provinces.shp
+
+tippecanoe -zg -o ne_10m_admin_1_states_provinces.mbtiles --coalesce-densest-as-needed --extend-zooms-if-still-dropping ne_10m_admin_1_states_provinces.geojson
+```
+
+* `-zg`: Automatically choose a maxzoom that should be sufficient to clearly distinguish the features and the detail within each feature
+* `--coalesce-densest-as-needed`: If the tiles are too big at low or medium zoom levels, merge as many features together as are necessary to allow tiles to be created with those features that are still distinguished
+* `--extend-zooms-if-still-dropping`: If even the tiles at high zoom levels are too big, keep adding zoom levels until one is reached that can represent all the features
+
+### Large point dataset (GPS bus locations), for visualization at all zoom levels
+
+```
+curl -L -O ftp://avl-data.sfmta.com/avl_data/avl_raw/sfmtaAVLRawData01012013.csv
+sed 's/PREDICTABLE.*/PREDICTABLE/' sfmtaAVLRawData01012013.csv > sfmta.csv
+tippecanoe -zg -o sfmta.mbtiles --drop-densest-as-needed --extend-zooms-if-still-dropping sfmta.csv
+```
+
+(The `sed` line is to clean the corrupt CSV header, which contains the wrong number of fields.)
+
+* `-zg`: Automatically choose a maxzoom that should be sufficient to clearly distinguish the features and the detail within each feature
+* `--drop-densest-as-needed`: If the tiles are too big at low or medium zoom levels, drop the least-visible features to allow tiles to be created with those features that remain
+* `--extend-zooms-if-still-dropping`: If even the tiles at high zoom levels are too big, keep adding zoom levels until one is reached that can represent all the features
+
+### Clustered points (world cities), summing the clustered population, visible at all zoom levels
+
+```
+curl -L -O https://www.naturalearthdata.com/http//www.naturalearthdata.com/download/10m/cultural/ne_10m_populated_places.zip
+unzip -o ne_10m_populated_places.zip
+ogr2ogr -f GeoJSON ne_10m_populated_places.geojson ne_10m_populated_places.shp
+
+tippecanoe -zg -o ne_10m_populated_places.mbtiles -r1 --cluster-distance=10 --accumulate-attribute=POP_MAX:sum ne_10m_populated_places.geojson
+```
+
+* `-zg`: Automatically choose a maxzoom that should be sufficient to clearly distinguish the features and the detail within each feature
+* `-r1`: Do not automatically drop a fraction of points at low zoom levels, since clustering will be used instead
+* `--cluster-distance=10`: Cluster together features that are closer than about 10 pixels from each other
+* `--accumulate-attribute=POP_MAX:sum`: Sum the `POP_MAX` (population) attribute in features that are clustered together. Other attributes will be arbitrarily taken from the first feature in the cluster.
+
+### Show countries at low zoom levels but states at higher zoom levels
+
+```
+curl -L -O https://www.naturalearthdata.com/http//www.naturalearthdata.com/download/10m/cultural/ne_10m_admin_0_countries.zip
+unzip ne_10m_admin_0_countries.zip
+ogr2ogr -f GeoJSON ne_10m_admin_0_countries.geojson ne_10m_admin_0_countries.shp
+
+curl -L -O https://www.naturalearthdata.com/http//www.naturalearthdata.com/download/10m/cultural/ne_10m_admin_1_states_provinces.zip
+unzip -o ne_10m_admin_1_states_provinces.zip
+ogr2ogr -f GeoJSON ne_10m_admin_1_states_provinces.geojson ne_10m_admin_1_states_provinces.shp
+
+tippecanoe -z3 -o countries-z3.mbtiles --coalesce-densest-as-needed ne_10m_admin_0_countries.geojson
+tippecanoe -zg -Z4 -o states-Z4.mbtiles --coalesce-densest-as-needed --extend-zooms-if-still-dropping ne_10m_admin_1_states_provinces.geojson
+tile-join -o states-countries.mbtiles countries-z3.mbtiles states-Z4.mbtiles
+```
+
+Countries:
+
+* `-z3`: Only generate zoom levels 0 through 3
+* `--coalesce-densest-as-needed`: If the tiles are too big at low or medium zoom levels, merge as many features together as are necessary to allow tiles to be created with those features that are still distinguished
+
+States and Provinces:
+
+* `-Z4`: Only generate zoom levels 4 and beyond
+* `-zg`: Automatically choose a maxzoom that should be sufficient to clearly distinguish the features and the detail within each feature
+* `--coalesce-densest-as-needed`: If the tiles are too big at low or medium zoom levels, merge as many features together as are necessary to allow tiles to be created with those features that are still distinguished
+* `--extend-zooms-if-still-dropping`: If even the tiles at high zoom levels are too big, keep adding zoom levels until one is reached that can represent all the features
+
+### Represent multiple sources (Illinois and Indiana counties) as separate layers
+
+```
+curl -L -O https://www2.census.gov/geo/tiger/TIGER2010/COUNTY/2010/tl_2010_17_county10.zip
+unzip tl_2010_17_county10.zip
+ogr2ogr -f GeoJSON tl_2010_17_county10.geojson tl_2010_17_county10.shp
+
+curl -L -O https://www2.census.gov/geo/tiger/TIGER2010/COUNTY/2010/tl_2010_18_county10.zip
+unzip tl_2010_18_county10.zip
+ogr2ogr -f GeoJSON tl_2010_18_county10.geojson tl_2010_18_county10.shp
+
+tippecanoe -zg -o counties-separate.mbtiles --coalesce-densest-as-needed --extend-zooms-if-still-dropping tl_2010_17_county10.geojson tl_2010_18_county10.geojson
+```
+
+* `-zg`: Automatically choose a maxzoom that should be sufficient to clearly distinguish the features and the detail within each feature
+* `--coalesce-densest-as-needed`: If the tiles are too big at low or medium zoom levels, merge as many features together as are necessary to allow tiles to be created with those features that are still distinguished
+* `--extend-zooms-if-still-dropping`: If even the tiles at high zoom levels are too big, keep adding zoom levels until one is reached that can represent all the features
+
+### Merge multiple sources (Illinois and Indiana counties) into the same layer
+
+```
+curl -L -O https://www2.census.gov/geo/tiger/TIGER2010/COUNTY/2010/tl_2010_17_county10.zip
+unzip tl_2010_17_county10.zip
+ogr2ogr -f GeoJSON tl_2010_17_county10.geojson tl_2010_17_county10.shp
+
+curl -L -O https://www2.census.gov/geo/tiger/TIGER2010/COUNTY/2010/tl_2010_18_county10.zip
+unzip tl_2010_18_county10.zip
+ogr2ogr -f GeoJSON tl_2010_18_county10.geojson tl_2010_18_county10.shp
+
+tippecanoe -zg -o counties-merged.mbtiles -l counties --coalesce-densest-as-needed --extend-zooms-if-still-dropping tl_2010_17_county10.geojson tl_2010_18_county10.geojson
+```
+
+As above, but
+
+* `-l counties`: Specify the layer name instead of letting it be derived from the source file names
+
+### Selectively remove and replace features (Census tracts) to update a tileset
+
+```
+# Retrieve and tile California 2000 Census tracts
+curl -L -O https://www2.census.gov/geo/tiger/TIGER2010/TRACT/2000/tl_2010_06_tract00.zip
+unzip tl_2010_06_tract00.zip
+ogr2ogr -f GeoJSON tl_2010_06_tract00.shp.json tl_2010_06_tract00.shp
+tippecanoe -z11 -o tracts.mbtiles -l tracts tl_2010_06_tract00.shp.json
+
+# Create a copy of the tileset, minus Alameda County (FIPS code 001)
+tile-join -j '{"*":["none",["==","COUNTYFP00","001"]]}' -f -o tracts-filtered.mbtiles tracts.mbtiles
+
+# Retrieve and tile Alameda County Census tracts for 2010
+curl -L -O https://www2.census.gov/geo/tiger/TIGER2010/TRACT/2010/tl_2010_06001_tract10.zip
+unzip tl_2010_06001_tract10.zip
+ogr2ogr -f GeoJSON tl_2010_06001_tract10.shp.json tl_2010_06001_tract10.shp
+tippecanoe -z11 -o tracts-added.mbtiles -l tracts tl_2010_06001_tract10.shp.json
+
+# Merge the filtered tileset and the tileset of new tracts into a final tileset
+tile-join -o tracts-final.mbtiles tracts-filtered.mbtiles tracts-added.mbtiles
+```
+
+The `-z11` option explicitly specifies the maxzoom, to make sure both the old and new tilesets have the same zoom range.
+
+The `-j` option to `tile-join` specifies a filter, so that only the desired features will be copied to the new tileset.
+This filter excludes (using `none`) any features whose FIPS code (`COUNTYFP00`) is the code for Alameda County (`001`).
+
 Options
 -------
 
-### Naming
+There are a lot of options. A lot of the time you won't want to use any of them
+other than `-o` _output_`.mbtiles` to name the output file, and probably `-f` to
+delete the file that already exists with that name.
 
- * -l _name_ or --layer=_name_: Layer name (default "file" if source is file.json or output is file.mbtiles). If there are multiple input files
-   specified, the files are all merged into the single named layer, even if they try to specify individual names with -L.
- * -L _name_:_file.json_ or --named-layer=_name_:_file.json_: Specify layer names for individual files. If your shell supports it, you can use a subshell redirect like -L _name_:<(cat dir/*.json) to specify a layer name for the output of streamed input.
- * -n _name_ or --name=_name_: Human-readable name for the tileset (default file.json)
- * -A _text_ or --attribution=_text_: Attribution (HTML) to be shown with maps that use data from this tileset.
+If you aren't sure what the right maxzoom is for your data, `-zg` will guess one for you
+based on the density of features.
 
-### File control
+Tippecanoe will normally drop a fraction of point features at zooms below the maxzoom,
+to keep the low-zoom tiles from getting too big. If you have a smaller data set where
+all the points would fit without dropping any of them, use `-r1` to keep them all.
+If you do want point dropping, but you still want the tiles to be denser than `-zg`
+thinks they should be, use `-B` to set a basezoom lower than the maxzoom.
 
- * -o _file_.mbtiles or --output=_file_.mbtiles: Name the output file.
- * -f or --force: Delete the mbtiles file if it already exists instead of giving an error
- * -F or --allow-existing: Proceed (without deleting existing data) if the metadata or tiles table already exists
-   or if metadata fields can't be set
- * -t _directory_ or --temporary-directory=_directory_: Put the temporary files in _directory_.
-   If you don't specify, it will use `/tmp`.
- * -P or --read-parallel: Use multiple threads to read different parts of each input file at once.
+If some of your tiles are coming out too big in spite of the settings above, you will
+often want to use `--drop-densest-as-needed` to drop whatever fraction of the features
+is necessary at each zoom level to make that zoom level's tiles work.
+
+If your features have a lot of attributes, use `-y` to keep only the ones you really need.
+
+If your input is formatted as newline-delimited GeoJSON, use `-P` to make input parsing a lot faster.
+
+### Output tileset
+
+ * `-o` _file_`.mbtiles` or `--output=`_file_`.mbtiles`: Name the output file.
+ * `-e` _directory_ or `--output-to-directory`=_directory_: Write tiles to the specified *directory* instead of to an mbtiles file.
+ * `-f` or `--force`: Delete the mbtiles file if it already exists instead of giving an error
+ * `-F` or `--allow-existing`: Proceed (without deleting existing data) if the metadata or tiles table already exists
+   or if metadata fields can't be set. You probably don't want to use this.
+
+### Tileset description and attribution
+
+ * `-n` _name_ or `--name=`_name_: Human-readable name for the tileset (default file.json)
+ * `-A` _text_ or `--attribution=`_text_: Attribution (HTML) to be shown with maps that use data from this tileset.
+ * `-N` _description_ or `--description=`_description_: Description for the tileset (default file.mbtiles)
+
+### Input files and layer names
+
+ * _name_`.json` or _name_`.geojson`: Read the named GeoJSON input file into a layer called _name_.
+ * _name_`.json.gz` or _name_`.geojson.gz`: Read the named gzipped GeoJSON input file into a layer called _name_.
+ * _name_`.geobuf`: Read the named Geobuf input file into a layer called _name_.
+ * _name_`.csv`: Read the named CSV input file into a layer called _name_.
+ * `-l` _name_ or `--layer=`_name_: Use the specified layer name instead of deriving a name from the input filename or output tileset. If there are multiple input files
+   specified, the files are all merged into the single named layer, even if they try to specify individual names with `-L`.
+ * `-L` _name_`:`_file.json_ or `--named-layer=`_name_`:`_file.json_: Specify layer names for individual files. If your shell supports it, you can use a subshell redirect like `-L` _name_`:<(cat dir/*.json)` to specify a layer name for the output of streamed input.
+ * `-L{`_layer-json_`}` or `--named-layer={`_layer-json_`}`: Specify an input file and layer options by a JSON object. The JSON object must contain a `"file"` key to specify the filename to read from. (If the `"file"` key is an empty string, it means to read from the standard input stream.) It may also contain a `"layer"` field to specify the name of the layer, and/or a `"description"` field to specify the layer's description in the tileset metadata, and/or a `"format"` field to specify `csv` or `geobuf` file format if it is not obvious from the `name`. Example:
+
+```
+tippecanoe -z5 -o world.mbtiles -L'{"file":"ne_10m_admin_0_countries.json", "layer":"countries", "description":"Natural Earth countries"}'
+```
+
+CSV input files currently support only Point geometries, from columns named `latitude`, `longitude`, `lat`, `lon`, `long`, `lng`, `x`, or `y`.
+
+### Parallel processing of input
+
+ * `-P` or `--read-parallel`: Use multiple threads to read different parts of each GeoJSON input file at once.
    This will only work if the input is line-delimited JSON with each Feature on its
    own line, because it knows nothing of the top-level structure around the Features. Spurious "EOF" error
    messages may result otherwise.
    Performance will be better if the input is a named file that can be mapped into memory
    rather than a stream that can only be read sequentially.
 
-### Zoom levels and resolution
+If the input file begins with the [RFC 8142](https://tools.ietf.org/html/rfc8142) record separator,
+parallel processing of input will be invoked automatically, splitting at record separators rather
+than at all newlines.
 
- * -z _zoom_ or --maximum-zoom=_zoom_: Maxzoom: the highest zoom level for which tiles are generated (default 14)
- * -Z _zoom_ or --minimum-zoom=_zoom_: Minzoom: the lowest zoom level for which tiles are generated (default 0)
- * -B _zoom_ or --base-zoom=_zoom_: Base zoom, the level at and above which all points are included in the tiles (default maxzoom).
-   If you use -Bg, it will guess a zoom level that will keep at most 50,000 features in the densest tile.
-   You can also specify a marker-width with -Bg*width* to allow fewer features in the densest tile to
-   compensate for the larger marker, or -Bf*number* to allow at most *number* features in the densest tile.
- * -d _detail_ or --full-detail=_detail_: Detail at max zoom level (default 12, for tile resolution of 4096)
- * -D _detail_ or --low-detail=_detail_: Detail at lower zoom levels (default 12, for tile resolution of 4096)
- * -m _detail_ or --minimum-detail=_detail_: Minimum detail that it will try if tiles are too big at regular detail (default 7)
- * -b _pixels_ or --buffer=_pixels_: Buffer size where features are duplicated from adjacent tiles. Units are "screen pixels"--1/256th of the tile width or height. (default 5)
- * -s _projection_ or --projection=_projection_: Specify the projection of the input data. Currently supported are EPSG:4326 (WGS84, the default) and EPSG:3857 (Web Mercator).
- * -M _bytes_ or --maximum-tile-bytes=_bytes_: Use the specified number of _bytes_ as the maximum compressed tile size instead of 500K.
+Parallel processing will also be automatic if the input file is in Geobuf format.
+
+### Projection of input
+
+ * `-s` _projection_ or `--projection=`_projection_: Specify the projection of the input data. Currently supported are `EPSG:4326` (WGS84, the default) and `EPSG:3857` (Web Mercator). In general you should use WGS84 for your input files if at all possible.
+
+### Zoom levels
+
+ * `-z` _zoom_ or `--maximum-zoom=`_zoom_: Maxzoom: the highest zoom level for which tiles are generated (default 14)
+ * `-zg` or `--maximum-zoom=g`: Guess what is probably a reasonable maxzoom based on the spacing of features.
+ * `-Z` _zoom_ or `--minimum-zoom=`_zoom_: Minzoom: the lowest zoom level for which tiles are generated (default 0)
+ * `-ae` or `--extend-zooms-if-still-dropping`: Increase the maxzoom if features are still being dropped at that zoom level.
+   The detail and simplification options that ordinarily apply only to the maximum zoom level will apply both to the originally
+   specified maximum zoom and to any levels added beyond that.
+ * `-R` _zoom_`/`_x_`/`_y_ or `--one-tile=`_zoom_`/`_x_`/`_y_: Set the minzoom and maxzoom to _zoom_ and produce only
+   the single specified tile at that zoom level.
+
+If you know the precision to which you want your data to be represented,
+or the map scale of a corresponding printed map,
+this table shows the approximate precision and scale corresponding to various
+`-z` options if you use the default `-d` detail of 12:
+
+zoom level | precision (ft) | precision (m) | map scale
+---------- | -------------- | ------------- | ---------
+`-z0` | 32000 ft | 10000 m | 1:320,000,000
+`-z1` | 16000 ft | 5000 m | 1:160,000,000
+`-z2` | 8000 ft | 2500 m | 1:80,000,000
+`-z3` | 4000 ft | 1250 m | 1:40,000,000
+`-z4` | 2000 ft | 600 m | 1:20,000,000
+`-z5` | 1000 ft | 300 m | 1:10,000,000
+`-z6` | 500 ft | 150 m | 1:5,000,000
+`-z7` | 250 ft | 80 m | 1:2,500,000
+`-z8` | 125 ft | 40 m | 1:1,250,000
+`-z9` | 64 ft | 20 m | 1:640,000
+`-z10` | 32 ft | 10 m | 1:320,000
+`-z11` | 16 ft | 5 m | 1:160,000
+`-z12` | 8 ft | 2 m | 1:80,000
+`-z13` | 4 ft | 1 m | 1:40,000
+`-z14` | 2 ft | 0.5 m | 1:20,000
+`-z15` | 1 ft | 0.25 m | 1:10,000
+`-z16` | 6 in | 15 cm | 1:5000
+`-z17` | 3 in | 8 cm | 1:2500
+`-z18` | 1.5 in | 4 cm | 1:1250
+`-z19` | 0.8 in | 2 cm | 1:600
+`-z20` | 0.4 in | 1 cm | 1:300
+`-z21` | 0.2 in | 0.5 cm | 1:150
+`-z22` | 0.1 in | 0.25 cm | 1:75
+
+### Tile resolution
+
+ * `-d` _detail_ or `--full-detail=`_detail_: Detail at max zoom level (default 12, for tile resolution of 2^12=4096)
+ * `-D` _detail_ or `--low-detail=`_detail_: Detail at lower zoom levels (default 12, for tile resolution of 2^12=4096)
+ * `-m` _detail_ or `--minimum-detail=`_detail_: Minimum detail that it will try if tiles are too big at regular detail (default 7)
 
 All internal math is done in terms of a 32-bit tile coordinate system, so 1/(2^32) of the size of Earth,
 or about 1cm, is the smallest distinguishable distance. If _maxzoom_ + _detail_ > 32, no additional
 resolution is obtained than by using a smaller _maxzoom_ or _detail_.
 
-### Properties
+### Filtering feature attributes
 
- * -x _name_ or --exclude=_name_: Exclude the named properties from all features
- * -y _name_ or --include=_name_: Include the named properties in all features, excluding all those not explicitly named
- * -X or --exclude-all: Exclude all properties and encode only geometries
+ * `-x` _name_ or `--exclude=`_name_: Exclude the named attributes from all features. You can specify multiple `-x` options to exclude several attributes. (Don't comma-separate names within a single `-x`.)
+ * `-y` _name_ or `--include=`_name_: Include the named attributes in all features, excluding all those not explicitly named. You can specify multiple `-y` options to explicitly include several attributes. (Don't comma-separate names within a single `-y`.)
+ * `-X` or `--exclude-all`: Exclude all attributes and encode only geometries
 
-### Point simplification
+### Modifying feature attributes
 
- * -r _rate_ or --drop-rate=_rate_: Rate at which dots are dropped at zoom levels below basezoom (default 2.5).
-   If you use -rg, it will guess a drop rate that will keep at most 50,000 features in the densest tile.
-   You can also specify a marker-width with -rg*width* to allow fewer features in the densest tile to
-   compensate for the larger marker, or -rf*number* to allow at most *number* features in the densest tile.
- * -g _gamma_ or --gamma=_gamma_: Rate at which especially dense dots are dropped (default 0, for no effect). A gamma of 2 reduces the number of dots less than a pixel apart to the square root of their original number.
+ * `-T`_attribute_`:`_type_ or `--attribute-type=`_attribute_`:`_type_: Coerce the named feature _attribute_ to be of the specified _type_.
+   The _type_ may be `string`, `float`, `int`, or `bool`.
+   If the type is `bool`, then original attributes of `0` (or, if numeric, `0.0`, etc.), `false`, `null`, or the empty string become `false`, and otherwise become `true`.
+   If the type is `float` or `int` and the original attribute was non-numeric, it becomes `0`.
+   If the type is `int` and the original attribute was floating-point, it is rounded to the nearest integer.
+ * `-Y`_attribute_`:`_description_ or `--attribute-description=`_attribute_`:`_description_: Set the `description` for the specified attribute in the tileset metadata to _description_ instead of the usual `String`, `Number`, or `Boolean`.
+ * `-E`_attribute_`:`_operation_ or `--accumulate-attribute=`_attribute_`:`_operation_: Preserve the named _attribute_ from features
+   that are dropped, coalesced-as-needed, or clustered. The _operation_ may be
+   `sum`, `product`, `mean`, `max`, `min`, `concat`, or `comma`
+   to specify how the named _attribute_ is accumulated onto the attribute of the same name in a feature that does survive.
+ * `-pe` or `--empty-csv-columns-are-null`: Treat empty CSV columns as nulls rather than as empty strings.
+ * `-aI` or `--convert-stringified-ids-to-numbers`: If a feature ID is the string representation of a number, convert it to a plain number to use as the feature ID.
+ * `--use-attribute-for-id=`*name*: Use the attribute with the specified *name* as if it were specified as the feature ID. (If this attribute is a stringified number, you must also use `-aI` to convert it to a number.)
+
+### Filtering features by attributes
+
+ * `-j` *filter* or `--feature-filter`=*filter*: Check features against a per-layer filter (as defined in the [Mapbox GL Style Specification](https://docs.mapbox.com/mapbox-gl-js/style-spec/#other-filter)) and only include those that match. Any features in layers that have no filter specified will be passed through. Filters for the layer `"*"` apply to all layers. The special variable `$zoom` refers to the current zoom level.
+ * `-J` *filter-file* or `--feature-filter-file`=*filter-file*: Like `-j`, but read the filter from a file.
+
+Example: to find the Natural Earth countries with low `scalerank` but high `LABELRANK`:
+
+```
+tippecanoe -z5 -o filtered.mbtiles -j '{ "ne_10m_admin_0_countries": [ "all", [ "<", "scalerank", 3 ], [ ">", "LABELRANK", 5 ] ] }' ne_10m_admin_0_countries.geojson
+```
+
+Example: to retain only major TIGER roads at low zoom levels:
+
+```
+tippecanoe -o roads.mbtiles -j '{ "*": [ "any", [ ">=", "$zoom", 11 ], [ "in", "MTFCC", "S1100", "S1200" ] ] }' tl_2015_06001_roads.json
+```
+
+Tippecanoe also accepts expressions of the form `[ "attribute-filter", name, expression ]`, to filter individual feature attributes
+instead of entire features. For example, you can exclude the road names at low zoom levels by doing
+
+```
+tippecanoe -o roads.mbtiles -j '{ "*": [ "attribute-filter", "FULLNAME", [ ">=", "$zoom", 9 ] ] }' tl_2015_06001_roads.json
+```
+
+An `attribute-filter` expression itself is always considered to evaluate to `true` (in other words, to retain the feature instead
+of dropping it). If you want to use multiple `attribute-filter` expressions, or to use other expressions to remove features from
+the same layer, enclose them in an `all` expression so they will all be evaluated.
+
+### Dropping a fixed fraction of features by zoom level
+
+ * `-r` _rate_ or `--drop-rate=`_rate_: Rate at which dots are dropped at zoom levels below basezoom (default 2.5).
+   If you use `-rg`, it will guess a drop rate that will keep at most 50,000 features in the densest tile.
+   You can also specify a marker-width with `-rg`*width* to allow fewer features in the densest tile to
+   compensate for the larger marker, or `-rf`*number* to allow at most *number* features in the densest tile.
+ * `-B` _zoom_ or `--base-zoom=`_zoom_: Base zoom, the level at and above which all points are included in the tiles (default maxzoom).
+   If you use `-Bg`, it will guess a zoom level that will keep at most 50,000 features in the densest tile.
+   You can also specify a marker-width with `-Bg`*width* to allow fewer features in the densest tile to
+   compensate for the larger marker, or `-Bf`*number* to allow at most *number* features in the densest tile.
+ * `-al` or `--drop-lines`: Let "dot" dropping at lower zooms apply to lines too
+ * `-ap` or `--drop-polygons`: Let "dot" dropping at lower zooms apply to polygons too
+ * `-K` _distance_ or `--cluster-distance=`_distance_: Cluster points (as with `--cluster-densest-as-needed`, but without the experimental discovery process) that are approximately within _distance_ of each other. The units are tile coordinates within a nominally 256-pixel tile, so the maximum value of 255 allows only one feature per tile. Values around 10 are probably appropriate for typical marker sizes. See `--cluster-densest-as-needed` below for behavior.
+
+### Dropping a fraction of features to keep under tile size limits
+
+ * `-as` or `--drop-densest-as-needed`: If a tile is too large, try to reduce it to under 500K by increasing the minimum spacing between features. The discovered spacing applies to the entire zoom level.
+ * `-ad` or `--drop-fraction-as-needed`: Dynamically drop some fraction of features from each zoom level to keep large tiles under the 500K size limit. (This is like `-pd` but applies to the entire zoom level, not to each tile.)
+ * `-an` or `--drop-smallest-as-needed`: Dynamically drop the smallest features (physically smallest: the shortest lines or the smallest polygons) from each zoom level to keep large tiles under the 500K size limit. This option will not work for point features.
+ * `-aN` or `--coalesce-smallest-as-needed`: Dynamically combine the smallest features (physically smallest: the shortest lines or the smallest polygons) from each zoom level into other nearby features to keep large tiles under the 500K size limit. This option will not work for point features, and will probably not help very much with LineStrings. It is mostly intended for polygons, to maintain the full original area covered by polygons while still reducing the feature count somehow. The attributes of the small polygons are *not* preserved into the combined features (except through `--accumulate-attribute`), only their geometry. Furthermore, the polygons to which nested polygons are coalesced may not necessarily be the immediately enclosing features.
+ * `-aD` or `--coalesce-densest-as-needed`: Dynamically combine the densest features from each zoom level into other nearby features to keep large tiles under the 500K size limit. (Again, mostly useful for polygons.)
+ * `-aS` or `--coalesce-fraction-as-needed`: Dynamically combine a fraction of features from each zoom level into other nearby features to keep large tiles under the 500K size limit. (Again, mostly useful for polygons.)
+ * `-pd` or `--force-feature-limit`: Dynamically drop some fraction of features from large tiles to keep them under the 500K size limit. It will probably look ugly at the tile boundaries. (This is like `-ad` but applies to each tile individually, not to the entire zoom level.) You probably don't want to use this.
+ * `-aC` or `--cluster-densest-as-needed`: If a tile is too large, try to reduce its size by increasing the minimum spacing between features, and leaving one placeholder feature from each group.  The remaining feature will be given a `"clustered": true` attribute to indicate that it represents a cluster, a `"point_count"` attribute to indicate the number of features that were clustered into it, and a `"sqrt_point_count"` attribute to indicate the relative width of a feature to represent the cluster. If the features being clustered are points, the representative feature will be located at the average of the original points' locations; otherwise, one of the original features will be left as the representative.
+
+### Dropping tightly overlapping features
+
+ * `-g` _gamma_ or `--gamma=_gamma`_: Rate at which especially dense dots are dropped (default 0, for no effect). A gamma of 2 reduces the number of dots less than a pixel apart to the square root of their original number.
+ * `-aG` or `--increase-gamma-as-needed`: If a tile is too large, try to reduce it to under 500K by increasing the `-g` gamma. The discovered gamma applies to the entire zoom level. You probably want to use `--drop-densest-as-needed` instead.
 
 ### Line and polygon simplification
 
- * -S _scale_ or --simplification=_scale_: Multiply the tolerance for line and polygon simplification by _scale_. The standard tolerance tries to keep
+ * `-S` _scale_ or `--simplification=`_scale_: Multiply the tolerance for line and polygon simplification by _scale_. The standard tolerance tries to keep
    the line or polygon within one tile unit of its proper location. You can probably go up to about 10 without too much visible difference.
+ * `-ps` or `--no-line-simplification`: Don't simplify lines and polygons
+ * `-pS` or `--simplify-only-low-zooms`: Don't simplify lines and polygons at maxzoom (but do simplify at lower zooms)
+ * `-pn` or `--no-simplification-of-shared-nodes`: Don't simplify away nodes that appear in more than one feature or are used multiple times within the same feature, so that the intersection node will not be lost from intersecting roads. (This will not be effective if you also use `--coalesce` or `--detect-shared-borders`.)
+ * `-pt` or `--no-tiny-polygon-reduction`: Don't combine the area of very small polygons into small squares that represent their combined area.
 
-### Doing more
+### Attempts to improve shared polygon boundaries
 
- * -ac or --coalesce: Coalesce adjacent line and polygon features that have the same properties.
-   Note that when overlapping polygons are coalesced, the overlapping region is treated as a hole,
-   which may not be what you want.
- * -ar or --reverse: Try reversing the directions of lines to make them coalesce and compress better
- * -ao or --reorder: Reorder features to put ones with the same properties in sequence, to try to get them to coalesce
- * -al or --drop-lines: Let "dot" dropping at lower zooms apply to lines too
- * -ap or --drop-polygons: Let "dot" dropping at lower zooms apply to polygons too
- * -ag or --calculate-feature-density: Add a new attribute, `tippecanoe_feature_density`, to each feature, to record how densely features are spaced in that area of the tile. You can use this attribute in the style to produce a glowing effect where points are densely packed. It can range from 0 in the sparsest areas to 255 in the densest.
- * -ab or --detect-shared-borders: In the manner of [TopoJSON](https://github.com/mbostock/topojson/wiki/Introduction), detect borders that are shared between multiple polygons and simplify them identically in each polygon. This takes more time and memory than considering each polygon individually.
- * -aG or --increase-gamma-as-needed: If a tile is too large, try to reduce it to under 500K by increasing the `-g` gamma. The discovered gamma applies to the entire zoom level.
- * -as or --drop-densest-as-needed: If a tile is too large, try to reduce it to under 500K by increasing the minimum spacing between features. The discovered spacing applies to the entire zoom level.
- * -ad or --drop-fraction-as-needed: Dynamically drop some fraction of features from each zoom level to keep large tiles under the 500K size limit. (This is like `-pd` but applies to the entire zoom level, not to each tile.)
- * -an or --drop-smallest-as-needed: Dynamically drop the smallest features (physically smallest: the shortest lines or the smallest polygons) from each zoom level to keep large tiles under the 500K size limit. This option will not work for point features.
- * -aL or --grid-low-zooms: At all zoom levels below _maxzoom_, snap all lines and polygons to a stairstep grid instead of allowing diagonals. You will also want to specify a tile resolution, probably `-D8`. This option provides a way to display continuous parcel, gridded, or binned data at low zooms without overwhelming the tiles with tiny polygons, since features will either get stretched out to the grid unit or lost entirely, depending on how they happened to be aligned in the original data.
+ * `-ab` or `--detect-shared-borders`: In the manner of [TopoJSON](https://github.com/mbostock/topojson/wiki/Introduction), detect borders that are shared between multiple polygons and simplify them identically in each polygon. This takes more time and memory than considering each polygon individually.
+ * `-aL` or `--grid-low-zooms`: At all zoom levels below _maxzoom_, snap all lines and polygons to a stairstep grid instead of allowing diagonals. You will also want to specify a tile resolution, probably `-D8`. This option provides a way to display continuous parcel, gridded, or binned data at low zooms without overwhelming the tiles with tiny polygons, since features will either get stretched out to the grid unit or lost entirely, depending on how they happened to be aligned in the original data. You probably don't want to use this.
 
-### Doing less
+### Controlling clipping to tile boundaries
 
- * -ps or --no-line-simplification: Don't simplify lines
- * -pS or --simplify-only-low-zooms: Don't simplify lines at maxzoom (but do simplify at lower zooms)
- * -pf or --no-feature-limit: Don't limit tiles to 200,000 features
- * -pk or --no-tile-size-limit: Don't limit tiles to 500K bytes
- * -pd or --force-feature-limit: Dynamically drop some fraction of features from large tiles to keep them under the 500K size limit. It will probably look ugly at the tile boundaries. (This is like `-ad` but applies to each tile individually, not to the entire zoom level.)
- * -pi or --preserve-input-order: Preserve the original input order of features as the drawing order instead of ordering geographically. (This is implemented as a restoration of the original order at the end, so that dot-dropping is still geographic, which means it also undoes -ao).
- * -pp or --no-polygon-splitting: Don't split complex polygons (over 700 vertices after simplification) into multiple features.
- * -pc or --no-clipping: Don't clip features to the size of the tile. If a feature overlaps the tile's bounds or buffer at all, it is included completely. Be careful: this can produce very large tilesets, especially with large polygons.
- * -pD or --no-duplication: As with --no-clipping, each feature is included intact instead of cut to tile boundaries. In addition, it is included only in a single tile per zoom level rather than potentially in multiple copies. Clients of the tileset must check adjacent tiles (possibly some distance away) to ensure they have all features.
- * -pt or --no-tiny-polygon-reduction: Don't combine the area of very small polygons into small squares that represent their combined area.
- * -q or --quiet: Work quietly instead of reporting progress
+ * `-b` _pixels_ or `--buffer=`_pixels_: Buffer size where features are duplicated from adjacent tiles. Units are "screen pixels"—1/256th of the tile width or height. (default 5)
+ * `-pc` or `--no-clipping`: Don't clip features to the size of the tile. If a feature overlaps the tile's bounds or buffer at all, it is included completely. Be careful: this can produce very large tilesets, especially with large polygons.
+ * `-pD` or `--no-duplication`: As with `--no-clipping`, each feature is included intact instead of cut to tile boundaries. In addition, it is included only in a single tile per zoom level rather than potentially in multiple copies. Clients of the tileset must check adjacent tiles (possibly some distance away) to ensure they have all features.
 
-Example
--------
+### Reordering features within each tile
 
-```sh
-$ tippecanoe -o alameda.mbtiles -l alameda -n "Alameda County from TIGER" -z13 tl_2014_06001_roads.json
-```
+ * `-pi` or `--preserve-input-order`: Preserve the original input order of features as the drawing order instead of ordering geographically. (This is implemented as a restoration of the original order at the end, so that dot-dropping is still geographic, which means it also undoes `-ao`).
+ * `-ac` or `--coalesce`: Coalesce consecutive features that have the same attributes. This can be useful if you have lots of small polygons with identical attributes and you would like to merge them together.
+ * `-ao` or `--reorder`: Reorder features to put ones with the same attributes in sequence (instead of ones that are approximately spatially adjacent), to try to get them to coalesce. You probably want to use this if you use `--coalesce`.
+ * `-ar` or `--reverse`: Try reversing the directions of lines to make them coalesce and compress better. You probably don't want to use this.
+ * `-ah` or `--hilbert`: Put features in Hilbert Curve order instead of the usual Z-Order. This improves the odds that spatially adjacent features will be sequentially adjacent, and should improve density calculations and spatial coalescing. It should be the default eventually.
+
+### Adding calculated attributes
+
+ * `-ag` or `--calculate-feature-density`: Add a new attribute, `tippecanoe_feature_density`, to each feature, to record how densely features are spaced in that area of the tile. You can use this attribute in the style to produce a glowing effect where points are densely packed. It can range from 0 in the sparsest areas to 255 in the densest.
+ * `-ai` or `--generate-ids`: Add an `id` (a feature ID, not an attribute named `id`) to each feature that does not already have one. There is currently no guarantee that the `id` added will be stable between runs or that it will not conflict with manually-assigned feature IDs. Future versions of Tippecanoe may change the mechanism for allocating IDs.
+
+### Trying to correct bad source geometry
+
+ * `-aw` or `--detect-longitude-wraparound`: Detect when consecutive points within a feature jump to the other side of the world, and try to fix the geometry.
+ * `-pw` or `--use-source-polygon-winding`: Instead of respecting GeoJSON polygon ring order, use the original polygon winding in the source data to distinguish inner (clockwise) and outer (counterclockwise) polygon rings.
+ * `-pW` or `--reverse-source-polygon-winding`: Instead of respecting GeoJSON polygon ring order, use the opposite of the original polygon winding in the source data to distinguish inner (counterclockwise) and outer (clockwise) polygon rings.
+ * `--clip-bounding-box=`*minlon*`,`*minlat*`,`*maxlon*`,`*maxlat*: Clip all features to the specified bounding box.
+
+### Setting or disabling tile size limits
+
+ * `-M` _bytes_ or `--maximum-tile-bytes=`_bytes_: Use the specified number of _bytes_ as the maximum compressed tile size instead of 500K.
+ * `-O` _features_ or `--maximum-tile-features=`_features_: Use the specified number of _features_ as the maximum in a tile instead of 200,000.
+ * `-pf` or `--no-feature-limit`: Don't limit tiles to 200,000 features
+ * `-pk` or `--no-tile-size-limit`: Don't limit tiles to 500K bytes
+ * `-pC` or `--no-tile-compression`: Don't compress the PBF vector tile data. If you are getting "Unimplemented type 3" error messages from a renderer, it is probably because it expects uncompressed tiles using this option rather than the normal gzip-compressed tiles.
+ * `-pg` or `--no-tile-stats`: Don't generate the `tilestats` row in the tileset metadata. Uploads without [tilestats](https://github.com/mapbox/mapbox-geostats) will take longer to process.
+ * `--tile-stats-attributes-limit=`*count*: Include `tilestats` information about at most *count* attributes instead of the default 1000.
+ * `--tile-stats-sample-values-limit=`*count*: Calculate `tilestats` attribute statistics based on *count* values instead of the default 1000.
+ * `--tile-stats-values-limit=`*count*: Report *count* unique attribute values in `tilestats` instead of the default 100.
+
+### Temporary storage
+
+ * `-t` _directory_ or `--temporary-directory=`_directory_: Put the temporary files in _directory_.
+   If you don't specify, it will use `/tmp`.
+
+### Progress indicator
+
+ * `-q` or `--quiet`: Work quietly instead of reporting progress or warning messages
+ * `-Q` or `--no-progress-indicator`: Don't report progress, but still give warnings
+ * `-U` _seconds_ or `--progress-interval=`_seconds_: Don't report progress more often than the specified number of _seconds_.
+ * `-v` or `--version`: Report Tippecanoe's version number
+
+### Filters
+
+ * `-C` _command_ or `--prefilter=`_command_: Specify a shell filter command to be run at the start of assembling each tile
+ * `-c` _command_ or `--postfilter=`_command_: Specify a shell filter command to be run at the end of assembling each tile
+
+The pre- and post-filter commands allow you to do optional filtering or transformation on the features of each tile
+as it is created. They are shell commands, run with the zoom level, X, and Y as the `$1`, `$2`, and `$3` arguments.
+Future versions of Tippecanoe may add additional arguments for more context.
+
+The features are provided to the filter
+as a series of newline-delimited GeoJSON objects on the standard input, and `tippecanoe` expects to read another
+set of GeoJSON features from the filter's standard output.
+
+The prefilter receives the features at the highest available resolution, before line simplification,
+polygon topology repair, gamma calculation, dynamic feature dropping, or other internal processing.
+The postfilter receives the features at tile resolution, after simplification, cleaning, and dropping.
+
+The layer name is provided as part of the `tippecanoe` element of the feature and must be passed through
+to keep the feature in its correct layer. In the case of the prefilter, the `tippecanoe` element may also
+contain `index`, `sequence`, `extent`, and `dropped`, elements, which must be passed through for internal operations like
+`--drop-densest-as-needed`, `--drop-smallest-as-needed`, and `--preserve-input-order` to work.
+
+#### Examples:
+
+ * Make a tileset of the Natural Earth countries to zoom level 5, and also copy the GeoJSON features
+   to files in a `tiles/z/x/y.geojson` directory hierarchy.
 
 ```
-$ cat tiger/tl_2014_*_roads.json | tippecanoe -o tiger.mbtiles -l roads -n "All TIGER roads, one zoom" -z12 -Z12 -d14 -x LINEARID -x RTTYP
+tippecanoe -o countries.mbtiles -z5 -C 'mkdir -p tiles/$1/$2; tee tiles/$1/$2/$3.geojson' ne_10m_admin_0_countries.json
 ```
 
+ * Make a tileset of the Natural Earth countries to zoom level 5, but including only those tiles that
+   intersect the [bounding box of Germany](https://www.flickr.com/places/info/23424829).
+   (The `limit-tiles-to-bbox` script is [in the Tippecanoe source directory](filters/limit-tiles-to-bbox).)
+
+```
+tippecanoe -o countries.mbtiles -z5 -C './filters/limit-tiles-to-bbox 5.8662 47.2702 15.0421 55.0581 $*' ne_10m_admin_0_countries.json
+```
+
+ * Make a tileset of TIGER roads in Tippecanoe County, leaving out all but primary and secondary roads (as [classified by TIGER](https://www.census.gov/geo/reference/mtfcc.html)) below zoom level 11.
+
+```
+tippecanoe -o roads.mbtiles -c 'if [ $1 -lt 11 ]; then grep "\"MTFCC\": \"S1[12]00\""; else cat; fi' tl_2016_18157_roads.json
+```
+
+Environment
+-----------
+
+Tippecanoe ordinarily uses as many parallel threads as the operating system claims that CPUs are available.
+You can override this number by setting the `TIPPECANOE_MAX_THREADS` environmental variable.
+
 GeoJSON extension
 -----------------
 
@@ -198,32 +626,11 @@ the filename or name specified using `--layer`, like this:
 }
 ```
 
-Point styling
--------------
+If your source GeoJSON only has `minzoom`, `maxzoom` and/or `layer` within `properties` you can use [ndjson-cli](https://github.com/mbostock/ndjson-cli/blob/master/README.md) to move them into the required `tippecanoe` object by piping the GeoJSON like this:
 
-To provide a consistent density gradient as you zoom, the Mapbox Studio style needs to be
-coordinated with the base zoom level and dot-dropping rate. You can use this shell script to
-calculate the appropriate marker-width at high zoom levels to match the fraction of dots
-that were dropped at low zoom levels.
-
-If you used `-B` or `-z` to change the base zoom level or `-r` to change the
-dot-dropping rate, replace them in the `basezoom` and `rate` below.
-
-    awk 'BEGIN {
-        dotsize = 2;    # up to you to decide
-        basezoom = 14;  # tippecanoe -z 14
-        rate = 2.5;     # tippecanoe -r 2.5
-
-        print "  marker-line-width: 0;";
-        print "  marker-ignore-placement: true;";
-        print "  marker-allow-overlap: true;";
-        print "  marker-width: " dotsize ";";
-        for (i = basezoom + 1; i <= 22; i++) {
-            print "  [zoom >= " i "] { marker-width: " (dotsize * exp(log(sqrt(rate)) * (i - basezoom))) "; }";
-        }
-
-        exit(0);
-    }'
+```sh
+ndjson-map 'd.tippecanoe = { minzoom: d.properties.minzoom, maxzoom: d.properties.maxzoom, layer: d.properties.layer }, delete d.properties.minzoom, delete d.properties.maxzoom, delete d.properties.layer, d'
+```
 
 Geometric simplifications
 -------------------------
@@ -251,12 +658,9 @@ have their probability diffused, so that some of them will be drawn as a square
 this minimum size and others will not be drawn at all, preserving the total area that
 all of them should have had together.
 
-Any polygons that have over 700 vertices after line simplification will be split into
-multiple features so they can be rendered efficiently, unless you use -pp to prevent this.
-
 Features in the same tile that share the same type and attributes are coalesced
 together into a single geometry if you use `--coalesce`. You are strongly encouraged to use -x to exclude
-any unnecessary properties to reduce wasted file size.
+any unnecessary attributes to reduce wasted file size.
 
 If a tile is larger than 500K, it will try encoding that tile at progressively
 lower resolutions before failing if it still doesn't fit.
@@ -269,7 +673,7 @@ uses md2man (`gem install md2man`).
 
 Linux:
 
-    sudo apt-get install libsqlite3-dev zlib1g-dev
+    sudo apt-get install build-essential libsqlite3-dev zlib1g-dev
 
 Then build:
 
@@ -279,6 +683,35 @@ and perhaps
 
     make install
 
+Tippecanoe now requires features from the 2011 C++ standard. If your compiler is older than
+that, you will need to install a newer one. On MacOS, updating to the lastest XCode should
+get you a new enough version of `clang++`. On Linux, you should be able to upgrade `g++` with
+
+```
+sudo add-apt-repository -y ppa:ubuntu-toolchain-r/test
+sudo apt-get update -y
+sudo apt-get install -y g++-5
+export CXX=g++-5
+```
+
+Docker Image
+------------
+
+A tippecanoe Docker image can be built from source and executed as a task to
+automatically install dependencies and allow tippecanoe to run on any system
+supported by Docker.
+
+```docker
+$ docker build -t tippecanoe:latest .
+$ docker run -it --rm \
+  -v /tiledata:/data \
+  tippecanoe:latest \
+  tippecanoe --output=/data/output.mbtiles /data/example.geojson
+```
+
+The commands above will build a Docker image from the source and compile the
+latest version. The image supports all tippecanoe flags and options.
+
 Examples
 ------
 
@@ -292,22 +725,61 @@ The name is [a joking reference](http://en.wikipedia.org/wiki/Tippecanoe_and_Tyl
 tile-join
 =========
 
-Tile-join is a tool for joining new attributes from a CSV file to features that
-have already been tiled with tippecanoe. It reads the tiles from an existing .mbtiles
-file, matches them against the records of the CSV, and writes out a new tileset.
+Tile-join is a tool for copying and merging vector mbtiles files and for
+joining new attributes from a CSV file to existing features in them.
 
-If you specify multiple source mbtiles files, they are all read and their combined
-contents are written to the new mbtiles output. If they define the same layers or
-the same tiles, the layers or tiles are merged.
+It reads the tiles from an
+existing .mbtiles file or a directory of tiles, matches them against the
+records of the CSV (if one is specified), and writes out a new tileset.
+
+If you specify multiple source mbtiles files or source directories of tiles,
+all the sources are read and their combined contents are written to the new
+mbtiles output. If they define the same layers or the same tiles, the layers
+or tiles are merged.
 
 The options are:
 
- * -o *out.mbtiles*: Write the new tiles to the specified .mbtiles file
- * -f: Remove *out.mbtiles* if it already exists
- * -c *match.csv*: Use *match.csv* as the source for new attributes to join to the features. The first line of the file should be the key names; the other lines are values. The first column is the one to match against the existing features; the other columns are the new data to add.
- * -x *key*: Remove attributes of type *key* from the output. You can use this to remove the field you are matching against if you no longer need it after joining, or to remove any other attributes you don't want.
- * -i: Only include features that matched the CSV.
- * -pk: Don't skip tiles larger than 500K.
+### Output tileset
+
+ * `-o` *out.mbtiles* or `--output=`*out.mbtiles*: Write the new tiles to the specified .mbtiles file.
+ * `-e` *directory* or `--output-to-directory=`*directory*: Write the new tiles to the specified directory instead of to an mbtiles file.
+ * `-f` or `--force`: Remove *out.mbtiles* if it already exists.
+
+### Tileset description and attribution
+
+ * `-A` *attribution* or `--attribution=`*attribution*: Set the attribution string.
+ * `-n` *name* or `--name=`*name*: Set the tileset name.
+ * `-N` *description* or `--description=`*description*: Set the tileset description.
+
+### Layer filtering and naming
+
+ * `-l` *layer* or `--layer=`*layer*: Include the named layer in the output. You can specify multiple `-l` options to keep multiple layers. If you don't specify, they will all be retained.
+ * `-L` *layer* or `--exclude-layer=`*layer*: Remove the named layer from the output. You can specify multiple `-L` options to remove multiple layers.
+ * `-R`*old*`:`*new* or `--rename-layer=`*old*`:`*new*: Rename the layer named *old* to be named *new* instead. You can specify multiple `-R` options to rename multiple layers. Renaming happens before filtering.
+
+### Zoom levels
+
+ * `-z` _zoom_ or `--maximum-zoom=`_zoom_: Don't copy tiles from higher zoom levels than the specified zoom
+ * `-Z` _zoom_ or `--minimum-zoom=`_zoom_: Don't copy tiles from lower zoom levels than the specified zoom
+
+### Merging attributes from a CSV file
+
+ * `-c` *match*`.csv` or `--csv=`*match*`.csv`: Use *match*`.csv` as the source for new attributes to join to the features. The first line of the file should be the key names; the other lines are values. The first column is the one to match against the existing features; the other columns are the new data to add.
+
+### Filtering features and feature attributes
+
+ * `-x` *key* or `--exclude=`*key*: Remove attributes of type *key* from the output. You can use this to remove the field you are matching against if you no longer need it after joining, or to remove any other attributes you don't want.
+ * `-X` or `--exclude-all`: Remove all attributes from the output.
+ * `-i` or `--if-matched`: Only include features that matched the CSV.
+ * `-j` *filter* or `--feature-filter`=*filter*: Check features against a per-layer filter (as defined in the [Mapbox GL Style Specification](https://docs.mapbox.com/mapbox-gl-js/style-spec/#other-filter)) and only include those that match. Any features in layers that have no filter specified will be passed through. Filters for the layer `"*"` apply to all layers.
+ * `-J` *filter-file* or `--feature-filter-file`=*filter-file*: Like `-j`, but read the filter from a file.
+ * `-pe` or `--empty-csv-columns-are-null`: Treat empty CSV columns as nulls rather than as empty strings.
+
+### Setting or disabling tile size limits
+
+ * `-pk` or `--no-tile-size-limit`: Don't skip tiles larger than 500K.
+ * `-pC` or `--no-tile-compression`: Don't compress the PBF vector tile data.
+ * `-pg` or `--no-tile-stats`: Don't generate the `tilestats` row in the tileset metadata. Uploads without [tilestats](https://github.com/mapbox/mapbox-geostats) will take longer to process.
 
 Because tile-join just copies the geometries to the new .mbtiles without processing them
 (except to rescale the extents if necessary),
@@ -384,11 +856,80 @@ or on an individual tile:
     tippecanoe-decode file.mbtiles zoom x y
     tippecanoe-decode file.vector.pbf zoom x y
 
-If you decode an entire file, you get a nested `FeatureCollection` identifying each
+Unless you use `-c`, the output is a set of nested FeatureCollections identifying each
 tile and layer separately. Note that the same features generally appear at all zooms,
 so the output for the file will have many copies of the same features at different
 resolutions.
 
 ### Options
 
- * -t _projection_: Specify the projection of the output data. Currently supported are EPSG:4326 (WGS84, the default) and EPSG:3857 (Web Mercator).
+ * `-s` _projection_ or `--projection=`*projection*: Specify the projection of the output data. Currently supported are EPSG:4326 (WGS84, the default) and EPSG:3857 (Web Mercator).
+ * `-z` _maxzoom_ or `--maximum-zoom=`*maxzoom*: Specify the highest zoom level to decode from the tileset
+ * `-Z` _minzoom_ or `--minimum-zoom=`*minzoom*: Specify the lowest zoom level to decode from the tileset
+ * `-l` _layer_ or `--layer=`*layer*: Decode only layers with the specified names. (Multiple `-l` options can be specified.)
+ * `-c` or `--tag-layer-and-zoom`: Include each feature's layer and zoom level as part of its `tippecanoe` object rather than as a FeatureCollection wrapper
+ * `-S` or `--stats`: Just report statistics about each tile's size and the number of features in it, as a JSON structure.
+ * `-f` or `--force`: Decode tiles even if polygon ring order or closure problems are detected
+
+tippecanoe-json-tool
+====================
+
+Extracts GeoJSON features or standalone geometries as line-delimited JSON objects from a larger JSON file,
+following the same extraction rules that Tippecanoe uses when parsing JSON.
+
+    tippecanoe-json-tool file.json [... file.json]
+
+Optionally also wraps them in a FeatureCollection or GeometryCollection as appropriate.
+
+Optionally extracts an attribute from the GeoJSON `properties` for sorting.
+
+Optionally joins a sorted CSV of new attributes to a sorted GeoJSON file.
+
+The reason for requiring sorting is so that it is possible to work on CSV and GeoJSON files that are larger
+than can comfortably fit in memory by streaming through them in parallel, in the same way that the Unix
+`join` command does. The Unix `sort` command can be used to sort large files to prepare them for joining.
+
+The sorting interface is weird, and future version of `tippecanoe-json-tool` will replace it with
+something better.
+
+### Options
+
+ * `-w` or `--wrap`: Add the FeatureCollection or GeometryCollection wrapper.
+ * `-e` *attribute* or `--extract=`*attribute*: Extract the named attribute as a prefix to each feature.
+   The formatting makes excessive use of `\u` quoting so that it follows JSON string rules but will still
+   be sorted correctly by tools that just do ASCII comparisons.
+ * `-c` *file.csv* or `--csv=`*file.csv*: Join attributes from the named sorted CSV file, using its first column as the join key. Geometries will be passed through even if they do not match the CSV; CSV lines that do not match a geometry will be discarded.
+ * `-pe` or `--empty-csv-columns-are-null`: Treat empty CSV columns as nulls rather than as empty strings.
+
+### Example
+
+Join Census LEHD ([Longitudinal Employer-Household Dynamics](https://lehd.ces.census.gov/)) employment data to a file of Census block geography
+for Tippecanoe County, Indiana.
+
+Download Census block geometry, and convert to GeoJSON:
+
+```
+$ curl -L -O https://www2.census.gov/geo/tiger/TIGER2010/TABBLOCK/2010/tl_2010_18157_tabblock10.zip
+$ unzip tl_2010_18157_tabblock10.zip
+$ ogr2ogr -f GeoJSON tl_2010_18157_tabblock10.json tl_2010_18157_tabblock10.shp
+```
+
+Download Indiana employment data, and fix name of join key in header
+
+```
+$ curl -L -O https://lehd.ces.census.gov/data/lodes/LODES7/in/wac/in_wac_S000_JT00_2015.csv.gz
+$ gzip -dc in_wac_S000_JT00_2015.csv.gz | sed '1s/w_geocode/GEOID10/' > in_wac_S000_JT00_2015.csv
+```
+
+Sort GeoJSON block geometry so it is ordered by block ID. If you don't do this, you will get a
+"GeoJSON file is out of sort" error.
+
+```
+$ tippecanoe-json-tool -e GEOID10 tl_2010_18157_tabblock10.json | LC_ALL=C sort > tl_2010_18157_tabblock10.sort.json
+```
+
+Join block geometries to employment attributes:
+
+```
+$ tippecanoe-json-tool -c in_wac_S000_JT00_2015.csv tl_2010_18157_tabblock10.sort.json > blocks-wac.json
+```

codecov.yml

@@ -0,0 +1,7 @@
+ignore:
+  - "test"
+  - "mapbox"
+
+coverage:
+  status:
+    patch: off

csv.cpp

@@ -0,0 +1,174 @@
+#include "csv.hpp"
+#include "text.hpp"
+
+std::vector<std::string> csv_split(const char *s) {
+	std::vector<std::string> ret;
+
+	while (*s && *s != '\n' && *s != '\r') {
+		const char *start = s;
+		int within = 0;
+
+		for (; *s && *s != '\n' && *s != '\r'; s++) {
+			if (*s == '"') {
+				within = !within;
+			}
+
+			if (*s == ',' && !within) {
+				break;
+			}
+		}
+
+		std::string v = std::string(start, s - start);
+		ret.push_back(v);
+
+		if (*s == ',') {
+			s++;
+
+			while (*s && isspace(*s)) {
+				s++;
+			}
+
+			if (*s == '\0' || *s == '\r' || *s == '\n') {
+				ret.push_back(std::string(""));
+				break;
+			}
+		}
+	}
+
+	return ret;
+}
+
+std::string csv_dequote(std::string s) {
+	std::string out;
+	for (size_t i = 0; i < s.size(); i++) {
+		if (s[i] == '"') {
+			if (i + 1 < s.size() && s[i + 1] == '"') {
+				out.push_back('"');
+			}
+		} else {
+			out.push_back(s[i]);
+		}
+	}
+	return out;
+}
+
+std::string csv_getline(FILE *f) {
+	std::string out;
+	int c;
+	while ((c = getc(f)) != EOF) {
+		out.push_back(c);
+		if (c == '\n') {
+			break;
+		}
+	}
+	return out;
+}
+
+void readcsv(const char *fn, std::vector<std::string> &header, std::map<std::string, std::vector<std::string>> &mapping) {
+	FILE *f = fopen(fn, "r");
+	if (f == NULL) {
+		perror(fn);
+		exit(EXIT_FAILURE);
+	}
+
+	std::string s;
+	if ((s = csv_getline(f)).size() > 0) {
+		std::string err = check_utf8(s);
+		if (err != "") {
+			fprintf(stderr, "%s: %s\n", fn, err.c_str());
+			exit(EXIT_FAILURE);
+		}
+
+		header = csv_split(s.c_str());
+
+		for (size_t i = 0; i < header.size(); i++) {
+			header[i] = csv_dequote(header[i]);
+		}
+	}
+	while ((s = csv_getline(f)).size() > 0) {
+		std::string err = check_utf8(s);
+		if (err != "") {
+			fprintf(stderr, "%s: %s\n", fn, err.c_str());
+			exit(EXIT_FAILURE);
+		}
+
+		std::vector<std::string> line = csv_split(s.c_str());
+		if (line.size() > 0) {
+			line[0] = csv_dequote(line[0]);
+		}
+
+		for (size_t i = 0; i < line.size() && i < header.size(); i++) {
+			// printf("putting %s\n", line[0].c_str());
+			mapping.insert(std::pair<std::string, std::vector<std::string>>(line[0], line));
+		}
+	}
+
+	if (fclose(f) != 0) {
+		perror("fclose");
+		exit(EXIT_FAILURE);
+	}
+}
+
+// Follow JSON rules for what looks like a number
+bool is_number(std::string const &s) {
+	const char *cp = s.c_str();
+	char c = *(cp++);
+
+	if (c == '-' || (c >= '0' && c <= '9')) {
+		if (c == '-') {
+			c = *(cp++);
+		}
+
+		if (c == '0') {
+			;
+		} else if (c >= '1' && c <= '9') {
+			c = *cp;
+
+			while (c >= '0' && c <= '9') {
+				cp++;
+				c = *cp;
+			}
+		}
+
+		if (*cp == '.') {
+			cp++;
+
+			c = *cp;
+			if (c < '0' || c > '9') {
+				return false;
+			}
+			while (c >= '0' && c <= '9') {
+				cp++;
+				c = *cp;
+			}
+		}
+
+		c = *cp;
+		if (c == 'e' || c == 'E') {
+			cp++;
+
+			c = *cp;
+			if (c == '+' || c == '-') {
+				cp++;
+			}
+
+			c = *cp;
+			if (c < '0' || c > '9') {
+				return false;
+			}
+			while (c >= '0' && c <= '9') {
+				cp++;
+				c = *cp;
+			}
+		}
+
+		if (*cp == '\0') {
+			return true;
+		} else {
+			// Something non-numeric at the end
+			return false;
+		}
+	}
+
+	return false;
+}

csv.hpp

@@ -0,0 +1,16 @@
+#ifndef CSV_HPP
+#define CSV_HPP
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <vector>
+#include <string>
+#include <map>
+
+std::vector<std::string> csv_split(const char *s);
+std::string csv_dequote(std::string s);
+void readcsv(const char *fn, std::vector<std::string> &header, std::map<std::string, std::vector<std::string>> &mapping);
+std::string csv_getline(FILE *f);
+bool is_number(std::string const &s);
+
+#endif

decode.cpp

@@ -3,339 +3,234 @@
 #include <string.h>
 #include <unistd.h>
 #include <sqlite3.h>
+#include <getopt.h>
 #include <string>
 #include <vector>
 #include <map>
+#include <set>
 #include <zlib.h>
 #include <math.h>
 #include <fcntl.h>
+#include <dirent.h>
 #include <sys/stat.h>
 #include <sys/mman.h>
 #include <protozero/pbf_reader.hpp>
+#include <sys/stat.h>
 #include "mvt.hpp"
 #include "projection.hpp"
 #include "geometry.hpp"
+#include "write_json.hpp"
+#include "jsonpull/jsonpull.h"
+#include "dirtiles.hpp"
 
-void printq(const char *s) {
-	putchar('"');
-	for (; *s; s++) {
-		if (*s == '\\' || *s == '"') {
-			printf("\\%c", *s);
-		} else if (*s >= 0 && *s < ' ') {
-			printf("\\u%04x", *s);
-		} else {
-			putchar(*s);
+int minzoom = 0;
+int maxzoom = 32;
+bool force = false;
+
+void do_stats(mvt_tile &tile, size_t size, bool compressed, int z, unsigned x, unsigned y, json_writer &state) {
+	state.json_write_hash();
+
+	state.json_write_string("zoom");
+	state.json_write_signed(z);
+
+	state.json_write_string("x");
+	state.json_write_unsigned(x);
+
+	state.json_write_string("y");
+	state.json_write_unsigned(y);
+
+	state.json_write_string("bytes");
+	state.json_write_unsigned(size);
+
+	state.json_write_string("compressed");
+	state.json_write_bool(compressed);
+
+	state.json_write_string("layers");
+	state.json_write_hash();
+
+	for (size_t i = 0; i < tile.layers.size(); i++) {
+		state.json_write_string(tile.layers[i].name);
+
+		size_t points = 0, lines = 0, polygons = 0;
+		for (size_t j = 0; j < tile.layers[i].features.size(); j++) {
+			if (tile.layers[i].features[j].type == mvt_point) {
+				points++;
+			} else if (tile.layers[i].features[j].type == mvt_linestring) {
+				lines++;
+			} else if (tile.layers[i].features[j].type == mvt_polygon) {
+				polygons++;
+			}
 		}
+
+		state.json_write_hash();
+
+		state.json_write_string("points");
+		state.json_write_unsigned(points);
+
+		state.json_write_string("lines");
+		state.json_write_unsigned(lines);
+
+		state.json_write_string("polygons");
+		state.json_write_unsigned(polygons);
+
+		state.json_write_string("extent");
+		state.json_write_signed(tile.layers[i].extent);
+
+		state.json_end_hash();
 	}
-	putchar('"');
+
+	state.json_end_hash();
+	state.json_end_hash();
+
+	state.json_write_newline();
 }
 
-struct lonlat {
-	int op;
-	double lon;
-	double lat;
-	int x;
-	int y;
-
-	lonlat(int nop, double nlon, double nlat, int nx, int ny) {
-		this->op = nop;
-		this->lon = nlon;
-		this->lat = nlat;
-		this->x = nx;
-		this->y = ny;
-	}
-};
-
-void handle(std::string message, int z, unsigned x, unsigned y, int describe) {
-	int within = 0;
+void handle(std::string message, int z, unsigned x, unsigned y, std::set<std::string> const &to_decode, bool pipeline, bool stats, json_writer &state) {
 	mvt_tile tile;
+	bool was_compressed;
 
 	try {
-		if (!tile.decode(message)) {
+		if (!tile.decode(message, was_compressed)) {
 			fprintf(stderr, "Couldn't parse tile %d/%u/%u\n", z, x, y);
 			exit(EXIT_FAILURE);
 		}
-	} catch (protozero::unknown_pbf_wire_type_exception e) {
+	} catch (std::exception const &e) {
 		fprintf(stderr, "PBF decoding error in tile %d/%u/%u\n", z, x, y);
 		exit(EXIT_FAILURE);
 	}
 
-	printf("{ \"type\": \"FeatureCollection\"");
-
-	if (describe) {
-		printf(", \"properties\": { \"zoom\": %d, \"x\": %d, \"y\": %d }", z, x, y);
-
-		if (projection != projections) {
-			printf(", \"crs\": { \"type\": \"name\", \"properties\": { \"name\": ");
-			printq(projection->alias);
-			printf(" } }");
-		}
+	if (stats) {
+		do_stats(tile, message.size(), was_compressed, z, x, y, state);
+		return;
 	}
 
-	printf(", \"features\": [\n");
+	if (!pipeline) {
+		state.json_write_hash();
 
+		state.json_write_string("type");
+		state.json_write_string("FeatureCollection");
+
+		if (true) {
+			state.json_write_string("properties");
+			state.json_write_hash();
+
+			state.json_write_string("zoom");
+			state.json_write_signed(z);
+
+			state.json_write_string("x");
+			state.json_write_signed(x);
+
+			state.json_write_string("y");
+			state.json_write_signed(y);
+
+			if (!was_compressed) {
+				state.json_write_string("compressed");
+				state.json_write_bool(false);
+			}
+
+			state.json_end_hash();
+
+			if (projection != projections) {
+				state.json_write_string("crs");
+				state.json_write_hash();
+
+				state.json_write_string("type");
+				state.json_write_string("name");
+
+				state.json_write_string("properties");
+				state.json_write_hash();
+
+				state.json_write_string("name");
+				state.json_write_string(projection->alias);
+
+				state.json_end_hash();
+				state.json_end_hash();
+			}
+		}
+
+		state.json_write_string("features");
+		state.json_write_array();
+		state.json_write_newline();
+	}
+
+	bool first_layer = true;
 	for (size_t l = 0; l < tile.layers.size(); l++) {
 		mvt_layer &layer = tile.layers[l];
-		int extent = layer.extent;
 
-		if (describe) {
-			if (l != 0) {
-				printf(",\n");
-			}
-
-			printf("{ \"type\": \"FeatureCollection\"");
-			printf(", \"properties\": { \"layer\": ");
-			printq(layer.name.c_str());
-			printf(", \"version\": %d, \"extent\": %d", layer.version, layer.extent);
-			printf(" }");
-			printf(", \"features\": [\n");
-
-			within = 0;
+		if (layer.extent <= 0) {
+			fprintf(stderr, "Impossible layer extent %lld in mbtiles\n", layer.extent);
+			exit(EXIT_FAILURE);
 		}
 
-		for (size_t f = 0; f < layer.features.size(); f++) {
-			mvt_feature &feat = layer.features[f];
-
-			if (within) {
-				printf(",\n");
-			}
-			within = 1;
-
-			printf("{ \"type\": \"Feature\"");
-
-			if (feat.has_id) {
-				printf(", \"id\": %llu", feat.id);
-			}
-
-			printf(", \"properties\": { ");
-
-			for (size_t t = 0; t + 1 < feat.tags.size(); t += 2) {
-				if (t != 0) {
-					printf(", ");
-				}
-
-				if (feat.tags[t] >= layer.keys.size()) {
-					fprintf(stderr, "Error: out of bounds feature key\n");
-					exit(EXIT_FAILURE);
-				}
-				if (feat.tags[t + 1] >= layer.values.size()) {
-					fprintf(stderr, "Error: out of bounds feature value\n");
-					exit(EXIT_FAILURE);
-				}
-
-				const char *key = layer.keys[feat.tags[t]].c_str();
-				mvt_value const &val = layer.values[feat.tags[t + 1]];
-
-				if (val.type == mvt_string) {
-					printq(key);
-					printf(": ");
-					printq(val.string_value.c_str());
-				} else if (val.type == mvt_int) {
-					printq(key);
-					printf(": %lld", (long long) val.numeric_value.int_value);
-				} else if (val.type == mvt_double) {
-					printq(key);
-					double v = val.numeric_value.double_value;
-					if (v == (long long) v) {
-						printf(": %lld", (long long) v);
-					} else {
-						printf(": %g", v);
-					}
-				} else if (val.type == mvt_float) {
-					printq(key);
-					double v = val.numeric_value.float_value;
-					if (v == (long long) v) {
-						printf(": %lld", (long long) v);
-					} else {
-						printf(": %g", v);
-					}
-				} else if (val.type == mvt_sint) {
-					printq(key);
-					printf(": %lld", (long long) val.numeric_value.sint_value);
-				} else if (val.type == mvt_uint) {
-					printq(key);
-					printf(": %lld", (long long) val.numeric_value.uint_value);
-				} else if (val.type == mvt_bool) {
-					printq(key);
-					printf(": %s", val.numeric_value.bool_value ? "true" : "false");
-				}
-			}
-
-			printf(" }, \"geometry\": { ");
-
-			std::vector<lonlat> ops;
-
-			for (size_t g = 0; g < feat.geometry.size(); g++) {
-				int op = feat.geometry[g].op;
-				long long px = feat.geometry[g].x;
-				long long py = feat.geometry[g].y;
-
-				if (op == VT_MOVETO || op == VT_LINETO) {
-					long long scale = 1LL << (32 - z);
-					long long wx = scale * x + (scale / extent) * px;
-					long long wy = scale * y + (scale / extent) * py;
-
-					double lat, lon;
-					projection->unproject(wx, wy, 32, &lon, &lat);
-
-					ops.push_back(lonlat(op, lon, lat, px, py));
-				} else {
-					ops.push_back(lonlat(op, 0, 0, 0, 0));
-				}
-			}
-
-			if (feat.type == VT_POINT) {
-				if (ops.size() == 1) {
-					printf("\"type\": \"Point\", \"coordinates\": [ %f, %f ]", ops[0].lon, ops[0].lat);
-				} else {
-					printf("\"type\": \"MultiPoint\", \"coordinates\": [ ");
-					for (size_t i = 0; i < ops.size(); i++) {
-						if (i != 0) {
-							printf(", ");
-						}
-						printf("[ %f, %f ]", ops[i].lon, ops[i].lat);
-					}
-					printf(" ]");
-				}
-			} else if (feat.type == VT_LINE) {
-				int movetos = 0;
-				for (size_t i = 0; i < ops.size(); i++) {
-					if (ops[i].op == VT_MOVETO) {
-						movetos++;
-					}
-				}
-
-				if (movetos < 2) {
-					printf("\"type\": \"LineString\", \"coordinates\": [ ");
-					for (size_t i = 0; i < ops.size(); i++) {
-						if (i != 0) {
-							printf(", ");
-						}
-						printf("[ %f, %f ]", ops[i].lon, ops[i].lat);
-					}
-					printf(" ]");
-				} else {
-					printf("\"type\": \"MultiLineString\", \"coordinates\": [ [ ");
-					int state = 0;
-					for (size_t i = 0; i < ops.size(); i++) {
-						if (ops[i].op == VT_MOVETO) {
-							if (state == 0) {
-								printf("[ %f, %f ]", ops[i].lon, ops[i].lat);
-								state = 1;
-							} else {
-								printf(" ], [ ");
-								printf("[ %f, %f ]", ops[i].lon, ops[i].lat);
-								state = 1;
-							}
-						} else {
-							printf(", [ %f, %f ]", ops[i].lon, ops[i].lat);
-						}
-					}
-					printf(" ] ]");
-				}
-			} else if (feat.type == VT_POLYGON) {
-				std::vector<std::vector<lonlat> > rings;
-				std::vector<double> areas;
-
-				for (size_t i = 0; i < ops.size(); i++) {
-					if (ops[i].op == VT_MOVETO) {
-						rings.push_back(std::vector<lonlat>());
-						areas.push_back(0);
-					}
-
-					int n = rings.size() - 1;
-					if (n >= 0) {
-						if (ops[i].op == VT_CLOSEPATH) {
-							rings[n].push_back(rings[n][0]);
-						} else {
-							rings[n].push_back(ops[i]);
-						}
-					}
-				}
-
-				int outer = 0;
-
-				for (size_t i = 0; i < rings.size(); i++) {
-					long double area = 0;
-					for (size_t k = 0; k < rings[i].size(); k++) {
-						if (rings[i][k].op != VT_CLOSEPATH) {
-							area += rings[i][k].x * rings[i][(k + 1) % rings[i].size()].y;
-							area -= rings[i][k].y * rings[i][(k + 1) % rings[i].size()].x;
-						}
-					}
-
-					areas[i] = area;
-					if (areas[i] >= 0 || i == 0) {
-						outer++;
-					}
-
-					// printf("area %f\n", area / .00000274 / .00000274);
-				}
-
-				if (outer > 1) {
-					printf("\"type\": \"MultiPolygon\", \"coordinates\": [ [ [ ");
-				} else {
-					printf("\"type\": \"Polygon\", \"coordinates\": [ [ ");
-				}
-
-				int state = 0;
-				for (size_t i = 0; i < rings.size(); i++) {
-					if (areas[i] >= 0) {
-						if (state != 0) {
-							// new multipolygon
-							printf(" ] ], [ [ ");
-						}
-						state = 1;
-					}
-
-					if (state == 2) {
-						// new ring in the same polygon
-						printf(" ], [ ");
-					}
-
-					for (size_t j = 0; j < rings[i].size(); j++) {
-						if (rings[i][j].op != VT_CLOSEPATH) {
-							if (j != 0) {
-								printf(", ");
-							}
-
-							printf("[ %f, %f ]", rings[i][j].lon, rings[i][j].lat);
-						} else {
-							if (j != 0) {
-								printf(", ");
-							}
-
-							printf("[ %f, %f ]", rings[i][0].lon, rings[i][0].lat);
-						}
-					}
-
-					state = 2;
-				}
-
-				if (outer > 1) {
-					printf(" ] ] ]");
-				} else {
-					printf(" ] ]");
-				}
-			}
-
-			printf(" } }\n");
+		if (to_decode.size() != 0 && !to_decode.count(layer.name)) {
+			continue;
 		}
 
-		if (describe) {
-			printf("] }\n");
+		if (!pipeline) {
+			if (true) {
+				if (!first_layer) {
+					state.json_comma_newline();
+				}
+
+				state.json_write_hash();
+
+				state.json_write_string("type");
+				state.json_write_string("FeatureCollection");
+
+				state.json_write_string("properties");
+				state.json_write_hash();
+
+				state.json_write_string("layer");
+				state.json_write_string(layer.name);
+
+				state.json_write_string("version");
+				state.json_write_signed(layer.version);
+
+				state.json_write_string("extent");
+				state.json_write_signed(layer.extent);
+
+				state.json_end_hash();
+
+				state.json_write_string("features");
+				state.json_write_array();
+
+				state.json_write_newline();
+				first_layer = false;
+			}
+		}
+
+		// X and Y are unsigned, so no need to check <0
+		if (x > (1ULL << z) || y > (1ULL << z)) {
+			fprintf(stderr, "Impossible tile %d/%u/%u\n", z, x, y);
+			exit(EXIT_FAILURE);
+		}
+
+		layer_to_geojson(layer, z, x, y, !pipeline, pipeline, pipeline, false, 0, 0, 0, !force, state);
+
+		if (!pipeline) {
+			if (true) {
+				state.json_end_array();
+				state.json_end_hash();
+				state.json_write_newline();
+			}
 		}
 	}
 
-	printf("] }\n");
+	if (!pipeline) {
+		state.json_end_array();
+		state.json_end_hash();
+		state.json_write_newline();
+	}
 }
 
-void decode(char *fname, int z, unsigned x, unsigned y) {
-	sqlite3 *db;
+void decode(char *fname, int z, unsigned x, unsigned y, std::set<std::string> const &to_decode, bool pipeline, bool stats, std::set<std::string> const &exclude_meta) {
+	sqlite3 *db = NULL;
+	bool isdir = false;
 	int oz = z;
 	unsigned ox = x, oy = y;
+	json_writer state(stdout);
 
-	int fd = open(fname, O_RDONLY);
+	int fd = open(fname, O_RDONLY | O_CLOEXEC);
 	if (fd >= 0) {
 		struct stat st;
 		if (fstat(fd, &st) == 0) {
@@ -345,7 +240,7 @@ void decode(char *fname, int z, unsigned x, unsigned y) {
 					if (strcmp(map, "SQLite format 3") != 0) {
 						if (z >= 0) {
 							std::string s = std::string(map, st.st_size);
-							handle(s, z, x, y, 1);
+							handle(s, z, x, y, to_decode, pipeline, stats, state);
 							munmap(map, st.st_size);
 							return;
 						} else {
@@ -359,72 +254,188 @@ void decode(char *fname, int z, unsigned x, unsigned y) {
 		} else {
 			perror("fstat");
 		}
-		close(fd);
+		if (close(fd) != 0) {
+			perror("close");
+			exit(EXIT_FAILURE);
+		}
 	} else {
 		perror(fname);
 	}
 
-	if (sqlite3_open(fname, &db) != SQLITE_OK) {
-		fprintf(stderr, "%s: %s\n", fname, sqlite3_errmsg(db));
-		exit(EXIT_FAILURE);
+	struct stat st;
+	std::vector<zxy> tiles;
+	if (stat(fname, &st) == 0 && (st.st_mode & S_IFDIR) != 0) {
+		isdir = true;
+
+		db = dirmeta2tmp(fname);
+		tiles = enumerate_dirtiles(fname, minzoom, maxzoom);
+	} else {
+		if (sqlite3_open(fname, &db) != SQLITE_OK) {
+			fprintf(stderr, "%s: %s\n", fname, sqlite3_errmsg(db));
+			exit(EXIT_FAILURE);
+		}
+
+		char *err = NULL;
+		if (sqlite3_exec(db, "PRAGMA integrity_check;", NULL, NULL, &err) != SQLITE_OK) {
+			fprintf(stderr, "%s: integrity_check: %s\n", fname, err);
+			exit(EXIT_FAILURE);
+		}
 	}
 
 	if (z < 0) {
-		printf("{ \"type\": \"FeatureCollection\", \"properties\": {\n");
-
-		const char *sql2 = "SELECT name, value from metadata order by name;";
-		sqlite3_stmt *stmt2;
-		if (sqlite3_prepare_v2(db, sql2, -1, &stmt2, NULL) != SQLITE_OK) {
-			fprintf(stderr, "%s: select failed: %s\n", fname, sqlite3_errmsg(db));
-			exit(EXIT_FAILURE);
-		}
-
 		int within = 0;
-		while (sqlite3_step(stmt2) == SQLITE_ROW) {
-			if (within) {
-				printf(",\n");
+
+		if (!pipeline && !stats) {
+			state.json_write_hash();
+
+			state.json_write_string("type");
+			state.json_write_string("FeatureCollection");
+
+			state.json_write_string("properties");
+			state.json_write_hash();
+			state.json_write_newline();
+
+			const char *sql2 = "SELECT name, value from metadata order by name;";
+			sqlite3_stmt *stmt2;
+			if (sqlite3_prepare_v2(db, sql2, -1, &stmt2, NULL) != SQLITE_OK) {
+				fprintf(stderr, "%s: select failed: %s\n", fname, sqlite3_errmsg(db));
+				exit(EXIT_FAILURE);
 			}
-			within = 1;
 
-			const unsigned char *name = sqlite3_column_text(stmt2, 0);
-			const unsigned char *value = sqlite3_column_text(stmt2, 1);
+			while (sqlite3_step(stmt2) == SQLITE_ROW) {
+				const unsigned char *name = sqlite3_column_text(stmt2, 0);
+				const unsigned char *value = sqlite3_column_text(stmt2, 1);
 
-			printq((char *) name);
-			printf(": ");
-			printq((char *) value);
-		}
+				if (name == NULL || value == NULL) {
+					fprintf(stderr, "Corrupt mbtiles file: null metadata\n");
+					exit(EXIT_FAILURE);
+				}
 
-		sqlite3_finalize(stmt2);
+				if (exclude_meta.count((char *) name) == 0) {
+					if (within) {
+						state.json_comma_newline();
+					}
+					within = 1;
 
-		const char *sql = "SELECT tile_data, zoom_level, tile_column, tile_row from tiles order by zoom_level, tile_column, tile_row;";
-		sqlite3_stmt *stmt;
-		if (sqlite3_prepare_v2(db, sql, -1, &stmt, NULL) != SQLITE_OK) {
-			fprintf(stderr, "%s: select failed: %s\n", fname, sqlite3_errmsg(db));
-			exit(EXIT_FAILURE);
-		}
-
-		printf("\n}, \"features\": [\n");
-
-		within = 0;
-		while (sqlite3_step(stmt) == SQLITE_ROW) {
-			if (within) {
-				printf(",\n");
+					state.json_write_string((char *) name);
+					state.json_write_string((char *) value);
+				}
 			}
-			within = 1;
 
-			int len = sqlite3_column_bytes(stmt, 0);
-			int tz = sqlite3_column_int(stmt, 1);
-			int tx = sqlite3_column_int(stmt, 2);
-			int ty = sqlite3_column_int(stmt, 3);
-			ty = (1LL << tz) - 1 - ty;
-			const char *s = (const char *) sqlite3_column_blob(stmt, 0);
+			state.json_write_newline();
+			state.wantnl = false;  // XXX
 
-			handle(std::string(s, len), tz, tx, ty, 1);
+			sqlite3_finalize(stmt2);
 		}
 
-		printf("] }\n");
+		if (stats) {
+			state.json_write_array();
+			state.json_write_newline();
+		}
 
-		sqlite3_finalize(stmt);
+		if (!pipeline && !stats) {
+			state.json_end_hash();
+
+			state.json_write_string("features");
+			state.json_write_array();
+			state.json_write_newline();
+		}
+
+		if (isdir) {
+			within = 0;
+			for (size_t i = 0; i < tiles.size(); i++) {
+				if (!pipeline && !stats) {
+					if (within) {
+						state.json_comma_newline();
+					}
+					within = 1;
+				}
+				if (stats) {
+					if (within) {
+						state.json_comma_newline();
+					}
+					within = 1;
+				}
+
+				std::string fn = std::string(fname) + "/" + tiles[i].path();
+				FILE *f = fopen(fn.c_str(), "rb");
+				if (f == NULL) {
+					perror(fn.c_str());
+					exit(EXIT_FAILURE);
+				}
+
+				std::string s;
+				char buf[2000];
+				ssize_t n;
+				while ((n = fread(buf, 1, 2000, f)) > 0) {
+					s.append(std::string(buf, n));
+				}
+				fclose(f);
+
+				handle(s, tiles[i].z, tiles[i].x, tiles[i].y, to_decode, pipeline, stats, state);
+			}
+		} else {
+			const char *sql = "SELECT tile_data, zoom_level, tile_column, tile_row from tiles where zoom_level between ? and ? order by zoom_level, tile_column, tile_row;";
+			sqlite3_stmt *stmt;
+			if (sqlite3_prepare_v2(db, sql, -1, &stmt, NULL) != SQLITE_OK) {
+				fprintf(stderr, "%s: select failed: %s\n", fname, sqlite3_errmsg(db));
+				exit(EXIT_FAILURE);
+			}
+
+			sqlite3_bind_int(stmt, 1, minzoom);
+			sqlite3_bind_int(stmt, 2, maxzoom);
+
+			within = 0;
+			while (sqlite3_step(stmt) == SQLITE_ROW) {
+				if (!pipeline && !stats) {
+					if (within) {
+						state.json_comma_newline();
+					}
+					within = 1;
+				}
+				if (stats) {
+					if (within) {
+						state.json_comma_newline();
+					}
+					within = 1;
+				}
+
+				int len = sqlite3_column_bytes(stmt, 0);
+				int tz = sqlite3_column_int(stmt, 1);
+				int tx = sqlite3_column_int(stmt, 2);
+				int ty = sqlite3_column_int(stmt, 3);
+
+				if (tz < 0 || tz >= 32) {
+					fprintf(stderr, "Impossible zoom level %d in mbtiles\n", tz);
+					exit(EXIT_FAILURE);
+				}
+
+				ty = (1LL << tz) - 1 - ty;
+				const char *s = (const char *) sqlite3_column_blob(stmt, 0);
+
+				if (s == NULL) {
+					fprintf(stderr, "Corrupt mbtiles file: null entry in tiles table\n");
+					exit(EXIT_FAILURE);
+				}
+
+				handle(std::string(s, len), tz, tx, ty, to_decode, pipeline, stats, state);
+			}
+
+			sqlite3_finalize(stmt);
+		}
+
+		if (!pipeline && !stats) {
+			state.json_end_array();
+			state.json_end_hash();
+			state.json_write_newline();
+		}
+		if (stats) {
+			state.json_end_array();
+			state.json_write_newline();
+		}
+		if (pipeline) {
+			state.json_write_newline();
+		}
 	} else {
 		int handled = 0;
 		while (z >= 0 && !handled) {
@@ -443,11 +454,16 @@ void decode(char *fname, int z, unsigned x, unsigned y) {
 				int len = sqlite3_column_bytes(stmt, 0);
 				const char *s = (const char *) sqlite3_column_blob(stmt, 0);
 
+				if (s == NULL) {
+					fprintf(stderr, "Corrupt mbtiles file: null entry in tiles table\n");
+					exit(EXIT_FAILURE);
+				}
+
 				if (z != oz) {
 					fprintf(stderr, "%s: Warning: using tile %d/%u/%u instead of %d/%u/%u\n", fname, z, x, y, oz, ox, oy);
 				}
 
-				handle(std::string(s, len), z, x, y, 0);
+				handle(std::string(s, len), z, x, y, to_decode, pipeline, stats, state);
 				handled = 1;
 			}
 
@@ -466,7 +482,7 @@ void decode(char *fname, int z, unsigned x, unsigned y) {
 }
 
 void usage(char **argv) {
-	fprintf(stderr, "Usage: %s [-t projection] file.mbtiles zoom x y\n", argv[0]);
+	fprintf(stderr, "Usage: %s [-s projection] [-Z minzoom] [-z maxzoom] [-l layer ...] file.mbtiles [zoom x y]\n", argv[0]);
 	exit(EXIT_FAILURE);
 }
 
@@ -474,22 +490,80 @@ int main(int argc, char **argv) {
 	extern int optind;
 	extern char *optarg;
 	int i;
+	std::set<std::string> to_decode;
+	bool pipeline = false;
+	bool stats = false;
+	std::set<std::string> exclude_meta;
 
-	while ((i = getopt(argc, argv, "t:")) != -1) {
+	struct option long_options[] = {
+		{"projection", required_argument, 0, 's'},
+		{"maximum-zoom", required_argument, 0, 'z'},
+		{"minimum-zoom", required_argument, 0, 'Z'},
+		{"layer", required_argument, 0, 'l'},
+		{"tag-layer-and-zoom", no_argument, 0, 'c'},
+		{"stats", no_argument, 0, 'S'},
+		{"force", no_argument, 0, 'f'},
+		{"exclude-metadata-row", required_argument, 0, 'x'},
+		{0, 0, 0, 0},
+	};
+
+	std::string getopt_str;
+	for (size_t lo = 0; long_options[lo].name != NULL; lo++) {
+		if (long_options[lo].val > ' ') {
+			getopt_str.push_back(long_options[lo].val);
+
+			if (long_options[lo].has_arg == required_argument) {
+				getopt_str.push_back(':');
+			}
+		}
+	}
+
+	while ((i = getopt_long(argc, argv, getopt_str.c_str(), long_options, NULL)) != -1) {
 		switch (i) {
-		case 't':
+		case 0:
+			break;
+
+		case 's':
 			set_projection_or_exit(optarg);
 			break;
 
+		case 'z':
+			maxzoom = atoi(optarg);
+			break;
+
+		case 'Z':
+			minzoom = atoi(optarg);
+			break;
+
+		case 'l':
+			to_decode.insert(optarg);
+			break;
+
+		case 'c':
+			pipeline = true;
+			break;
+
+		case 'S':
+			stats = true;
+			break;
+
+		case 'f':
+			force = true;
+			break;
+
+		case 'x':
+			exclude_meta.insert(optarg);
+			break;
+
 		default:
 			usage(argv);
 		}
 	}
 
 	if (argc == optind + 4) {
-		decode(argv[optind], atoi(argv[optind + 1]), atoi(argv[optind + 2]), atoi(argv[optind + 3]));
+		decode(argv[optind], atoi(argv[optind + 1]), atoi(argv[optind + 2]), atoi(argv[optind + 3]), to_decode, pipeline, stats, exclude_meta);
 	} else if (argc == optind + 1) {
-		decode(argv[optind], -1, -1, -1);
+		decode(argv[optind], -1, -1, -1, to_decode, pipeline, stats, exclude_meta);
 	} else {
 		usage(argv);
 	}

dirtiles.cpp

@@ -0,0 +1,211 @@
+#include <iostream>
+#include <fstream>
+#include <sstream>
+#include <string>
+#include <algorithm>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <dirent.h>
+#include <limits.h>
+#include <sys/stat.h>
+#include <sqlite3.h>
+#include "jsonpull/jsonpull.h"
+#include "dirtiles.hpp"
+
+std::string dir_read_tile(std::string base, struct zxy tile) {
+	std::ifstream pbfFile(base + "/" + tile.path(), std::ios::in | std::ios::binary);
+	std::ostringstream contents;
+	contents << pbfFile.rdbuf();
+	pbfFile.close();
+
+	return (contents.str());
+}
+
+void dir_write_tile(const char *outdir, int z, int tx, int ty, std::string const &pbf) {
+	mkdir(outdir, S_IRWXU | S_IRWXG | S_IRWXO);
+	std::string curdir(outdir);
+	std::string slash("/");
+	std::string newdir = curdir + slash + std::to_string(z);
+	mkdir(newdir.c_str(), S_IRWXU | S_IRWXG | S_IRWXO);
+	newdir = newdir + "/" + std::to_string(tx);
+	mkdir(newdir.c_str(), S_IRWXU | S_IRWXG | S_IRWXO);
+	newdir = newdir + "/" + std::to_string(ty) + ".pbf";
+
+	struct stat st;
+	if (stat(newdir.c_str(), &st) == 0) {
+		fprintf(stderr, "Can't write tile to already existing %s\n", newdir.c_str());
+		exit(EXIT_FAILURE);
+	}
+
+	std::ofstream pbfFile(newdir, std::ios::out | std::ios::binary);
+	pbfFile.write(pbf.data(), pbf.size());
+	pbfFile.close();
+}
+
+static bool numeric(const char *s) {
+	if (*s == '\0') {
+		return false;
+	}
+	for (; *s != 0; s++) {
+		if (*s < '0' || *s > '9') {
+			return false;
+		}
+	}
+	return true;
+}
+
+static bool pbfname(const char *s) {
+	while (*s >= '0' && *s <= '9') {
+		s++;
+	}
+
+	return strcmp(s, ".pbf") == 0 || strcmp(s, ".mvt") == 0;
+}
+
+void check_dir(const char *dir, char **argv, bool force, bool forcetable) {
+	struct stat st;
+
+	mkdir(dir, S_IRWXU | S_IRWXG | S_IRWXO);
+	std::string meta = std::string(dir) + "/" + "metadata.json";
+	if (force) {
+		unlink(meta.c_str());  // error OK since it may not exist;
+	} else {
+		if (stat(meta.c_str(), &st) == 0) {
+			fprintf(stderr, "%s: Tileset \"%s\" already exists. You can use --force if you want to delete the old tileset.\n", argv[0], dir);
+			fprintf(stderr, "%s: %s: file exists\n", argv[0], meta.c_str());
+			if (!forcetable) {
+				exit(EXIT_FAILURE);
+			}
+		}
+	}
+
+	if (forcetable) {
+		// Don't clear existing tiles
+		return;
+	}
+
+	std::vector<zxy> tiles = enumerate_dirtiles(dir, INT_MIN, INT_MAX);
+
+	for (size_t i = 0; i < tiles.size(); i++) {
+		std::string fn = std::string(dir) + "/" + tiles[i].path();
+
+		if (force) {
+			if (unlink(fn.c_str()) != 0) {
+				perror(fn.c_str());
+				exit(EXIT_FAILURE);
+			}
+		} else {
+			fprintf(stderr, "%s: file exists\n", fn.c_str());
+			exit(EXIT_FAILURE);
+		}
+	}
+}
+
+std::vector<zxy> enumerate_dirtiles(const char *fname, int minzoom, int maxzoom) {
+	std::vector<zxy> tiles;
+
+	DIR *d1 = opendir(fname);
+	if (d1 != NULL) {
+		struct dirent *dp;
+		while ((dp = readdir(d1)) != NULL) {
+			if (numeric(dp->d_name) && atoi(dp->d_name) >= minzoom && atoi(dp->d_name) <= maxzoom) {
+				std::string z = std::string(fname) + "/" + dp->d_name;
+				int tz = atoi(dp->d_name);
+
+				DIR *d2 = opendir(z.c_str());
+				if (d2 == NULL) {
+					perror(z.c_str());
+					exit(EXIT_FAILURE);
+				}
+
+				struct dirent *dp2;
+				while ((dp2 = readdir(d2)) != NULL) {
+					if (numeric(dp2->d_name)) {
+						std::string x = z + "/" + dp2->d_name;
+						int tx = atoi(dp2->d_name);
+
+						DIR *d3 = opendir(x.c_str());
+						if (d3 == NULL) {
+							perror(x.c_str());
+							exit(EXIT_FAILURE);
+						}
+
+						struct dirent *dp3;
+						while ((dp3 = readdir(d3)) != NULL) {
+							if (pbfname(dp3->d_name)) {
+								int ty = atoi(dp3->d_name);
+								zxy tile(tz, tx, ty);
+								if (strstr(dp3->d_name, ".mvt") != NULL) {
+									tile.extension = ".mvt";
+								}
+
+								tiles.push_back(tile);
+							}
+						}
+
+						closedir(d3);
+					}
+				}
+
+				closedir(d2);
+			}
+		}
+
+		closedir(d1);
+	}
+
+	std::sort(tiles.begin(), tiles.end());
+	return tiles;
+}
+
+sqlite3 *dirmeta2tmp(const char *fname) {
+	sqlite3 *db;
+	char *err = NULL;
+
+	if (sqlite3_open("", &db) != SQLITE_OK) {
+		fprintf(stderr, "Temporary db: %s\n", sqlite3_errmsg(db));
+		exit(EXIT_FAILURE);
+	}
+	if (sqlite3_exec(db, "CREATE TABLE metadata (name text, value text);", NULL, NULL, &err) != SQLITE_OK) {
+		fprintf(stderr, "Create metadata table: %s\n", err);
+		exit(EXIT_FAILURE);
+	}
+
+	std::string name = fname;
+	name += "/metadata.json";
+
+	FILE *f = fopen(name.c_str(), "r");
+	if (f == NULL) {
+		perror(name.c_str());
+	} else {
+		json_pull *jp = json_begin_file(f);
+		json_object *o = json_read_tree(jp);
+		if (o == NULL) {
+			fprintf(stderr, "%s: metadata parsing error: %s\n", name.c_str(), jp->error);
+			exit(EXIT_FAILURE);
+		}
+
+		if (o->type != JSON_HASH) {
+			fprintf(stderr, "%s: bad metadata format\n", name.c_str());
+			exit(EXIT_FAILURE);
+		}
+
+		for (size_t i = 0; i < o->length; i++) {
+			if (o->keys[i]->type != JSON_STRING || o->values[i]->type != JSON_STRING) {
+				fprintf(stderr, "%s: non-string in metadata\n", name.c_str());
+			}
+
+			char *sql = sqlite3_mprintf("INSERT INTO metadata (name, value) VALUES (%Q, %Q);", o->keys[i]->string, o->values[i]->string);
+			if (sqlite3_exec(db, sql, NULL, NULL, &err) != SQLITE_OK) {
+				fprintf(stderr, "set %s in metadata: %s\n", o->keys[i]->string, err);
+			}
+			sqlite3_free(sql);
+		}
+
+		json_end(jp);
+		fclose(f);
+	}
+
+	return db;
+}

dirtiles.hpp

@@ -0,0 +1,49 @@
+#include <string>
+#include <vector>
+#include <sys/stat.h>
+
+#ifndef DIRTILES_HPP
+#define DIRTILES_HPP
+
+void dir_write_tile(const char *outdir, int z, int tx, int ty, std::string const &pbf);
+
+void check_dir(const char *d, char **argv, bool force, bool forcetable);
+
+struct zxy {
+	long long z;
+	long long x;
+	long long y;
+	std::string extension = ".pbf";
+
+	zxy(int _z, int _x, int _y)
+	    : z(_z), x(_x), y(_y) {
+	}
+
+	bool operator<(const zxy &other) const {
+		if (z < other.z) {
+			return true;
+		}
+		if (z == other.z) {
+			if (x < other.x) {
+				return true;
+			}
+			if (x == other.x) {
+				if (y > other.y) {
+					return true;  // reversed for TMS
+				}
+			}
+		}
+
+		return false;
+	}
+
+	std::string path() {
+		return std::to_string(z) + "/" + std::to_string(x) + "/" + std::to_string(y) + extension;
+	}
+};
+
+std::vector<zxy> enumerate_dirtiles(const char *fname, int minzoom, int maxzoom);
+sqlite3 *dirmeta2tmp(const char *fname);
+std::string dir_read_tile(std::string pbfPath, struct zxy tile);
+
+#endif

enumerate.cpp

@@ -11,6 +11,12 @@ void enumerate(char *fname) {
 		exit(EXIT_FAILURE);
 	}
 
+	char *err = NULL;
+	if (sqlite3_exec(db, "PRAGMA integrity_check;", NULL, NULL, &err) != SQLITE_OK) {
+		fprintf(stderr, "%s: integrity_check: %s\n", fname, err);
+		exit(EXIT_FAILURE);
+	}
+
 	const char *sql = "SELECT zoom_level, tile_column, tile_row from tiles order by zoom_level, tile_column, tile_row;";
 
 	sqlite3_stmt *stmt;
@@ -24,6 +30,11 @@ void enumerate(char *fname) {
 		long long x = sqlite3_column_int(stmt, 1);
 		long long y = sqlite3_column_int(stmt, 2);
 
+		if (zoom < 0 || zoom > 31) {
+			fprintf(stderr, "Corrupt mbtiles file: impossible zoom level %lld\n", zoom);
+			exit(EXIT_FAILURE);
+		}
+
 		y = (1LL << zoom) - 1 - y;
 		printf("%s %lld %lld %lld\n", fname, zoom, x, y);
 	}

evaluator.cpp

@@ -0,0 +1,347 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <map>
+#include "mvt.hpp"
+#include "evaluator.hpp"
+
+int compare(mvt_value one, json_object *two, bool &fail) {
+	if (one.type == mvt_string) {
+		if (two->type != JSON_STRING) {
+			fail = true;
+			return false;  // string vs non-string
+		}
+
+		return strcmp(one.string_value.c_str(), two->string);
+	}
+
+	if (one.type == mvt_double || one.type == mvt_float || one.type == mvt_int || one.type == mvt_uint || one.type == mvt_sint) {
+		if (two->type != JSON_NUMBER) {
+			fail = true;
+			return false;  // number vs non-number
+		}
+
+		double v;
+		if (one.type == mvt_double) {
+			v = one.numeric_value.double_value;
+		} else if (one.type == mvt_float) {
+			v = one.numeric_value.float_value;
+		} else if (one.type == mvt_int) {
+			v = one.numeric_value.int_value;
+		} else if (one.type == mvt_uint) {
+			v = one.numeric_value.uint_value;
+		} else if (one.type == mvt_sint) {
+			v = one.numeric_value.sint_value;
+		} else {
+			fprintf(stderr, "Internal error: bad mvt type %d\n", one.type);
+			exit(EXIT_FAILURE);
+		}
+
+		if (v < two->number) {
+			return -1;
+		} else if (v > two->number) {
+			return 1;
+		} else {
+			return 0;
+		}
+	}
+
+	if (one.type == mvt_bool) {
+		if (two->type != JSON_TRUE && two->type != JSON_FALSE) {
+			fail = true;
+			return false;  // bool vs non-bool
+		}
+
+		bool b = two->type != JSON_FALSE;
+		return one.numeric_value.bool_value > b;
+	}
+
+	if (one.type == mvt_null) {
+		if (two->type != JSON_NULL) {
+			fail = true;
+			return false;  // null vs non-null
+		}
+
+		return 0;  // null equals null
+	}
+
+	fprintf(stderr, "Internal error: bad mvt type %d\n", one.type);
+	exit(EXIT_FAILURE);
+}
+
+bool eval(std::map<std::string, mvt_value> const &feature, json_object *f, std::set<std::string> &exclude_attributes) {
+	if (f == NULL || f->type != JSON_ARRAY) {
+		fprintf(stderr, "Filter is not an array: %s\n", json_stringify(f));
+		exit(EXIT_FAILURE);
+	}
+
+	if (f->length < 1) {
+		fprintf(stderr, "Array too small in filter: %s\n", json_stringify(f));
+		exit(EXIT_FAILURE);
+	}
+
+	if (f->array[0]->type != JSON_STRING) {
+		fprintf(stderr, "Filter operation is not a string: %s\n", json_stringify(f));
+		exit(EXIT_FAILURE);
+	}
+
+	if (strcmp(f->array[0]->string, "has") == 0 ||
+	    strcmp(f->array[0]->string, "!has") == 0) {
+		if (f->length != 2) {
+			fprintf(stderr, "Wrong number of array elements in filter: %s\n", json_stringify(f));
+			exit(EXIT_FAILURE);
+		}
+
+		if (strcmp(f->array[0]->string, "has") == 0) {
+			if (f->array[1]->type != JSON_STRING) {
+				fprintf(stderr, "\"has\" key is not a string: %s\n", json_stringify(f));
+				exit(EXIT_FAILURE);
+			}
+			return feature.count(std::string(f->array[1]->string)) != 0;
+		}
+
+		if (strcmp(f->array[0]->string, "!has") == 0) {
+			if (f->array[1]->type != JSON_STRING) {
+				fprintf(stderr, "\"!has\" key is not a string: %s\n", json_stringify(f));
+				exit(EXIT_FAILURE);
+			}
+			return feature.count(std::string(f->array[1]->string)) == 0;
+		}
+	}
+
+	if (strcmp(f->array[0]->string, "==") == 0 ||
+	    strcmp(f->array[0]->string, "!=") == 0 ||
+	    strcmp(f->array[0]->string, ">") == 0 ||
+	    strcmp(f->array[0]->string, ">=") == 0 ||
+	    strcmp(f->array[0]->string, "<") == 0 ||
+	    strcmp(f->array[0]->string, "<=") == 0) {
+		if (f->length != 3) {
+			fprintf(stderr, "Wrong number of array elements in filter: %s\n", json_stringify(f));
+			exit(EXIT_FAILURE);
+		}
+		if (f->array[1]->type != JSON_STRING) {
+			fprintf(stderr, "\"!has\" key is not a string: %s\n", json_stringify(f));
+			exit(EXIT_FAILURE);
+		}
+
+		auto ff = feature.find(std::string(f->array[1]->string));
+		if (ff == feature.end()) {
+			static bool warned = false;
+			if (!warned) {
+				const char *s = json_stringify(f);
+				fprintf(stderr, "Warning: attribute not found for comparison: %s\n", s);
+				free((void *) s);
+				warned = true;
+			}
+			if (strcmp(f->array[0]->string, "!=") == 0) {
+				return true;  //  attributes that aren't found are not equal
+			}
+			return false;  // not found: comparison is false
+		}
+
+		bool fail = false;
+		int cmp = compare(ff->second, f->array[2], fail);
+
+		if (fail) {
+			static bool warned = false;
+			if (!warned) {
+				const char *s = json_stringify(f);
+				fprintf(stderr, "Warning: mismatched type in comparison: %s\n", s);
+				free((void *) s);
+				warned = true;
+			}
+			if (strcmp(f->array[0]->string, "!=") == 0) {
+				return true;  // mismatched types are not equal
+			}
+			return false;
+		}
+
+		if (strcmp(f->array[0]->string, "==") == 0) {
+			return cmp == 0;
+		}
+		if (strcmp(f->array[0]->string, "!=") == 0) {
+			return cmp != 0;
+		}
+		if (strcmp(f->array[0]->string, ">") == 0) {
+			return cmp > 0;
+		}
+		if (strcmp(f->array[0]->string, ">=") == 0) {
+			return cmp >= 0;
+		}
+		if (strcmp(f->array[0]->string, "<") == 0) {
+			return cmp < 0;
+		}
+		if (strcmp(f->array[0]->string, "<=") == 0) {
+			return cmp <= 0;
+		}
+
+		fprintf(stderr, "Internal error: can't happen: %s\n", json_stringify(f));
+		exit(EXIT_FAILURE);
+	}
+
+	if (strcmp(f->array[0]->string, "all") == 0 ||
+	    strcmp(f->array[0]->string, "any") == 0 ||
+	    strcmp(f->array[0]->string, "none") == 0) {
+		bool v;
+
+		if (strcmp(f->array[0]->string, "all") == 0) {
+			v = true;
+		} else {
+			v = false;
+		}
+
+		for (size_t i = 1; i < f->length; i++) {
+			bool out = eval(feature, f->array[i], exclude_attributes);
+
+			if (strcmp(f->array[0]->string, "all") == 0) {
+				v = v && out;
+				if (!v) {
+					break;
+				}
+			} else {
+				v = v || out;
+				if (v) {
+					break;
+				}
+			}
+		}
+
+		if (strcmp(f->array[0]->string, "none") == 0) {
+			return !v;
+		} else {
+			return v;
+		}
+	}
+
+	if (strcmp(f->array[0]->string, "in") == 0 ||
+	    strcmp(f->array[0]->string, "!in") == 0) {
+		if (f->length < 2) {
+			fprintf(stderr, "Array too small in filter: %s\n", json_stringify(f));
+			exit(EXIT_FAILURE);
+		}
+
+		if (f->array[1]->type != JSON_STRING) {
+			fprintf(stderr, "\"!has\" key is not a string: %s\n", json_stringify(f));
+			exit(EXIT_FAILURE);
+		}
+
+		auto ff = feature.find(std::string(f->array[1]->string));
+		if (ff == feature.end()) {
+			static bool warned = false;
+			if (!warned) {
+				const char *s = json_stringify(f);
+				fprintf(stderr, "Warning: attribute not found for comparison: %s\n", s);
+				free((void *) s);
+				warned = true;
+			}
+			if (strcmp(f->array[0]->string, "!in") == 0) {
+				return true;  // attributes that aren't found are not in
+			}
+			return false;  // not found: comparison is false
+		}
+
+		bool found = false;
+		for (size_t i = 2; i < f->length; i++) {
+			bool fail = false;
+			int cmp = compare(ff->second, f->array[i], fail);
+
+			if (fail) {
+				static bool warned = false;
+				if (!warned) {
+					const char *s = json_stringify(f);
+					fprintf(stderr, "Warning: mismatched type in comparison: %s\n", s);
+					free((void *) s);
+					warned = true;
+				}
+				cmp = 1;
+			}
+
+			if (cmp == 0) {
+				found = true;
+				break;
+			}
+		}
+
+		if (strcmp(f->array[0]->string, "in") == 0) {
+			return found;
+		} else {
+			return !found;
+		}
+	}
+
+	if (strcmp(f->array[0]->string, "attribute-filter") == 0) {
+		if (f->length != 3) {
+			fprintf(stderr, "Wrong number of array elements in filter: %s\n", json_stringify(f));
+			exit(EXIT_FAILURE);
+		}
+
+		if (f->array[1]->type != JSON_STRING) {
+			fprintf(stderr, "\"attribute-filter\" key is not a string: %s\n", json_stringify(f));
+			exit(EXIT_FAILURE);
+		}
+
+		bool ok = eval(feature, f->array[2], exclude_attributes);
+		if (!ok) {
+			exclude_attributes.insert(f->array[1]->string);
+		}
+
+		return true;
+	}
+
+	fprintf(stderr, "Unknown filter %s\n", json_stringify(f));
+	exit(EXIT_FAILURE);
+}
+
+bool evaluate(std::map<std::string, mvt_value> const &feature, std::string const &layer, json_object *filter, std::set<std::string> &exclude_attributes) {
+	if (filter == NULL || filter->type != JSON_HASH) {
+		fprintf(stderr, "Error: filter is not a hash: %s\n", json_stringify(filter));
+		exit(EXIT_FAILURE);
+	}
+
+	bool ok = true;
+	json_object *f;
+
+	f = json_hash_get(filter, layer.c_str());
+	if (ok && f != NULL) {
+		ok = eval(feature, f, exclude_attributes);
+	}
+
+	f = json_hash_get(filter, "*");
+	if (ok && f != NULL) {
+		ok = eval(feature, f, exclude_attributes);
+	}
+
+	return ok;
+}
+
+json_object *read_filter(const char *fname) {
+	FILE *fp = fopen(fname, "r");
+	if (fp == NULL) {
+		perror(fname);
+		exit(EXIT_FAILURE);
+	}
+
+	json_pull *jp = json_begin_file(fp);
+	json_object *filter = json_read_tree(jp);
+	if (filter == NULL) {
+		fprintf(stderr, "%s: %s\n", fname, jp->error);
+		exit(EXIT_FAILURE);
+	}
+	json_disconnect(filter);
+	json_end(jp);
+	fclose(fp);
+	return filter;
+}
+
+json_object *parse_filter(const char *s) {
+	json_pull *jp = json_begin_string(s);
+	json_object *filter = json_read_tree(jp);
+	if (filter == NULL) {
+		fprintf(stderr, "Could not parse filter %s\n", s);
+		fprintf(stderr, "%s\n", jp->error);
+		exit(EXIT_FAILURE);
+	}
+	json_disconnect(filter);
+	json_end(jp);
+	return filter;
+}

evaluator.hpp

@@ -0,0 +1,14 @@
+#ifndef EVALUATOR_HPP
+#define EVALUATOR HPP
+
+#include <map>
+#include <string>
+#include <set>
+#include "jsonpull/jsonpull.h"
+#include "mvt.hpp"
+
+bool evaluate(std::map<std::string, mvt_value> const &feature, std::string const &layer, json_object *filter, std::set<std::string> &exclude_attributes);
+json_object *parse_filter(const char *s);
+json_object *read_filter(const char *fname);
+
+#endif

filters/limit-tiles-to-bbox

@@ -0,0 +1,27 @@
+#!/usr/bin/perl
+
+use Math::Trig;
+use strict;
+
+# http://wiki.openstreetmap.org/wiki/Slippy_map_tilenames
+sub getTileNumber {
+	my ($lat, $lon, $zoom) = @_;
+	my $xtile = int(($lon + 180) / 360 * 2 ** $zoom);
+	my $ytile = int((1 - log(tan(deg2rad($lat)) + sec(deg2rad($lat))) / pi) / 2 * 2 ** $zoom);
+	return ($xtile, $ytile);
+}
+
+my ($minlon, $minlat, $maxlon, $maxlat, $z, $x, $y) = @ARGV;
+
+my ($x1, $y1) = getTileNumber($maxlat, $minlon, $z);
+my ($x2, $y2) = getTileNumber($minlat, $maxlon, $z);
+
+if ($x >= $x1 && $x <= $x2 && $y >= $y1 && $y <= $y2) {
+	while (<STDIN>) {
+		print;
+	}
+} else {
+	while (<STDIN>) {
+
+	}
+}

geobuf.cpp

@@ -0,0 +1,585 @@
+#include <stdio.h>
+#include <string>
+#include <limits.h>
+#include <pthread.h>
+#include "mvt.hpp"
+#include "serial.hpp"
+#include "geobuf.hpp"
+#include "geojson.hpp"
+#include "projection.hpp"
+#include "main.hpp"
+#include "protozero/varint.hpp"
+#include "protozero/pbf_reader.hpp"
+#include "protozero/pbf_writer.hpp"
+#include "milo/dtoa_milo.h"
+#include "jsonpull/jsonpull.h"
+#include "text.hpp"
+
+#define POINT 0
+#define MULTIPOINT 1
+#define LINESTRING 2
+#define MULTILINESTRING 3
+#define POLYGON 4
+#define MULTIPOLYGON 5
+
+struct queued_feature {
+	protozero::pbf_reader pbf{};
+	size_t dim = 0;
+	double e = 0;
+	std::vector<std::string> *keys = NULL;
+	std::vector<struct serialization_state> *sst = NULL;
+	int layer = 0;
+	std::string layername = "";
+};
+
+static std::vector<queued_feature> feature_queue;
+
+void ensureDim(size_t dim) {
+	if (dim < 2) {
+		fprintf(stderr, "Geometry has fewer than 2 dimensions: %zu\n", dim);
+		exit(EXIT_FAILURE);
+	}
+}
+
+serial_val readValue(protozero::pbf_reader &pbf) {
+	serial_val sv;
+	sv.type = mvt_null;
+	sv.s = "null";
+
+	while (pbf.next()) {
+		switch (pbf.tag()) {
+		case 1:
+			sv.type = mvt_string;
+			sv.s = pbf.get_string();
+			break;
+
+		case 2:
+			sv.type = mvt_double;
+			sv.s = milo::dtoa_milo(pbf.get_double());
+			break;
+
+		case 3:
+			sv.type = mvt_double;
+			sv.s = std::to_string(pbf.get_uint64());
+			break;
+
+		case 4:
+			sv.type = mvt_double;
+			sv.s = std::to_string(-(long long) pbf.get_uint64());
+			break;
+
+		case 5:
+			sv.type = mvt_bool;
+			if (pbf.get_bool()) {
+				sv.s = "true";
+			} else {
+				sv.s = "false";
+			}
+			break;
+
+		case 6:
+			sv.type = mvt_string;  // stringified JSON
+			sv.s = pbf.get_string();
+
+			if (sv.s == "null") {
+				sv.type = mvt_null;
+			}
+
+			break;
+
+		default:
+			pbf.skip();
+		}
+	}
+
+	return sv;
+}
+
+drawvec readPoint(std::vector<long long> &coords, size_t dim, double e) {
+	ensureDim(dim);
+
+	long long x, y;
+	projection->project(coords[0] / e, coords[1] / e, 32, &x, &y);
+	drawvec dv;
+	dv.push_back(draw(VT_MOVETO, x, y));
+	return dv;
+}
+
+drawvec readLinePart(std::vector<long long> &coords, size_t dim, double e, size_t start, size_t end, bool closed) {
+	ensureDim(dim);
+
+	drawvec dv;
+	std::vector<long long> prev;
+	std::vector<double> p;
+	prev.resize(dim);
+	p.resize(dim);
+
+	for (size_t i = start; i + dim - 1 < end; i += dim) {
+		if (i + dim - 1 >= coords.size()) {
+			fprintf(stderr, "Internal error: line segment %zu vs %zu\n", i + dim - 1, coords.size());
+			exit(EXIT_FAILURE);
+		}
+
+		for (size_t d = 0; d < dim; d++) {
+			prev[d] += coords[i + d];
+			p[d] = prev[d] / e;
+		}
+
+		long long x, y;
+		projection->project(p[0], p[1], 32, &x, &y);
+
+		if (i == start) {
+			dv.push_back(draw(VT_MOVETO, x, y));
+		} else {
+			dv.push_back(draw(VT_LINETO, x, y));
+		}
+	}
+
+	if (closed && dv.size() > 0) {
+		dv.push_back(draw(VT_LINETO, dv[0].x, dv[0].y));
+	}
+
+	return dv;
+}
+
+drawvec readLine(std::vector<long long> &coords, size_t dim, double e, bool closed) {
+	return readLinePart(coords, dim, e, 0, coords.size(), closed);
+}
+
+drawvec readMultiLine(std::vector<long long> &coords, std::vector<int> &lengths, size_t dim, double e, bool closed) {
+	if (lengths.size() == 0) {
+		return readLinePart(coords, dim, e, 0, coords.size(), closed);
+	}
+
+	drawvec dv;
+	size_t here = 0;
+	for (size_t i = 0; i < lengths.size(); i++) {
+		drawvec dv2 = readLinePart(coords, dim, e, here, here + lengths[i] * dim, closed);
+		here += lengths[i] * dim;
+
+		for (size_t j = 0; j < dv2.size(); j++) {
+			dv.push_back(dv2[j]);
+		}
+	}
+
+	return dv;
+}
+
+drawvec readMultiPolygon(std::vector<long long> &coords, std::vector<int> &lengths, size_t dim, double e) {
+	ensureDim(dim);
+
+	if (lengths.size() == 0) {
+		return readLinePart(coords, dim, e, 0, coords.size(), true);
+	}
+
+	size_t polys = lengths[0];
+	size_t n = 1;
+	size_t here = 0;
+	drawvec dv;
+
+	for (size_t i = 0; i < polys; i++) {
+		size_t rings = lengths[n++];
+
+		for (size_t j = 0; j < rings; j++) {
+			drawvec dv2 = readLinePart(coords, dim, e, here, here + lengths[n] * dim, true);
+			here += lengths[n] * dim;
+			n++;
+
+			for (size_t k = 0; k < dv2.size(); k++) {
+				dv.push_back(dv2[k]);
+			}
+		}
+
+		dv.push_back(draw(VT_CLOSEPATH, 0, 0));  // mark that the next ring is outer
+	}
+
+	return dv;
+}
+
+struct drawvec_type {
+	drawvec dv{};
+	int type = 0;
+};
+
+std::vector<drawvec_type> readGeometry(protozero::pbf_reader &pbf, size_t dim, double e, std::vector<std::string> &keys) {
+	std::vector<drawvec_type> ret;
+	std::vector<long long> coords;
+	std::vector<int> lengths;
+	int type = -1;
+
+	while (pbf.next()) {
+		switch (pbf.tag()) {
+		case 1:
+			type = pbf.get_enum();
+			break;
+
+		case 2: {
+			auto pi = pbf.get_packed_uint32();
+			for (auto it = pi.first; it != pi.second; ++it) {
+				lengths.push_back(*it);
+			}
+			break;
+		}
+
+		case 3: {
+			auto pi = pbf.get_packed_sint64();
+			for (auto it = pi.first; it != pi.second; ++it) {
+				coords.push_back(*it);
+			}
+			break;
+		}
+
+		case 4: {
+			protozero::pbf_reader geometry_reader(pbf.get_message());
+			std::vector<drawvec_type> dv2 = readGeometry(geometry_reader, dim, e, keys);
+
+			for (size_t i = 0; i < dv2.size(); i++) {
+				ret.push_back(dv2[i]);
+			}
+
+			break;
+		}
+
+		default:
+			pbf.skip();
+		}
+	}
+
+	drawvec_type dv;
+	if (type == POINT) {
+		dv.dv = readPoint(coords, dim, e);
+	} else if (type == MULTIPOINT) {
+		dv.dv = readLine(coords, dim, e, false);
+	} else if (type == LINESTRING) {
+		dv.dv = readLine(coords, dim, e, false);
+	} else if (type == POLYGON) {
+		dv.dv = readMultiLine(coords, lengths, dim, e, true);
+	} else if (type == MULTILINESTRING) {
+		dv.dv = readMultiLine(coords, lengths, dim, e, false);
+	} else if (type == MULTIPOLYGON) {
+		dv.dv = readMultiPolygon(coords, lengths, dim, e);
+	} else {
+		// GeometryCollection
+		return ret;
+	}
+
+	dv.type = type / 2 + 1;
+	ret.push_back(dv);
+	return ret;
+}
+
+void readFeature(protozero::pbf_reader &pbf, size_t dim, double e, std::vector<std::string> &keys, struct serialization_state *sst, int layer, std::string layername) {
+	std::vector<drawvec_type> dv;
+	long long id = 0;
+	bool has_id = false;
+	std::vector<serial_val> values;
+	std::map<std::string, serial_val> other;
+
+	std::vector<std::string> full_keys;
+	std::vector<serial_val> full_values;
+
+	while (pbf.next()) {
+		switch (pbf.tag()) {
+		case 1: {
+			protozero::pbf_reader geometry_reader(pbf.get_message());
+			std::vector<drawvec_type> dv2 = readGeometry(geometry_reader, dim, e, keys);
+			for (size_t i = 0; i < dv2.size(); i++) {
+				dv.push_back(dv2[i]);
+			}
+			break;
+		}
+
+		case 11: {
+			static bool warned = false;
+			if (!warned) {
+				fprintf(stderr, "Non-numeric feature IDs not supported\n");
+				warned = true;
+			}
+			pbf.skip();
+			break;
+		}
+
+		case 12:
+			has_id = true;
+			id = pbf.get_sint64();
+			if (id < 0) {
+				static bool warned = false;
+				if (!warned) {
+					fprintf(stderr, "Out of range feature id %lld\n", id);
+					warned = true;
+				}
+				has_id = false;
+			}
+			break;
+
+		case 13: {
+			protozero::pbf_reader value_reader(pbf.get_message());
+			values.push_back(readValue(value_reader));
+			break;
+		}
+
+		case 14: {
+			std::vector<size_t> properties;
+			auto pi = pbf.get_packed_uint32();
+			for (auto it = pi.first; it != pi.second; ++it) {
+				properties.push_back(*it);
+			}
+
+			for (size_t i = 0; i + 1 < properties.size(); i += 2) {
+				if (properties[i] >= keys.size()) {
+					fprintf(stderr, "Out of bounds key: %zu in %zu\n", properties[i], keys.size());
+					exit(EXIT_FAILURE);
+				}
+
+				if (properties[i + 1] >= values.size()) {
+					fprintf(stderr, "Out of bounds value: %zu in %zu\n", properties[i + 1], values.size());
+					exit(EXIT_FAILURE);
+				}
+
+				full_keys.push_back(keys[properties[i]]);
+				full_values.push_back(values[properties[i + 1]]);
+			}
+
+			values.clear();
+			break;
+		}
+
+		case 15: {
+			std::vector<size_t> misc;
+			auto pi = pbf.get_packed_uint32();
+			for (auto it = pi.first; it != pi.second; ++it) {
+				misc.push_back(*it);
+			}
+
+			for (size_t i = 0; i + 1 < misc.size(); i += 2) {
+				if (misc[i] >= keys.size()) {
+					fprintf(stderr, "Out of bounds key: %zu in %zu\n", misc[i], keys.size());
+					exit(EXIT_FAILURE);
+				}
+
+				if (misc[i + 1] >= values.size()) {
+					fprintf(stderr, "Out of bounds value: %zu in %zu\n", misc[i + 1], values.size());
+					exit(EXIT_FAILURE);
+				}
+
+				other.insert(std::pair<std::string, serial_val>(keys[misc[i]], values[misc[i + 1]]));
+			}
+
+			values.clear();
+			break;
+		}
+
+		default:
+			pbf.skip();
+		}
+	}
+
+	for (size_t i = 0; i < dv.size(); i++) {
+		serial_feature sf;
+
+		sf.layer = layer;
+		sf.layername = layername;
+		sf.segment = sst->segment;
+		sf.has_id = has_id;
+		sf.id = id;
+		sf.has_tippecanoe_minzoom = false;
+		sf.has_tippecanoe_maxzoom = false;
+		sf.feature_minzoom = false;
+		sf.seq = *(sst->layer_seq);
+		sf.geometry = dv[i].dv;
+		sf.t = dv[i].type;
+		sf.full_keys = full_keys;
+		sf.full_values = full_values;
+
+		auto tip = other.find("tippecanoe");
+		if (tip != other.end()) {
+			json_pull *jp = json_begin_string(tip->second.s.c_str());
+			json_object *o = json_read_tree(jp);
+
+			if (o != NULL) {
+				json_object *min = json_hash_get(o, "minzoom");
+				if (min != NULL && (min->type == JSON_STRING || min->type == JSON_NUMBER)) {
+					sf.has_tippecanoe_minzoom = true;
+					sf.tippecanoe_minzoom = integer_zoom(sst->fname, min->string);
+				}
+
+				json_object *max = json_hash_get(o, "maxzoom");
+				if (max != NULL && (max->type == JSON_STRING || max->type == JSON_NUMBER)) {
+					sf.has_tippecanoe_maxzoom = true;
+					sf.tippecanoe_maxzoom = integer_zoom(sst->fname, max->string);
+				}
+
+				json_object *tlayer = json_hash_get(o, "layer");
+				if (tlayer != NULL && (tlayer->type == JSON_STRING || tlayer->type == JSON_NUMBER)) {
+					sf.layername = tlayer->string;
+				}
+			}
+
+			json_free(o);
+			json_end(jp);
+		}
+
+		serialize_feature(sst, sf);
+	}
+}
+
+struct queue_run_arg {
+	size_t start;
+	size_t end;
+	size_t segment;
+
+	queue_run_arg(size_t start1, size_t end1, size_t segment1)
+	    : start(start1), end(end1), segment(segment1) {
+	}
+};
+
+void *run_parse_feature(void *v) {
+	struct queue_run_arg *qra = (struct queue_run_arg *) v;
+
+	for (size_t i = qra->start; i < qra->end; i++) {
+		struct queued_feature &qf = feature_queue[i];
+		readFeature(qf.pbf, qf.dim, qf.e, *qf.keys, &(*qf.sst)[qra->segment], qf.layer, qf.layername);
+	}
+
+	return NULL;
+}
+
+void runQueue() {
+	if (feature_queue.size() == 0) {
+		return;
+	}
+
+	std::vector<struct queue_run_arg> qra;
+
+	std::vector<pthread_t> pthreads;
+	pthreads.resize(CPUS);
+
+	for (size_t i = 0; i < CPUS; i++) {
+		*((*(feature_queue[0].sst))[i].layer_seq) = *((*(feature_queue[0].sst))[0].layer_seq) + feature_queue.size() * i / CPUS;
+
+		qra.push_back(queue_run_arg(
+			feature_queue.size() * i / CPUS,
+			feature_queue.size() * (i + 1) / CPUS,
+			i));
+	}
+
+	for (size_t i = 0; i < CPUS; i++) {
+		if (pthread_create(&pthreads[i], NULL, run_parse_feature, &qra[i]) != 0) {
+			perror("pthread_create");
+			exit(EXIT_FAILURE);
+		}
+	}
+
+	for (size_t i = 0; i < CPUS; i++) {
+		void *retval;
+
+		if (pthread_join(pthreads[i], &retval) != 0) {
+			perror("pthread_join");
+		}
+	}
+
+	// Lack of atomicity is OK, since we are single-threaded again here
+	long long was = *((*(feature_queue[0].sst))[CPUS - 1].layer_seq);
+	*((*(feature_queue[0].sst))[0].layer_seq) = was;
+	feature_queue.clear();
+}
+
+void queueFeature(protozero::pbf_reader &pbf, size_t dim, double e, std::vector<std::string> &keys, std::vector<struct serialization_state> *sst, int layer, std::string layername) {
+	struct queued_feature qf;
+	qf.pbf = pbf;
+	qf.dim = dim;
+	qf.e = e;
+	qf.keys = &keys;
+	qf.sst = sst;
+	qf.layer = layer;
+	qf.layername = layername;
+
+	feature_queue.push_back(qf);
+
+	if (feature_queue.size() > CPUS * 500) {
+		runQueue();
+	}
+}
+
+void outBareGeometry(drawvec const &dv, int type, struct serialization_state *sst, int layer, std::string layername) {
+	serial_feature sf;
+
+	sf.layer = layer;
+	sf.layername = layername;
+	sf.segment = sst->segment;
+	sf.has_id = false;
+	sf.has_tippecanoe_minzoom = false;
+	sf.has_tippecanoe_maxzoom = false;
+	sf.feature_minzoom = false;
+	sf.seq = (*sst->layer_seq);
+	sf.geometry = dv;
+	sf.t = type;
+
+	serialize_feature(sst, sf);
+}
+
+void readFeatureCollection(protozero::pbf_reader &pbf, size_t dim, double e, std::vector<std::string> &keys, std::vector<struct serialization_state> *sst, int layer, std::string layername) {
+	while (pbf.next()) {
+		switch (pbf.tag()) {
+		case 1: {
+			protozero::pbf_reader feature_reader(pbf.get_message());
+			queueFeature(feature_reader, dim, e, keys, sst, layer, layername);
+			break;
+		}
+
+		default:
+			pbf.skip();
+		}
+	}
+}
+
+void parse_geobuf(std::vector<struct serialization_state> *sst, const char *src, size_t len, int layer, std::string layername) {
+	protozero::pbf_reader pbf(src, len);
+
+	size_t dim = 2;
+	double e = 1e6;
+	std::vector<std::string> keys;
+
+	while (pbf.next()) {
+		switch (pbf.tag()) {
+		case 1:
+			keys.push_back(pbf.get_string());
+			break;
+
+		case 2:
+			dim = pbf.get_int64();
+			break;
+
+		case 3:
+			e = pow(10, pbf.get_int64());
+			break;
+
+		case 4: {
+			protozero::pbf_reader feature_collection_reader(pbf.get_message());
+			readFeatureCollection(feature_collection_reader, dim, e, keys, sst, layer, layername);
+			break;
+		}
+
+		case 5: {
+			protozero::pbf_reader feature_reader(pbf.get_message());
+			queueFeature(feature_reader, dim, e, keys, sst, layer, layername);
+			break;
+		}
+
+		case 6: {
+			protozero::pbf_reader geometry_reader(pbf.get_message());
+			std::vector<drawvec_type> dv = readGeometry(geometry_reader, dim, e, keys);
+			for (size_t i = 0; i < dv.size(); i++) {
+				// Always on thread 0
+				outBareGeometry(dv[i].dv, dv[i].type, &(*sst)[0], layer, layername);
+			}
+			break;
+		}
+
+		default:
+			pbf.skip();
+		}
+	}
+
+	runQueue();
+}

geobuf.hpp

@@ -0,0 +1,13 @@
+#ifndef GEOBUF_HPP
+#define GEOBUF_HPP
+
+#include <stdio.h>
+#include <set>
+#include <map>
+#include <string>
+#include "mbtiles.hpp"
+#include "serial.hpp"
+
+void parse_geobuf(std::vector<struct serialization_state> *sst, const char *s, size_t len, int layer, std::string layername);
+
+#endif

geocsv.cpp

@@ -0,0 +1,139 @@
+#include <stdlib.h>
+#include <algorithm>
+#include "geocsv.hpp"
+#include "mvt.hpp"
+#include "serial.hpp"
+#include "projection.hpp"
+#include "main.hpp"
+#include "text.hpp"
+#include "csv.hpp"
+#include "milo/dtoa_milo.h"
+#include "options.hpp"
+
+void parse_geocsv(std::vector<struct serialization_state> &sst, std::string fname, int layer, std::string layername) {
+	FILE *f;
+
+	if (fname.size() == 0) {
+		f = stdin;
+	} else {
+		f = fopen(fname.c_str(), "r");
+		if (f == NULL) {
+			perror(fname.c_str());
+			exit(EXIT_FAILURE);
+		}
+	}
+
+	std::string s;
+	std::vector<std::string> header;
+	ssize_t latcol = -1, loncol = -1;
+
+	if ((s = csv_getline(f)).size() > 0) {
+		std::string err = check_utf8(s);
+		if (err != "") {
+			fprintf(stderr, "%s: %s\n", fname.c_str(), err.c_str());
+			exit(EXIT_FAILURE);
+		}
+
+		header = csv_split(s.c_str());
+
+		for (size_t i = 0; i < header.size(); i++) {
+			header[i] = csv_dequote(header[i]);
+
+			std::string lower(header[i]);
+			std::transform(lower.begin(), lower.end(), lower.begin(), ::tolower);
+
+			if (lower == "y" || lower == "lat" || (lower.find("latitude") != std::string::npos)) {
+				latcol = i;
+			}
+			if (lower == "x" || lower == "lon" || lower == "lng" || lower == "long" || (lower.find("longitude") != std::string::npos)) {
+				loncol = i;
+			}
+		}
+	}
+
+	if (latcol < 0 || loncol < 0) {
+		fprintf(stderr, "%s: Can't find \"lat\" and \"lon\" columns\n", fname.c_str());
+		exit(EXIT_FAILURE);
+	}
+
+	size_t seq = 0;
+	while ((s = csv_getline(f)).size() > 0) {
+		std::string err = check_utf8(s);
+		if (err != "") {
+			fprintf(stderr, "%s: %s\n", fname.c_str(), err.c_str());
+			exit(EXIT_FAILURE);
+		}
+
+		seq++;
+		std::vector<std::string> line = csv_split(s.c_str());
+
+		if (line.size() != header.size()) {
+			fprintf(stderr, "%s:%zu: Mismatched column count: %zu in line, %zu in header\n", fname.c_str(), seq + 1, line.size(), header.size());
+			exit(EXIT_FAILURE);
+		}
+
+		if (line[loncol].empty() || line[latcol].empty()) {
+			static int warned = 0;
+			if (!warned) {
+				fprintf(stderr, "%s:%zu: null geometry (additional not reported)\n", fname.c_str(), seq + 1);
+				warned = 1;
+			}
+			continue;
+		}
+		double lon = atof(line[loncol].c_str());
+		double lat = atof(line[latcol].c_str());
+
+		long long x, y;
+		projection->project(lon, lat, 32, &x, &y);
+		drawvec dv;
+		dv.push_back(draw(VT_MOVETO, x, y));
+
+		std::vector<std::string> full_keys;
+		std::vector<serial_val> full_values;
+
+		for (size_t i = 0; i < line.size(); i++) {
+			if (i != (size_t) latcol && i != (size_t) loncol) {
+				line[i] = csv_dequote(line[i]);
+
+				serial_val sv;
+				if (is_number(line[i])) {
+					sv.type = mvt_double;
+				} else if (line[i].size() == 0 && prevent[P_EMPTY_CSV_COLUMNS]) {
+					sv.type = mvt_null;
+					line[i] = "null";
+				} else {
+					sv.type = mvt_string;
+				}
+				sv.s = line[i];
+
+				full_keys.push_back(header[i]);
+				full_values.push_back(sv);
+			}
+		}
+
+		serial_feature sf;
+
+		sf.layer = layer;
+		sf.layername = layername;
+		sf.segment = sst[0].segment;
+		sf.has_id = false;
+		sf.id = 0;
+		sf.has_tippecanoe_minzoom = false;
+		sf.has_tippecanoe_maxzoom = false;
+		sf.feature_minzoom = false;
+		sf.seq = *(sst[0].layer_seq);
+		sf.geometry = dv;
+		sf.t = 1;  // POINT
+		sf.full_keys = full_keys;
+		sf.full_values = full_values;
+
+		serialize_feature(&sst[0], sf);
+	}
+
+	if (fname.size() != 0) {
+		if (fclose(f) != 0) {
+			perror("fclose");
+			exit(EXIT_FAILURE);
+		}
+	}
+}

geocsv.hpp

@@ -0,0 +1,13 @@
+#ifndef GEOCSV_HPP
+#define GEOCSV_HPP
+
+#include <stdio.h>
+#include <set>
+#include <map>
+#include <string>
+#include "mbtiles.hpp"
+#include "serial.hpp"
+
+void parse_geocsv(std::vector<struct serialization_state> &sst, std::string fname, int layer, std::string layername);
+
+#endif

geojson-loop.cpp

@@ -0,0 +1,184 @@
+#ifdef MTRACE
+#include <mcheck.h>
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <ctype.h>
+#include <errno.h>
+#include "geojson-loop.hpp"
+#include "jsonpull/jsonpull.h"
+
+// XXX duplicated
+#define GEOM_TYPES 6
+static const char *geometry_names[GEOM_TYPES] = {
+	"Point", "MultiPoint", "LineString", "MultiLineString", "Polygon", "MultiPolygon",
+};
+
+// XXX duplicated
+static void json_context(json_object *j) {
+	char *s = json_stringify(j);
+
+	if (strlen(s) >= 500) {
+		sprintf(s + 497, "...");
+	}
+
+	fprintf(stderr, "In JSON object %s\n", s);
+	free(s);  // stringify
+}
+
+void parse_json(json_feature_action *jfa, json_pull *jp) {
+	long long found_hashes = 0;
+	long long found_features = 0;
+	long long found_geometries = 0;
+
+	while (1) {
+		json_object *j = json_read(jp);
+		if (j == NULL) {
+			if (jp->error != NULL) {
+				fprintf(stderr, "%s:%d: %s\n", jfa->fname.c_str(), jp->line, jp->error);
+				if (jp->root != NULL) {
+					json_context(jp->root);
+				}
+			}
+
+			json_free(jp->root);
+			break;
+		}
+
+		if (j->type == JSON_HASH) {
+			found_hashes++;
+
+			if (found_hashes == 50 && found_features == 0 && found_geometries == 0) {
+				fprintf(stderr, "%s:%d: Warning: not finding any GeoJSON features or geometries in input yet after 50 objects.\n", jfa->fname.c_str(), jp->line);
+			}
+		}
+
+		json_object *type = json_hash_get(j, "type");
+		if (type == NULL || type->type != JSON_STRING) {
+			continue;
+		}
+
+		if (found_features == 0) {
+			int i;
+			int is_geometry = 0;
+			for (i = 0; i < GEOM_TYPES; i++) {
+				if (strcmp(type->string, geometry_names[i]) == 0) {
+					is_geometry = 1;
+					break;
+				}
+			}
+
+			if (is_geometry) {
+				if (j->parent != NULL) {
+					if (j->parent->type == JSON_ARRAY && j->parent->parent != NULL) {
+						if (j->parent->parent->type == JSON_HASH) {
+							json_object *geometries = json_hash_get(j->parent->parent, "geometries");
+							if (geometries != NULL) {
+								// Parent of Parent must be a GeometryCollection
+								is_geometry = 0;
+							}
+						}
+					} else if (j->parent->type == JSON_HASH) {
+						json_object *geometry = json_hash_get(j->parent, "geometry");
+						if (geometry != NULL) {
+							// Parent must be a Feature
+							is_geometry = 0;
+						}
+					}
+				}
+			}
+
+			if (is_geometry) {
+				json_object *jo = j;
+				while (jo != NULL) {
+					if (jo->parent != NULL && jo->parent->type == JSON_HASH) {
+						if (json_hash_get(jo->parent, "properties") == jo) {
+							// Ancestor is the value corresponding to a properties key
+							is_geometry = 0;
+							break;
+						}
+					}
+					jo = jo->parent;
+				}
+			}
+
+			if (is_geometry) {
+				if (found_features != 0 && found_geometries == 0) {
+					fprintf(stderr, "%s:%d: Warning: found a mixture of features and bare geometries\n", jfa->fname.c_str(), jp->line);
+				}
+				found_geometries++;
+
+				jfa->add_feature(j, false, NULL, NULL, NULL, j);
+				json_free(j);
+				continue;
+			}
+		}
+
+		if (strcmp(type->string, "Feature") != 0) {
+			if (strcmp(type->string, "FeatureCollection") == 0) {
+				jfa->check_crs(j);
+				json_free(j);
+			}
+
+			continue;
+		}
+
+		if (found_features == 0 && found_geometries != 0) {
+			fprintf(stderr, "%s:%d: Warning: found a mixture of features and bare geometries\n", jfa->fname.c_str(), jp->line);
+		}
+		found_features++;
+
+		json_object *geometry = json_hash_get(j, "geometry");
+		if (geometry == NULL) {
+			fprintf(stderr, "%s:%d: feature with no geometry\n", jfa->fname.c_str(), jp->line);
+			json_context(j);
+			json_free(j);
+			continue;
+		}
+
+		json_object *properties = json_hash_get(j, "properties");
+		if (properties == NULL || (properties->type != JSON_HASH && properties->type != JSON_NULL)) {
+			fprintf(stderr, "%s:%d: feature without properties hash\n", jfa->fname.c_str(), jp->line);
+			json_context(j);
+			json_free(j);
+			continue;
+		}
+
+		bool is_feature = true;
+		{
+			json_object *jo = j;
+			while (jo != NULL) {
+				if (jo->parent != NULL && jo->parent->type == JSON_HASH) {
+					if (json_hash_get(jo->parent, "properties") == jo) {
+						// Ancestor is the value corresponding to a properties key
+						is_feature = false;
+						break;
+					}
+				}
+				jo = jo->parent;
+			}
+		}
+		if (!is_feature) {
+			continue;
+		}
+
+		json_object *tippecanoe = json_hash_get(j, "tippecanoe");
+		json_object *id = json_hash_get(j, "id");
+
+		json_object *geometries = json_hash_get(geometry, "geometries");
+		if (geometries != NULL && geometries->type == JSON_ARRAY) {
+			jfa->add_feature(geometries, true, properties, id, tippecanoe, j);
+		} else {
+			jfa->add_feature(geometry, false, properties, id, tippecanoe, j);
+		}
+
+		json_free(j);
+
+		/* XXX check for any non-features in the outer object */
+	}
+}

geojson-loop.hpp

@@ -0,0 +1,11 @@
+#include <string>
+#include "jsonpull/jsonpull.h"
+
+struct json_feature_action {
+	std::string fname;
+
+	virtual int add_feature(json_object *geometry, bool geometrycollection, json_object *properties, json_object *id, json_object *tippecanoe, json_object *feature) = 0;
+	virtual void check_crs(json_object *j) = 0;
+};
+
+void parse_json(json_feature_action *action, json_pull *jp);

geojson.cpp

@@ -20,14 +20,11 @@
 #include <sys/resource.h>
 #include <pthread.h>
 #include <vector>
+#include <algorithm>
 #include <set>
 #include <map>
 #include <string>
-
-extern "C" {
 #include "jsonpull/jsonpull.h"
-}
-
 #include "pool.hpp"
 #include "projection.hpp"
 #include "memfile.hpp"
@@ -38,141 +35,16 @@ extern "C" {
 #include "options.hpp"
 #include "serial.hpp"
 #include "text.hpp"
+#include "read_json.hpp"
+#include "mvt.hpp"
+#include "geojson-loop.hpp"
 
-#define GEOM_POINT 0	   /* array of positions */
-#define GEOM_MULTIPOINT 1      /* array of arrays of positions */
-#define GEOM_LINESTRING 2      /* array of arrays of positions */
-#define GEOM_MULTILINESTRING 3 /* array of arrays of arrays of positions */
-#define GEOM_POLYGON 4	 /* array of arrays of arrays of positions */
-#define GEOM_MULTIPOLYGON 5    /* array of arrays of arrays of arrays of positions */
-#define GEOM_TYPES 6
-
-static const char *geometry_names[GEOM_TYPES] = {
-	"Point", "MultiPoint", "LineString", "MultiLineString", "Polygon", "MultiPolygon",
-};
-
-static int geometry_within[GEOM_TYPES] = {
-	-1,		 /* point */
-	GEOM_POINT,      /* multipoint */
-	GEOM_POINT,      /* linestring */
-	GEOM_LINESTRING, /* multilinestring */
-	GEOM_LINESTRING, /* polygon */
-	GEOM_POLYGON,    /* multipolygon */
-};
-
-static int mb_geometry[GEOM_TYPES] = {
-	VT_POINT, VT_POINT, VT_LINE, VT_LINE, VT_POLYGON, VT_POLYGON,
-};
-
-void json_context(json_object *j) {
-	char *s = json_stringify(j);
-
-	if (strlen(s) >= 500) {
-		sprintf(s + 497, "...");
-	}
-
-	fprintf(stderr, "In JSON object %s\n", s);
-	free(s);  // stringify
-}
-
-long long parse_geometry(int t, json_object *j, long long *bbox, drawvec &out, int op, const char *fname, int line, int *initialized, unsigned *initial_x, unsigned *initial_y, json_object *feature) {
-	long long g = 0;
-
-	if (j == NULL || j->type != JSON_ARRAY) {
-		fprintf(stderr, "%s:%d: expected array for type %d\n", fname, line, t);
-		json_context(feature);
-		return g;
-	}
-
-	int within = geometry_within[t];
-	if (within >= 0) {
-		size_t i;
-		for (i = 0; i < j->length; i++) {
-			if (within == GEOM_POINT) {
-				if (i == 0 || mb_geometry[t] == GEOM_MULTIPOINT) {
-					op = VT_MOVETO;
-				} else {
-					op = VT_LINETO;
-				}
-			}
-
-			g += parse_geometry(within, j->array[i], bbox, out, op, fname, line, initialized, initial_x, initial_y, feature);
-		}
-	} else {
-		if (j->length >= 2 && j->array[0]->type == JSON_NUMBER && j->array[1]->type == JSON_NUMBER) {
-			long long x, y;
-			double lon = j->array[0]->number;
-			double lat = j->array[1]->number;
-			projection->project(lon, lat, 32, &x, &y);
-
-			if (j->length > 2) {
-				static int warned = 0;
-
-				if (!warned) {
-					fprintf(stderr, "%s:%d: ignoring dimensions beyond two\n", fname, line);
-					json_context(j);
-					json_context(feature);
-					warned = 1;
-				}
-			}
-
-			if (x < bbox[0]) {
-				bbox[0] = x;
-			}
-			if (y < bbox[1]) {
-				bbox[1] = y;
-			}
-			if (x > bbox[2]) {
-				bbox[2] = x;
-			}
-			if (y > bbox[3]) {
-				bbox[3] = y;
-			}
-
-			if (!*initialized) {
-				if (x < 0 || x >= (1LL << 32) || y < 0 || y >= (1LL < 32)) {
-					*initial_x = 1LL << 31;
-					*initial_y = 1LL << 31;
-				} else {
-					*initial_x = (x >> geometry_scale) << geometry_scale;
-					*initial_y = (y >> geometry_scale) << geometry_scale;
-				}
-
-				*initialized = 1;
-			}
-
-			draw d(op, (x >> geometry_scale), (y >> geometry_scale));
-			out.push_back(d);
-			g++;
-		} else {
-			fprintf(stderr, "%s:%d: malformed point\n", fname, line);
-			json_context(j);
-			json_context(feature);
-		}
-	}
-
-	if (t == GEOM_POLYGON) {
-		// Note that this is not using the correct meaning of closepath.
-		//
-		// We are using it here to close an entire Polygon, to distinguish
-		// the Polygons within a MultiPolygon from each other.
-		//
-		// This will be undone in fix_polygon(), which needs to know which
-		// rings come from which Polygons so that it can make the winding order
-		// of the outer ring be the opposite of the order of the inner rings.
-
-		out.push_back(draw(VT_CLOSEPATH, 0, 0));
-	}
-
-	return g;
-}
-
-int serialize_geometry(json_object *geometry, json_object *properties, json_object *id, const char *reading, int line, volatile long long *layer_seq, volatile long long *progress_seq, long long *metapos, long long *geompos, long long *indexpos, std::set<std::string> *exclude, std::set<std::string> *include, int exclude_all, FILE *metafile, FILE *geomfile, FILE *indexfile, struct memfile *poolfile, struct memfile *treefile, const char *fname, int basezoom, int layer, double droprate, long long *file_bbox, json_object *tippecanoe, int segment, int *initialized, unsigned *initial_x, unsigned *initial_y, struct reader *readers, int maxzoom, json_object *feature, std::map<std::string, layermap_entry> *layermap, std::string const &layername, bool uses_gamma) {
+int serialize_geojson_feature(struct serialization_state *sst, json_object *geometry, json_object *properties, json_object *id, int layer, json_object *tippecanoe, json_object *feature, std::string layername) {
 	json_object *geometry_type = json_hash_get(geometry, "type");
 	if (geometry_type == NULL) {
 		static int warned = 0;
 		if (!warned) {
-			fprintf(stderr, "%s:%d: null geometry (additional not reported)\n", reading, line);
+			fprintf(stderr, "%s:%d: null geometry (additional not reported)\n", sst->fname, sst->line);
 			json_context(feature);
 			warned = 1;
 		}
@@ -181,14 +53,14 @@ int serialize_geometry(json_object *geometry, json_object *properties, json_obje
 	}
 
 	if (geometry_type->type != JSON_STRING) {
-		fprintf(stderr, "%s:%d: geometry type is not a string\n", reading, line);
+		fprintf(stderr, "%s:%d: geometry type is not a string\n", sst->fname, sst->line);
 		json_context(feature);
 		return 0;
 	}
 
 	json_object *coordinates = json_hash_get(geometry, "coordinates");
 	if (coordinates == NULL || coordinates->type != JSON_ARRAY) {
-		fprintf(stderr, "%s:%d: feature without coordinates array\n", reading, line);
+		fprintf(stderr, "%s:%d: feature without coordinates array\n", sst->fname, sst->line);
 		json_context(feature);
 		return 0;
 	}
@@ -200,7 +72,7 @@ int serialize_geometry(json_object *geometry, json_object *properties, json_obje
 		}
 	}
 	if (t >= GEOM_TYPES) {
-		fprintf(stderr, "%s:%d: Can't handle geometry type %s\n", reading, line, geometry_type->string);
+		fprintf(stderr, "%s:%d: Can't handle geometry type %s\n", sst->fname, sst->line, geometry_type->string);
 		json_context(feature);
 		return 0;
 	}
@@ -211,19 +83,13 @@ int serialize_geometry(json_object *geometry, json_object *properties, json_obje
 
 	if (tippecanoe != NULL) {
 		json_object *min = json_hash_get(tippecanoe, "minzoom");
-		if (min != NULL && min->type == JSON_NUMBER) {
-			tippecanoe_minzoom = min->number;
-		}
-		if (min != NULL && min->type == JSON_STRING) {
-			tippecanoe_minzoom = atoi(min->string);
+		if (min != NULL && (min->type == JSON_STRING || min->type == JSON_NUMBER)) {
+			tippecanoe_minzoom = integer_zoom(sst->fname, min->string);
 		}
 
 		json_object *max = json_hash_get(tippecanoe, "maxzoom");
-		if (max != NULL && max->type == JSON_NUMBER) {
-			tippecanoe_maxzoom = max->number;
-		}
-		if (max != NULL && max->type == JSON_STRING) {
-			tippecanoe_maxzoom = atoi(max->string);
+		if (max != NULL && (max->type == JSON_STRING || max->type == JSON_NUMBER)) {
+			tippecanoe_maxzoom = integer_zoom(sst->fname, max->string);
 		}
 
 		json_object *ln = json_hash_get(tippecanoe, "layer");
@@ -241,162 +107,114 @@ int serialize_geometry(json_object *geometry, json_object *properties, json_obje
 				id_value = strtoull(id->string, &err, 10);
 
 				if (err != NULL && *err != '\0') {
-					fprintf(stderr, "Warning: Can't represent non-integer feature ID %s\n", id->string);
+					static bool warned_frac = false;
+
+					if (!warned_frac) {
+						fprintf(stderr, "Warning: Can't represent non-integer feature ID %s\n", id->string);
+						warned_frac = true;
+					}
+				} else if (std::to_string(id_value) != id->string) {
+					static bool warned = false;
+
+					if (!warned) {
+						fprintf(stderr, "Warning: Can't represent too-large feature ID %s\n", id->string);
+						warned = true;
+					}
 				} else {
 					has_id = true;
 				}
 			} else {
-				fprintf(stderr, "Warning: Can't represent negative feature ID %s\n", id->string);
+				static bool warned_neg = false;
+
+				if (!warned_neg) {
+					fprintf(stderr, "Warning: Can't represent negative feature ID %s\n", id->string);
+					warned_neg = true;
+				}
 			}
 		} else {
-			char *s = json_stringify(id);
-			fprintf(stderr, "Warning: Can't represent non-numeric feature ID %s\n", s);
-			free(s);  // stringify
+			bool converted = false;
+
+			if (additional[A_CONVERT_NUMERIC_IDS] && id->type == JSON_STRING) {
+				char *err = NULL;
+				id_value = strtoull(id->string, &err, 10);
+
+				if (err != NULL && *err != '\0') {
+					static bool warned_frac = false;
+
+					if (!warned_frac) {
+						fprintf(stderr, "Warning: Can't represent non-integer feature ID %s\n", id->string);
+						warned_frac = true;
+					}
+				} else if (std::to_string(id_value) != id->string) {
+					static bool warned = false;
+
+					if (!warned) {
+						fprintf(stderr, "Warning: Can't represent too-large feature ID %s\n", id->string);
+						warned = true;
+					}
+				} else {
+					has_id = true;
+					converted = true;
+				}
+			}
+
+			if (!converted) {
+				static bool warned_nan = false;
+
+				if (!warned_nan) {
+					char *s = json_stringify(id);
+					fprintf(stderr, "Warning: Can't represent non-numeric feature ID %s\n", s);
+					free(s);  // stringify
+					warned_nan = true;
+				}
+			}
 		}
 	}
 
-	long long bbox[] = {LLONG_MAX, LLONG_MAX, LLONG_MIN, LLONG_MIN};
-
 	size_t nprop = 0;
 	if (properties != NULL && properties->type == JSON_HASH) {
 		nprop = properties->length;
 	}
 
-	char *metakey[nprop];
+	std::vector<char *> metakey;
+	metakey.resize(nprop);
+
 	std::vector<std::string> metaval;
 	metaval.resize(nprop);
-	int metatype[nprop];
+
+	std::vector<int> metatype;
+	metatype.resize(nprop);
+
 	size_t m = 0;
 
 	for (size_t i = 0; i < nprop; i++) {
 		if (properties->keys[i]->type == JSON_STRING) {
 			std::string s(properties->keys[i]->string);
 
-			if (exclude_all) {
-				if (include->count(s) == 0) {
-					continue;
-				}
-			} else if (exclude->count(s) != 0) {
-				continue;
-			}
+			int type = -1;
+			std::string val;
+			stringify_value(properties->values[i], type, val, sst->fname, sst->line, feature);
 
-			type_and_string tas;
-			tas.string = s;
-			tas.type = -1;
-
-			metakey[m] = properties->keys[i]->string;
-
-			if (properties->values[i] != NULL && properties->values[i]->type == JSON_STRING) {
-				tas.type = metatype[m] = VT_STRING;
-				metaval[m] = std::string(properties->values[i]->string);
-				std::string err = check_utf8(metaval[m]);
-				if (err != "") {
-					fprintf(stderr, "%s:%d: %s\n", reading, line, err.c_str());
-					json_context(feature);
-					exit(EXIT_FAILURE);
-				}
+			if (type >= 0) {
+				metakey[m] = properties->keys[i]->string;
+				metatype[m] = type;
+				metaval[m] = val;
 				m++;
-			} else if (properties->values[i] != NULL && properties->values[i]->type == JSON_NUMBER) {
-				tas.type = metatype[m] = VT_NUMBER;
-				metaval[m] = std::string(properties->values[i]->string);
-				m++;
-			} else if (properties->values[i] != NULL && (properties->values[i]->type == JSON_TRUE || properties->values[i]->type == JSON_FALSE)) {
-				tas.type = metatype[m] = VT_BOOLEAN;
-				metaval[m] = std::string(properties->values[i]->type == JSON_TRUE ? "true" : "false");
-				m++;
-			} else if (properties->values[i] != NULL && (properties->values[i]->type == JSON_NULL)) {
-				;
 			} else {
-				tas.type = metatype[m] = VT_STRING;
-				const char *v = json_stringify(properties->values[i]);
-				metaval[m] = std::string(v);
-				free((void *) v);  // stringify
+				metakey[m] = properties->keys[i]->string;
+				metatype[m] = mvt_null;
+				metaval[m] = "null";
 				m++;
 			}
-
-			if (tas.type >= 0) {
-				auto fk = layermap->find(layername);
-				fk->second.file_keys.insert(tas);
-			}
 		}
 	}
 
 	drawvec dv;
-	long long g = parse_geometry(t, coordinates, bbox, dv, VT_MOVETO, fname, line, initialized, initial_x, initial_y, feature);
-	if (mb_geometry[t] == VT_POLYGON) {
-		dv = fix_polygon(dv);
-	}
-
-	bool inline_meta = true;
-	// Don't inline metadata for features that will span several tiles at maxzoom
-	if (g > 0 && (bbox[2] < bbox[0] || bbox[3] < bbox[1])) {
-		fprintf(stderr, "Internal error: impossible feature bounding box %llx,%llx,%llx,%llx\n", bbox[0], bbox[1], bbox[2], bbox[3]);
-	}
-	if (bbox[2] - bbox[0] > (2LL << (32 - maxzoom)) || bbox[3] - bbox[1] > (2LL << (32 - maxzoom))) {
-		inline_meta = false;
-
-		if (prevent[P_CLIPPING]) {
-			static volatile long long warned = 0;
-			long long extent = ((bbox[2] - bbox[0]) / ((1LL << (32 - maxzoom)) + 1)) * ((bbox[3] - bbox[1]) / ((1LL << (32 - maxzoom)) + 1));
-			if (extent > warned) {
-				fprintf(stderr, "Warning: %s:%d: Large unclipped (-pc) feature may be duplicated across %lld tiles\n", fname, line, extent);
-				warned = extent;
-
-				if (extent > 10000) {
-					fprintf(stderr, "Exiting because this can't be right.\n");
-					exit(EXIT_FAILURE);
-				}
-			}
-		}
-	}
-
-	double extent = 0;
-	if (additional[A_DROP_SMALLEST_AS_NEEDED]) {
-		if (mb_geometry[t] == VT_POLYGON) {
-			for (size_t i = 0; i < dv.size(); i++) {
-				if (dv[i].op == VT_MOVETO) {
-					size_t j;
-					for (j = i + 1; j < dv.size(); j++) {
-						if (dv[j].op != VT_LINETO) {
-							break;
-						}
-					}
-
-					extent += get_area(dv, i, j);
-					i = j - 1;
-				}
-			}
-		} else if (mb_geometry[t] == VT_LINE) {
-			for (size_t i = 1; i < dv.size(); i++) {
-				if (dv[i].op == VT_LINETO) {
-					double xd = dv[i].x - dv[i - 1].x;
-					double yd = dv[i].y - dv[i - 1].y;
-					extent += sqrt(xd * xd + yd * yd);
-				}
-			}
-		}
-	}
-
-	if (tippecanoe_layername.size() != 0) {
-		if (layermap->count(tippecanoe_layername) == 0) {
-			layermap->insert(std::pair<std::string, layermap_entry>(tippecanoe_layername, layermap_entry(layermap->size())));
-		}
-
-		auto ai = layermap->find(tippecanoe_layername);
-		if (ai != layermap->end()) {
-			layer = ai->second.id;
-		} else {
-			fprintf(stderr, "Internal error: can't find layer name %s\n", tippecanoe_layername.c_str());
-			exit(EXIT_FAILURE);
-		}
-	}
-
-	long long geomstart = *geompos;
-	long long bbox_index;
+	parse_geometry(t, coordinates, dv, VT_MOVETO, sst->fname, sst->line, feature);
 
 	serial_feature sf;
 	sf.layer = layer;
-	sf.segment = segment;
+	sf.segment = sst->segment;
 	sf.t = mb_geometry[t];
 	sf.has_id = has_id;
 	sf.id = id_value;
@@ -405,74 +223,26 @@ int serialize_geometry(json_object *geometry, json_object *properties, json_obje
 	sf.has_tippecanoe_maxzoom = (tippecanoe_maxzoom != -1);
 	sf.tippecanoe_maxzoom = tippecanoe_maxzoom;
 	sf.geometry = dv;
-	sf.m = m;
 	sf.feature_minzoom = 0;  // Will be filled in during index merging
-	sf.extent = (long long) extent;
+	sf.seq = *(sst->layer_seq);
 
-	if (prevent[P_INPUT_ORDER]) {
-		sf.seq = *layer_seq;
+	if (tippecanoe_layername.size() != 0) {
+		sf.layername = tippecanoe_layername;
 	} else {
-		sf.seq = 0;
+		sf.layername = layername;
 	}
 
-	// Calculate the center even if off the edge of the plane,
-	// and then mask to bring it back into the addressable area
-	long long midx = (bbox[0] / 2 + bbox[2] / 2) & ((1LL << 32) - 1);
-	long long midy = (bbox[1] / 2 + bbox[3] / 2) & ((1LL << 32) - 1);
-	bbox_index = encode(midx, midy);
+	for (size_t i = 0; i < m; i++) {
+		sf.full_keys.push_back(metakey[i]);
 
-	if (additional[A_DROP_DENSEST_AS_NEEDED] || additional[A_CALCULATE_FEATURE_DENSITY] || additional[A_INCREASE_GAMMA_AS_NEEDED] || uses_gamma) {
-		sf.index = bbox_index;
+		serial_val sv;
+		sv.type = metatype[i];
+		sv.s = metaval[i];
+
+		sf.full_values.push_back(sv);
 	}
 
-	if (inline_meta) {
-		sf.metapos = -1;
-		for (size_t i = 0; i < m; i++) {
-			sf.keys.push_back(addpool(poolfile, treefile, metakey[i], VT_STRING));
-			sf.values.push_back(addpool(poolfile, treefile, metaval[i].c_str(), metatype[i]));
-		}
-	} else {
-		sf.metapos = *metapos;
-		for (size_t i = 0; i < m; i++) {
-			serialize_long_long(metafile, addpool(poolfile, treefile, metakey[i], VT_STRING), metapos, fname);
-			serialize_long_long(metafile, addpool(poolfile, treefile, metaval[i].c_str(), metatype[i]), metapos, fname);
-		}
-	}
-
-	serialize_feature(geomfile, &sf, geompos, fname, *initial_x >> geometry_scale, *initial_y >> geometry_scale, false);
-
-	struct index index;
-	index.start = geomstart;
-	index.end = *geompos;
-	index.segment = segment;
-	index.seq = *layer_seq;
-	index.t = sf.t;
-	index.index = bbox_index;
-
-	fwrite_check(&index, sizeof(struct index), 1, indexfile, fname);
-	*indexpos += sizeof(struct index);
-
-	for (size_t i = 0; i < 2; i++) {
-		if (bbox[i] < file_bbox[i]) {
-			file_bbox[i] = bbox[i];
-		}
-	}
-	for (size_t i = 2; i < 4; i++) {
-		if (bbox[i] > file_bbox[i]) {
-			file_bbox[i] = bbox[i];
-		}
-	}
-
-	if (*progress_seq % 10000 == 0) {
-		checkdisk(readers, CPUS);
-		if (!quiet) {
-			fprintf(stderr, "Read %.2f million features\r", *progress_seq / 1000000.0);
-		}
-	}
-	(*progress_seq)++;
-	(*layer_seq)++;
-
-	return 1;
+	return serialize_feature(sst, sf);
 }
 
 void check_crs(json_object *j, const char *reading) {
@@ -481,141 +251,55 @@ void check_crs(json_object *j, const char *reading) {
 		json_object *properties = json_hash_get(crs, "properties");
 		if (properties != NULL) {
 			json_object *name = json_hash_get(properties, "name");
-			if (name->type == JSON_STRING) {
+			if (name != NULL && name->type == JSON_STRING) {
 				if (strcmp(name->string, projection->alias) != 0) {
-					fprintf(stderr, "%s: Warning: GeoJSON specified projection \"%s\", not \"%s\".\n", reading, name->string, projection->alias);
+					if (!quiet) {
+						fprintf(stderr, "%s: Warning: GeoJSON specified projection \"%s\", not the expected \"%s\".\n", reading, name->string, projection->alias);
+						fprintf(stderr, "%s: If \"%s\" is not the expected projection, use -s to specify the right one.\n", reading, projection->alias);
+					}
 				}
 			}
 		}
 	}
 }
 
-void parse_json(json_pull *jp, const char *reading, volatile long long *layer_seq, volatile long long *progress_seq, long long *metapos, long long *geompos, long long *indexpos, std::set<std::string> *exclude, std::set<std::string> *include, int exclude_all, FILE *metafile, FILE *geomfile, FILE *indexfile, struct memfile *poolfile, struct memfile *treefile, char *fname, int basezoom, int layer, double droprate, long long *file_bbox, int segment, int *initialized, unsigned *initial_x, unsigned *initial_y, struct reader *readers, int maxzoom, std::map<std::string, layermap_entry> *layermap, std::string layername, bool uses_gamma) {
-	long long found_hashes = 0;
-	long long found_features = 0;
-	long long found_geometries = 0;
+struct json_serialize_action : json_feature_action {
+	serialization_state *sst;
+	int layer;
+	std::string layername;
 
-	while (1) {
-		json_object *j = json_read(jp);
-		if (j == NULL) {
-			if (jp->error != NULL) {
-				fprintf(stderr, "%s:%d: %s\n", reading, jp->line, jp->error);
-				if (jp->root != NULL) {
-					json_context(jp->root);
-				}
-			}
-
-			json_free(jp->root);
-			break;
-		}
-
-		if (j->type == JSON_HASH) {
-			found_hashes++;
-
-			if (found_hashes == 50 && found_features == 0 && found_geometries == 0) {
-				fprintf(stderr, "%s:%d: Warning: not finding any GeoJSON features or geometries in input yet after 50 objects.\n", reading, jp->line);
-			}
-		}
-
-		json_object *type = json_hash_get(j, "type");
-		if (type == NULL || type->type != JSON_STRING) {
-			continue;
-		}
-
-		if (found_features == 0) {
-			int i;
-			int is_geometry = 0;
-			for (i = 0; i < GEOM_TYPES; i++) {
-				if (strcmp(type->string, geometry_names[i]) == 0) {
-					is_geometry = 1;
-					break;
-				}
-			}
-
-			if (is_geometry) {
-				if (j->parent != NULL) {
-					if (j->parent->type == JSON_ARRAY) {
-						if (j->parent->parent->type == JSON_HASH) {
-							json_object *geometries = json_hash_get(j->parent->parent, "geometries");
-							if (geometries != NULL) {
-								// Parent of Parent must be a GeometryCollection
-								is_geometry = 0;
-							}
-						}
-					} else if (j->parent->type == JSON_HASH) {
-						json_object *geometry = json_hash_get(j->parent, "geometry");
-						if (geometry != NULL) {
-							// Parent must be a Feature
-							is_geometry = 0;
-						}
-					}
-				}
-			}
-
-			if (is_geometry) {
-				if (found_features != 0 && found_geometries == 0) {
-					fprintf(stderr, "%s:%d: Warning: found a mixture of features and bare geometries\n", reading, jp->line);
-				}
-				found_geometries++;
-
-				serialize_geometry(j, NULL, NULL, reading, jp->line, layer_seq, progress_seq, metapos, geompos, indexpos, exclude, include, exclude_all, metafile, geomfile, indexfile, poolfile, treefile, fname, basezoom, layer, droprate, file_bbox, NULL, segment, initialized, initial_x, initial_y, readers, maxzoom, j, layermap, layername, uses_gamma);
-				json_free(j);
-				continue;
-			}
-		}
-
-		if (strcmp(type->string, "Feature") != 0) {
-			if (strcmp(type->string, "FeatureCollection") == 0) {
-				check_crs(j, reading);
-			}
-
-			continue;
-		}
-
-		if (found_features == 0 && found_geometries != 0) {
-			fprintf(stderr, "%s:%d: Warning: found a mixture of features and bare geometries\n", reading, jp->line);
-		}
-		found_features++;
-
-		json_object *geometry = json_hash_get(j, "geometry");
-		if (geometry == NULL) {
-			fprintf(stderr, "%s:%d: feature with no geometry\n", reading, jp->line);
-			json_context(j);
-			json_free(j);
-			continue;
-		}
-
-		json_object *properties = json_hash_get(j, "properties");
-		if (properties == NULL || (properties->type != JSON_HASH && properties->type != JSON_NULL)) {
-			fprintf(stderr, "%s:%d: feature without properties hash\n", reading, jp->line);
-			json_context(j);
-			json_free(j);
-			continue;
-		}
-
-		json_object *tippecanoe = json_hash_get(j, "tippecanoe");
-		json_object *id = json_hash_get(j, "id");
-
-		json_object *geometries = json_hash_get(geometry, "geometries");
-		if (geometries != NULL) {
-			size_t g;
-			for (g = 0; g < geometries->length; g++) {
-				serialize_geometry(geometries->array[g], properties, id, reading, jp->line, layer_seq, progress_seq, metapos, geompos, indexpos, exclude, include, exclude_all, metafile, geomfile, indexfile, poolfile, treefile, fname, basezoom, layer, droprate, file_bbox, tippecanoe, segment, initialized, initial_x, initial_y, readers, maxzoom, j, layermap, layername, uses_gamma);
+	int add_feature(json_object *geometry, bool geometrycollection, json_object *properties, json_object *id, json_object *tippecanoe, json_object *feature) {
+		sst->line = geometry->parser->line;
+		if (geometrycollection) {
+			int ret = 1;
+			for (size_t g = 0; g < geometry->length; g++) {
+				ret &= serialize_geojson_feature(sst, geometry->array[g], properties, id, layer, tippecanoe, feature, layername);
 			}
+			return ret;
 		} else {
-			serialize_geometry(geometry, properties, id, reading, jp->line, layer_seq, progress_seq, metapos, geompos, indexpos, exclude, include, exclude_all, metafile, geomfile, indexfile, poolfile, treefile, fname, basezoom, layer, droprate, file_bbox, tippecanoe, segment, initialized, initial_x, initial_y, readers, maxzoom, j, layermap, layername, uses_gamma);
+			return serialize_geojson_feature(sst, geometry, properties, id, layer, tippecanoe, feature, layername);
 		}
-
-		json_free(j);
-
-		/* XXX check for any non-features in the outer object */
 	}
+
+	void check_crs(json_object *j) {
+		::check_crs(j, fname.c_str());
+	}
+};
+
+void parse_json(struct serialization_state *sst, json_pull *jp, int layer, std::string layername) {
+	json_serialize_action jsa;
+	jsa.fname = sst->fname;
+	jsa.sst = sst;
+	jsa.layer = layer;
+	jsa.layername = layername;
+
+	parse_json(&jsa, jp);
 }
 
 void *run_parse_json(void *v) {
 	struct parse_json_args *pja = (struct parse_json_args *) v;
 
-	parse_json(pja->jp, pja->reading, pja->layer_seq, pja->progress_seq, pja->metapos, pja->geompos, pja->indexpos, pja->exclude, pja->include, pja->exclude_all, pja->metafile, pja->geomfile, pja->indexfile, pja->poolfile, pja->treefile, pja->fname, pja->basezoom, pja->layer, pja->droprate, pja->file_bbox, pja->segment, pja->initialized, pja->initial_x, pja->initial_y, pja->readers, pja->maxzoom, pja->layermap, *pja->layername, pja->uses_gamma);
+	parse_json(pja->sst, pja->jp, pja->layer, *pja->layername);
 
 	return NULL;
 }

geojson.hpp

@@ -1,37 +1,30 @@
+#ifndef GEOJSON_HPP
+#define GEOJSON_HPP
+
+#include <stdio.h>
+#include <set>
+#include <map>
+#include <string>
+#include "mbtiles.hpp"
+#include "jsonpull/jsonpull.h"
+#include "serial.hpp"
+
 struct parse_json_args {
 	json_pull *jp;
-	const char *reading;
-	volatile long long *layer_seq;
-	volatile long long *progress_seq;
-	long long *metapos;
-	long long *geompos;
-	long long *indexpos;
-	std::set<std::string> *exclude;
-	std::set<std::string> *include;
-	int exclude_all;
-	FILE *metafile;
-	FILE *geomfile;
-	FILE *indexfile;
-	struct memfile *poolfile;
-	struct memfile *treefile;
-	char *fname;
-	int basezoom;
 	int layer;
-	double droprate;
-	long long *file_bbox;
-	int segment;
-	int *initialized;
-	unsigned *initial_x;
-	unsigned *initial_y;
-	struct reader *readers;
-	int maxzoom;
-	std::map<std::string, layermap_entry> *layermap;
 	std::string *layername;
-	bool uses_gamma;
+
+	struct serialization_state *sst;
+
+	parse_json_args(json_pull *jp1, int layer1, std::string *layername1, struct serialization_state *sst1)
+	    : jp(jp1), layer(layer1), layername(layername1), sst(sst1) {
+	}
 };
 
 struct json_pull *json_begin_map(char *map, long long len);
 void json_end_map(struct json_pull *jp);
 
-void parse_json(json_pull *jp, const char *reading, volatile long long *layer_seq, volatile long long *progress_seq, long long *metapos, long long *geompos, long long *indexpos, std::set<std::string> *exclude, std::set<std::string> *include, int exclude_all, FILE *metafile, FILE *geomfile, FILE *indexfile, struct memfile *poolfile, struct memfile *treefile, char *fname, int basezoom, int layer, double droprate, long long *file_bbox, int segment, int *initialized, unsigned *initial_x, unsigned *initial_y, struct reader *readers, int maxzoom, std::map<std::string, layermap_entry> *layermap, std::string layername, bool uses_gamma);
+void parse_json(struct serialization_state *sst, json_pull *jp, int layer, std::string layername);
 void *run_parse_json(void *v);
+
+#endif

geometry.cpp

@@ -3,23 +3,28 @@
 #include <string>
 #include <stack>
 #include <vector>
+#include <map>
 #include <algorithm>
 #include <cstdio>
 #include <unistd.h>
 #include <cmath>
 #include <limits.h>
 #include <sqlite3.h>
-#include <mapbox/geometry.hpp>
+#include <mapbox/geometry/point.hpp>
+#include <mapbox/geometry/multi_polygon.hpp>
 #include <mapbox/geometry/wagyu/wagyu.hpp>
+#include <mapbox/geometry/wagyu/quick_clip.hpp>
+#include <mapbox/geometry/snap_rounding.hpp>
 #include "geometry.hpp"
 #include "projection.hpp"
 #include "serial.hpp"
 #include "main.hpp"
+#include "options.hpp"
 
 static int pnpoly(drawvec &vert, size_t start, size_t nvert, long long testx, long long testy);
 static int clip(double *x0, double *y0, double *x1, double *y1, double xmin, double ymin, double xmax, double ymax);
 
-drawvec decode_geometry(FILE *meta, long long *geompos, int z, unsigned tx, unsigned ty, int detail, long long *bbox, unsigned initial_x, unsigned initial_y) {
+drawvec decode_geometry(FILE *meta, std::atomic<long long> *geompos, int z, unsigned tx, unsigned ty, long long *bbox, unsigned initial_x, unsigned initial_y) {
 	drawvec out;
 
 	bbox[0] = LLONG_MAX;
@@ -164,6 +169,27 @@ double get_area(drawvec &geom, size_t i, size_t j) {
 	return area;
 }
 
+double get_mp_area(drawvec &geom) {
+	double ret = 0;
+
+	for (size_t i = 0; i < geom.size(); i++) {
+		if (geom[i].op == VT_MOVETO) {
+			size_t j;
+
+			for (j = i + 1; j < geom.size(); j++) {
+				if (geom[j].op != VT_LINETO) {
+					break;
+				}
+			}
+
+			ret += get_area(geom, i, j);
+			i = j - 1;
+		}
+	}
+
+	return ret;
+}
+
 static void decode_clipped(mapbox::geometry::multi_polygon<long long> &t, drawvec &out) {
 	out.clear();
 
@@ -194,9 +220,10 @@ static void decode_clipped(mapbox::geometry::multi_polygon<long long> &t, drawve
 	}
 }
 
-drawvec clean_or_clip_poly(drawvec &geom, int z, int detail, int buffer, bool clip) {
+drawvec clean_or_clip_poly(drawvec &geom, int z, int buffer, bool clip) {
 	mapbox::geometry::wagyu::wagyu<long long> wagyu;
 
+	geom = remove_noop(geom, VT_POLYGON, 0);
 	for (size_t i = 0; i < geom.size(); i++) {
 		if (geom[i].op == VT_MOVETO) {
 			size_t j;
@@ -319,30 +346,42 @@ static int pnpoly(drawvec &vert, size_t start, size_t nvert, long long testx, lo
 	return c;
 }
 
-void check_polygon(drawvec &geom, drawvec &before) {
-	for (size_t i = 0; i + 1 < geom.size(); i++) {
-		for (size_t j = i + 1; j + 1 < geom.size(); j++) {
-			if (geom[i + 1].op == VT_LINETO && geom[j + 1].op == VT_LINETO) {
-				double s1_x = geom[i + 1].x - geom[i + 0].x;
-				double s1_y = geom[i + 1].y - geom[i + 0].y;
-				double s2_x = geom[j + 1].x - geom[j + 0].x;
-				double s2_y = geom[j + 1].y - geom[j + 0].y;
+void check_polygon(drawvec &geom) {
+	geom = remove_noop(geom, VT_POLYGON, 0);
 
-				double s, t;
-				s = (-s1_y * (geom[i + 0].x - geom[j + 0].x) + s1_x * (geom[i + 0].y - geom[j + 0].y)) / (-s2_x * s1_y + s1_x * s2_y);
-				t = (s2_x * (geom[i + 0].y - geom[j + 0].y) - s2_y * (geom[i + 0].x - geom[j + 0].x)) / (-s2_x * s1_y + s1_x * s2_y);
-
-				if (t > 0 && t < 1 && s > 0 && s < 1) {
-					printf("Internal error: self-intersecting polygon. %lld,%lld to %lld,%lld intersects %lld,%lld to %lld,%lld\n",
-					       geom[i + 0].x, geom[i + 0].y,
-					       geom[i + 1].x, geom[i + 1].y,
-					       geom[j + 0].x, geom[j + 0].y,
-					       geom[j + 1].x, geom[j + 1].y);
+	mapbox::geometry::multi_polygon<long long> mp;
+	for (size_t i = 0; i < geom.size(); i++) {
+		if (geom[i].op == VT_MOVETO) {
+			size_t j;
+			for (j = i + 1; j < geom.size(); j++) {
+				if (geom[j].op != VT_LINETO) {
+					break;
 				}
 			}
+
+			if (j >= i + 4) {
+				mapbox::geometry::linear_ring<long long> lr;
+
+				for (size_t k = i; k < j; k++) {
+					lr.push_back(mapbox::geometry::point<long long>(geom[k].x, geom[k].y));
+				}
+
+				if (lr.size() >= 3) {
+					mapbox::geometry::polygon<long long> p;
+					p.push_back(lr);
+					mp.push_back(p);
+				}
+			}
+
+			i = j - 1;
 		}
 	}
 
+	mapbox::geometry::multi_polygon<long long> mp2 = mapbox::geometry::snap_round(mp, true, true);
+	if (mp != mp2) {
+		fprintf(stderr, "Internal error: self-intersecting polygon\n");
+	}
+
 	size_t outer_start = -1;
 	size_t outer_len = 0;
 
@@ -422,103 +461,13 @@ drawvec close_poly(drawvec &geom) {
 	return out;
 }
 
-static bool inside(draw d, int edge, long long minx, long long miny, long long maxx, long long maxy) {
-	switch (edge) {
-	case 0:  // top
-		return d.y > miny;
-
-	case 1:  // right
-		return d.x < maxx;
-
-	case 2:  // bottom
-		return d.y < maxy;
-
-	case 3:  // left
-		return d.x > minx;
-	}
-
-	fprintf(stderr, "internal error inside\n");
-	exit(EXIT_FAILURE);
-}
-
-static draw intersect(draw a, draw b, int edge, long long minx, long long miny, long long maxx, long long maxy) {
-	// The casts to double are because the product of coordinates
-	// can overflow a long long if the tile buffer is large.
-
-	switch (edge) {
-	case 0:  // top
-		return draw(VT_LINETO, a.x + (double) (b.x - a.x) * (miny - a.y) / (b.y - a.y), miny);
-
-	case 1:  // right
-		return draw(VT_LINETO, maxx, a.y + (double) (b.y - a.y) * (maxx - a.x) / (b.x - a.x));
-
-	case 2:  // bottom
-		return draw(VT_LINETO, a.x + (double) (b.x - a.x) * (maxy - a.y) / (b.y - a.y), maxy);
-
-	case 3:  // left
-		return draw(VT_LINETO, minx, a.y + (double) (b.y - a.y) * (minx - a.x) / (b.x - a.x));
-	}
-
-	fprintf(stderr, "internal error intersecting\n");
-	exit(EXIT_FAILURE);
-}
-
-// http://en.wikipedia.org/wiki/Sutherland%E2%80%93Hodgman_algorithm
-static drawvec clip_poly1(drawvec &geom, long long minx, long long miny, long long maxx, long long maxy) {
-	drawvec out = geom;
-
-	for (int edge = 0; edge < 4; edge++) {
-		if (out.size() > 0) {
-			drawvec in = out;
-			out.resize(0);
-
-			draw S = in[in.size() - 1];
-
-			for (size_t e = 0; e < in.size(); e++) {
-				draw E = in[e];
-
-				if (inside(E, edge, minx, miny, maxx, maxy)) {
-					if (!inside(S, edge, minx, miny, maxx, maxy)) {
-						out.push_back(intersect(S, E, edge, minx, miny, maxx, maxy));
-					}
-					out.push_back(E);
-				} else if (inside(S, edge, minx, miny, maxx, maxy)) {
-					out.push_back(intersect(S, E, edge, minx, miny, maxx, maxy));
-				}
-
-				S = E;
-			}
-		}
-	}
-
-	if (out.size() > 0) {
-		// If the polygon begins and ends outside the edge,
-		// the starting and ending points will be left as the
-		// places where it intersects the edge. Need to add
-		// another point to close the loop.
-
-		if (out[0].x != out[out.size() - 1].x || out[0].y != out[out.size() - 1].y) {
-			out.push_back(out[0]);
-		}
-
-		if (out.size() < 3) {
-			// fprintf(stderr, "Polygon degenerated to a line segment\n");
-			out.clear();
-			return out;
-		}
-
-		out[0].op = VT_MOVETO;
-		for (size_t i = 1; i < out.size(); i++) {
-			out[i].op = VT_LINETO;
-		}
-	}
-
-	return out;
-}
-
 drawvec simple_clip_poly(drawvec &geom, long long minx, long long miny, long long maxx, long long maxy) {
 	drawvec out;
 
+	mapbox::geometry::point<long long> min(minx, miny);
+	mapbox::geometry::point<long long> max(maxx, maxy);
+	mapbox::geometry::box<long long> bbox(min, max);
+
 	for (size_t i = 0; i < geom.size(); i++) {
 		if (geom[i].op == VT_MOVETO) {
 			size_t j;
@@ -528,19 +477,25 @@ drawvec simple_clip_poly(drawvec &geom, long long minx, long long miny, long lon
 				}
 			}
 
-			drawvec tmp;
+			mapbox::geometry::linear_ring<long long> ring;
 			for (size_t k = i; k < j; k++) {
-				tmp.push_back(geom[k]);
+				ring.push_back(mapbox::geometry::point<long long>(geom[k].x, geom[k].y));
 			}
-			tmp = clip_poly1(tmp, minx, miny, maxx, maxy);
-			if (tmp.size() > 0) {
-				if (tmp[0].x != tmp[tmp.size() - 1].x || tmp[0].y != tmp[tmp.size() - 1].y) {
-					fprintf(stderr, "Internal error: Polygon ring not closed\n");
-					exit(EXIT_FAILURE);
+
+			mapbox::geometry::linear_ring<long long> lr = mapbox::geometry::wagyu::quick_clip::quick_lr_clip(ring, bbox);
+
+			if (lr.size() > 0) {
+				for (size_t k = 0; k < lr.size(); k++) {
+					if (k == 0) {
+						out.push_back(draw(VT_MOVETO, lr[k].x, lr[k].y));
+					} else {
+						out.push_back(draw(VT_LINETO, lr[k].x, lr[k].y));
+					}
+				}
+
+				if (lr.size() > 0 && lr[0] != lr[lr.size() - 1]) {
+					out.push_back(draw(VT_LINETO, lr[0].x, lr[0].y));
 				}
-			}
-			for (size_t k = 0; k < tmp.size(); k++) {
-				out.push_back(tmp[k]);
 			}
 
 			i = j - 1;
@@ -553,7 +508,7 @@ drawvec simple_clip_poly(drawvec &geom, long long minx, long long miny, long lon
 	return out;
 }
 
-drawvec simple_clip_poly(drawvec &geom, int z, int detail, int buffer) {
+drawvec simple_clip_poly(drawvec &geom, int z, int buffer) {
 	long long area = 1LL << (32 - z);
 	long long clip_buffer = buffer * area / 256;
 
@@ -639,17 +594,21 @@ drawvec reduce_tiny_poly(drawvec &geom, int z, int detail, bool *reduced, double
 	return out;
 }
 
-drawvec clip_point(drawvec &geom, int z, int detail, long long buffer) {
-	drawvec out;
-
+drawvec clip_point(drawvec &geom, int z, long long buffer) {
 	long long min = 0;
 	long long area = 1LL << (32 - z);
 
 	min -= buffer * area / 256;
 	area += buffer * area / 256;
 
+	return clip_point(geom, min, min, area, area);
+}
+
+drawvec clip_point(drawvec &geom, long long minx, long long miny, long long maxx, long long maxy) {
+	drawvec out;
+
 	for (size_t i = 0; i < geom.size(); i++) {
-		if (geom[i].x >= min && geom[i].y >= min && geom[i].x <= area && geom[i].y <= area) {
+		if (geom[i].x >= minx && geom[i].y >= miny && geom[i].x <= maxx && geom[i].y <= maxy) {
 			out.push_back(geom[i]);
 		}
 	}
@@ -657,7 +616,7 @@ drawvec clip_point(drawvec &geom, int z, int detail, long long buffer) {
 	return out;
 }
 
-int quick_check(long long *bbox, int z, int detail, long long buffer) {
+int quick_check(long long *bbox, int z, long long buffer) {
 	long long min = 0;
 	long long area = 1LL << (32 - z);
 
@@ -681,7 +640,7 @@ int quick_check(long long *bbox, int z, int detail, long long buffer) {
 	return 2;
 }
 
-bool point_within_tile(long long x, long long y, int z, int detail, long long buffer) {
+bool point_within_tile(long long x, long long y, int z) {
 	// No adjustment for buffer, because the point must be
 	// strictly within the tile to appear exactly once
 
@@ -690,14 +649,18 @@ bool point_within_tile(long long x, long long y, int z, int detail, long long bu
 	return x >= 0 && y >= 0 && x < area && y < area;
 }
 
-drawvec clip_lines(drawvec &geom, int z, int detail, long long buffer) {
-	drawvec out;
-
+drawvec clip_lines(drawvec &geom, int z, long long buffer) {
 	long long min = 0;
 	long long area = 1LL << (32 - z);
 	min -= buffer * area / 256;
 	area += buffer * area / 256;
 
+	return clip_lines(geom, min, min, area, area);
+}
+
+drawvec clip_lines(drawvec &geom, long long minx, long long miny, long long maxx, long long maxy) {
+	drawvec out;
+
 	for (size_t i = 0; i < geom.size(); i++) {
 		if (i > 0 && (geom[i - 1].op == VT_MOVETO || geom[i - 1].op == VT_LINETO) && geom[i].op == VT_LINETO) {
 			double x1 = geom[i - 1].x;
@@ -706,7 +669,7 @@ drawvec clip_lines(drawvec &geom, int z, int detail, long long buffer) {
 			double x2 = geom[i - 0].x;
 			double y2 = geom[i - 0].y;
 
-			int c = clip(&x1, &y1, &x2, &y2, min, min, area, area);
+			int c = clip(&x1, &y1, &x2, &y2, minx, miny, maxx, maxy);
 
 			if (c > 1) {  // clipped
 				out.push_back(draw(VT_MOVETO, x1, y1));
@@ -839,7 +802,7 @@ drawvec impose_tile_boundaries(drawvec &geom, long long extent) {
 	return out;
 }
 
-drawvec simplify_lines(drawvec &geom, int z, int detail, bool mark_tile_bounds, double simplification, size_t retain) {
+drawvec simplify_lines(drawvec &geom, int z, int detail, bool mark_tile_bounds, double simplification, size_t retain, drawvec const &shared_nodes) {
 	int res = 1 << (32 - detail - z);
 	long long area = 1LL << (32 - z);
 
@@ -851,6 +814,13 @@ drawvec simplify_lines(drawvec &geom, int z, int detail, bool mark_tile_bounds,
 		} else {
 			geom[i].necessary = 1;
 		}
+
+		if (prevent[P_SIMPLIFY_SHARED_NODES]) {
+			auto pt = std::lower_bound(shared_nodes.begin(), shared_nodes.end(), geom[i]);
+			if (pt != shared_nodes.end() && *pt == geom[i]) {
+				geom[i].necessary = true;
+			}
+		}
 	}
 
 	if (mark_tile_bounds) {
@@ -911,8 +881,8 @@ drawvec reorder_lines(drawvec &geom) {
 	// instead of down and to the right
 	// so that it will coalesce better
 
-	unsigned long long l1 = encode(geom[0].x, geom[0].y);
-	unsigned long long l2 = encode(geom[geom.size() - 1].x, geom[geom.size() - 1].y);
+	unsigned long long l1 = encode_index(geom[0].x, geom[0].y);
+	unsigned long long l2 = encode_index(geom[geom.size() - 1].x, geom[geom.size() - 1].y);
 
 	if (l1 > l2) {
 		drawvec out;
@@ -958,8 +928,21 @@ drawvec fix_polygon(drawvec &geom) {
 			// Reverse ring if winding order doesn't match
 			// inner/outer expectation
 
-			double area = get_area(ring, 0, ring.size());
-			if ((area > 0) != outer) {
+			bool reverse_ring = false;
+			if (prevent[P_USE_SOURCE_POLYGON_WINDING]) {
+				// GeoJSON winding is reversed from vector winding
+				reverse_ring = true;
+			} else if (prevent[P_REVERSE_SOURCE_POLYGON_WINDING]) {
+				// GeoJSON winding is reversed from vector winding
+				reverse_ring = false;
+			} else {
+				double area = get_area(ring, 0, ring.size());
+				if ((area > 0) != outer) {
+					reverse_ring = true;
+				}
+			}
+
+			if (reverse_ring) {
 				drawvec tmp;
 				for (int a = ring.size() - 1; a >= 0; a--) {
 					tmp.push_back(ring[a]);
@@ -1159,14 +1142,14 @@ drawvec stairstep(drawvec &geom, int z, int detail) {
 	double scale = 1 << (32 - detail - z);
 
 	for (size_t i = 0; i < geom.size(); i++) {
-		geom[i].x = std::round(geom[i].x / scale);
-		geom[i].y = std::round(geom[i].y / scale);
+		geom[i].x = std::floor(geom[i].x / scale);
+		geom[i].y = std::floor(geom[i].y / scale);
 	}
 
 	for (size_t i = 0; i < geom.size(); i++) {
 		if (geom[i].op == VT_MOVETO) {
 			out.push_back(geom[i]);
-		} else {
+		} else if (out.size() > 0) {
 			long long x0 = out[out.size() - 1].x;
 			long long y0 = out[out.size() - 1].y;
 			long long x1 = geom[i].x;
@@ -1226,12 +1209,15 @@ drawvec stairstep(drawvec &geom, int z, int detail) {
 			}
 
 			// out.push_back(draw(VT_LINETO, xx, yy));
+		} else {
+			fprintf(stderr, "Can't happen: stairstepping lineto with no moveto\n");
+			exit(EXIT_FAILURE);
 		}
 	}
 
 	for (size_t i = 0; i < out.size(); i++) {
-		out[i].x <<= (32 - detail - z);
-		out[i].y <<= (32 - detail - z);
+		out[i].x *= 1 << (32 - detail - z);
+		out[i].y *= 1 << (32 - detail - z);
 	}
 
 	return out;

geometry.hpp

@@ -1,3 +1,10 @@
+#ifndef GEOMETRY_HPP
+#define GEOMETRY_HPP
+
+#include <vector>
+#include <atomic>
+#include <sqlite3.h>
+
 #define VT_POINT 1
 #define VT_LINE 2
 #define VT_POLYGON 3
@@ -7,10 +14,6 @@
 #define VT_LINETO 2
 #define VT_CLOSEPATH 7
 
-#define VT_STRING 1
-#define VT_NUMBER 2
-#define VT_BOOLEAN 7
-
 // The bitfield is to make sizeof(draw) be 16 instead of 24
 // at the cost, apparently, of a 0.7% increase in running time
 // for packing and unpacking.
@@ -20,18 +23,18 @@ struct draw {
 	long long y : 40;
 	signed char necessary;
 
-	draw(int nop, long long nx, long long ny) {
-		this->op = nop;
-		this->x = nx;
-		this->y = ny;
-		this->necessary = 0;
+	draw(int nop, long long nx, long long ny)
+	    : x(nx),
+	      op(nop),
+	      y(ny),
+	      necessary(0) {
 	}
 
-	draw() {
-		this->op = 0;
-		this->x = 0;
-		this->y = 0;
-		this->necessary = 0;
+	draw()
+	    : x(0),
+	      op(0),
+	      y(0),
+	      necessary(0) {
 	}
 
 	bool operator<(draw const &s) const {
@@ -53,21 +56,28 @@ struct draw {
 
 typedef std::vector<draw> drawvec;
 
-drawvec decode_geometry(FILE *meta, long long *geompos, int z, unsigned tx, unsigned ty, int detail, long long *bbox, unsigned initial_x, unsigned initial_y);
+drawvec decode_geometry(FILE *meta, std::atomic<long long> *geompos, int z, unsigned tx, unsigned ty, long long *bbox, unsigned initial_x, unsigned initial_y);
 void to_tile_scale(drawvec &geom, int z, int detail);
 drawvec remove_noop(drawvec geom, int type, int shift);
-drawvec clip_point(drawvec &geom, int z, int detail, long long buffer);
-drawvec clean_or_clip_poly(drawvec &geom, int z, int detail, int buffer, bool clip);
-drawvec simple_clip_poly(drawvec &geom, int z, int detail, int buffer);
+drawvec clip_point(drawvec &geom, int z, long long buffer);
+drawvec clean_or_clip_poly(drawvec &geom, int z, int buffer, bool clip);
+drawvec simple_clip_poly(drawvec &geom, int z, int buffer);
 drawvec close_poly(drawvec &geom);
 drawvec reduce_tiny_poly(drawvec &geom, int z, int detail, bool *reduced, double *accum_area);
-drawvec clip_lines(drawvec &geom, int z, int detail, long long buffer);
+drawvec clip_lines(drawvec &geom, int z, long long buffer);
 drawvec stairstep(drawvec &geom, int z, int detail);
-bool point_within_tile(long long x, long long y, int z, int detail, long long buffer);
-int quick_check(long long *bbox, int z, int detail, long long buffer);
-drawvec simplify_lines(drawvec &geom, int z, int detail, bool mark_tile_bounds, double simplification, size_t retain);
+bool point_within_tile(long long x, long long y, int z);
+int quick_check(long long *bbox, int z, long long buffer);
+drawvec simplify_lines(drawvec &geom, int z, int detail, bool mark_tile_bounds, double simplification, size_t retain, drawvec const &shared_nodes);
 drawvec reorder_lines(drawvec &geom);
 drawvec fix_polygon(drawvec &geom);
 std::vector<drawvec> chop_polygon(std::vector<drawvec> &geoms);
-void check_polygon(drawvec &geom, drawvec &before);
+void check_polygon(drawvec &geom);
 double get_area(drawvec &geom, size_t i, size_t j);
+double get_mp_area(drawvec &geom);
+
+drawvec simple_clip_poly(drawvec &geom, long long x1, long long y1, long long x2, long long y2);
+drawvec clip_lines(drawvec &geom, long long x1, long long y1, long long x2, long long y2);
+drawvec clip_point(drawvec &geom, long long x1, long long y1, long long x2, long long y2);
+
+#endif

jsonpull/jsonpull.c

@@ -36,14 +36,14 @@ json_pull *json_begin(ssize_t (*read)(struct json_pull *, char *buffer, size_t n
 
 static inline int peek(json_pull *j) {
 	if (j->buffer_head < j->buffer_tail) {
-		return j->buffer[j->buffer_head];
+		return (unsigned char) j->buffer[j->buffer_head];
 	} else {
 		j->buffer_head = 0;
 		j->buffer_tail = j->read(j, j->buffer, BUFFER);
 		if (j->buffer_head >= j->buffer_tail) {
 			return EOF;
 		}
-		return j->buffer[j->buffer_head];
+		return (unsigned char) j->buffer[j->buffer_head];
 	}
 }
 
@@ -69,7 +69,7 @@ json_pull *json_begin_file(FILE *f) {
 }
 
 static ssize_t read_string(json_pull *j, char *buffer, size_t n) {
-	char *cp = j->source;
+	const char *cp = j->source;
 	size_t out = 0;
 
 	while (out < n && cp[out] != '\0') {
@@ -77,12 +77,12 @@ static ssize_t read_string(json_pull *j, char *buffer, size_t n) {
 		out++;
 	}
 
-	j->source = cp + out;
+	j->source = (void *) (cp + out);
 	return out;
 }
 
-json_pull *json_begin_string(char *s) {
-	return json_begin(read_string, s);
+json_pull *json_begin_string(const char *s) {
+	return json_begin(read_string, (void *) s);
 }
 
 void json_end(json_pull *p) {
@@ -295,7 +295,23 @@ again:
 
 			return NULL;
 		}
-	} while (c == ' ' || c == '\t' || c == '\r' || c == '\n');
+
+		// Byte-order mark
+		if (c == 0xEF) {
+			int c2 = peek(j);
+			if (c2 == 0xBB) {
+				c2 = read_wrap(j);
+				c2 = peek(j);
+				if (c2 == 0xBF) {
+					c2 = read_wrap(j);
+					c = ' ';
+					continue;
+				}
+			}
+			j->error = "Corrupt byte-order mark found";
+			return NULL;
+		}
+	} while (c == ' ' || c == '\t' || c == '\r' || c == '\n' || c == 0x1E);
 
 	/////////////////////////// Arrays
 
@@ -384,6 +400,32 @@ again:
 		return add_object(j, JSON_NULL);
 	}
 
+	/////////////////////////// NaN
+
+	if (c == 'N') {
+		if (read_wrap(j) != 'a' || read_wrap(j) != 'N') {
+			j->error = "Found misspelling of NaN";
+			return NULL;
+		}
+
+		j->error = "JSON does not allow NaN";
+		return NULL;
+	}
+
+	/////////////////////////// Infinity
+
+	if (c == 'I') {
+		if (read_wrap(j) != 'n' || read_wrap(j) != 'f' || read_wrap(j) != 'i' ||
+		    read_wrap(j) != 'n' || read_wrap(j) != 'i' || read_wrap(j) != 't' ||
+		    read_wrap(j) != 'y') {
+			j->error = "Found misspelling of Infinity";
+			return NULL;
+		}
+
+		j->error = "JSON does not allow Infinity";
+		return NULL;
+	}
+
 	/////////////////////////// True
 
 	if (c == 't') {
@@ -527,29 +569,21 @@ again:
 		struct string val;
 		string_init(&val);
 
+		int surrogate = -1;
 		while ((c = read_wrap(j)) != EOF) {
 			if (c == '"') {
+				if (surrogate >= 0) {
+					string_append(&val, 0xE0 | (surrogate >> 12));
+					string_append(&val, 0x80 | ((surrogate >> 6) & 0x3F));
+					string_append(&val, 0x80 | (surrogate & 0x3F));
+					surrogate = -1;
+				}
+
 				break;
 			} else if (c == '\\') {
 				c = read_wrap(j);
 
-				if (c == '"') {
-					string_append(&val, '"');
-				} else if (c == '\\') {
-					string_append(&val, '\\');
-				} else if (c == '/') {
-					string_append(&val, '/');
-				} else if (c == 'b') {
-					string_append(&val, '\b');
-				} else if (c == 'f') {
-					string_append(&val, '\f');
-				} else if (c == 'n') {
-					string_append(&val, '\n');
-				} else if (c == 'r') {
-					string_append(&val, '\r');
-				} else if (c == 't') {
-					string_append(&val, '\t');
-				} else if (c == 'u') {
+				if (c == 'u') {
 					char hex[5] = "aaaa";
 					int i;
 					for (i = 0; i < 4; i++) {
@@ -560,27 +594,93 @@ again:
 							return NULL;
 						}
 					}
+
 					unsigned long ch = strtoul(hex, NULL, 16);
+					if (ch >= 0xd800 && ch <= 0xdbff) {
+						if (surrogate < 0) {
+							surrogate = ch;
+						} else {
+							// Impossible surrogate, so output the first half,
+							// keep what might be a legitimate new first half.
+							string_append(&val, 0xE0 | (surrogate >> 12));
+							string_append(&val, 0x80 | ((surrogate >> 6) & 0x3F));
+							string_append(&val, 0x80 | (surrogate & 0x3F));
+							surrogate = ch;
+						}
+						continue;
+					} else if (ch >= 0xdc00 && c <= 0xdfff) {
+						if (surrogate >= 0) {
+							long c1 = surrogate - 0xd800;
+							long c2 = ch - 0xdc00;
+							ch = ((c1 << 10) | c2) + 0x010000;
+							surrogate = -1;
+						}
+					}
+
+					if (surrogate >= 0) {
+						string_append(&val, 0xE0 | (surrogate >> 12));
+						string_append(&val, 0x80 | ((surrogate >> 6) & 0x3F));
+						string_append(&val, 0x80 | (surrogate & 0x3F));
+						surrogate = -1;
+					}
+
 					if (ch <= 0x7F) {
 						string_append(&val, ch);
 					} else if (ch <= 0x7FF) {
 						string_append(&val, 0xC0 | (ch >> 6));
 						string_append(&val, 0x80 | (ch & 0x3F));
-					} else {
+					} else if (ch < 0xFFFF) {
 						string_append(&val, 0xE0 | (ch >> 12));
 						string_append(&val, 0x80 | ((ch >> 6) & 0x3F));
 						string_append(&val, 0x80 | (ch & 0x3F));
+					} else {
+						string_append(&val, 0xF0 | (ch >> 18));
+						string_append(&val, 0x80 | ((ch >> 12) & 0x3F));
+						string_append(&val, 0x80 | ((ch >> 6) & 0x3F));
+						string_append(&val, 0x80 | (ch & 0x3F));
 					}
 				} else {
-					j->error = "Found backslash followed by unknown character";
-					string_free(&val);
-					return NULL;
+					if (surrogate >= 0) {
+						string_append(&val, 0xE0 | (surrogate >> 12));
+						string_append(&val, 0x80 | ((surrogate >> 6) & 0x3F));
+						string_append(&val, 0x80 | (surrogate & 0x3F));
+						surrogate = -1;
+					}
+
+					if (c == '"') {
+						string_append(&val, '"');
+					} else if (c == '\\') {
+						string_append(&val, '\\');
+					} else if (c == '/') {
+						string_append(&val, '/');
+					} else if (c == 'b') {
+						string_append(&val, '\b');
+					} else if (c == 'f') {
+						string_append(&val, '\f');
+					} else if (c == 'n') {
+						string_append(&val, '\n');
+					} else if (c == 'r') {
+						string_append(&val, '\r');
+					} else if (c == 't') {
+						string_append(&val, '\t');
+					} else {
+						j->error = "Found backslash followed by unknown character";
+						string_free(&val);
+						return NULL;
+					}
 				}
 			} else if (c < ' ') {
 				j->error = "Found control character in string";
 				string_free(&val);
 				return NULL;
 			} else {
+				if (surrogate >= 0) {
+					string_append(&val, 0xE0 | (surrogate >> 12));
+					string_append(&val, 0x80 | ((surrogate >> 6) & 0x3F));
+					string_append(&val, 0x80 | (surrogate & 0x3F));
+					surrogate = -1;
+				}
+
 				string_append(&val, c);
 			}
 		}
@@ -666,6 +766,23 @@ void json_free(json_object *o) {
 	free(o);
 }
 
+static void json_disconnect_parser(json_object *o) {
+	if (o->type == JSON_HASH) {
+		size_t i;
+		for (i = 0; i < o->length; i++) {
+			json_disconnect_parser(o->keys[i]);
+			json_disconnect_parser(o->values[i]);
+		}
+	} else if (o->type == JSON_ARRAY) {
+		size_t i;
+		for (i = 0; i < o->length; i++) {
+			json_disconnect_parser(o->array[i]);
+		}
+	}
+
+	o->parser = NULL;
+}
+
 void json_disconnect(json_object *o) {
 	// Expunge references to this as an array element
 	// or a hash key or value.
@@ -719,12 +836,13 @@ void json_disconnect(json_object *o) {
 		o->parser->root = NULL;
 	}
 
+	json_disconnect_parser(o);
 	o->parent = NULL;
 }
 
 static void json_print_one(struct string *val, json_object *o) {
 	if (o == NULL) {
-		string_append_string(val, "NULL");
+		string_append_string(val, "...");
 	} else if (o->type == JSON_STRING) {
 		string_append(val, '\"');
 
@@ -763,7 +881,7 @@ static void json_print_one(struct string *val, json_object *o) {
 static void json_print(struct string *val, json_object *o) {
 	if (o == NULL) {
 		// Hash value in incompletely read hash
-		string_append_string(val, "NULL");
+		string_append_string(val, "...");
 	} else if (o->type == JSON_HASH) {
 		string_append(val, '{');
 

jsonpull/jsonpull.h

@@ -1,3 +1,10 @@
+#ifndef JSONPULL_H
+#define JSONPULL_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef enum json_type {
 	// These types can be returned by json_read()
 	JSON_HASH,
@@ -49,7 +56,7 @@ typedef struct json_pull {
 } json_pull;
 
 json_pull *json_begin_file(FILE *f);
-json_pull *json_begin_string(char *s);
+json_pull *json_begin_string(const char *s);
 
 json_pull *json_begin(ssize_t (*read)(struct json_pull *, char *buffer, size_t n), void *source);
 void json_end(json_pull *p);
@@ -65,3 +72,9 @@ void json_disconnect(json_object *j);
 json_object *json_hash_get(json_object *o, const char *s);
 
 char *json_stringify(json_object *o);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

jsontool.cpp

@@ -0,0 +1,499 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <string.h>
+#include <stdarg.h>
+#include <unistd.h>
+#include <string>
+#include <getopt.h>
+#include <vector>
+#include "jsonpull/jsonpull.h"
+#include "csv.hpp"
+#include "text.hpp"
+#include "geojson-loop.hpp"
+
+int fail = EXIT_SUCCESS;
+bool wrap = false;
+const char *extract = NULL;
+
+FILE *csvfile = NULL;
+std::vector<std::string> header;
+std::vector<std::string> fields;
+int pe = false;
+
+std::string buffered;
+int buffered_type = -1;
+// 0: nothing yet
+// 1: buffered a line
+// 2: wrote the line and the wrapper
+int buffer_state = 0;
+
+std::vector<unsigned long> decode32(const char *s) {
+	std::vector<unsigned long> utf32;
+
+	while (*s != '\0') {
+		unsigned long b = *(s++) & 0xFF;
+
+		if (b < 0x80) {
+			utf32.push_back(b);
+		} else if ((b & 0xe0) == 0xc0) {
+			unsigned long c = (b & 0x1f) << 6;
+			unsigned long b1 = *(s++) & 0xFF;
+
+			if ((b1 & 0xc0) == 0x80) {
+				c |= b1 & 0x3f;
+				utf32.push_back(c);
+			} else {
+				s--;
+				utf32.push_back(0xfffd);
+			}
+		} else if ((b & 0xf0) == 0xe0) {
+			unsigned long c = (b & 0x0f) << 12;
+			unsigned long b1 = *(s++) & 0xFF;
+
+			if ((b1 & 0xc0) == 0x80) {
+				c |= (b1 & 0x3f) << 6;
+				unsigned long b2 = *(s++) & 0xFF;
+
+				if ((b2 & 0xc0) == 0x80) {
+					c |= b2 & 0x3f;
+					utf32.push_back(c);
+				} else {
+					s -= 2;
+					utf32.push_back(0xfffd);
+				}
+			} else {
+				s--;
+				utf32.push_back(0xfffd);
+			}
+		} else if ((b & 0xf8) == 0xf0) {
+			unsigned long c = (b & 0x07) << 18;
+			unsigned long b1 = *(s++) & 0xFF;
+
+			if ((b1 & 0xc0) == 0x80) {
+				c |= (b1 & 0x3f) << 12;
+				unsigned long b2 = *(s++) & 0xFF;
+
+				if ((b2 & 0xc0) == 0x80) {
+					c |= (b2 & 0x3f) << 6;
+					unsigned long b3 = *(s++) & 0xFF;
+
+					if ((b3 & 0xc0) == 0x80) {
+						c |= b3 & 0x3f;
+
+						utf32.push_back(c);
+					} else {
+						s -= 3;
+						utf32.push_back(0xfffd);
+					}
+				} else {
+					s -= 2;
+					utf32.push_back(0xfffd);
+				}
+			} else {
+				s -= 1;
+				utf32.push_back(0xfffd);
+			}
+		} else {
+			utf32.push_back(0xfffd);
+		}
+	}
+
+	return utf32;
+}
+
+// This uses a really weird encoding for strings
+// so that they will sort in UTF-32 order in spite of quoting
+
+std::string sort_quote(const char *s) {
+	std::vector<unsigned long> utf32 = decode32(s);
+	std::string ret;
+
+	for (size_t i = 0; i < utf32.size(); i++) {
+		if (utf32[i] < 0xD800) {
+			char buf[7];
+			sprintf(buf, "\\u%04lu", utf32[i]);
+			ret.append(std::string(buf));
+		} else {
+			unsigned long c = utf32[i];
+
+			if (c <= 0x7f) {
+				ret.push_back(c);
+			} else if (c <= 0x7ff) {
+				ret.push_back(0xc0 | (c >> 6));
+				ret.push_back(0x80 | (c & 0x3f));
+			} else if (c <= 0xffff) {
+				ret.push_back(0xe0 | (c >> 12));
+				ret.push_back(0x80 | ((c >> 6) & 0x3f));
+				ret.push_back(0x80 | (c & 0x3f));
+			} else {
+				ret.push_back(0xf0 | (c >> 18));
+				ret.push_back(0x80 | ((c >> 12) & 0x3f));
+				ret.push_back(0x80 | ((c >> 6) & 0x3f));
+				ret.push_back(0x80 | (c & 0x3f));
+			}
+		}
+	}
+
+	return ret;
+}
+
+void out(std::string const &s, int type, json_object *properties) {
+	if (extract != NULL) {
+		std::string extracted = sort_quote("null");
+		bool found = false;
+
+		json_object *o = json_hash_get(properties, extract);
+		if (o != NULL) {
+			found = true;
+			if (o->type == JSON_STRING || o->type == JSON_NUMBER) {
+				extracted = sort_quote(o->string);
+			} else {
+				// Don't really know what to do about sort quoting
+				// for arbitrary objects
+
+				const char *out = json_stringify(o);
+				extracted = sort_quote(out);
+				free((void *) out);
+			}
+		}
+
+		if (!found) {
+			static bool warned = false;
+			if (!warned) {
+				fprintf(stderr, "Warning: extract key \"%s\" not found in JSON\n", extract);
+				warned = true;
+			}
+		}
+
+		printf("{\"%s\":%s}\n", extracted.c_str(), s.c_str());
+		return;
+	}
+
+	if (!wrap) {
+		printf("%s\n", s.c_str());
+		return;
+	}
+
+	if (buffer_state == 0) {
+		buffered = s;
+		buffered_type = type;
+		buffer_state = 1;
+		return;
+	}
+
+	if (buffer_state == 1) {
+		if (buffered_type == 1) {
+			printf("{\"type\":\"FeatureCollection\",\"features\":[\n");
+		} else {
+			printf("{\"type\":\"GeometryCollection\",\"geometries\":[\n");
+		}
+
+		printf("%s\n", buffered.c_str());
+		buffer_state = 2;
+	}
+
+	printf(",\n%s\n", s.c_str());
+
+	if (type != buffered_type) {
+		fprintf(stderr, "Error: mix of bare geometries and features\n");
+		exit(EXIT_FAILURE);
+	}
+}
+
+std::string prev_joinkey;
+
+void join_csv(json_object *j) {
+	if (header.size() == 0) {
+		std::string s = csv_getline(csvfile);
+		if (s.size() == 0) {
+			fprintf(stderr, "Couldn't get column header from CSV file\n");
+			exit(EXIT_FAILURE);
+		}
+
+		std::string err = check_utf8(s);
+		if (err != "") {
+			fprintf(stderr, "%s\n", err.c_str());
+			exit(EXIT_FAILURE);
+		}
+
+		header = csv_split(s.c_str());
+
+		for (size_t i = 0; i < header.size(); i++) {
+			header[i] = csv_dequote(header[i]);
+		}
+
+		if (header.size() == 0) {
+			fprintf(stderr, "No columns in CSV header \"%s\"\n", s.c_str());
+			exit(EXIT_FAILURE);
+		}
+	}
+
+	json_object *properties = json_hash_get(j, "properties");
+	json_object *key = NULL;
+
+	if (properties != NULL) {
+		key = json_hash_get(properties, header[0].c_str());
+	}
+
+	if (key == NULL) {
+		static bool warned = false;
+		if (!warned) {
+			fprintf(stderr, "Warning: couldn't find CSV key \"%s\" in JSON\n", header[0].c_str());
+			warned = true;
+		}
+		return;
+	}
+
+	std::string joinkey;
+	if (key->type == JSON_STRING || key->type == JSON_NUMBER) {
+		joinkey = key->string;
+	} else {
+		const char *s = json_stringify(key);
+		joinkey = s;
+		free((void *) s);
+	}
+
+	if (joinkey < prev_joinkey) {
+		fprintf(stderr, "GeoJSON file is out of sort: \"%s\" follows \"%s\"\n", joinkey.c_str(), prev_joinkey.c_str());
+		exit(EXIT_FAILURE);
+	}
+	prev_joinkey = joinkey;
+
+	if (fields.size() == 0 || joinkey > fields[0]) {
+		std::string prevkey;
+		if (fields.size() > 0) {
+			prevkey = fields[0];
+		}
+
+		while (true) {
+			std::string s = csv_getline(csvfile);
+			if (s.size() == 0) {
+				fields.clear();
+				break;
+			}
+
+			std::string err = check_utf8(s);
+			if (err != "") {
+				fprintf(stderr, "%s\n", err.c_str());
+				exit(EXIT_FAILURE);
+			}
+
+			fields = csv_split(s.c_str());
+
+			for (size_t i = 0; i < fields.size(); i++) {
+				fields[i] = csv_dequote(fields[i]);
+			}
+
+			if (fields.size() > 0 && fields[0] < prevkey) {
+				fprintf(stderr, "CSV file is out of sort: \"%s\" follows \"%s\"\n", fields[0].c_str(), prevkey.c_str());
+				exit(EXIT_FAILURE);
+			}
+
+			if (fields.size() > 0 && fields[0] >= joinkey) {
+				break;
+			}
+
+			if (fields.size() > 0) {
+				prevkey = fields[0];
+			}
+		}
+	}
+
+	if (fields.size() > 0 && joinkey == fields[0]) {
+		// This knows more about the structure of JSON objects than it ought to
+		properties->keys = (json_object **) realloc((void *) properties->keys, (properties->length + 32 + fields.size()) * sizeof(json_object *));
+		properties->values = (json_object **) realloc((void *) properties->values, (properties->length + 32 + fields.size()) * sizeof(json_object *));
+		if (properties->keys == NULL || properties->values == NULL) {
+			perror("realloc");
+			exit(EXIT_FAILURE);
+		}
+
+		for (size_t i = 1; i < fields.size(); i++) {
+			std::string k = header[i];
+			std::string v = fields[i];
+			json_type attr_type = JSON_STRING;
+
+			if (v.size() > 0) {
+				if (v[0] == '"') {
+					v = csv_dequote(v);
+				} else if (is_number(v)) {
+					attr_type = JSON_NUMBER;
+				}
+			} else if (pe) {
+				attr_type = JSON_NULL;
+			}
+
+			if (attr_type != JSON_NULL) {
+				// This knows more about the structure of JSON objects than it ought to
+
+				json_object *ko = (json_object *) malloc(sizeof(json_object));
+				json_object *vo = (json_object *) malloc(sizeof(json_object));
+				if (ko == NULL || vo == NULL) {
+					perror("malloc");
+					exit(EXIT_FAILURE);
+				}
+
+				ko->type = JSON_STRING;
+				vo->type = attr_type;
+
+				ko->parent = vo->parent = properties;
+				ko->array = vo->array = NULL;
+				ko->keys = vo->keys = NULL;
+				ko->values = vo->values = NULL;
+				ko->parser = vo->parser = properties->parser;
+
+				ko->string = strdup(k.c_str());
+				vo->string = strdup(v.c_str());
+
+				if (ko->string == NULL || vo->string == NULL) {
+					perror("strdup");
+					exit(EXIT_FAILURE);
+				}
+
+				ko->length = strlen(ko->string);
+				vo->length = strlen(vo->string);
+				vo->number = atof(vo->string);
+
+				properties->keys[properties->length] = ko;
+				properties->values[properties->length] = vo;
+				properties->length++;
+			}
+		}
+	}
+}
+
+struct json_join_action : json_feature_action {
+	int add_feature(json_object *geometry, bool, json_object *, json_object *, json_object *, json_object *feature) {
+		if (feature != geometry) {  // a real feature, not a bare geometry
+			if (csvfile != NULL) {
+				join_csv(feature);
+			}
+
+			char *s = json_stringify(feature);
+			out(s, 1, json_hash_get(feature, "properties"));
+			free(s);
+		} else {
+			char *s = json_stringify(geometry);
+			out(s, 2, NULL);
+			free(s);
+		}
+
+		return 1;
+	}
+
+	void check_crs(json_object *) {
+	}
+};
+
+void process(FILE *fp, const char *fname) {
+	json_pull *jp = json_begin_file(fp);
+
+	json_join_action jja;
+	jja.fname = fname;
+	parse_json(&jja, jp);
+	json_end(jp);
+}
+
+int main(int argc, char **argv) {
+	const char *csv = NULL;
+
+	struct option long_options[] = {
+		{"wrap", no_argument, 0, 'w'},
+		{"extract", required_argument, 0, 'e'},
+		{"csv", required_argument, 0, 'c'},
+		{"empty-csv-columns-are-null", no_argument, &pe, 1},
+		{"prevent", required_argument, 0, 'p'},
+
+		{0, 0, 0, 0},
+	};
+
+	std::string getopt_str;
+	for (size_t lo = 0; long_options[lo].name != NULL; lo++) {
+		if (long_options[lo].val > ' ') {
+			getopt_str.push_back(long_options[lo].val);
+
+			if (long_options[lo].has_arg == required_argument) {
+				getopt_str.push_back(':');
+			}
+		}
+	}
+
+	extern int optind;
+	int i;
+
+	while ((i = getopt_long(argc, argv, getopt_str.c_str(), long_options, NULL)) != -1) {
+		switch (i) {
+		case 0:
+			break;
+
+		case 'w':
+			wrap = true;
+			break;
+
+		case 'e':
+			extract = optarg;
+			break;
+
+		case 'c':
+			csv = optarg;
+			break;
+
+		case 'p':
+			if (strcmp(optarg, "e") == 0) {
+				pe = true;
+			} else {
+				fprintf(stderr, "%s: Unknown option for -p%s\n", argv[0], optarg);
+				exit(EXIT_FAILURE);
+			}
+			break;
+
+		default:
+			fprintf(stderr, "Unexpected option -%c\n", i);
+			exit(EXIT_FAILURE);
+		}
+	}
+
+	if (extract != NULL && wrap) {
+		fprintf(stderr, "%s: --wrap and --extract not supported together\n", argv[0]);
+		exit(EXIT_FAILURE);
+	}
+
+	if (csv != NULL) {
+		csvfile = fopen(csv, "r");
+		if (csvfile == NULL) {
+			perror(csv);
+			exit(EXIT_FAILURE);
+		}
+	}
+
+	if (optind >= argc) {
+		process(stdin, "standard input");
+	} else {
+		for (i = optind; i < argc; i++) {
+			FILE *f = fopen(argv[i], "r");
+			if (f == NULL) {
+				perror(argv[i]);
+				exit(EXIT_FAILURE);
+			}
+
+			process(f, argv[i]);
+			fclose(f);
+		}
+	}
+
+	if (buffer_state == 1) {
+		printf("%s\n", buffered.c_str());
+	} else if (buffer_state == 2) {
+		printf("]}\n");
+	}
+
+	if (csvfile != NULL) {
+		if (fclose(csvfile) != 0) {
+			perror("close");
+			exit(EXIT_FAILURE);
+		}
+	}
+
+	return fail;
+}

main.hpp

@@ -1,18 +1,58 @@
+#ifndef MAIN_HPP
+#define MAIN_HPP
+
+#include <stddef.h>
+#include <atomic>
+#include <string>
+
 struct index {
-	long long start;
-	long long end;
-	unsigned long long index;
-	short segment;
+	long long start = 0;
+	long long end = 0;
+	unsigned long long ix = 0;
+	short segment = 0;
 	unsigned short t : 2;
 	unsigned long long seq : (64 - 18);  // pack with segment and t to stay in 32 bytes
+
+	index()
+	    : t(0),
+	      seq(0) {
+	}
 };
 
-void checkdisk(struct reader *r, int nreader);
+struct clipbbox {
+	double lon1;
+	double lat1;
+	double lon2;
+	double lat2;
+
+	long long minx;
+	long long miny;
+	long long maxx;
+	long long maxy;
+};
+
+extern std::vector<clipbbox> clipbboxes;
+
+void checkdisk(std::vector<struct reader> *r);
 
 extern int geometry_scale;
 extern int quiet;
+extern int quiet_progress;
+extern double progress_interval;
+extern std::atomic<double> last_progress;
 
 extern size_t CPUS;
 extern size_t TEMP_FILES;
 
 extern size_t max_tile_size;
+extern size_t max_tile_features;
+extern int cluster_distance;
+extern std::string attribute_for_id;
+
+int mkstemp_cloexec(char *name);
+FILE *fopen_oflag(const char *name, const char *mode, int oflag);
+bool progress_time();
+
+#define MAX_ZOOM 24
+
+#endif

mapbox/LICENSE-geometry.hpp

@@ -0,0 +1,13 @@
+Copyright (c) 2016, Mapbox
+
+Permission to use, copy, modify, and/or distribute this software for any
+purpose with or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

mapbox/LICENSE-variant

@@ -0,0 +1,25 @@
+Copyright (c) MapBox
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
+
+- Redistributions of source code must retain the above copyright notice, this
+  list of conditions and the following disclaimer.
+- Redistributions in binary form must reproduce the above copyright notice, this
+  list of conditions and the following disclaimer in the documentation and/or
+  other materials provided with the distribution.
+- Neither the name "MapBox" nor the names of its contributors may be
+  used to endorse or promote products derived from this software without
+  specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

mapbox/LICENSE-wagyu

@@ -0,0 +1,39 @@
+Parts of the code in the Wagyu Library are derived from the version of the
+Clipper Library by Angus Johnson listed below.
+
+Author    :  Angus Johnson
+Version   :  6.4.0
+Date      :  2 July 2015
+Website   :  http://www.angusj.com
+
+Copyright for portions of the derived code in the Wagyu library are held
+by Angus Johnson, 2010-2015. Copyright for the "include/mapbox/geometry/wagyu/almost_equal.hpp"
+file is held by Google Inc and its license is listed at the top of that file.
+All other copyright for the Wagyu Library are held by Mapbox, 2016. This code
+is published in accordance with, and retains the same license as the Clipper
+Library by Angus Johnson.
+
+Copyright (c) 2010-2015, Angus Johnson
+Copyright (c) 2016-2020, Mapbox
+
+Permission is hereby granted, free of charge, to any person or organization
+obtaining a copy of the software and accompanying documentation covered by
+this license (the "Software") to use, reproduce, display, distribute,
+execute, and transmit the Software, and to prepare derivative works of the
+Software, and to permit third-parties to whom the Software is furnished to
+do so, all subject to the following:
+
+The copyright notices in the Software and this entire statement, including
+the above license grant, this restriction and the following disclaimer,
+must be included in all copies of the Software, in whole or in part, and
+all derivative works of the Software, unless such copies or derivative
+works are solely in the form of machine-executable object code generated by
+a source language processor.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
+SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
+FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
+ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.

mapbox/geometry.hpp

@@ -0,0 +1,13 @@
+#pragma once
+
+#include <mapbox/geometry/point.hpp>
+#include <mapbox/geometry/line_string.hpp>
+#include <mapbox/geometry/polygon.hpp>
+#include <mapbox/geometry/multi_point.hpp>
+#include <mapbox/geometry/multi_line_string.hpp>
+#include <mapbox/geometry/multi_polygon.hpp>
+#include <mapbox/geometry/geometry.hpp>
+#include <mapbox/geometry/feature.hpp>
+#include <mapbox/geometry/point_arithmetic.hpp>
+#include <mapbox/geometry/for_each_point.hpp>
+#include <mapbox/geometry/envelope.hpp>

mapbox/geometry/box.hpp

@@ -0,0 +1,34 @@
+#pragma once
+
+#include <mapbox/geometry/point.hpp>
+
+namespace mapbox {
+namespace geometry {
+
+template <typename T>
+struct box
+{
+    using point_type = point<T>;
+
+    constexpr box(point_type const& min_, point_type const& max_)
+        : min(min_), max(max_)
+    {}
+
+    point_type min;
+    point_type max;
+};
+
+template <typename T>
+constexpr bool operator==(box<T> const& lhs, box<T> const& rhs)
+{
+    return lhs.min == rhs.min && lhs.max == rhs.max;
+}
+
+template <typename T>
+constexpr bool operator!=(box<T> const& lhs, box<T> const& rhs)
+{
+    return lhs.min != rhs.min || lhs.max != rhs.max;
+}
+
+} // namespace geometry
+} // namespace mapbox

mapbox/geometry/envelope.hpp

@@ -0,0 +1,33 @@
+#pragma once
+
+#include <mapbox/geometry/box.hpp>
+#include <mapbox/geometry/for_each_point.hpp>
+
+#include <limits>
+
+namespace mapbox {
+namespace geometry {
+
+template <typename G, typename T = typename G::coordinate_type>
+box<T> envelope(G const& geometry)
+{
+    using limits = std::numeric_limits<T>;
+
+    T min_t = limits::has_infinity ? -limits::infinity() : limits::min();
+    T max_t = limits::has_infinity ?  limits::infinity() : limits::max();
+
+    point<T> min(max_t, max_t);
+    point<T> max(min_t, min_t);
+
+    for_each_point(geometry, [&] (point<T> const& point) {
+        if (min.x > point.x) min.x = point.x;
+        if (min.y > point.y) min.y = point.y;
+        if (max.x < point.x) max.x = point.x;
+        if (max.y < point.y) max.y = point.y;
+    });
+
+    return box<T>(min, max);
+}
+
+} // namespace geometry
+} // namespace mapbox

mapbox/geometry/feature.hpp

@@ -0,0 +1,81 @@
+#pragma once
+
+#include <mapbox/geometry/geometry.hpp>
+
+#include <mapbox/variant.hpp>
+
+#include <cstdint>
+#include <string>
+#include <vector>
+#include <unordered_map>
+#include <experimental/optional>
+
+namespace mapbox {
+namespace geometry {
+
+struct value;
+
+struct null_value_t
+{
+    constexpr null_value_t() {}
+    constexpr null_value_t(std::nullptr_t) {}
+};
+
+constexpr bool operator==(const null_value_t&, const null_value_t&) { return true; }
+constexpr bool operator!=(const null_value_t&, const null_value_t&) { return false; }
+
+constexpr null_value_t null_value = null_value_t();
+
+// Multiple numeric types (uint64_t, int64_t, double) are present in order to support
+// the widest possible range of JSON numbers, which do not have a maximum range.
+// Implementations that produce `value`s should use that order for type preference,
+// using uint64_t for positive integers, int64_t for negative integers, and double
+// for non-integers and integers outside the range of 64 bits.
+using value_base = mapbox::util::variant<null_value_t, bool, uint64_t, int64_t, double, std::string,
+                                         mapbox::util::recursive_wrapper<std::vector<value>>,
+                                         mapbox::util::recursive_wrapper<std::unordered_map<std::string, value>>>;
+
+struct value : value_base
+{
+    using value_base::value_base;
+};
+
+using property_map = std::unordered_map<std::string, value>;
+
+// The same considerations and requirement for numeric types apply as for `value_base`.
+using identifier = mapbox::util::variant<uint64_t, int64_t, double, std::string>;
+
+template <class T>
+struct feature
+{
+    using coordinate_type = T;
+    using geometry_type = mapbox::geometry::geometry<T>; // Fully qualified to avoid GCC -fpermissive error.
+
+    geometry_type geometry;
+    property_map properties {};
+    std::experimental::optional<identifier> id {};
+};
+
+template <class T>
+constexpr bool operator==(feature<T> const& lhs, feature<T> const& rhs)
+{
+    return lhs.id == rhs.id && lhs.geometry == rhs.geometry && lhs.properties == rhs.properties;
+}
+
+template <class T>
+constexpr bool operator!=(feature<T> const& lhs, feature<T> const& rhs)
+{
+    return !(lhs == rhs);
+}
+
+template <class T, template <typename...> class Cont = std::vector>
+struct feature_collection : Cont<feature<T>>
+{
+    using coordinate_type = T;
+    using feature_type = feature<T>;
+    using container_type = Cont<feature_type>;
+    using container_type::container_type;
+};
+
+} // namespace geometry
+} // namespace mapbox

mapbox/geometry/for_each_point.hpp

@@ -0,0 +1,45 @@
+#pragma once
+
+#include <mapbox/geometry/geometry.hpp>
+
+namespace mapbox {
+namespace geometry {
+
+template <typename Point, typename F>
+auto for_each_point(Point&& point, F&& f)
+    -> decltype(point.x, point.y, void())
+{
+    f(std::forward<Point>(point));
+}
+
+template <typename Container, typename F>
+auto for_each_point(Container&& container, F&& f)
+    -> decltype(container.begin(), container.end(), void());
+
+template <typename...Types, typename F>
+void for_each_point(mapbox::util::variant<Types...> const& geom, F&& f)
+{
+    mapbox::util::variant<Types...>::visit(geom, [&] (auto const& g) {
+        for_each_point(g, f);
+    });
+}
+
+template <typename...Types, typename F>
+void for_each_point(mapbox::util::variant<Types...> & geom, F&& f)
+{
+    mapbox::util::variant<Types...>::visit(geom, [&] (auto & g) {
+        for_each_point(g, f);
+    });
+}
+
+template <typename Container, typename F>
+auto for_each_point(Container&& container, F&& f)
+    -> decltype(container.begin(), container.end(), void())
+{
+    for (auto& e: container) {
+        for_each_point(e, f);
+    }
+}
+
+} // namespace geometry
+} // namespace mapbox

mapbox/geometry/geometry.hpp

@@ -0,0 +1,53 @@
+#pragma once
+
+#include <mapbox/geometry/point.hpp>
+#include <mapbox/geometry/line_string.hpp>
+#include <mapbox/geometry/polygon.hpp>
+#include <mapbox/geometry/multi_point.hpp>
+#include <mapbox/geometry/multi_line_string.hpp>
+#include <mapbox/geometry/multi_polygon.hpp>
+
+#include <mapbox/variant.hpp>
+
+// stl
+#include <vector>
+
+namespace mapbox {
+namespace geometry {
+
+template <typename T, template <typename...> class Cont = std::vector>
+struct geometry_collection;
+
+template <typename T>
+using geometry_base = mapbox::util::variant<point<T>,
+                                            line_string<T>,
+                                            polygon<T>,
+                                            multi_point<T>,
+                                            multi_line_string<T>,
+                                            multi_polygon<T>,
+                                            geometry_collection<T>>;
+
+template <typename T>
+struct geometry : geometry_base<T>
+{
+    using coordinate_type = T;
+    using geometry_base<T>::geometry_base;
+
+    /*
+     * The default constructor would create a point geometry with default-constructed coordinates;
+     * i.e. (0, 0). Since this is not particularly useful, and could hide bugs, it is disabled.
+     */
+    geometry() = delete;
+};
+
+template <typename T, template <typename...> class Cont>
+struct geometry_collection : Cont<geometry<T>>
+{
+    using coordinate_type = T;
+    using geometry_type = geometry<T>;
+    using container_type = Cont<geometry_type>;
+    using container_type::container_type;
+};
+
+} // namespace geometry
+} // namespace mapbox

mapbox/geometry/line_string.hpp

@@ -0,0 +1,21 @@
+#pragma once
+
+// mapbox
+#include <mapbox/geometry/point.hpp>
+// stl
+#include <vector>
+
+namespace mapbox {
+namespace geometry {
+
+template <typename T, template <typename...> class Cont = std::vector>
+struct line_string : Cont<point<T> >
+{
+    using coordinate_type = T;
+    using point_type = point<T>;
+    using container_type = Cont<point_type>;
+    using container_type::container_type;
+};
+
+} // namespace geometry
+} // namespace mapbox

mapbox/geometry/multi_line_string.hpp

@@ -0,0 +1,21 @@
+#pragma once
+
+// mapbox
+#include <mapbox/geometry/line_string.hpp>
+// stl
+#include <vector>
+
+namespace mapbox {
+namespace geometry {
+
+template <typename T, template <typename...> class Cont = std::vector>
+struct multi_line_string : Cont<line_string<T>>
+{
+    using coordinate_type = T;
+    using line_string_type = line_string<T>;
+    using container_type = Cont<line_string_type>;
+    using container_type::container_type;
+};
+
+} // namespace geometry
+} // namespace mapbox

mapbox/geometry/multi_point.hpp

@@ -0,0 +1,21 @@
+#pragma once
+
+// mapbox
+#include <mapbox/geometry/point.hpp>
+// stl
+#include <vector>
+
+namespace mapbox {
+namespace geometry {
+
+template <typename T, template <typename...> class Cont = std::vector>
+struct multi_point : Cont<point<T>>
+{
+    using coordinate_type = T;
+    using point_type = point<T>;
+    using container_type = Cont<point_type>;
+    using container_type::container_type;
+};
+
+} // namespace geometry
+} // namespace mapbox

mapbox/geometry/multi_polygon.hpp

@@ -0,0 +1,21 @@
+#pragma once
+
+// mapbox
+#include <mapbox/geometry/polygon.hpp>
+// stl
+#include <vector>
+
+namespace mapbox {
+namespace geometry {
+
+template <typename T, template <typename...> class Cont = std::vector>
+struct multi_polygon : Cont<polygon<T>>
+{
+    using coordinate_type = T;
+    using polygon_type = polygon<T>;
+    using container_type = Cont<polygon_type>;
+    using container_type::container_type;
+};
+
+} // namespace geometry
+} // namespace mapbox

mapbox/geometry/point.hpp

@@ -0,0 +1,35 @@
+#pragma once
+
+namespace mapbox {
+namespace geometry {
+
+template <typename T>
+struct point
+{
+    using coordinate_type = T;
+
+    constexpr point()
+        : x(), y()
+    {}
+    constexpr point(T x_, T y_)
+        : x(x_), y(y_)
+    {}
+
+    T x;
+    T y;
+};
+
+template <typename T>
+constexpr bool operator==(point<T> const& lhs, point<T> const& rhs)
+{
+    return lhs.x == rhs.x && lhs.y == rhs.y;
+}
+
+template <typename T>
+constexpr bool operator!=(point<T> const& lhs, point<T> const& rhs)
+{
+    return !(lhs == rhs);
+}
+
+} // namespace geometry
+} // namespace mapbox

mapbox/geometry/point_arithmetic.hpp

@@ -0,0 +1,119 @@
+#pragma once
+
+namespace mapbox {
+namespace geometry {
+
+template <typename T>
+constexpr point<T> operator+(point<T> const& lhs, point<T> const& rhs)
+{
+    return point<T>(lhs.x + rhs.x, lhs.y + rhs.y);
+}
+
+template <typename T>
+constexpr point<T> operator+(point<T> const& lhs, T const& rhs)
+{
+    return point<T>(lhs.x + rhs, lhs.y + rhs);
+}
+
+template <typename T>
+constexpr point<T> operator-(point<T> const& lhs, point<T> const& rhs)
+{
+    return point<T>(lhs.x - rhs.x, lhs.y - rhs.y);
+}
+
+template <typename T>
+constexpr point<T> operator-(point<T> const& lhs, T const& rhs)
+{
+    return point<T>(lhs.x - rhs, lhs.y - rhs);
+}
+
+template <typename T>
+constexpr point<T> operator*(point<T> const& lhs, point<T> const& rhs)
+{
+    return point<T>(lhs.x * rhs.x, lhs.y * rhs.y);
+}
+
+template <typename T>
+constexpr point<T> operator*(point<T> const& lhs, T const& rhs)
+{
+    return point<T>(lhs.x * rhs, lhs.y * rhs);
+}
+
+template <typename T>
+constexpr point<T> operator/(point<T> const& lhs, point<T> const& rhs)
+{
+    return point<T>(lhs.x / rhs.x, lhs.y / rhs.y);
+}
+
+template <typename T>
+constexpr point<T> operator/(point<T> const& lhs, T const& rhs)
+{
+    return point<T>(lhs.x / rhs, lhs.y / rhs);
+}
+
+template <typename T>
+constexpr point<T>& operator+=(point<T>& lhs, point<T> const& rhs)
+{
+    lhs.x += rhs.x;
+    lhs.y += rhs.y;
+    return lhs;
+}
+
+template <typename T>
+constexpr point<T>& operator+=(point<T>& lhs, T const& rhs)
+{
+    lhs.x += rhs;
+    lhs.y += rhs;
+    return lhs;
+}
+
+template <typename T>
+constexpr point<T>& operator-=(point<T>& lhs, point<T> const& rhs)
+{
+    lhs.x -= rhs.x;
+    lhs.y -= rhs.y;
+    return lhs;
+}
+
+template <typename T>
+constexpr point<T>& operator-=(point<T>& lhs, T const& rhs)
+{
+    lhs.x -= rhs;
+    lhs.y -= rhs;
+    return lhs;
+}
+
+template <typename T>
+constexpr point<T>& operator*=(point<T>& lhs, point<T> const& rhs)
+{
+    lhs.x *= rhs.x;
+    lhs.y *= rhs.y;
+    return lhs;
+}
+
+template <typename T>
+constexpr point<T>& operator*=(point<T>& lhs, T const& rhs)
+{
+    lhs.x *= rhs;
+    lhs.y *= rhs;
+    return lhs;
+}
+
+template <typename T>
+constexpr point<T>& operator/=(point<T>& lhs, point<T> const& rhs)
+{
+    lhs.x /= rhs.x;
+    lhs.y /= rhs.y;
+    return lhs;
+}
+
+template <typename T>
+constexpr point<T>& operator/=(point<T>& lhs, T const& rhs)
+{
+    lhs.x /= rhs;
+    lhs.y /= rhs;
+    return lhs;
+}
+
+} // namespace geometry
+} // namespace mapbox

mapbox/geometry/polygon.hpp

@@ -0,0 +1,31 @@
+#pragma once
+
+// mapbox
+#include <mapbox/geometry/point.hpp>
+
+// stl
+#include <vector>
+
+namespace mapbox {
+namespace geometry {
+
+template <typename T, template <typename...> class Cont = std::vector>
+struct linear_ring : Cont<point<T>>
+{
+    using coordinate_type = T;
+    using point_type = point<T>;
+    using container_type = Cont<point_type>;
+    using container_type::container_type;
+};
+
+template <typename T, template <typename...> class Cont = std::vector>
+struct polygon : Cont<linear_ring<T>>
+{
+    using coordinate_type = T;
+    using linear_ring_type = linear_ring<T>;
+    using container_type = Cont<linear_ring_type>;
+    using container_type::container_type;
+};
+
+} // namespace geometry
+} // namespace mapbox

mapbox/geometry/snap_rounding.hpp

@@ -0,0 +1,466 @@
+#include <mapbox/geometry/geometry.hpp>
+#include <math.h>
+#include <map>
+#include <set>
+#include <vector>
+#include <algorithm>
+#include <cmath>
+
+namespace mapbox {
+namespace geometry {
+
+template <typename T>
+void add_vertical(size_t intermediate, size_t which_end, size_t into, std::vector<std::vector<point<T>>> &segments, bool &again, std::vector<size_t> &nexts) {
+	again = true;
+	std::vector<point<T>> dv;
+	dv.push_back(segments[intermediate][which_end]);
+	dv.push_back(segments[into][1]);
+	segments.push_back(dv);
+	segments[into][1] = segments[intermediate][which_end];
+	nexts.push_back(nexts[into]);
+	nexts[into] = nexts.size() - 1;
+}
+
+template <typename T>
+void add_horizontal(size_t intermediate, size_t which_end, size_t into, std::vector<std::vector<point<T>>> &segments, bool &again, std::vector<size_t> &nexts) {
+	again = true;
+
+	T x = segments[intermediate][which_end].x;
+	T y = segments[intermediate][0].y +
+	      (segments[intermediate][which_end].x - segments[intermediate][0].x) *
+		      (segments[intermediate][1].y - segments[intermediate][0].y) /
+		      (segments[intermediate][1].x - segments[intermediate][0].x);
+	point<T> d(x, y);
+
+	std::vector<point<T>> dv;
+	dv.push_back(d);
+	dv.push_back(segments[into][1]);
+	segments.push_back(dv);
+	segments[into][1] = d;
+	nexts.push_back(nexts[into]);
+	nexts[into] = nexts.size() - 1;
+}
+
+template <typename T>
+void warn(std::vector<std::vector<point<T>>> &segments, size_t a, size_t b, bool do_warn) {
+	if (do_warn) {
+		fprintf(stderr, "%lld,%lld to %lld,%lld intersects %lld,%lld to %lld,%lld\n",
+			(long long) segments[a][0].x, (long long) segments[a][0].y,
+			(long long) segments[a][1].x, (long long) segments[a][1].y,
+			(long long) segments[b][0].x, (long long) segments[b][0].y,
+			(long long) segments[b][1].x, (long long) segments[b][1].y);
+	}
+}
+
+template <typename T>
+void check_intersection(std::vector<std::vector<point<T>>> &segments, size_t a, size_t b, bool &again, std::vector<size_t> &nexts, bool do_warn, bool endpoint_ok) {
+	T s10_x = segments[a][1].x - segments[a][0].x;
+	T s10_y = segments[a][1].y - segments[a][0].y;
+	T s32_x = segments[b][1].x - segments[b][0].x;
+	T s32_y = segments[b][1].y - segments[b][0].y;
+
+	// http://stackoverflow.com/questions/563198/how-do-you-detect-where-two-line-segments-intersect
+	T denom = s10_x * s32_y - s32_x * s10_y;
+
+	if (denom == 0) {
+		// They are parallel or collinear. Find out if they are collinear.
+		// http://www.cpsc.ucalgary.ca/~marina/papers/Segment_intersection.ps
+
+		T ccw =
+			segments[a][0].x * segments[a][1].y +
+			segments[a][1].x * segments[b][0].y +
+			segments[b][0].x * segments[a][0].y -
+			segments[a][0].x * segments[b][0].y -
+			segments[a][1].x * segments[a][0].y -
+			segments[b][0].x * segments[a][1].y;
+
+		if (ccw == 0) {
+			if (segments[a][0].x == segments[a][1].x) {
+				// Vertical
+
+				T amin, amax, bmin, bmax;
+				if (segments[a][0].y < segments[a][1].y) {
+					amin = segments[a][0].y;
+					amax = segments[a][1].y;
+				} else {
+					amin = segments[a][1].y;
+					amax = segments[a][0].y;
+				}
+				if (segments[b][0].y < segments[b][1].y) {
+					bmin = segments[b][0].y;
+					bmax = segments[b][1].y;
+				} else {
+					bmin = segments[b][1].y;
+					bmax = segments[b][0].y;
+				}
+
+				// All of these transformations preserve verticality so we can check multiple cases
+				if (segments[b][0].y > amin && segments[b][0].y < amax) {
+					// B0 is in A
+					warn(segments, a, b, do_warn);
+					add_vertical(b, 0, a, segments, again, nexts);
+				}
+				if (segments[b][1].y > amin && segments[b][1].y < amax) {
+					// B1 is in A
+					warn(segments, a, b, do_warn);
+					add_vertical(b, 1, a, segments, again, nexts);
+				}
+				if (segments[a][0].y > bmin && segments[a][0].y < bmax) {
+					// A0 is in B
+					warn(segments, a, b, do_warn);
+					add_vertical(a, 0, b, segments, again, nexts);
+				}
+				if (segments[a][1].y > bmin && segments[a][1].y < bmax) {
+					// A1 is in B
+					warn(segments, a, b, do_warn);
+					add_vertical(a, 1, b, segments, again, nexts);
+				}
+			} else {
+				// Horizontal or diagonal
+
+				T amin, amax, bmin, bmax;
+				if (segments[a][0].x < segments[a][1].x) {
+					amin = segments[a][0].x;
+					amax = segments[a][1].x;
+				} else {
+					amin = segments[a][1].x;
+					amax = segments[a][0].x;
+				}
+				if (segments[b][0].x < segments[b][1].x) {
+					bmin = segments[b][0].x;
+					bmax = segments[b][1].x;
+				} else {
+					bmin = segments[b][1].x;
+					bmax = segments[b][0].x;
+				}
+
+				// Don't check multiples, because rounding may corrupt collinearity
+				if (segments[b][0].x > amin && segments[b][0].x < amax) {
+					// B0 is in A
+					add_horizontal(b, 0, a, segments, again, nexts);
+					warn(segments, a, b, do_warn);
+				} else if (segments[b][1].x > amin && segments[b][1].x < amax) {
+					// B1 is in A
+					add_horizontal(b, 1, a, segments, again, nexts);
+					warn(segments, a, b, do_warn);
+				} else if (segments[a][0].x > bmin && segments[a][0].x < bmax) {
+					// A0 is in B
+					warn(segments, a, b, do_warn);
+					add_horizontal(a, 0, b, segments, again, nexts);
+				} else if (segments[a][1].x > bmin && segments[a][1].x < bmax) {
+					// A1 is in B
+					warn(segments, a, b, do_warn);
+					add_horizontal(a, 1, b, segments, again, nexts);
+				}
+			}
+		}
+	} else {
+		// Neither parallel nor collinear, so may intersect at a single point
+
+		T s02_x = segments[a][0].x - segments[b][0].x;
+		T s02_y = segments[a][0].y - segments[b][0].y;
+
+		double s = (s10_x * s02_y - s10_y * s02_x) / (long double) denom;
+		double t = (s32_x * s02_y - s32_y * s02_x) / (long double) denom;
+
+		if (t >= 0 && t <= 1 && s >= 0 && s <= 1) {
+			T x = (T) round(segments[a][0].x + t * s10_x);
+			T y = (T) round(segments[a][0].y + t * s10_y);
+
+			if ((t > 0 && t < 1 && s > 0 && s < 1) || !endpoint_ok) {
+				if (t >= 0 && t <= 1) {
+					if ((x != segments[a][0].x || y != segments[a][0].y) && (x != segments[a][1].x || y != segments[a][1].y)) {
+						warn(segments, a, b, do_warn);
+						// splitting a
+						std::vector<point<T>> dv;
+						dv.push_back(point<T>(x, y));
+						dv.push_back(segments[a][1]);
+						segments.push_back(dv);
+						segments[a][1] = point<T>(x, y);
+						nexts.push_back(nexts[a]);
+						nexts[a] = nexts.size() - 1;
+						again = true;
+					}
+				}
+
+				if (s >= 0 && s <= 1) {
+					if ((x != segments[b][0].x || y != segments[b][0].y) && (x != segments[b][1].x || y != segments[b][1].y)) {
+						// splitting b
+						warn(segments, a, b, do_warn);
+						std::vector<point<T>> dv;
+						dv.push_back(point<T>(x, y));
+						dv.push_back(segments[b][1]);
+						segments.push_back(dv);
+						segments[b][1] = point<T>(x, y);
+						nexts.push_back(nexts[b]);
+						nexts[b] = nexts.size() - 1;
+						again = true;
+					}
+				}
+			}
+		}
+	}
+}
+
+template <typename T>
+void partition(std::vector<std::vector<point<T>>> &segs, std::vector<size_t> &subset, int direction, std::set<std::pair<size_t, size_t>> &possible) {
+	std::vector<T> points;
+
+	// List of X or Y midpoints of edges, so we can find the median
+
+	if (direction == 0) {
+		for (size_t i = 0; i < subset.size(); i++) {
+			points.push_back((segs[subset[i]][0].x + segs[subset[i]][1].x) / 2);
+		}
+	} else {
+		for (size_t i = 0; i < subset.size(); i++) {
+			points.push_back((segs[subset[i]][0].y + segs[subset[i]][1].y) / 2);
+		}
+	}
+
+	if (points.size() == 0) {
+		return;
+	}
+
+	size_t mid = points.size() / 2;
+	std::nth_element(points.begin(), points.begin() + mid, points.end());
+	T median = points[mid];
+
+	// Partition into sets that are above or below, or to the left or to the right of, the median.
+	// Segments that cross the median appear in both.
+
+	std::vector<size_t> one;
+	std::vector<size_t> two;
+
+	if (direction == 0) {
+		for (size_t i = 0; i < subset.size(); i++) {
+			if (segs[subset[i]][0].x <= median || segs[subset[i]][1].x <= median) {
+				one.push_back(subset[i]);
+			}
+			if (segs[subset[i]][0].x >= median || segs[subset[i]][1].x >= median) {
+				two.push_back(subset[i]);
+			}
+		}
+	} else {
+		for (size_t i = 0; i < subset.size(); i++) {
+			if (segs[subset[i]][0].y <= median || segs[subset[i]][1].y <= median) {
+				one.push_back(subset[i]);
+			}
+			if (segs[subset[i]][0].y >= median || segs[subset[i]][1].y >= median) {
+				two.push_back(subset[i]);
+			}
+		}
+	}
+
+	if (one.size() >= subset.size() || two.size() >= subset.size()) {
+		for (size_t i = 0; i < subset.size(); i++) {
+			for (size_t j = i + 1; j < subset.size(); j++) {
+				possible.insert(std::pair<size_t, size_t>(subset[i], subset[j]));
+			}
+		}
+	} else {
+		// By experiment, stopping at 10 is a little faster than either 5 or 20
+
+		if (one.size() < 10) {
+			for (size_t i = 0; i < one.size(); i++) {
+				for (size_t j = i + 1; j < one.size(); j++) {
+					possible.insert(std::pair<size_t, size_t>(one[i], one[j]));
+				}
+			}
+		} else {
+			partition(segs, one, !direction, possible);
+		}
+
+		if (two.size() < 10) {
+			for (size_t i = 0; i < two.size(); i++) {
+				for (size_t j = i + 1; j < two.size(); j++) {
+					possible.insert(std::pair<size_t, size_t>(two[i], two[j]));
+				}
+			}
+		} else {
+			partition(segs, two, !direction, possible);
+		}
+	}
+}
+
+template <typename T>
+std::vector<std::vector<point<T>>> intersect_segments(std::vector<std::vector<point<T>>> segments, std::vector<size_t> &nexts, bool do_warn, bool endpoint_ok) {
+	bool again = true;
+
+	while (again) {
+		again = false;
+
+		std::set<std::pair<size_t, size_t>> possible;
+
+		std::vector<size_t> subset;
+		for (size_t i = 0; i < segments.size(); i++) {
+			subset.push_back(i);
+		}
+
+		partition(segments, subset, 0, possible);
+
+		for (auto it = possible.begin(); it != possible.end(); ++it) {
+			check_intersection(segments, it->first, it->second, again, nexts, do_warn, endpoint_ok);
+		}
+	}
+
+	return segments;
+}
+
+template <typename T>
+linear_ring<T> remove_collinear(linear_ring<T> ring) {
+	linear_ring<T> out;
+
+	size_t len = ring.size() - 1;  // Exclude duplicated last point
+	for (size_t j = 0; j < len; j++) {
+		long long ccw =
+			ring[(j + len - 1) % len].x * ring[(j + len - 0) % len].y +
+			ring[(j + len - 0) % len].x * ring[(j + len + 1) % len].y +
+			ring[(j + len + 1) % len].x * ring[(j + len - 1) % len].y -
+			ring[(j + len - 1) % len].x * ring[(j + len + 1) % len].y -
+			ring[(j + len - 0) % len].x * ring[(j + len - 1) % len].y -
+			ring[(j + len + 1) % len].x * ring[(j + len - 0) % len].y;
+
+		if (ccw != 0) {
+			out.push_back(ring[j]);
+		}
+
+		if (ring.size() > 0 && ring[0] != ring[ring.size() - 1]) {
+			ring.push_back(ring[0]);
+		}
+	}
+
+	return out;
+}
+
+template <typename T>
+multi_polygon<T> snap_round(multi_polygon<T> geom, bool do_warn, bool endpoint_ok) {
+	std::vector<std::vector<point<T>>> segments;
+	std::vector<size_t> nexts;
+	std::vector<std::vector<size_t>> ring_starts;
+
+	// Crunch out any 0-length segments
+	for (size_t i = 0; i < geom.size(); i++) {
+		for (size_t j = 0; j < geom[i].size(); j++) {
+			for (ssize_t k = geom[i][j].size() - 1; k > 0; k--) {
+				if (geom[i][j][k] == geom[i][j][k - 1]) {
+					geom[i][j].erase(geom[i][j].begin() + k);
+				}
+			}
+		}
+	}
+
+	for (size_t i = 0; i < geom.size(); i++) {
+		ring_starts.push_back(std::vector<size_t>());
+
+		for (size_t j = 0; j < geom[i].size(); j++) {
+			size_t s = geom[i][j].size();
+
+			if (s > 1) {
+				ring_starts[i].push_back(segments.size());
+				size_t first = nexts.size();
+
+				for (size_t k = 0; k + 1 < s; k++) {
+					std::vector<point<T>> dv;
+					dv.push_back(geom[i][j][k]);
+					dv.push_back(geom[i][j][k + 1]);
+
+					segments.push_back(dv);
+					nexts.push_back(nexts.size() + 1);
+				}
+
+				// Fabricate a point if ring was not closed
+				if (geom[i][j][0] != geom[i][j][s - 1]) {
+					std::vector<point<T>> dv;
+					dv.push_back(geom[i][j][s - 1]);
+					dv.push_back(geom[i][j][0]);
+
+					segments.push_back(dv);
+					nexts.push_back(nexts.size() + 1);
+				}
+
+				// Last point of ring points back to first
+				nexts[nexts.size() - 1] = first;
+			}
+		}
+	}
+
+	segments = intersect_segments(segments, nexts, do_warn, endpoint_ok);
+
+	multi_polygon<T> mp;
+	for (size_t i = 0; i < ring_starts.size(); i++) {
+		mp.push_back(polygon<T>());
+
+		for (size_t j = 0; j < ring_starts[i].size(); j++) {
+			mp[i].push_back(linear_ring<T>());
+
+			size_t k = ring_starts[i][j];
+			do {
+				mp[i][j].push_back(segments[k][0]);
+				k = nexts[k];
+			} while (k != ring_starts[i][j]);
+
+			mp[i][j].push_back(segments[ring_starts[i][j]][0]);
+		}
+	}
+
+	return mp;
+}
+
+template <typename T>
+multi_line_string<T> snap_round(multi_line_string<T> geom, bool do_warn, bool endpoint_ok) {
+	std::vector<std::vector<point<T>>> segments;
+	std::vector<size_t> nexts;
+	std::vector<size_t> ring_starts;
+
+	// Crunch out any 0-length segments
+	for (size_t j = 0; j < geom.size(); j++) {
+		for (ssize_t k = geom[j].size() - 1; k > 0; k--) {
+			if (geom[j][k] == geom[j][k - 1]) {
+				geom[j].erase(geom[j].begin() + k);
+			}
+		}
+	}
+
+	for (size_t j = 0; j < geom.size(); j++) {
+		size_t s = geom[j].size();
+
+		if (s > 1) {
+			ring_starts.push_back(segments.size());
+			size_t first = nexts.size();
+
+			for (size_t k = 0; k + 1 < s; k++) {
+				std::vector<point<T>> dv;
+				dv.push_back(geom[j][k]);
+				dv.push_back(geom[j][k + 1]);
+
+				segments.push_back(dv);
+				nexts.push_back(nexts.size() + 1);
+			}
+
+			// Last point of ring points back to first
+			nexts[nexts.size() - 1] = first;
+		}
+	}
+
+	segments = intersect_segments(segments, nexts, do_warn, endpoint_ok);
+
+	multi_line_string<T> mp;
+	for (size_t j = 0; j < ring_starts.size(); j++) {
+		mp.push_back(line_string<T>());
+
+		size_t k = ring_starts[j];
+		size_t last = k;
+		do {
+			mp[j].push_back(segments[k][0]);
+			last = k;
+			k = nexts[k];
+		} while (k != ring_starts[j]);
+
+		mp[j].push_back(segments[last][1]);
+	}
+
+	return mp;
+}
+}
+}

mapbox/geometry/wagyu/active_bound_list.hpp

@@ -0,0 +1,396 @@
+#pragma once
+
+#ifdef DEBUG
+#include <iostream>
+#include <sstream>
+#endif
+
+#include <mapbox/geometry/wagyu/bound.hpp>
+#include <mapbox/geometry/wagyu/config.hpp>
+#include <mapbox/geometry/wagyu/edge.hpp>
+#include <mapbox/geometry/wagyu/local_minimum.hpp>
+#include <mapbox/geometry/wagyu/local_minimum_util.hpp>
+#include <mapbox/geometry/wagyu/ring.hpp>
+#include <mapbox/geometry/wagyu/scanbeam.hpp>
+#include <mapbox/geometry/wagyu/util.hpp>
+
+namespace mapbox {
+namespace geometry {
+namespace wagyu {
+
+template <typename T>
+using active_bound_list = std::vector<bound_ptr<T>>;
+
+template <typename T>
+using active_bound_list_itr = typename active_bound_list<T>::iterator;
+
+template <typename T>
+using active_bound_list_rev_itr = typename active_bound_list<T>::reverse_iterator;
+
+#ifdef DEBUG
+
+template <class charT, class traits, typename T>
+inline std::basic_ostream<charT, traits>& operator<<(std::basic_ostream<charT, traits>& out,
+                                                     const active_bound_list<T>& bnds) {
+    std::size_t c = 0;
+    for (auto const& bnd : bnds) {
+        out << "Index: " << c++ << std::endl;
+        out << *bnd;
+    }
+    return out;
+}
+
+template <typename T>
+std::string output_edges(active_bound_list<T> const& bnds) {
+    std::ostringstream out;
+    out << "[";
+    bool first = true;
+    for (auto const& bnd : bnds) {
+        if (first) {
+            first = false;
+        } else {
+            out << ",";
+        }
+        out << "[[" << bnd->current_edge->bot.x << "," << bnd->current_edge->bot.y << "],[";
+        out << bnd->current_edge->top.x << "," << bnd->current_edge->top.y << "]]";
+    }
+    out << "]";
+    return out.str();
+}
+
+#endif
+
+template <typename T>
+bool is_even_odd_fill_type(bound<T> const& bound, fill_type subject_fill_type, fill_type clip_fill_type) {
+    if (bound.poly_type == polygon_type_subject) {
+        return subject_fill_type == fill_type_even_odd;
+    } else {
+        return clip_fill_type == fill_type_even_odd;
+    }
+}
+
+template <typename T>
+bool is_even_odd_alt_fill_type(bound<T> const& bound, fill_type subject_fill_type, fill_type clip_fill_type) {
+    if (bound.poly_type == polygon_type_subject) {
+        return clip_fill_type == fill_type_even_odd;
+    } else {
+        return subject_fill_type == fill_type_even_odd;
+    }
+}
+
+template <typename T>
+struct bound_insert_location {
+
+    bound<T> const& bound2;
+
+    bound_insert_location(bound<T> const& b) : bound2(b) {
+    }
+
+    bool operator()(bound_ptr<T> const& b) {
+        auto const& bound1 = *b;
+        if (values_are_equal(bound2.current_x, bound1.current_x)) {
+            if (bound2.current_edge->top.y > bound1.current_edge->top.y) {
+                return less_than(static_cast<double>(bound2.current_edge->top.x),
+                                 get_current_x(*(bound1.current_edge), bound2.current_edge->top.y));
+            } else {
+                return greater_than(static_cast<double>(bound1.current_edge->top.x),
+                                    get_current_x(*(bound2.current_edge), bound1.current_edge->top.y));
+            }
+        } else {
+            return bound2.current_x < bound1.current_x;
+        }
+    }
+};
+
+template <typename T>
+active_bound_list_itr<T> insert_bound_into_ABL(bound<T>& left, bound<T>& right, active_bound_list<T>& active_bounds) {
+
+    auto itr = std::find_if(active_bounds.begin(), active_bounds.end(), bound_insert_location<T>(left));
+#ifdef GCC_MISSING_VECTOR_RANGE_INSERT
+    itr = active_bounds.insert(itr, &right);
+    return active_bounds.insert(itr, &left);
+#else
+    return active_bounds.insert(itr, { &left, &right });
+#endif
+}
+
+template <typename T>
+inline bool is_maxima(bound<T> const& bnd, T y) {
+    return bnd.next_edge == bnd.edges.end() && bnd.current_edge->top.y == y;
+}
+
+template <typename T>
+inline bool is_maxima(active_bound_list_itr<T> const& bnd, T y) {
+    return is_maxima(*(*bnd), y);
+}
+
+template <typename T>
+inline bool is_intermediate(bound<T> const& bnd, T y) {
+    return bnd.next_edge != bnd.edges.end() && bnd.current_edge->top.y == y;
+}
+
+template <typename T>
+inline bool is_intermediate(active_bound_list_itr<T> const& bnd, T y) {
+    return is_intermediate(*(*bnd), y);
+}
+
+template <typename T>
+inline bool current_edge_is_horizontal(active_bound_list_itr<T> const& bnd) {
+    return is_horizontal(*((*bnd)->current_edge));
+}
+
+template <typename T>
+inline bool next_edge_is_horizontal(active_bound_list_itr<T> const& bnd) {
+    return is_horizontal(*((*bnd)->next_edge));
+}
+
+template <typename T>
+void next_edge_in_bound(bound<T>& bnd, scanbeam_list<T>& scanbeam) {
+    auto& current_edge = bnd.current_edge;
+    ++current_edge;
+    if (current_edge != bnd.edges.end()) {
+        ++(bnd.next_edge);
+        bnd.current_x = static_cast<double>(current_edge->bot.x);
+        if (!is_horizontal<T>(*current_edge)) {
+            insert_sorted_scanbeam(scanbeam, current_edge->top.y);
+        }
+    }
+}
+
+template <typename T>
+active_bound_list_itr<T> get_maxima_pair(active_bound_list_itr<T> bnd, active_bound_list<T>& active_bounds) {
+    bound_ptr<T> maximum = (*bnd)->maximum_bound;
+    return std::find(active_bounds.begin(), active_bounds.end(), maximum);
+}
+
+template <typename T>
+void set_winding_count(active_bound_list_itr<T> bnd_itr,
+                       active_bound_list<T>& active_bounds,
+                       fill_type subject_fill_type,
+                       fill_type clip_fill_type) {
+
+    auto rev_bnd_itr = active_bound_list_rev_itr<T>(bnd_itr);
+    if (rev_bnd_itr == active_bounds.rend()) {
+        (*bnd_itr)->winding_count = (*bnd_itr)->winding_delta;
+        (*bnd_itr)->winding_count2 = 0;
+        return;
+    }
+
+    // find the edge of the same polytype that immediately preceeds 'edge' in
+    // AEL
+    while (rev_bnd_itr != active_bounds.rend() && (*rev_bnd_itr)->poly_type != (*bnd_itr)->poly_type) {
+        ++rev_bnd_itr;
+    }
+    if (rev_bnd_itr == active_bounds.rend()) {
+        (*bnd_itr)->winding_count = (*bnd_itr)->winding_delta;
+        (*bnd_itr)->winding_count2 = 0;
+    } else if (is_even_odd_fill_type(*(*bnd_itr), subject_fill_type, clip_fill_type)) {
+        // EvenOdd filling ...
+        (*bnd_itr)->winding_count = (*bnd_itr)->winding_delta;
+        (*bnd_itr)->winding_count2 = (*rev_bnd_itr)->winding_count2;
+    } else {
+        // nonZero, Positive or Negative filling ...
+        if ((*rev_bnd_itr)->winding_count * (*rev_bnd_itr)->winding_delta < 0) {
+            // prev edge is 'decreasing' WindCount (WC) toward zero
+            // so we're outside the previous polygon ...
+            if (std::abs(static_cast<int>((*rev_bnd_itr)->winding_count)) > 1) {
+                // outside prev poly but still inside another.
+                // when reversing direction of prev poly use the same WC
+                if ((*rev_bnd_itr)->winding_delta * (*bnd_itr)->winding_delta < 0) {
+                    (*bnd_itr)->winding_count = (*rev_bnd_itr)->winding_count;
+                } else {
+                    // otherwise continue to 'decrease' WC ...
+                    (*bnd_itr)->winding_count = (*rev_bnd_itr)->winding_count + (*bnd_itr)->winding_delta;
+                }
+            } else {
+                // now outside all polys of same polytype so set own WC ...
+                (*bnd_itr)->winding_count = (*bnd_itr)->winding_delta;
+            }
+        } else {
+            // prev edge is 'increasing' WindCount (WC) away from zero
+            // so we're inside the previous polygon ...
+            if ((*rev_bnd_itr)->winding_delta * (*bnd_itr)->winding_delta < 0) {
+                // if wind direction is reversing prev then use same WC
+                (*bnd_itr)->winding_count = (*rev_bnd_itr)->winding_count;
+            } else {
+                // otherwise add to WC ...
+                (*bnd_itr)->winding_count = (*rev_bnd_itr)->winding_count + (*bnd_itr)->winding_delta;
+            }
+        }
+        (*bnd_itr)->winding_count2 = (*rev_bnd_itr)->winding_count2;
+    }
+
+    // update winding_count2 ...
+    auto bnd_itr_forward = rev_bnd_itr.base();
+    if (is_even_odd_alt_fill_type(*(*bnd_itr), subject_fill_type, clip_fill_type)) {
+        // EvenOdd filling ...
+        while (bnd_itr_forward != bnd_itr) {
+            (*bnd_itr)->winding_count2 = ((*bnd_itr)->winding_count2 == 0 ? 1 : 0);
+            ++bnd_itr_forward;
+        }
+    } else {
+        // nonZero, Positive or Negative filling ...
+        while (bnd_itr_forward != bnd_itr) {
+            (*bnd_itr)->winding_count2 += (*bnd_itr_forward)->winding_delta;
+            ++bnd_itr_forward;
+        }
+    }
+}
+
+template <typename T>
+bool is_contributing(bound<T> const& bnd, clip_type cliptype, fill_type subject_fill_type, fill_type clip_fill_type) {
+    fill_type pft = subject_fill_type;
+    fill_type pft2 = clip_fill_type;
+    if (bnd.poly_type != polygon_type_subject) {
+        pft = clip_fill_type;
+        pft2 = subject_fill_type;
+    }
+
+    switch (pft) {
+    case fill_type_even_odd:
+        break;
+    case fill_type_non_zero:
+        if (std::abs(static_cast<int>(bnd.winding_count)) != 1) {
+            return false;
+        }
+        break;
+    case fill_type_positive:
+        if (bnd.winding_count != 1) {
+            return false;
+        }
+        break;
+    case fill_type_negative:
+    default:
+        if (bnd.winding_count != -1) {
+            return false;
+        }
+    }
+
+    switch (cliptype) {
+    case clip_type_intersection:
+        switch (pft2) {
+        case fill_type_even_odd:
+        case fill_type_non_zero:
+            return (bnd.winding_count2 != 0);
+        case fill_type_positive:
+            return (bnd.winding_count2 > 0);
+        case fill_type_negative:
+        default:
+            return (bnd.winding_count2 < 0);
+        }
+        break;
+    case clip_type_union:
+        switch (pft2) {
+        case fill_type_even_odd:
+        case fill_type_non_zero:
+            return (bnd.winding_count2 == 0);
+        case fill_type_positive:
+            return (bnd.winding_count2 <= 0);
+        case fill_type_negative:
+        default:
+            return (bnd.winding_count2 >= 0);
+        }
+        break;
+    case clip_type_difference:
+        if (bnd.poly_type == polygon_type_subject) {
+            switch (pft2) {
+            case fill_type_even_odd:
+            case fill_type_non_zero:
+                return (bnd.winding_count2 == 0);
+            case fill_type_positive:
+                return (bnd.winding_count2 <= 0);
+            case fill_type_negative:
+            default:
+                return (bnd.winding_count2 >= 0);
+            }
+        } else {
+            switch (pft2) {
+            case fill_type_even_odd:
+            case fill_type_non_zero:
+                return (bnd.winding_count2 != 0);
+            case fill_type_positive:
+                return (bnd.winding_count2 > 0);
+            case fill_type_negative:
+            default:
+                return (bnd.winding_count2 < 0);
+            }
+        }
+        break;
+    case clip_type_x_or:
+        return true;
+        break;
+    default:
+        return true;
+    }
+}
+
+template <typename T>
+void insert_lm_left_and_right_bound(bound<T>& left_bound,
+                                    bound<T>& right_bound,
+                                    active_bound_list<T>& active_bounds,
+                                    ring_manager<T>& rings,
+                                    scanbeam_list<T>& scanbeam,
+                                    clip_type cliptype,
+                                    fill_type subject_fill_type,
+                                    fill_type clip_fill_type) {
+
+    // Both left and right bound
+    auto lb_abl_itr = insert_bound_into_ABL(left_bound, right_bound, active_bounds);
+    auto rb_abl_itr = std::next(lb_abl_itr);
+    set_winding_count(lb_abl_itr, active_bounds, subject_fill_type, clip_fill_type);
+    (*rb_abl_itr)->winding_count = (*lb_abl_itr)->winding_count;
+    (*rb_abl_itr)->winding_count2 = (*lb_abl_itr)->winding_count2;
+    if (is_contributing(left_bound, cliptype, subject_fill_type, clip_fill_type)) {
+        add_local_minimum_point(*(*lb_abl_itr), *(*rb_abl_itr), active_bounds, (*lb_abl_itr)->current_edge->bot, rings);
+    }
+
+    // Add top of edges to scanbeam
+    insert_sorted_scanbeam(scanbeam, (*lb_abl_itr)->current_edge->top.y);
+
+    if (!current_edge_is_horizontal<T>(rb_abl_itr)) {
+        insert_sorted_scanbeam(scanbeam, (*rb_abl_itr)->current_edge->top.y);
+    }
+}
+
+template <typename T>
+void insert_local_minima_into_ABL(T const bot_y,
+                                  local_minimum_ptr_list<T> const& minima_sorted,
+                                  local_minimum_ptr_list_itr<T>& current_lm,
+                                  active_bound_list<T>& active_bounds,
+                                  ring_manager<T>& rings,
+                                  scanbeam_list<T>& scanbeam,
+                                  clip_type cliptype,
+                                  fill_type subject_fill_type,
+                                  fill_type clip_fill_type) {
+    while (current_lm != minima_sorted.end() && bot_y == (*current_lm)->y) {
+        initialize_lm<T>(current_lm);
+        auto& left_bound = (*current_lm)->left_bound;
+        auto& right_bound = (*current_lm)->right_bound;
+        insert_lm_left_and_right_bound(left_bound, right_bound, active_bounds, rings, scanbeam, cliptype,
+                                       subject_fill_type, clip_fill_type);
+        ++current_lm;
+    }
+}
+
+template <typename T>
+void insert_horizontal_local_minima_into_ABL(T const top_y,
+                                             local_minimum_ptr_list<T> const& minima_sorted,
+                                             local_minimum_ptr_list_itr<T>& current_lm,
+                                             active_bound_list<T>& active_bounds,
+                                             ring_manager<T>& rings,
+                                             scanbeam_list<T>& scanbeam,
+                                             clip_type cliptype,
+                                             fill_type subject_fill_type,
+                                             fill_type clip_fill_type) {
+    while (current_lm != minima_sorted.end() && top_y == (*current_lm)->y && (*current_lm)->minimum_has_horizontal) {
+        initialize_lm<T>(current_lm);
+        auto& left_bound = (*current_lm)->left_bound;
+        auto& right_bound = (*current_lm)->right_bound;
+        insert_lm_left_and_right_bound(left_bound, right_bound, active_bounds, rings, scanbeam, cliptype,
+                                       subject_fill_type, clip_fill_type);
+        ++current_lm;
+    }
+}
+} // namespace wagyu
+} // namespace geometry
+} // namespace mapbox

mapbox/geometry/wagyu/almost_equal.hpp

@@ -0,0 +1,277 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// Authors: wan@google.com (Zhanyong Wan), eefacm@gmail.com (Sean Mcafee)
+//
+// The Google C++ Testing Framework (Google Test)
+
+// This template class serves as a compile-time function from size to
+// type.  It maps a size in bytes to a primitive type with that
+// size. e.g.
+//
+//   TypeWithSize<4>::UInt
+//
+// is typedef-ed to be unsigned int (unsigned integer made up of 4
+// bytes).
+//
+// Such functionality should belong to STL, but I cannot find it
+// there.
+//
+// Google Test uses this class in the implementation of floating-point
+// comparison.
+//
+// For now it only handles UInt (unsigned int) as that's all Google Test
+// needs.  Other types can be easily added in the future if need
+// arises.
+namespace mapbox {
+namespace geometry {
+namespace wagyu {
+namespace util {
+
+template <size_t size>
+class TypeWithSize {
+public:
+    // This prevents the user from using TypeWithSize<N> with incorrect
+    // values of N.
+    typedef void UInt;
+};
+
+// The specialization for size 4.
+template <>
+class TypeWithSize<4> {
+public:
+    // unsigned int has size 4 in both gcc and MSVC.
+    //
+    // As base/basictypes.h doesn't compile on Windows, we cannot use
+    // uint32, uint64, and etc here.
+    typedef int Int;
+    typedef unsigned int UInt;
+};
+
+// The specialization for size 8.
+template <>
+class TypeWithSize<8> {
+public:
+#if GTEST_OS_WINDOWS
+    typedef __int64 Int;
+    typedef unsigned __int64 UInt;
+#else
+    typedef long long Int;           // NOLINT
+    typedef unsigned long long UInt; // NOLINT
+#endif // GTEST_OS_WINDOWS
+};
+
+// This template class represents an IEEE floating-point number
+// (either single-precision or double-precision, depending on the
+// template parameters).
+//
+// The purpose of this class is to do more sophisticated number
+// comparison.  (Due to round-off error, etc, it's very unlikely that
+// two floating-points will be equal exactly.  Hence a naive
+// comparison by the == operation often doesn't work.)
+//
+// Format of IEEE floating-point:
+//
+//   The most-significant bit being the leftmost, an IEEE
+//   floating-point looks like
+//
+//     sign_bit exponent_bits fraction_bits
+//
+//   Here, sign_bit is a single bit that designates the sign of the
+//   number.
+//
+//   For float, there are 8 exponent bits and 23 fraction bits.
+//
+//   For double, there are 11 exponent bits and 52 fraction bits.
+//
+//   More details can be found at
+//   http://en.wikipedia.org/wiki/IEEE_floating-point_standard.
+//
+// Template parameter:
+//
+//   RawType: the raw floating-point type (either float or double)
+template <typename RawType>
+class FloatingPoint {
+public:
+    // Defines the unsigned integer type that has the same size as the
+    // floating point number.
+    typedef typename TypeWithSize<sizeof(RawType)>::UInt Bits;
+
+    // Constants.
+
+    // # of bits in a number.
+    static const size_t kBitCount = 8 * sizeof(RawType);
+
+    // # of fraction bits in a number.
+    static const size_t kFractionBitCount = std::numeric_limits<RawType>::digits - 1;
+
+    // # of exponent bits in a number.
+    static const size_t kExponentBitCount = kBitCount - 1 - kFractionBitCount;
+
+    // The mask for the sign bit.
+    static const Bits kSignBitMask = static_cast<Bits>(1) << (kBitCount - 1);
+
+    // The mask for the fraction bits.
+    static const Bits kFractionBitMask = ~static_cast<Bits>(0) >> (kExponentBitCount + 1);
+
+    // The mask for the exponent bits.
+    static const Bits kExponentBitMask = ~(kSignBitMask | kFractionBitMask);
+
+    // How many ULP's (Units in the Last Place) we want to tolerate when
+    // comparing two numbers.  The larger the value, the more error we
+    // allow.  A 0 value means that two numbers must be exactly the same
+    // to be considered equal.
+    //
+    // The maximum error of a single floating-point operation is 0.5
+    // units in the last place.  On Intel CPU's, all floating-point
+    // calculations are done with 80-bit precision, while double has 64
+    // bits.  Therefore, 4 should be enough for ordinary use.
+    //
+    // See the following article for more details on ULP:
+    // http://www.cygnus-software.com/papers/comparingfloats/comparingfloats.htm.
+    static const size_t kMaxUlps = 4;
+
+    // Constructs a FloatingPoint from a raw floating-point number.
+    //
+    // On an Intel CPU, passing a non-normalized NAN (Not a Number)
+    // around may change its bits, although the new value is guaranteed
+    // to be also a NAN.  Therefore, don't expect this constructor to
+    // preserve the bits in x when x is a NAN.
+    explicit FloatingPoint(const RawType& x) : u_(x) {
+    }
+
+    // Static methods
+
+    // Reinterprets a bit pattern as a floating-point number.
+    //
+    // This function is needed to test the AlmostEquals() method.
+    static RawType ReinterpretBits(const Bits bits) {
+        FloatingPoint fp(0);
+        fp.u_.bits_ = bits;
+        return fp.u_.value_;
+    }
+
+    // Returns the floating-point number that represent positive infinity.
+    static RawType Infinity() {
+        return ReinterpretBits(kExponentBitMask);
+    }
+
+    // Non-static methods
+
+    // Returns the bits that represents this number.
+    const Bits& bits() const {
+        return u_.bits_;
+    }
+
+    // Returns the exponent bits of this number.
+    Bits exponent_bits() const {
+        return kExponentBitMask & u_.bits_;
+    }
+
+    // Returns the fraction bits of this number.
+    Bits fraction_bits() const {
+        return kFractionBitMask & u_.bits_;
+    }
+
+    // Returns the sign bit of this number.
+    Bits sign_bit() const {
+        return kSignBitMask & u_.bits_;
+    }
+
+    // Returns true iff this is NAN (not a number).
+    bool is_nan() const {
+        // It's a NAN if the exponent bits are all ones and the fraction
+        // bits are not entirely zeros.
+        return (exponent_bits() == kExponentBitMask) && (fraction_bits() != 0);
+    }
+
+    // Returns true iff this number is at most kMaxUlps ULP's away from
+    // rhs.  In particular, this function:
+    //
+    //   - returns false if either number is (or both are) NAN.
+    //   - treats really large numbers as almost equal to infinity.
+    //   - thinks +0.0 and -0.0 are 0 DLP's apart.
+    bool AlmostEquals(const FloatingPoint& rhs) const {
+        // The IEEE standard says that any comparison operation involving
+        // a NAN must return false.
+        if (is_nan() || rhs.is_nan())
+            return false;
+
+        return DistanceBetweenSignAndMagnitudeNumbers(u_.bits_, rhs.u_.bits_) <= kMaxUlps;
+    }
+
+private:
+    // The data type used to store the actual floating-point number.
+    union FloatingPointUnion {
+        explicit FloatingPointUnion(RawType val) : value_(val) {
+        }
+        RawType value_; // The raw floating-point number.
+        Bits bits_;     // The bits that represent the number.
+    };
+
+    // Converts an integer from the sign-and-magnitude representation to
+    // the biased representation.  More precisely, let N be 2 to the
+    // power of (kBitCount - 1), an integer x is represented by the
+    // unsigned number x + N.
+    //
+    // For instance,
+    //
+    //   -N + 1 (the most negative number representable using
+    //          sign-and-magnitude) is represented by 1;
+    //   0      is represented by N; and
+    //   N - 1  (the biggest number representable using
+    //          sign-and-magnitude) is represented by 2N - 1.
+    //
+    // Read http://en.wikipedia.org/wiki/Signed_number_representations
+    // for more details on signed number representations.
+    static Bits SignAndMagnitudeToBiased(const Bits& sam) {
+        if (kSignBitMask & sam) {
+            // sam represents a negative number.
+            return ~sam + 1;
+        } else {
+            // sam represents a positive number.
+            return kSignBitMask | sam;
+        }
+    }
+
+    // Given two numbers in the sign-and-magnitude representation,
+    // returns the distance between them as an unsigned number.
+    static Bits DistanceBetweenSignAndMagnitudeNumbers(const Bits& sam1, const Bits& sam2) {
+        const Bits biased1 = SignAndMagnitudeToBiased(sam1);
+        const Bits biased2 = SignAndMagnitudeToBiased(sam2);
+        return (biased1 >= biased2) ? (biased1 - biased2) : (biased2 - biased1);
+    }
+
+    FloatingPointUnion u_;
+};
+
+} // namespace util
+} // namespace wagyu
+} // namespace geometry
+} // namespace mapbox

mapbox/geometry/wagyu/bound.hpp

@@ -0,0 +1,99 @@
+#pragma once
+
+#include <list>
+
+#include <mapbox/geometry/point.hpp>
+
+#include <mapbox/geometry/wagyu/config.hpp>
+#include <mapbox/geometry/wagyu/edge.hpp>
+#include <mapbox/geometry/wagyu/ring.hpp>
+
+#ifdef DEBUG
+#include <iostream>
+#endif
+
+namespace mapbox {
+namespace geometry {
+namespace wagyu {
+
+template <typename T>
+struct bound {
+
+    edge_list<T> edges;
+    edge_list_itr<T> current_edge;
+    edge_list_itr<T> next_edge;
+    mapbox::geometry::point<T> last_point;
+    ring_ptr<T> ring;
+    bound_ptr<T> maximum_bound; // the bound who's maximum connects with this bound
+    double current_x;
+    std::size_t pos;
+    std::int32_t winding_count;
+    std::int32_t winding_count2; // winding count of the opposite polytype
+    std::int8_t winding_delta;   // 1 or -1 depending on winding direction - 0 for linestrings
+    polygon_type poly_type;
+    edge_side side; // side only refers to current side of solution poly
+
+    bound() noexcept
+        : edges(),
+          current_edge(edges.end()),
+          next_edge(edges.end()),
+          last_point({ 0, 0 }),
+          ring(nullptr),
+          maximum_bound(nullptr),
+          current_x(0.0),
+          pos(0),
+          winding_count(0),
+          winding_count2(0),
+          winding_delta(0),
+          poly_type(polygon_type_subject),
+          side(edge_left) {
+    }
+
+    bound(bound<T>&& b) noexcept
+        : edges(std::move(b.edges)),
+          current_edge(std::move(b.current_edge)),
+          next_edge(std::move(b.next_edge)),
+          last_point(std::move(b.last_point)),
+          ring(std::move(b.ring)),
+          maximum_bound(std::move(b.maximum_bound)),
+          current_x(std::move(b.current_x)),
+          pos(std::move(b.pos)),
+          winding_count(std::move(b.winding_count)),
+          winding_count2(std::move(b.winding_count2)),
+          winding_delta(std::move(b.winding_delta)),
+          poly_type(std::move(b.poly_type)),
+          side(std::move(b.side)) {
+    }
+
+    bound(bound<T> const& b) = delete;
+    bound<T>& operator=(bound<T> const&) = delete;
+};
+
+#ifdef DEBUG
+
+template <class charT, class traits, typename T>
+inline std::basic_ostream<charT, traits>& operator<<(std::basic_ostream<charT, traits>& out, const bound<T>& bnd) {
+    out << "    Bound: " << &bnd << std::endl;
+    out << "        current_x: " << bnd.current_x << std::endl;
+    out << "        last_point: " << bnd.last_point.x << ", " << bnd.last_point.y << std::endl;
+    out << *(bnd.current_edge);
+    out << "        winding count: " << bnd.winding_count << std::endl;
+    out << "        winding_count2: " << bnd.winding_count2 << std::endl;
+    out << "        winding_delta: " << static_cast<int>(bnd.winding_delta) << std::endl;
+    out << "        maximum_bound: " << bnd.maximum_bound << std::endl;
+    if (bnd.side == edge_left) {
+        out << "        side: left" << std::endl;
+    } else {
+        out << "        side: right" << std::endl;
+    }
+    out << "        ring: " << bnd.ring << std::endl;
+    if (bnd.ring) {
+        out << "        ring index: " << bnd.ring->ring_index << std::endl;
+    }
+    return out;
+}
+
+#endif
+} // namespace wagyu
+} // namespace geometry
+} // namespace mapbox

mapbox/geometry/wagyu/bubble_sort.hpp

@@ -0,0 +1,28 @@
+#pragma once
+
+namespace mapbox {
+namespace geometry {
+namespace wagyu {
+
+template <typename It, class Compare, class MethodOnSwap>
+void bubble_sort(It begin, It end, Compare c, MethodOnSwap m) {
+    if (begin == end) {
+        return;
+    }
+    bool modified = false;
+    auto last = end - 1;
+    do {
+        modified = false;
+        for (auto itr = begin; itr != last; ++itr) {
+            auto next = std::next(itr);
+            if (!c(*itr, *next)) {
+                m(*itr, *next);
+                std::iter_swap(itr, next);
+                modified = true;
+            }
+        }
+    } while (modified);
+}
+} // namespace wagyu
+} // namespace geometry
+} // namespace mapbox

mapbox/geometry/wagyu/build_edges.hpp

@@ -0,0 +1,183 @@
+#pragma once
+
+#include <mapbox/geometry/line_string.hpp>
+#include <mapbox/geometry/point.hpp>
+#include <mapbox/geometry/polygon.hpp>
+
+#include <mapbox/geometry/wagyu/config.hpp>
+#include <mapbox/geometry/wagyu/edge.hpp>
+#include <mapbox/geometry/wagyu/util.hpp>
+
+namespace mapbox {
+namespace geometry {
+namespace wagyu {
+
+template <typename T>
+bool point_2_is_between_point_1_and_point_3(mapbox::geometry::point<T> const& pt1,
+                                            mapbox::geometry::point<T> const& pt2,
+                                            mapbox::geometry::point<T> const& pt3) {
+    if ((pt1 == pt3) || (pt1 == pt2) || (pt3 == pt2)) {
+        return false;
+    } else if (pt1.x != pt3.x) {
+        return (pt2.x > pt1.x) == (pt2.x < pt3.x);
+    } else {
+        return (pt2.y > pt1.y) == (pt2.y < pt3.y);
+    }
+}
+
+template <typename T1, typename T2>
+bool build_edge_list(mapbox::geometry::linear_ring<T2> const& path_geometry, edge_list<T1>& edges) {
+
+    if (path_geometry.size() < 3) {
+        return false;
+    }
+
+    // As this is a loop, we need to first go backwards from end to try and find
+    // the proper starting point for the iterators before the beginning
+
+    auto itr_rev = path_geometry.rbegin();
+    auto itr = path_geometry.begin();
+    mapbox::geometry::point<T2> pt1 = *itr_rev;
+    mapbox::geometry::point<T2> pt2 = *itr;
+
+    // Find next non repeated point going backwards from
+    // end for pt1
+    while (pt1 == pt2) {
+        ++itr_rev;
+        if (itr_rev == path_geometry.rend()) {
+            return false;
+        }
+        pt1 = *itr_rev;
+    }
+    ++itr;
+    mapbox::geometry::point<T2> pt3 = *itr;
+    auto itr_last = itr_rev.base();
+    mapbox::geometry::point<T2> front_pt;
+    mapbox::geometry::point<T2> back_pt;
+    while (true) {
+        if (pt3 == pt2) {
+            // Duplicate point advance itr, but do not
+            // advance other points
+            if (itr == itr_last) {
+                break;
+            }
+            ++itr;
+            if (itr == itr_last) {
+                if (edges.empty()) {
+                    break;
+                }
+                pt3 = front_pt;
+            } else {
+                pt3 = *itr;
+            }
+            continue;
+        }
+
+        // Now check if slopes are equal between two segments - either
+        // a spike or a collinear point - if so drop point number 2.
+        if (slopes_equal(pt1, pt2, pt3)) {
+            // We need to reconsider previously added points
+            // because the point it was using was found to be collinear
+            // or a spike
+            pt2 = pt1;
+            if (!edges.empty()) {
+                edges.pop_back(); // remove previous edge (pt1)
+            }
+            if (!edges.empty()) {
+                auto const& back_top = edges.back().top;
+                if (static_cast<T1>(back_pt.x) == back_top.x && static_cast<T1>(back_pt.y) == back_top.y) {
+                    auto const& back_bot = edges.back().bot;
+                    pt1 = mapbox::geometry::point<T2>(static_cast<T2>(back_bot.x), static_cast<T2>(back_bot.y));
+                } else {
+                    pt1 = mapbox::geometry::point<T2>(static_cast<T2>(back_top.x), static_cast<T2>(back_top.y));
+                }
+                back_pt = pt1;
+            } else {
+                // If this occurs we must look to the back of the
+                // ring for new points.
+                while (*itr_rev == pt2) {
+                    ++itr_rev;
+                    if ((itr + 1) == itr_rev.base()) {
+                        return false;
+                    }
+                }
+                pt1 = *itr_rev;
+                itr_last = itr_rev.base();
+            }
+            continue;
+        }
+
+        if (edges.empty()) {
+            front_pt = pt2;
+        }
+        edges.emplace_back(pt2, pt3);
+        back_pt = pt2;
+        if (itr == itr_last) {
+            break;
+        }
+        pt1 = pt2;
+        pt2 = pt3;
+        ++itr;
+        if (itr == itr_last) {
+            if (edges.empty()) {
+                break;
+            }
+            pt3 = front_pt;
+        } else {
+            pt3 = *itr;
+        }
+    }
+
+    bool modified = false;
+    do {
+        modified = false;
+        if (edges.size() < 3) {
+            return false;
+        }
+        auto& f = edges.front();
+        auto& b = edges.back();
+        if (slopes_equal(f, b)) {
+            if (f.bot == b.top) {
+                if (f.top == b.bot) {
+                    edges.pop_back();
+                    edges.erase(edges.begin());
+                } else {
+                    f.bot = b.bot;
+                    edges.pop_back();
+                }
+                modified = true;
+            } else if (f.top == b.bot) {
+                f.top = b.top;
+                edges.pop_back();
+                modified = true;
+            } else if (f.top == b.top && f.bot == b.bot) {
+                edges.pop_back();
+                edges.erase(edges.begin());
+                modified = true;
+            } else if (f.top == b.top) {
+                if (point_2_is_between_point_1_and_point_3(f.top, f.bot, b.bot)) {
+                    b.top = f.bot;
+                    edges.erase(edges.begin());
+                } else {
+                    f.top = b.bot;
+                    edges.pop_back();
+                }
+                modified = true;
+            } else if (f.bot == b.bot) {
+                if (point_2_is_between_point_1_and_point_3(f.bot, f.top, b.top)) {
+                    b.bot = f.top;
+                    edges.erase(edges.begin());
+                } else {
+                    f.bot = b.top;
+                    edges.pop_back();
+                }
+                modified = true;
+            }
+        }
+    } while (modified);
+
+    return true;
+}
+} // namespace wagyu
+} // namespace geometry
+} // namespace mapbox

mapbox/geometry/wagyu/build_local_minima_list.hpp

@@ -0,0 +1,26 @@
+#pragma once
+
+#include <mapbox/geometry/wagyu/build_edges.hpp>
+#include <mapbox/geometry/wagyu/config.hpp>
+#include <mapbox/geometry/wagyu/local_minimum.hpp>
+#include <mapbox/geometry/wagyu/local_minimum_util.hpp>
+
+namespace mapbox {
+namespace geometry {
+namespace wagyu {
+
+template <typename T1, typename T2>
+bool add_linear_ring(mapbox::geometry::linear_ring<T2> const& path_geometry,
+                     local_minimum_list<T1>& minima_list,
+                     polygon_type p_type) {
+    edge_list<T1> new_edges;
+    new_edges.reserve(path_geometry.size());
+    if (!build_edge_list<T1, T2>(path_geometry, new_edges) || new_edges.empty()) {
+        return false;
+    }
+    add_ring_to_local_minima_list(new_edges, minima_list, p_type);
+    return true;
+}
+} // namespace wagyu
+} // namespace geometry
+} // namespace mapbox

mapbox/geometry/wagyu/build_result.hpp

@@ -0,0 +1,68 @@
+#pragma once
+
+#include <mapbox/geometry/wagyu/ring.hpp>
+#include <mapbox/geometry/wagyu/ring_util.hpp>
+
+#include <mapbox/geometry/multi_polygon.hpp>
+
+namespace mapbox {
+namespace geometry {
+namespace wagyu {
+
+template <typename T1, typename T2>
+void push_ring_to_polygon(mapbox::geometry::polygon<T2>& poly, ring_ptr<T1> r, bool reverse_output) {
+    mapbox::geometry::linear_ring<T2> lr;
+    lr.reserve(r->size() + 1);
+    auto firstPt = r->points;
+    auto ptIt = r->points;
+    if (reverse_output) {
+        do {
+            lr.emplace_back(static_cast<T2>(ptIt->x), static_cast<T2>(ptIt->y));
+            ptIt = ptIt->next;
+        } while (ptIt != firstPt);
+    } else {
+        do {
+            lr.emplace_back(static_cast<T2>(ptIt->x), static_cast<T2>(ptIt->y));
+            ptIt = ptIt->prev;
+        } while (ptIt != firstPt);
+    }
+    lr.emplace_back(firstPt->x, firstPt->y); // close the ring
+    poly.push_back(lr);
+}
+
+template <typename T1, typename T2>
+void build_result_polygons(mapbox::geometry::multi_polygon<T2>& solution,
+                           ring_vector<T1> const& rings,
+                           bool reverse_output) {
+    for (auto r : rings) {
+        if (r == nullptr) {
+            continue;
+        }
+        assert(r->points);
+        solution.emplace_back();
+        push_ring_to_polygon(solution.back(), r, reverse_output);
+        for (auto c : r->children) {
+            if (c == nullptr) {
+                continue;
+            }
+            assert(c->points);
+            push_ring_to_polygon(solution.back(), c, reverse_output);
+        }
+        for (auto c : r->children) {
+            if (c == nullptr) {
+                continue;
+            }
+            if (!c->children.empty()) {
+                build_result_polygons(solution, c->children, reverse_output);
+            }
+        }
+    }
+}
+
+template <typename T1, typename T2>
+void build_result(mapbox::geometry::multi_polygon<T2>& solution, ring_manager<T1> const& rings, bool reverse_output) {
+    build_result_polygons(solution, rings.children, reverse_output);
+}
+} // namespace wagyu
+} // namespace geometry
+} // namespace mapbox

mapbox/geometry/wagyu/config.hpp

@@ -0,0 +1,50 @@
+#pragma once
+
+#include <cassert>
+#include <cstdint>
+#include <list>
+#include <stdexcept>
+
+// GCC 4.8 missing range std::vector::insert (c++11)
+#ifdef __GNUC__
+#if __GNUC__ == 4 && __GNUC_MINOR__ == 8
+#define GCC_MISSING_VECTOR_RANGE_INSERT
+#endif
+#endif
+
+namespace mapbox {
+namespace geometry {
+namespace wagyu {
+
+enum clip_type : std::uint8_t { clip_type_intersection = 0, clip_type_union, clip_type_difference, clip_type_x_or };
+
+enum polygon_type : std::uint8_t { polygon_type_subject = 0, polygon_type_clip };
+
+enum fill_type : std::uint8_t { fill_type_even_odd = 0, fill_type_non_zero, fill_type_positive, fill_type_negative };
+
+static double const def_arc_tolerance = 0.25;
+
+static int const EDGE_UNASSIGNED = -1; // edge not currently 'owning' a solution
+static int const EDGE_SKIP = -2;       // edge that would otherwise close a path
+static std::int64_t const LOW_RANGE = 0x3FFFFFFF;
+static std::int64_t const HIGH_RANGE = 0x3FFFFFFFFFFFFFFFLL;
+
+enum horizontal_direction : std::uint8_t { right_to_left = 0, left_to_right = 1 };
+
+enum edge_side : std::uint8_t { edge_left = 0, edge_right };
+
+enum join_type : std::uint8_t { join_type_square = 0, join_type_round, join_type_miter };
+
+enum end_type {
+    end_type_closed_polygon = 0,
+    end_type_closed_line,
+    end_type_open_butt,
+    end_type_open_square,
+    end_type_open_round
+};
+
+template <typename T>
+using maxima_list = std::list<T>;
+} // namespace wagyu
+} // namespace geometry
+} // namespace mapbox

mapbox/geometry/wagyu/edge.hpp

@@ -0,0 +1,120 @@
+#pragma once
+
+#include <cmath>
+#include <limits>
+#include <list>
+
+#include <mapbox/geometry/point.hpp>
+#include <mapbox/geometry/wagyu/config.hpp>
+#include <mapbox/geometry/wagyu/util.hpp>
+
+#ifdef DEBUG
+#include <iostream>
+#endif
+
+namespace mapbox {
+namespace geometry {
+namespace wagyu {
+
+template <typename T>
+struct bound;
+
+template <typename T>
+using bound_ptr = bound<T>*;
+
+template <typename T>
+struct edge {
+    mapbox::geometry::point<T> bot;
+    mapbox::geometry::point<T> top;
+    double dx;
+
+    edge(edge<T>&& e) noexcept : bot(std::move(e.bot)), top(std::move(e.top)), dx(std::move(e.dx)) {
+    }
+
+    edge& operator=(edge<T>&& e) noexcept {
+        bot = std::move(e.bot);
+        top = std::move(e.top);
+        dx = std::move(e.dx);
+        return *this;
+    }
+
+    template <typename T2>
+    edge(mapbox::geometry::point<T2> const& current, mapbox::geometry::point<T2> const& next_pt) noexcept
+        : bot(static_cast<T>(current.x), static_cast<T>(current.y)),
+          top(static_cast<T>(current.x), static_cast<T>(current.y)),
+          dx(0.0) {
+        if (current.y >= next_pt.y) {
+            top = mapbox::geometry::point<T>(static_cast<T>(next_pt.x), static_cast<T>(next_pt.y));
+        } else {
+            bot = mapbox::geometry::point<T>(static_cast<T>(next_pt.x), static_cast<T>(next_pt.y));
+        }
+        double dy = static_cast<double>(top.y - bot.y);
+        if (value_is_zero(dy)) {
+            dx = std::numeric_limits<double>::infinity();
+        } else {
+            dx = static_cast<double>(top.x - bot.x) / dy;
+        }
+    }
+};
+
+template <typename T>
+using edge_ptr = edge<T>*;
+
+template <typename T>
+using edge_list = std::vector<edge<T>>;
+
+template <typename T>
+using edge_list_itr = typename edge_list<T>::iterator;
+
+template <typename T>
+bool slopes_equal(edge<T> const& e1, edge<T> const& e2) {
+    return static_cast<std::int64_t>(e1.top.y - e1.bot.y) * static_cast<std::int64_t>(e2.top.x - e2.bot.x) ==
+           static_cast<std::int64_t>(e1.top.x - e1.bot.x) * static_cast<std::int64_t>(e2.top.y - e2.bot.y);
+}
+
+template <typename T>
+inline bool is_horizontal(edge<T> const& e) {
+    return std::isinf(e.dx);
+}
+
+template <typename T>
+inline double get_current_x(edge<T> const& edge, const T current_y) {
+    if (current_y == edge.top.y) {
+        return static_cast<double>(edge.top.x);
+    } else {
+        return static_cast<double>(edge.bot.x) + edge.dx * static_cast<double>(current_y - edge.bot.y);
+    }
+}
+
+#ifdef DEBUG
+
+template <class charT, class traits, typename T>
+inline std::basic_ostream<charT, traits>& operator<<(std::basic_ostream<charT, traits>& out, const edge<T>& e) {
+    out << "    Edge: " << std::endl;
+    out << "        bot x: " << e.bot.x << " y: " << e.bot.y << std::endl;
+    out << "        top x: " << e.top.x << " y: " << e.top.y << std::endl;
+    return out;
+}
+
+template <class charT, class traits, typename T>
+inline std::basic_ostream<charT, traits>& operator<<(std::basic_ostream<charT, traits>& out,
+                                                     edge_list<T> const& edges) {
+    out << "[";
+    bool first = true;
+    for (auto const& e : edges) {
+        if (first) {
+            first = false;
+        } else {
+            out << ",";
+        }
+        out << "[[" << e.bot.x << "," << e.bot.y << "],[";
+        out << e.top.x << "," << e.top.y << "]]";
+    }
+    out << "]";
+    return out;
+}
+
+#endif
+} // namespace wagyu
+} // namespace geometry
+} // namespace mapbox

mapbox/geometry/wagyu/interrupt.hpp

@@ -0,0 +1,50 @@
+#pragma once
+
+/**
+ * To enable this by the program, define USE_WAGYU_INTERRUPT before including wagyu.hpp
+ * To request an interruption, call `interrupt_request()`. As soon as Wagyu detects the request
+ * it will raise an exception (`std::runtime_error`).
+ */
+
+#ifdef USE_WAGYU_INTERRUPT
+
+namespace {
+thread_local bool WAGYU_INTERRUPT_REQUESTED = false;
+}
+
+namespace mapbox {
+namespace geometry {
+namespace wagyu {
+
+static void interrupt_reset(void) {
+    WAGYU_INTERRUPT_REQUESTED = false;
+}
+
+static void interrupt_request(void) {
+    WAGYU_INTERRUPT_REQUESTED = true;
+}
+
+static void interrupt_check(void) {
+    if (WAGYU_INTERRUPT_REQUESTED) {
+        interrupt_reset();
+        throw std::runtime_error("Wagyu interrupted");
+    }
+}
+} // namespace wagyu
+} // namespace geometry
+} // namespace mapbox
+
+#else /* ! USE_WAGYU_INTERRUPT */
+
+namespace mapbox {
+namespace geometry {
+namespace wagyu {
+
+static void interrupt_check(void) {
+}
+
+} // namespace wagyu
+} // namespace geometry
+} // namespace mapbox
+
+#endif /* USE_WAGYU_INTERRUPT */

mapbox/geometry/wagyu/intersect.hpp

@@ -0,0 +1,70 @@
+#pragma once
+
+#include <set>
+
+#include <mapbox/geometry/point.hpp>
+
+#include <mapbox/geometry/wagyu/active_bound_list.hpp>
+
+#ifdef DEBUG
+#include <iostream>
+#endif
+
+namespace mapbox {
+namespace geometry {
+namespace wagyu {
+
+template <typename T>
+struct intersect_node {
+
+    bound_ptr<T> bound1;
+    bound_ptr<T> bound2;
+    mapbox::geometry::point<double> pt;
+
+    intersect_node(intersect_node<T>&& n) noexcept
+        : bound1(std::move(n.bound1)), bound2(std::move(n.bound2)), pt(std::move(n.pt)) {
+    }
+
+    intersect_node& operator=(intersect_node<T>&& n) noexcept {
+        bound1 = std::move(n.bound1);
+        bound2 = std::move(n.bound2);
+        pt = std::move(n.pt);
+        return *this;
+    }
+
+    intersect_node(bound_ptr<T> const& bound1_, bound_ptr<T> const& bound2_, mapbox::geometry::point<double> const& pt_)
+        : bound1(bound1_), bound2(bound2_), pt(pt_) {
+    }
+};
+
+template <typename T>
+using intersect_list = std::vector<intersect_node<T>>;
+
+#ifdef DEBUG
+
+template <class charT, class traits, typename T>
+inline std::basic_ostream<charT, traits>& operator<<(std::basic_ostream<charT, traits>& out,
+                                                     const intersect_node<T>& e) {
+    out << " point x: " << e.pt.x << " y: " << e.pt.y << std::endl;
+    out << " bound 1: " << std::endl;
+    out << *e.bound1 << std::endl;
+    out << " bound 2: " << std::endl;
+    out << *e.bound2 << std::endl;
+    return out;
+}
+
+template <class charT, class traits, typename T>
+inline std::basic_ostream<charT, traits>& operator<<(std::basic_ostream<charT, traits>& out,
+                                                     const intersect_list<T>& ints) {
+    std::size_t c = 0;
+    for (auto const& i : ints) {
+        out << "Intersection: " << c++ << std::endl;
+        out << i;
+    }
+    return out;
+}
+
+#endif
+} // namespace wagyu
+} // namespace geometry
+} // namespace mapbox

mapbox/geometry/wagyu/intersect_util.hpp

@@ -0,0 +1,365 @@
+#pragma once
+
+#include <mapbox/geometry/wagyu/active_bound_list.hpp>
+#include <mapbox/geometry/wagyu/bound.hpp>
+#include <mapbox/geometry/wagyu/bubble_sort.hpp>
+#include <mapbox/geometry/wagyu/config.hpp>
+#include <mapbox/geometry/wagyu/intersect.hpp>
+#include <mapbox/geometry/wagyu/ring_util.hpp>
+#include <mapbox/geometry/wagyu/util.hpp>
+
+#include <algorithm>
+
+namespace mapbox {
+namespace geometry {
+namespace wagyu {
+
+template <typename T>
+struct intersect_list_sorter {
+    inline bool operator()(intersect_node<T> const& node1, intersect_node<T> const& node2) {
+        if (!values_are_equal(node2.pt.y, node1.pt.y)) {
+            return node2.pt.y < node1.pt.y;
+        } else {
+            return (node2.bound1->winding_count2 + node2.bound2->winding_count2) >
+                   (node1.bound1->winding_count2 + node1.bound2->winding_count2);
+        }
+    }
+};
+
+template <typename T>
+inline mapbox::geometry::point<T> round_point(mapbox::geometry::point<double> const& pt) {
+    return mapbox::geometry::point<T>(round_towards_max<T>(pt.x), round_towards_max<T>(pt.y));
+}
+
+template <typename T>
+inline void swap_rings(bound<T>& b1, bound<T>& b2) {
+    ring_ptr<T> ring = b1.ring;
+    b1.ring = b2.ring;
+    b2.ring = ring;
+}
+
+template <typename T>
+inline void swap_sides(bound<T>& b1, bound<T>& b2) {
+    edge_side side = b1.side;
+    b1.side = b2.side;
+    b2.side = side;
+}
+
+template <typename T1, typename T2>
+bool get_edge_intersection(edge<T1> const& e1, edge<T1> const& e2, mapbox::geometry::point<T2>& pt) {
+    T2 p0_x = static_cast<T2>(e1.bot.x);
+    T2 p0_y = static_cast<T2>(e1.bot.y);
+    T2 p1_x = static_cast<T2>(e1.top.x);
+    T2 p1_y = static_cast<T2>(e1.top.y);
+    T2 p2_x = static_cast<T2>(e2.bot.x);
+    T2 p2_y = static_cast<T2>(e2.bot.y);
+    T2 p3_x = static_cast<T2>(e2.top.x);
+    T2 p3_y = static_cast<T2>(e2.top.y);
+    T2 s1_x, s1_y, s2_x, s2_y;
+    s1_x = p1_x - p0_x;
+    s1_y = p1_y - p0_y;
+    s2_x = p3_x - p2_x;
+    s2_y = p3_y - p2_y;
+
+    T2 s = (-s1_y * (p0_x - p2_x) + s1_x * (p0_y - p2_y)) / (-s2_x * s1_y + s1_x * s2_y);
+    T2 t = (s2_x * (p0_y - p2_y) - s2_y * (p0_x - p2_x)) / (-s2_x * s1_y + s1_x * s2_y);
+
+    if (s >= 0.0 && s <= 1.0 && t >= 0.0 && t <= 1.0) {
+        pt.x = p0_x + (t * s1_x);
+        pt.y = p0_y + (t * s1_y);
+        return true;
+    }
+    // LCOV_EXCL_START
+    return false;
+    // LCOV_EXCL_END
+}
+
+template <typename T>
+struct intersection_compare {
+    bool operator()(bound_ptr<T> const& b1, bound_ptr<T> const& b2) {
+        return !(b1->current_x > b2->current_x && !slopes_equal(*(b1->current_edge), *(b2->current_edge)));
+    }
+};
+
+template <typename T>
+struct on_intersection_swap {
+
+    intersect_list<T>& intersects;
+
+    on_intersection_swap(intersect_list<T>& i) : intersects(i) {
+    }
+
+    void operator()(bound_ptr<T> const& b1, bound_ptr<T> const& b2) {
+        mapbox::geometry::point<double> pt;
+        if (!get_edge_intersection<T, double>(*(b1->current_edge), *(b2->current_edge), pt)) {
+            // LCOV_EXCL_START
+            throw std::runtime_error("Trying to find intersection of lines that do not intersect");
+            // LCOV_EXCL_END
+        }
+        intersects.emplace_back(b1, b2, pt);
+    }
+};
+
+template <typename T>
+void build_intersect_list(active_bound_list<T>& active_bounds, intersect_list<T>& intersects) {
+    bubble_sort(active_bounds.begin(), active_bounds.end(), intersection_compare<T>(),
+                on_intersection_swap<T>(intersects));
+}
+
+template <typename T>
+void intersect_bounds(bound<T>& b1,
+                      bound<T>& b2,
+                      mapbox::geometry::point<T> const& pt,
+                      clip_type cliptype,
+                      fill_type subject_fill_type,
+                      fill_type clip_fill_type,
+                      ring_manager<T>& rings,
+                      active_bound_list<T>& active_bounds) {
+    bool b1Contributing = (b1.ring != nullptr);
+    bool b2Contributing = (b2.ring != nullptr);
+
+    // update winding counts...
+    // assumes that b1 will be to the Right of b2 ABOVE the intersection
+    if (b1.poly_type == b2.poly_type) {
+        if (is_even_odd_fill_type(b1, subject_fill_type, clip_fill_type)) {
+            std::swap(b1.winding_count, b2.winding_count);
+        } else {
+            if (b1.winding_count + b2.winding_delta == 0) {
+                b1.winding_count = -b1.winding_count;
+            } else {
+                b1.winding_count += b2.winding_delta;
+            }
+            if (b2.winding_count - b1.winding_delta == 0) {
+                b2.winding_count = -b2.winding_count;
+            } else {
+                b2.winding_count -= b1.winding_delta;
+            }
+        }
+    } else {
+        if (!is_even_odd_fill_type(b2, subject_fill_type, clip_fill_type)) {
+            b1.winding_count2 += b2.winding_delta;
+        } else {
+            b1.winding_count2 = (b1.winding_count2 == 0) ? 1 : 0;
+        }
+        if (!is_even_odd_fill_type(b1, subject_fill_type, clip_fill_type)) {
+            b2.winding_count2 -= b1.winding_delta;
+        } else {
+            b2.winding_count2 = (b2.winding_count2 == 0) ? 1 : 0;
+        }
+    }
+
+    fill_type b1FillType, b2FillType, b1FillType2, b2FillType2;
+    if (b1.poly_type == polygon_type_subject) {
+        b1FillType = subject_fill_type;
+        b1FillType2 = clip_fill_type;
+    } else {
+        b1FillType = clip_fill_type;
+        b1FillType2 = subject_fill_type;
+    }
+    if (b2.poly_type == polygon_type_subject) {
+        b2FillType = subject_fill_type;
+        b2FillType2 = clip_fill_type;
+    } else {
+        b2FillType = clip_fill_type;
+        b2FillType2 = subject_fill_type;
+    }
+
+    std::int32_t b1Wc, b2Wc;
+    switch (b1FillType) {
+    case fill_type_positive:
+        b1Wc = b1.winding_count;
+        break;
+    case fill_type_negative:
+        b1Wc = -b1.winding_count;
+        break;
+    case fill_type_even_odd:
+    case fill_type_non_zero:
+    default:
+        b1Wc = std::abs(static_cast<int>(b1.winding_count));
+    }
+    switch (b2FillType) {
+    case fill_type_positive:
+        b2Wc = b2.winding_count;
+        break;
+    case fill_type_negative:
+        b2Wc = -b2.winding_count;
+        break;
+    case fill_type_even_odd:
+    case fill_type_non_zero:
+    default:
+        b2Wc = std::abs(static_cast<int>(b2.winding_count));
+    }
+    if (b1Contributing && b2Contributing) {
+        if ((b1Wc != 0 && b1Wc != 1) || (b2Wc != 0 && b2Wc != 1) ||
+            (b1.poly_type != b2.poly_type && cliptype != clip_type_x_or)) {
+            add_local_maximum_point(b1, b2, pt, rings, active_bounds);
+        } else {
+            add_point(b1, active_bounds, pt, rings);
+            add_point(b2, active_bounds, pt, rings);
+            swap_sides(b1, b2);
+            swap_rings(b1, b2);
+        }
+    } else if (b1Contributing) {
+        if (b2Wc == 0 || b2Wc == 1) {
+            add_point(b1, active_bounds, pt, rings);
+            b2.last_point = pt;
+            swap_sides(b1, b2);
+            swap_rings(b1, b2);
+        }
+    } else if (b2Contributing) {
+        if (b1Wc == 0 || b1Wc == 1) {
+            b1.last_point = pt;
+            add_point(b2, active_bounds, pt, rings);
+            swap_sides(b1, b2);
+            swap_rings(b1, b2);
+        }
+    } else if ((b1Wc == 0 || b1Wc == 1) && (b2Wc == 0 || b2Wc == 1)) {
+        // neither bound is currently contributing ...
+
+        std::int32_t b1Wc2, b2Wc2;
+        switch (b1FillType2) {
+        case fill_type_positive:
+            b1Wc2 = b1.winding_count2;
+            break;
+        case fill_type_negative:
+            b1Wc2 = -b1.winding_count2;
+            break;
+        case fill_type_even_odd:
+        case fill_type_non_zero:
+        default:
+            b1Wc2 = std::abs(static_cast<int>(b1.winding_count2));
+        }
+        switch (b2FillType2) {
+        case fill_type_positive:
+            b2Wc2 = b2.winding_count2;
+            break;
+        case fill_type_negative:
+            b2Wc2 = -b2.winding_count2;
+            break;
+        case fill_type_even_odd:
+        case fill_type_non_zero:
+        default:
+            b2Wc2 = std::abs(static_cast<int>(b2.winding_count2));
+        }
+
+        if (b1.poly_type != b2.poly_type) {
+            add_local_minimum_point(b1, b2, active_bounds, pt, rings);
+        } else if (b1Wc == 1 && b2Wc == 1) {
+            switch (cliptype) {
+            case clip_type_intersection:
+                if (b1Wc2 > 0 && b2Wc2 > 0) {
+                    add_local_minimum_point(b1, b2, active_bounds, pt, rings);
+                }
+                break;
+            default:
+            case clip_type_union:
+                if (b1Wc2 <= 0 && b2Wc2 <= 0) {
+                    add_local_minimum_point(b1, b2, active_bounds, pt, rings);
+                }
+                break;
+            case clip_type_difference:
+                if (((b1.poly_type == polygon_type_clip) && (b1Wc2 > 0) && (b2Wc2 > 0)) ||
+                    ((b1.poly_type == polygon_type_subject) && (b1Wc2 <= 0) && (b2Wc2 <= 0))) {
+                    add_local_minimum_point(b1, b2, active_bounds, pt, rings);
+                }
+                break;
+            case clip_type_x_or:
+                add_local_minimum_point(b1, b2, active_bounds, pt, rings);
+            }
+        } else {
+            swap_sides(b1, b2);
+        }
+    }
+}
+
+template <typename T>
+bool bounds_adjacent(intersect_node<T> const& inode, bound_ptr<T> next) {
+    return (next == inode.bound2) || (next == inode.bound1);
+}
+
+template <typename T>
+struct find_first_bound {
+    bound_ptr<T> b1;
+    bound_ptr<T> b2;
+
+    find_first_bound(intersect_node<T> const& inode) : b1(inode.bound1), b2(inode.bound2) {
+    }
+
+    bool operator()(bound_ptr<T> const& b) {
+        return b == b1 || b == b2;
+    }
+};
+
+template <typename T>
+void process_intersect_list(intersect_list<T>& intersects,
+                            clip_type cliptype,
+                            fill_type subject_fill_type,
+                            fill_type clip_fill_type,
+                            ring_manager<T>& rings,
+                            active_bound_list<T>& active_bounds) {
+    for (auto node_itr = intersects.begin(); node_itr != intersects.end(); ++node_itr) {
+        auto b1 = std::find_if(active_bounds.begin(), active_bounds.end(), find_first_bound<T>(*node_itr));
+        auto b2 = std::next(b1);
+        if (!bounds_adjacent(*node_itr, *b2)) {
+            auto next_itr = std::next(node_itr);
+            while (next_itr != intersects.end()) {
+                auto n1 = std::find_if(active_bounds.begin(), active_bounds.end(), find_first_bound<T>(*next_itr));
+                auto n2 = std::next(n1);
+                if (bounds_adjacent(*next_itr, *n2)) {
+                    b1 = n1;
+                    b2 = n2;
+                    break;
+                }
+                ++next_itr;
+            }
+            if (next_itr == intersects.end()) {
+                throw std::runtime_error("Could not properly correct intersection order.");
+            }
+            std::iter_swap(node_itr, next_itr);
+        }
+        mapbox::geometry::point<T> pt = round_point<T>(node_itr->pt);
+        intersect_bounds(*(node_itr->bound1), *(node_itr->bound2), pt, cliptype, subject_fill_type, clip_fill_type,
+                         rings, active_bounds);
+        std::iter_swap(b1, b2);
+    }
+}
+
+template <typename T>
+void update_current_x(active_bound_list<T>& active_bounds, T top_y) {
+    std::size_t pos = 0;
+    for (auto& bnd : active_bounds) {
+        bnd->pos = pos++;
+        bnd->current_x = get_current_x(*bnd->current_edge, top_y);
+    }
+}
+
+template <typename T>
+void process_intersections(T top_y,
+                           active_bound_list<T>& active_bounds,
+                           clip_type cliptype,
+                           fill_type subject_fill_type,
+                           fill_type clip_fill_type,
+                           ring_manager<T>& rings) {
+    if (active_bounds.empty()) {
+        return;
+    }
+    update_current_x(active_bounds, top_y);
+    intersect_list<T> intersects;
+    build_intersect_list(active_bounds, intersects);
+
+    if (intersects.empty()) {
+        return;
+    }
+
+    // Restore order of active bounds list
+    std::stable_sort(active_bounds.begin(), active_bounds.end(),
+                     [](bound_ptr<T> const& b1, bound_ptr<T> const& b2) { return b1->pos < b2->pos; });
+
+    // Sort the intersection list
+    std::stable_sort(intersects.begin(), intersects.end(), intersect_list_sorter<T>());
+
+    process_intersect_list(intersects, cliptype, subject_fill_type, clip_fill_type, rings, active_bounds);
+}
+} // namespace wagyu
+} // namespace geometry
+} // namespace mapbox

mapbox/geometry/wagyu/local_minimum.hpp

@@ -0,0 +1,117 @@
+#pragma once
+
+#ifdef DEBUG
+#include <iostream>
+#include <sstream>
+#endif
+
+#include <queue>
+
+#include <mapbox/geometry/wagyu/bound.hpp>
+
+namespace mapbox {
+namespace geometry {
+namespace wagyu {
+
+template <typename T>
+struct local_minimum {
+    bound<T> left_bound;
+    bound<T> right_bound;
+    T y;
+    bool minimum_has_horizontal;
+
+    local_minimum(bound<T>&& left_bound_, bound<T>&& right_bound_, T y_, bool has_horz_)
+        : left_bound(std::move(left_bound_)),
+          right_bound(std::move(right_bound_)),
+          y(y_),
+          minimum_has_horizontal(has_horz_) {
+    }
+};
+
+template <typename T>
+using local_minimum_list = std::deque<local_minimum<T>>;
+
+template <typename T>
+using local_minimum_itr = typename local_minimum_list<T>::iterator;
+
+template <typename T>
+using local_minimum_ptr = local_minimum<T>*;
+
+template <typename T>
+using local_minimum_ptr_list = std::vector<local_minimum_ptr<T>>;
+
+template <typename T>
+using local_minimum_ptr_list_itr = typename local_minimum_ptr_list<T>::iterator;
+
+template <typename T>
+struct local_minimum_sorter {
+    inline bool operator()(local_minimum_ptr<T> const& locMin1, local_minimum_ptr<T> const& locMin2) {
+        if (locMin2->y == locMin1->y) {
+            return locMin2->minimum_has_horizontal != locMin1->minimum_has_horizontal &&
+                   locMin1->minimum_has_horizontal;
+        }
+        return locMin2->y < locMin1->y;
+    }
+};
+
+#ifdef DEBUG
+
+template <class charT, class traits, typename T>
+inline std::basic_ostream<charT, traits>& operator<<(std::basic_ostream<charT, traits>& out,
+                                                     const local_minimum<T>& lm) {
+    out << " Local Minimum:" << std::endl;
+    out << "    y: " << lm.y << std::endl;
+    if (lm.minimum_has_horizontal) {
+        out << "    minimum_has_horizontal: true" << std::endl;
+    } else {
+        out << "    minimum_has_horizontal: false" << std::endl;
+    }
+    out << "   left_bound: " << std::endl;
+    out << lm.left_bound << std::endl;
+    out << "   right_bound: " << std::endl;
+    out << lm.right_bound << std::endl;
+    return out;
+}
+
+template <class charT, class traits, typename T>
+inline std::basic_ostream<charT, traits>& operator<<(std::basic_ostream<charT, traits>& out,
+                                                     const local_minimum_ptr_list<T>& lms) {
+    for (auto const& lm : lms) {
+        out << *lm;
+    }
+    return out;
+}
+
+template <typename T>
+std::string output_all_edges(local_minimum_ptr_list<T> const& lms) {
+    std::ostringstream out;
+    out << "[";
+    bool first = true;
+    for (auto const& lm : lms) {
+        for (auto const& e : lm->left_bound.edges) {
+            if (first) {
+                first = false;
+            } else {
+                out << ",";
+            }
+            out << "[[" << e.bot.x << "," << e.bot.y << "],[";
+            out << e.top.x << "," << e.top.y << "]]";
+        }
+        for (auto const& e : lm->right_bound.edges) {
+            if (first) {
+                first = false;
+            } else {
+                out << ",";
+            }
+            out << "[[" << e.bot.x << "," << e.bot.y << "],[";
+            out << e.top.x << "," << e.top.y << "]]";
+        }
+    }
+    out << "]";
+    return out.str();
+}
+
+#endif
+} // namespace wagyu
+} // namespace geometry
+} // namespace mapbox

mapbox/geometry/wagyu/local_minimum_util.hpp

@@ -0,0 +1,314 @@
+#pragma once
+
+#include <mapbox/geometry/wagyu/edge.hpp>
+#include <mapbox/geometry/wagyu/interrupt.hpp>
+#include <mapbox/geometry/wagyu/local_minimum.hpp>
+
+#include <algorithm>
+
+#ifdef DEBUG
+#include <stdexcept>
+#endif
+
+namespace mapbox {
+namespace geometry {
+namespace wagyu {
+
+template <typename T>
+inline void reverse_horizontal(edge<T>& e) {
+    // swap horizontal edges' top and bottom x's so they follow the natural
+    // progression of the bounds - ie so their xbots will align with the
+    // adjoining lower edge. [Helpful in the process_horizontal() method.]
+    std::swap(e.top.x, e.bot.x);
+}
+
+// Make a list start on a local maximum by
+// shifting all the points not on a local maximum to the
+template <typename T>
+void start_list_on_local_maximum(edge_list<T>& edges) {
+    if (edges.size() <= 2) {
+        return;
+    }
+    // Find the first local maximum going forward in the list
+    auto prev_edge = edges.end();
+    --prev_edge;
+    bool prev_edge_is_horizontal = is_horizontal(*prev_edge);
+    auto edge = edges.begin();
+    bool edge_is_horizontal;
+    bool y_decreasing_before_last_horizontal = false; // assume false at start
+
+    while (edge != edges.end()) {
+        edge_is_horizontal = is_horizontal(*edge);
+        if ((!prev_edge_is_horizontal && !edge_is_horizontal && edge->top == prev_edge->top)) {
+            break;
+        }
+        if (!edge_is_horizontal && prev_edge_is_horizontal) {
+            if (y_decreasing_before_last_horizontal && (edge->top == prev_edge->bot || edge->top == prev_edge->top)) {
+                break;
+            }
+        } else if (!y_decreasing_before_last_horizontal && !prev_edge_is_horizontal && edge_is_horizontal &&
+                   (prev_edge->top == edge->top || prev_edge->top == edge->bot)) {
+            y_decreasing_before_last_horizontal = true;
+        }
+        prev_edge_is_horizontal = edge_is_horizontal;
+        prev_edge = edge;
+        ++edge;
+    }
+    std::rotate(edges.begin(), edge, edges.end());
+}
+
+template <typename T>
+bound<T> create_bound_towards_minimum(edge_list<T>& edges) {
+    if (edges.size() == 1) {
+        if (is_horizontal(edges.front())) {
+            reverse_horizontal(edges.front());
+        }
+        bound<T> bnd;
+        std::swap(bnd.edges, edges);
+        return bnd;
+    }
+    auto next_edge = edges.begin();
+    auto edge = next_edge;
+    ++next_edge;
+    bool edge_is_horizontal = is_horizontal(*edge);
+    if (edge_is_horizontal) {
+        reverse_horizontal(*edge);
+    }
+    bool next_edge_is_horizontal;
+    bool y_increasing_before_last_horizontal = false; // assume false at start
+
+    while (next_edge != edges.end()) {
+        next_edge_is_horizontal = is_horizontal(*next_edge);
+        if ((!next_edge_is_horizontal && !edge_is_horizontal && edge->bot == next_edge->bot)) {
+            break;
+        }
+        if (!next_edge_is_horizontal && edge_is_horizontal) {
+            if (y_increasing_before_last_horizontal && (next_edge->bot == edge->bot || next_edge->bot == edge->top)) {
+                break;
+            }
+        } else if (!y_increasing_before_last_horizontal && !edge_is_horizontal && next_edge_is_horizontal &&
+                   (edge->bot == next_edge->top || edge->bot == next_edge->bot)) {
+            y_increasing_before_last_horizontal = true;
+        }
+        edge_is_horizontal = next_edge_is_horizontal;
+        edge = next_edge;
+        if (edge_is_horizontal) {
+            reverse_horizontal(*edge);
+        }
+        ++next_edge;
+    }
+    bound<T> bnd;
+    if (next_edge == edges.end()) {
+        std::swap(edges, bnd.edges);
+    } else {
+        bnd.edges.reserve(static_cast<std::size_t>(std::distance(edges.begin(), next_edge)));
+        std::move(edges.begin(), next_edge, std::back_inserter(bnd.edges));
+        edges.erase(edges.begin(), next_edge);
+    }
+    std::reverse(bnd.edges.begin(), bnd.edges.end());
+    return bnd;
+}
+
+template <typename T>
+bound<T> create_bound_towards_maximum(edge_list<T>& edges) {
+    if (edges.size() == 1) {
+        bound<T> bnd;
+        std::swap(bnd.edges, edges);
+        return bnd;
+    }
+    auto next_edge = edges.begin();
+    auto edge = next_edge;
+    ++next_edge;
+    bool edge_is_horizontal = is_horizontal(*edge);
+    bool next_edge_is_horizontal;
+    bool y_decreasing_before_last_horizontal = false; // assume false at start
+
+    while (next_edge != edges.end()) {
+        next_edge_is_horizontal = is_horizontal(*next_edge);
+        if ((!next_edge_is_horizontal && !edge_is_horizontal && edge->top == next_edge->top)) {
+            break;
+        }
+        if (!next_edge_is_horizontal && edge_is_horizontal) {
+            if (y_decreasing_before_last_horizontal && (next_edge->top == edge->bot || next_edge->top == edge->top)) {
+                break;
+            }
+        } else if (!y_decreasing_before_last_horizontal && !edge_is_horizontal && next_edge_is_horizontal &&
+                   (edge->top == next_edge->top || edge->top == next_edge->bot)) {
+            y_decreasing_before_last_horizontal = true;
+        }
+        edge_is_horizontal = next_edge_is_horizontal;
+        edge = next_edge;
+        ++next_edge;
+    }
+    bound<T> bnd;
+    if (next_edge == edges.end()) {
+        std::swap(bnd.edges, edges);
+    } else {
+        bnd.edges.reserve(static_cast<std::size_t>(std::distance(edges.begin(), next_edge)));
+        std::move(edges.begin(), next_edge, std::back_inserter(bnd.edges));
+        edges.erase(edges.begin(), next_edge);
+    }
+    return bnd;
+}
+
+template <typename T>
+void fix_horizontals(bound<T>& bnd) {
+
+    auto edge_itr = bnd.edges.begin();
+    auto next_itr = std::next(edge_itr);
+    if (next_itr == bnd.edges.end()) {
+        return;
+    }
+    if (is_horizontal(*edge_itr) && next_itr->bot != edge_itr->top) {
+        reverse_horizontal(*edge_itr);
+    }
+    auto prev_itr = edge_itr++;
+    while (edge_itr != bnd.edges.end()) {
+        if (is_horizontal(*edge_itr) && prev_itr->top != edge_itr->bot) {
+            reverse_horizontal(*edge_itr);
+        }
+        prev_itr = edge_itr;
+        ++edge_itr;
+    }
+}
+
+template <typename T>
+void move_horizontals_on_left_to_right(bound<T>& left_bound, bound<T>& right_bound) {
+    // We want all the horizontal segments that are at the same Y as the minimum to be on the right
+    // bound
+    auto edge_itr = left_bound.edges.begin();
+    while (edge_itr != left_bound.edges.end()) {
+        if (!is_horizontal(*edge_itr)) {
+            break;
+        }
+        reverse_horizontal(*edge_itr);
+        ++edge_itr;
+    }
+    if (edge_itr == left_bound.edges.begin()) {
+        return;
+    }
+    std::reverse(left_bound.edges.begin(), edge_itr);
+    auto dist = std::distance(left_bound.edges.begin(), edge_itr);
+    std::move(left_bound.edges.begin(), edge_itr, std::back_inserter(right_bound.edges));
+    left_bound.edges.erase(left_bound.edges.begin(), edge_itr);
+    std::rotate(right_bound.edges.begin(), std::prev(right_bound.edges.end(), dist), right_bound.edges.end());
+}
+
+template <typename T>
+void add_ring_to_local_minima_list(edge_list<T>& edges, local_minimum_list<T>& minima_list, polygon_type poly_type) {
+
+    if (edges.empty()) {
+        return;
+    }
+    // Adjust the order of the ring so we start on a local maximum
+    // therefore we start right away on a bound.
+    start_list_on_local_maximum(edges);
+
+    bound_ptr<T> first_minimum = nullptr;
+    bound_ptr<T> last_maximum = nullptr;
+    while (!edges.empty()) {
+        interrupt_check(); // Check for interruptions
+        bool lm_minimum_has_horizontal = false;
+        auto to_minimum = create_bound_towards_minimum(edges);
+        if (edges.empty()) {
+            throw std::runtime_error("Edges is empty after only creating a single bound.");
+        }
+        auto to_maximum = create_bound_towards_maximum(edges);
+        fix_horizontals(to_minimum);
+        fix_horizontals(to_maximum);
+        auto to_max_first_non_horizontal = to_maximum.edges.begin();
+        auto to_min_first_non_horizontal = to_minimum.edges.begin();
+        bool minimum_is_left = true;
+        while (to_max_first_non_horizontal != to_maximum.edges.end() && is_horizontal(*to_max_first_non_horizontal)) {
+            lm_minimum_has_horizontal = true;
+            ++to_max_first_non_horizontal;
+        }
+        while (to_min_first_non_horizontal != to_minimum.edges.end() && is_horizontal(*to_min_first_non_horizontal)) {
+            lm_minimum_has_horizontal = true;
+            ++to_min_first_non_horizontal;
+        }
+
+        if (to_max_first_non_horizontal == to_maximum.edges.end() ||
+            to_min_first_non_horizontal == to_minimum.edges.end()) {
+            throw std::runtime_error("should not have a horizontal only bound for a ring");
+        }
+
+        if (lm_minimum_has_horizontal) {
+            if (to_max_first_non_horizontal->bot.x > to_min_first_non_horizontal->bot.x) {
+                minimum_is_left = true;
+                move_horizontals_on_left_to_right(to_minimum, to_maximum);
+            } else {
+                minimum_is_left = false;
+                move_horizontals_on_left_to_right(to_maximum, to_minimum);
+            }
+        } else {
+            if (to_max_first_non_horizontal->dx > to_min_first_non_horizontal->dx) {
+                minimum_is_left = false;
+            } else {
+                minimum_is_left = true;
+            }
+        }
+        assert(!to_minimum.edges.empty());
+        assert(!to_maximum.edges.empty());
+        auto const& min_front = to_minimum.edges.front();
+        if (last_maximum) {
+            to_minimum.maximum_bound = last_maximum;
+        }
+        to_minimum.poly_type = poly_type;
+        to_maximum.poly_type = poly_type;
+        if (!minimum_is_left) {
+            to_minimum.side = edge_right;
+            to_maximum.side = edge_left;
+            to_minimum.winding_delta = -1;
+            to_maximum.winding_delta = 1;
+            minima_list.emplace_back(std::move(to_maximum), std::move(to_minimum), min_front.bot.y,
+                                     lm_minimum_has_horizontal);
+            if (!last_maximum) {
+                first_minimum = &(minima_list.back().right_bound);
+            } else {
+                last_maximum->maximum_bound = &(minima_list.back().right_bound);
+            }
+            last_maximum = &(minima_list.back().left_bound);
+        } else {
+            to_minimum.side = edge_left;
+            to_maximum.side = edge_right;
+            to_minimum.winding_delta = -1;
+            to_maximum.winding_delta = 1;
+            minima_list.emplace_back(std::move(to_minimum), std::move(to_maximum), min_front.bot.y,
+                                     lm_minimum_has_horizontal);
+            if (!last_maximum) {
+                first_minimum = &(minima_list.back().left_bound);
+            } else {
+                last_maximum->maximum_bound = &(minima_list.back().left_bound);
+            }
+            last_maximum = &(minima_list.back().right_bound);
+        }
+    }
+    last_maximum->maximum_bound = first_minimum;
+    first_minimum->maximum_bound = last_maximum;
+}
+
+template <typename T>
+void initialize_lm(local_minimum_ptr_list_itr<T>& lm) {
+    if (!(*lm)->left_bound.edges.empty()) {
+        (*lm)->left_bound.current_edge = (*lm)->left_bound.edges.begin();
+        (*lm)->left_bound.next_edge = std::next((*lm)->left_bound.current_edge);
+        (*lm)->left_bound.current_x = static_cast<double>((*lm)->left_bound.current_edge->bot.x);
+        (*lm)->left_bound.winding_count = 0;
+        (*lm)->left_bound.winding_count2 = 0;
+        (*lm)->left_bound.side = edge_left;
+        (*lm)->left_bound.ring = nullptr;
+    }
+    if (!(*lm)->right_bound.edges.empty()) {
+        (*lm)->right_bound.current_edge = (*lm)->right_bound.edges.begin();
+        (*lm)->right_bound.next_edge = std::next((*lm)->right_bound.current_edge);
+        (*lm)->right_bound.current_x = static_cast<double>((*lm)->right_bound.current_edge->bot.x);
+        (*lm)->right_bound.winding_count = 0;
+        (*lm)->right_bound.winding_count2 = 0;
+        (*lm)->right_bound.side = edge_right;
+        (*lm)->right_bound.ring = nullptr;
+    }
+}
+} // namespace wagyu
+} // namespace geometry
+} // namespace mapbox

mapbox/geometry/wagyu/point.hpp

@@ -0,0 +1,110 @@
+#pragma once
+
+#include <mapbox/geometry/point.hpp>
+
+#ifdef DEBUG
+#include <iostream>
+#endif
+
+namespace mapbox {
+namespace geometry {
+namespace wagyu {
+
+template <typename T>
+struct point;
+
+template <typename T>
+using point_ptr = point<T>*;
+
+template <typename T>
+using const_point_ptr = point<T>* const;
+
+template <typename T>
+struct ring;
+
+template <typename T>
+using ring_ptr = ring<T>*;
+
+template <typename T>
+using const_ring_ptr = ring<T>* const;
+
+template <typename T>
+struct point {
+    using coordinate_type = T;
+    ring_ptr<T> ring;
+    T x;
+    T y;
+    point_ptr<T> next;
+    point_ptr<T> prev;
+
+    point() : ring(nullptr), x(0), y(0), prev(this), next(this) {
+    }
+
+    point(T x_, T y_) : ring(nullptr), x(x_), y(y_), next(this), prev(this) {
+    }
+
+    point(ring_ptr<T> ring_, mapbox::geometry::point<T> const& pt)
+        : ring(ring_), x(pt.x), y(pt.y), next(this), prev(this) {
+    }
+
+    point(ring_ptr<T> ring_, mapbox::geometry::point<T> const& pt, point_ptr<T> before_this_point)
+        : ring(ring_), x(pt.x), y(pt.y), next(before_this_point), prev(before_this_point->prev) {
+        before_this_point->prev = this;
+        prev->next = this;
+    }
+};
+
+template <typename T>
+using point_vector = std::vector<point_ptr<T>>;
+
+template <typename T>
+using point_vector_itr = typename point_vector<T>::iterator;
+
+template <typename T>
+bool operator==(point<T> const& lhs, point<T> const& rhs) {
+    return lhs.x == rhs.x && lhs.y == rhs.y;
+}
+
+template <typename T>
+bool operator==(mapbox::geometry::point<T> const& lhs, point<T> const& rhs) {
+    return lhs.x == rhs.x && lhs.y == rhs.y;
+}
+
+template <typename T>
+bool operator==(point<T> const& lhs, mapbox::geometry::point<T> const& rhs) {
+    return lhs.x == rhs.x && lhs.y == rhs.y;
+}
+
+template <typename T>
+bool operator!=(point<T> const& lhs, point<T> const& rhs) {
+    return lhs.x != rhs.x || lhs.y != rhs.y;
+}
+
+template <typename T>
+bool operator!=(mapbox::geometry::point<T> const& lhs, point<T> const& rhs) {
+    return lhs.x != rhs.x || lhs.y != rhs.y;
+}
+
+template <typename T>
+bool operator!=(point<T> const& lhs, mapbox::geometry::point<T> const& rhs) {
+    return lhs.x != rhs.x || lhs.y != rhs.y;
+}
+
+#ifdef DEBUG
+
+template <class charT, class traits, typename T>
+inline std::basic_ostream<charT, traits>& operator<<(std::basic_ostream<charT, traits>& out, const point<T>& p) {
+    out << "  point at: " << p.x << ", " << p.y;
+    return out;
+}
+
+template <class charT, class traits, typename T>
+inline std::basic_ostream<charT, traits>& operator<<(std::basic_ostream<charT, traits>& out,
+                                                     const mapbox::geometry::point<T>& p) {
+    out << "  point at: " << p.x << ", " << p.y;
+    return out;
+}
+#endif
+} // namespace wagyu
+} // namespace geometry
+} // namespace mapbox

mapbox/geometry/wagyu/process_horizontal.hpp

@@ -0,0 +1,256 @@
+#pragma once
+
+#include <mapbox/geometry/line_string.hpp>
+#include <mapbox/geometry/point.hpp>
+#include <mapbox/geometry/polygon.hpp>
+
+#include <mapbox/geometry/wagyu/config.hpp>
+#include <mapbox/geometry/wagyu/edge.hpp>
+#include <mapbox/geometry/wagyu/local_minimum.hpp>
+#include <mapbox/geometry/wagyu/util.hpp>
+
+namespace mapbox {
+namespace geometry {
+namespace wagyu {
+
+template <typename T>
+active_bound_list_itr<T> process_horizontal_left_to_right(T scanline_y,
+                                                          active_bound_list_itr<T>& horz_bound,
+                                                          active_bound_list<T>& active_bounds,
+                                                          ring_manager<T>& rings,
+                                                          scanbeam_list<T>& scanbeam,
+                                                          clip_type cliptype,
+                                                          fill_type subject_fill_type,
+                                                          fill_type clip_fill_type) {
+    auto horizontal_itr_behind = horz_bound;
+    bool shifted = false;
+    bool is_maxima_edge = is_maxima(horz_bound, scanline_y);
+    auto bound_max_pair = active_bounds.end();
+    if (is_maxima_edge) {
+        bound_max_pair = get_maxima_pair<T>(horz_bound, active_bounds);
+    }
+
+    auto hp_itr = rings.current_hp_itr;
+    while (hp_itr != rings.hot_pixels.end() &&
+           (hp_itr->y > scanline_y || (hp_itr->y == scanline_y && hp_itr->x < (*horz_bound)->current_edge->bot.x))) {
+        ++hp_itr;
+    }
+
+    auto bnd = std::next(horz_bound);
+
+    while (bnd != active_bounds.end()) {
+        if (*bnd == nullptr) {
+            ++bnd;
+            continue;
+        }
+        // this code block inserts extra coords into horizontal edges (in output
+        // polygons) wherever hot pixels touch these horizontal edges. This helps
+        //'simplifying' polygons (ie if the Simplify property is set).
+        while (hp_itr != rings.hot_pixels.end() && hp_itr->y == scanline_y &&
+               hp_itr->x < wround<T>((*bnd)->current_x) && hp_itr->x < (*horz_bound)->current_edge->top.x) {
+            if ((*horz_bound)->ring) {
+                add_point_to_ring(*(*horz_bound), *hp_itr, rings);
+            }
+            ++hp_itr;
+        }
+
+        if (greater_than((*bnd)->current_x, static_cast<double>((*horz_bound)->current_edge->top.x))) {
+            break;
+        }
+
+        // Also break if we've got to the end of an intermediate horizontal edge ...
+        // nb: Smaller Dx's are to the right of larger Dx's ABOVE the horizontal.
+        if (wround<T>((*bnd)->current_x) == (*horz_bound)->current_edge->top.x &&
+            (*horz_bound)->next_edge != (*horz_bound)->edges.end() &&
+            (*horz_bound)->current_edge->dx < (*horz_bound)->next_edge->dx) {
+            break;
+        }
+
+        // note: may be done multiple times
+        if ((*horz_bound)->ring) {
+            add_point_to_ring(*(*horz_bound), mapbox::geometry::point<T>(wround<T>((*bnd)->current_x), scanline_y),
+                              rings);
+        }
+
+        // OK, so far we're still in range of the horizontal Edge  but make sure
+        // we're at the last of consec. horizontals when matching with eMaxPair
+        if (is_maxima_edge && bnd == bound_max_pair) {
+            if ((*horz_bound)->ring && (*bound_max_pair)->ring) {
+                add_local_maximum_point(*(*horz_bound), *(*bound_max_pair), (*horz_bound)->current_edge->top, rings,
+                                        active_bounds);
+            }
+            *bound_max_pair = nullptr;
+            *horz_bound = nullptr;
+            if (!shifted) {
+                ++horizontal_itr_behind;
+            }
+            return horizontal_itr_behind;
+        }
+
+        intersect_bounds(*(*horz_bound), *(*bnd), mapbox::geometry::point<T>(wround<T>((*bnd)->current_x), scanline_y),
+                         cliptype, subject_fill_type, clip_fill_type, rings, active_bounds);
+        std::iter_swap(horz_bound, bnd);
+        horz_bound = bnd;
+        ++bnd;
+        shifted = true;
+    } // end while (bnd != active_bounds.end())
+
+    if ((*horz_bound)->ring) {
+        while (hp_itr != rings.hot_pixels.end() && hp_itr->y == scanline_y &&
+               hp_itr->x < (*horz_bound)->current_edge->top.x) {
+            add_point_to_ring(*(*horz_bound), *hp_itr, rings);
+            ++hp_itr;
+        }
+    }
+
+    if ((*horz_bound)->ring) {
+        add_point_to_ring(*(*horz_bound), (*horz_bound)->current_edge->top, rings);
+    }
+
+    if ((*horz_bound)->next_edge != (*horz_bound)->edges.end()) {
+        next_edge_in_bound(*(*horz_bound), scanbeam);
+    } else {
+        *horz_bound = nullptr;
+    }
+    if (!shifted) {
+        ++horizontal_itr_behind;
+    }
+    return horizontal_itr_behind;
+}
+
+template <typename T>
+active_bound_list_itr<T> process_horizontal_right_to_left(T scanline_y,
+                                                          active_bound_list_itr<T>& horz_bound_fwd,
+                                                          active_bound_list<T>& active_bounds,
+                                                          ring_manager<T>& rings,
+                                                          scanbeam_list<T>& scanbeam,
+                                                          clip_type cliptype,
+                                                          fill_type subject_fill_type,
+                                                          fill_type clip_fill_type) {
+    auto next_bnd_itr = std::next(horz_bound_fwd);
+    bool is_maxima_edge = is_maxima(horz_bound_fwd, scanline_y);
+    auto bound_max_pair = active_bounds.rend();
+    if (is_maxima_edge) {
+        bound_max_pair = active_bound_list_rev_itr<T>(get_maxima_pair<T>(horz_bound_fwd, active_bounds));
+        --bound_max_pair;
+    }
+    auto hp_itr_fwd = rings.current_hp_itr;
+    while (hp_itr_fwd != rings.hot_pixels.end() &&
+           (hp_itr_fwd->y < scanline_y ||
+            (hp_itr_fwd->y == scanline_y && hp_itr_fwd->x < (*horz_bound_fwd)->current_edge->top.x))) {
+        ++hp_itr_fwd;
+    }
+    auto hp_itr = hot_pixel_rev_itr<T>(hp_itr_fwd);
+
+    auto bnd = active_bound_list_rev_itr<T>(horz_bound_fwd);
+    auto horz_bound = std::prev(bnd);
+    while (bnd != active_bounds.rend()) {
+        if (*bnd == nullptr) {
+            ++bnd;
+            continue;
+        }
+        // this code block inserts extra coords into horizontal edges (in output
+        // polygons) wherever hot pixels touch these horizontal edges.
+        while (hp_itr != rings.hot_pixels.rend() && hp_itr->y == scanline_y &&
+               hp_itr->x > wround<T>((*bnd)->current_x) && hp_itr->x > (*horz_bound)->current_edge->top.x) {
+            if ((*horz_bound)->ring) {
+                add_point_to_ring(*(*horz_bound), *hp_itr, rings);
+            }
+            ++hp_itr;
+        }
+
+        if (less_than((*bnd)->current_x, static_cast<double>((*horz_bound)->current_edge->top.x))) {
+            break;
+        }
+
+        // Also break if we've got to the end of an intermediate horizontal edge ...
+        // nb: Smaller Dx's are to the right of larger Dx's ABOVE the horizontal.
+        if (wround<T>((*bnd)->current_x) == (*horz_bound)->current_edge->top.x &&
+            (*horz_bound)->next_edge != (*horz_bound)->edges.end() &&
+            (*horz_bound)->current_edge->dx < (*horz_bound)->next_edge->dx) {
+            break;
+        }
+
+        // note: may be done multiple times
+        if ((*horz_bound)->ring) {
+            add_point_to_ring(*(*horz_bound), mapbox::geometry::point<T>(wround<T>((*bnd)->current_x), scanline_y),
+                              rings);
+        }
+
+        // OK, so far we're still in range of the horizontal Edge  but make sure
+        // we're at the last of consec. horizontals when matching with eMaxPair
+        if (is_maxima_edge && bnd == bound_max_pair) {
+            if ((*horz_bound)->ring && (*bound_max_pair)->ring) {
+                add_local_maximum_point(*(*horz_bound), *(*bound_max_pair), (*horz_bound)->current_edge->top, rings,
+                                        active_bounds);
+            }
+            *bound_max_pair = nullptr;
+            *horz_bound = nullptr;
+            return next_bnd_itr;
+        }
+
+        intersect_bounds(*(*bnd), *(*horz_bound), mapbox::geometry::point<T>(wround<T>((*bnd)->current_x), scanline_y),
+                         cliptype, subject_fill_type, clip_fill_type, rings, active_bounds);
+        std::iter_swap(horz_bound, bnd);
+        horz_bound = bnd;
+        ++bnd;
+    } // end while (bnd != active_bounds.rend())
+
+    if ((*horz_bound)->ring) {
+        while (hp_itr != rings.hot_pixels.rend() && hp_itr->y == scanline_y &&
+               hp_itr->x > (*horz_bound)->current_edge->top.x) {
+            add_point_to_ring(*(*horz_bound), *hp_itr, rings);
+            ++hp_itr;
+        }
+    }
+    if ((*horz_bound)->ring) {
+        add_point_to_ring(*(*horz_bound), (*horz_bound)->current_edge->top, rings);
+    }
+
+    if ((*horz_bound)->next_edge != (*horz_bound)->edges.end()) {
+        next_edge_in_bound(*(*horz_bound), scanbeam);
+    } else {
+        *horz_bound = nullptr;
+    }
+    return next_bnd_itr;
+}
+
+template <typename T>
+active_bound_list_itr<T> process_horizontal(T scanline_y,
+                                            active_bound_list_itr<T>& horz_bound,
+                                            active_bound_list<T>& active_bounds,
+                                            ring_manager<T>& rings,
+                                            scanbeam_list<T>& scanbeam,
+                                            clip_type cliptype,
+                                            fill_type subject_fill_type,
+                                            fill_type clip_fill_type) {
+    if ((*horz_bound)->current_edge->bot.x < (*horz_bound)->current_edge->top.x) {
+        return process_horizontal_left_to_right(scanline_y, horz_bound, active_bounds, rings, scanbeam, cliptype,
+                                                subject_fill_type, clip_fill_type);
+    } else {
+        return process_horizontal_right_to_left(scanline_y, horz_bound, active_bounds, rings, scanbeam, cliptype,
+                                                subject_fill_type, clip_fill_type);
+    }
+}
+
+template <typename T>
+void process_horizontals(T scanline_y,
+                         active_bound_list<T>& active_bounds,
+                         ring_manager<T>& rings,
+                         scanbeam_list<T>& scanbeam,
+                         clip_type cliptype,
+                         fill_type subject_fill_type,
+                         fill_type clip_fill_type) {
+    for (auto bnd_itr = active_bounds.begin(); bnd_itr != active_bounds.end();) {
+        if (*bnd_itr != nullptr && current_edge_is_horizontal<T>(bnd_itr)) {
+            bnd_itr = process_horizontal(scanline_y, bnd_itr, active_bounds, rings, scanbeam, cliptype,
+                                         subject_fill_type, clip_fill_type);
+        } else {
+            ++bnd_itr;
+        }
+    }
+    active_bounds.erase(std::remove(active_bounds.begin(), active_bounds.end(), nullptr), active_bounds.end());
+}
+} // namespace wagyu
+} // namespace geometry
+} // namespace mapbox

mapbox/geometry/wagyu/process_maxima.hpp

@@ -0,0 +1,123 @@
+#pragma once
+
+#include <mapbox/geometry/wagyu/active_bound_list.hpp>
+#include <mapbox/geometry/wagyu/config.hpp>
+#include <mapbox/geometry/wagyu/edge.hpp>
+#include <mapbox/geometry/wagyu/interrupt.hpp>
+#include <mapbox/geometry/wagyu/intersect_util.hpp>
+#include <mapbox/geometry/wagyu/local_minimum.hpp>
+#include <mapbox/geometry/wagyu/local_minimum_util.hpp>
+#include <mapbox/geometry/wagyu/process_horizontal.hpp>
+#include <mapbox/geometry/wagyu/ring.hpp>
+#include <mapbox/geometry/wagyu/ring_util.hpp>
+#include <mapbox/geometry/wagyu/topology_correction.hpp>
+#include <mapbox/geometry/wagyu/util.hpp>
+
+namespace mapbox {
+namespace geometry {
+namespace wagyu {
+
+template <typename T>
+active_bound_list_itr<T> do_maxima(active_bound_list_itr<T>& bnd,
+                                   active_bound_list_itr<T>& bndMaxPair,
+                                   clip_type cliptype,
+                                   fill_type subject_fill_type,
+                                   fill_type clip_fill_type,
+                                   ring_manager<T>& manager,
+                                   active_bound_list<T>& active_bounds) {
+    auto bnd_next = std::next(bnd);
+    auto return_bnd = bnd;
+    bool skipped = false;
+    while (bnd_next != active_bounds.end() && bnd_next != bndMaxPair) {
+        if (*bnd_next == nullptr) {
+            ++bnd_next;
+            continue;
+        }
+        skipped = true;
+        intersect_bounds(*(*bnd), *(*bnd_next), (*bnd)->current_edge->top, cliptype, subject_fill_type, clip_fill_type,
+                         manager, active_bounds);
+        std::iter_swap(bnd, bnd_next);
+        bnd = bnd_next;
+        ++bnd_next;
+    }
+
+    if ((*bnd)->ring && (*bndMaxPair)->ring) {
+        add_local_maximum_point(*(*bnd), *(*bndMaxPair), (*bnd)->current_edge->top, manager, active_bounds);
+    } else if ((*bnd)->ring || (*bndMaxPair)->ring) {
+        throw std::runtime_error("DoMaxima error");
+    }
+    *bndMaxPair = nullptr;
+    *bnd = nullptr;
+    if (!skipped) {
+        ++return_bnd;
+    }
+    return return_bnd;
+}
+
+template <typename T>
+void process_edges_at_top_of_scanbeam(T top_y,
+                                      active_bound_list<T>& active_bounds,
+                                      scanbeam_list<T>& scanbeam,
+                                      local_minimum_ptr_list<T> const& minima_sorted,
+                                      local_minimum_ptr_list_itr<T>& current_lm,
+                                      ring_manager<T>& manager,
+                                      clip_type cliptype,
+                                      fill_type subject_fill_type,
+                                      fill_type clip_fill_type) {
+
+    for (auto bnd = active_bounds.begin(); bnd != active_bounds.end();) {
+        interrupt_check(); // Check for interruptions
+        if (*bnd == nullptr) {
+            ++bnd;
+            continue;
+        }
+        // 1. Process maxima, treating them as if they are "bent" horizontal edges,
+        // but exclude maxima with horizontal edges.
+
+        bool is_maxima_edge = is_maxima(bnd, top_y);
+
+        if (is_maxima_edge) {
+            auto bnd_max_pair = get_maxima_pair(bnd, active_bounds);
+            is_maxima_edge = ((bnd_max_pair == active_bounds.end() || !current_edge_is_horizontal<T>(bnd_max_pair)) &&
+                              is_maxima(bnd_max_pair, top_y));
+            if (is_maxima_edge) {
+                bnd = do_maxima(bnd, bnd_max_pair, cliptype, subject_fill_type, clip_fill_type, manager, active_bounds);
+                continue;
+            }
+        }
+
+        // 2. Promote horizontal edges.
+        if (is_intermediate(bnd, top_y) && next_edge_is_horizontal<T>(bnd)) {
+            if ((*bnd)->ring) {
+                insert_hot_pixels_in_path(*(*bnd), (*bnd)->current_edge->top, manager, false);
+            }
+            next_edge_in_bound(*(*bnd), scanbeam);
+            if ((*bnd)->ring) {
+                add_point_to_ring(*(*bnd), (*bnd)->current_edge->bot, manager);
+            }
+        } else {
+            (*bnd)->current_x = get_current_x(*((*bnd)->current_edge), top_y);
+        }
+        ++bnd;
+    }
+    active_bounds.erase(std::remove(active_bounds.begin(), active_bounds.end(), nullptr), active_bounds.end());
+
+    insert_horizontal_local_minima_into_ABL(top_y, minima_sorted, current_lm, active_bounds, manager, scanbeam,
+                                            cliptype, subject_fill_type, clip_fill_type);
+
+    process_horizontals(top_y, active_bounds, manager, scanbeam, cliptype, subject_fill_type, clip_fill_type);
+
+    // 4. Promote intermediate vertices
+
+    for (auto bnd = active_bounds.begin(); bnd != active_bounds.end(); ++bnd) {
+        if (is_intermediate(bnd, top_y)) {
+            if ((*bnd)->ring) {
+                add_point_to_ring(*(*bnd), (*bnd)->current_edge->top, manager);
+            }
+            next_edge_in_bound(*(*bnd), scanbeam);
+        }
+    }
+}
+} // namespace wagyu
+} // namespace geometry
+} // namespace mapbox

mapbox/geometry/wagyu/quick_clip.hpp

@@ -0,0 +1,139 @@
+#pragma once
+
+#include <mapbox/geometry/box.hpp>
+#include <mapbox/geometry/multi_polygon.hpp>
+#include <mapbox/geometry/polygon.hpp>
+#include <mapbox/geometry/wagyu/wagyu.hpp>
+
+namespace mapbox {
+namespace geometry {
+namespace wagyu {
+namespace quick_clip {
+
+template <typename T>
+mapbox::geometry::point<T> intersect(mapbox::geometry::point<T> a,
+                                     mapbox::geometry::point<T> b,
+                                     size_t edge,
+                                     mapbox::geometry::box<T> const& box) {
+    switch (edge) {
+    case 0:
+        return mapbox::geometry::point<T>(
+            mapbox::geometry::wagyu::wround<T>(static_cast<double>(a.x) + static_cast<double>(b.x - a.x) *
+                                                                              static_cast<double>(box.min.y - a.y) /
+                                                                              static_cast<double>(b.y - a.y)),
+            box.min.y);
+
+    case 1:
+        return mapbox::geometry::point<T>(
+            box.max.x,
+            mapbox::geometry::wagyu::wround<T>(static_cast<double>(a.y) + static_cast<double>(b.y - a.y) *
+                                                                              static_cast<double>(box.max.x - a.x) /
+                                                                              static_cast<double>(b.x - a.x)));
+
+    case 2:
+        return mapbox::geometry::point<T>(
+            mapbox::geometry::wagyu::wround<T>(static_cast<double>(a.x) + static_cast<double>(b.x - a.x) *
+                                                                              static_cast<double>(box.max.y - a.y) /
+                                                                              static_cast<double>(b.y - a.y)),
+            box.max.y);
+
+    default: // case 3
+        return mapbox::geometry::point<T>(
+            box.min.x,
+            mapbox::geometry::wagyu::wround<T>(static_cast<double>(a.y) + static_cast<double>(b.y - a.y) *
+                                                                              static_cast<double>(box.min.x - a.x) /
+                                                                              static_cast<double>(b.x - a.x)));
+    }
+}
+
+template <typename T>
+bool inside(mapbox::geometry::point<T> p, size_t edge, mapbox::geometry::box<T> const& b) {
+    switch (edge) {
+    case 0:
+        return p.y > b.min.y;
+
+    case 1:
+        return p.x < b.max.x;
+
+    case 2:
+        return p.y < b.max.y;
+
+    default: // case 3
+        return p.x > b.min.x;
+    }
+}
+
+template <typename T>
+mapbox::geometry::linear_ring<T> quick_lr_clip(mapbox::geometry::linear_ring<T> const& ring,
+                                               mapbox::geometry::box<T> const& b) {
+    mapbox::geometry::linear_ring<T> out = ring;
+
+    for (size_t edge = 0; edge < 4; edge++) {
+        if (out.size() > 0) {
+            mapbox::geometry::linear_ring<T> in = out;
+            mapbox::geometry::point<T> S = in[in.size() - 1];
+            out.resize(0);
+
+            for (size_t e = 0; e < in.size(); e++) {
+                mapbox::geometry::point<T> E = in[e];
+
+                if (inside(E, edge, b)) {
+                    if (!inside(S, edge, b)) {
+                        out.push_back(intersect(S, E, edge, b));
+                    }
+                    out.push_back(E);
+                } else if (inside(S, edge, b)) {
+                    out.push_back(intersect(S, E, edge, b));
+                }
+
+                S = E;
+            }
+        }
+    }
+
+    if (out.size() < 3) {
+        out.clear();
+        return out;
+    }
+    // Close the ring if the first/last point was outside
+    if (out[0] != out[out.size() - 1]) {
+        out.push_back(out[0]);
+    }
+    return out;
+}
+} // namespace quick_clip
+
+template <typename T>
+mapbox::geometry::multi_polygon<T>
+clip(mapbox::geometry::polygon<T> const& poly, mapbox::geometry::box<T> const& b, fill_type subject_fill_type) {
+    mapbox::geometry::multi_polygon<T> result;
+    wagyu<T> clipper;
+    for (auto const& lr : poly) {
+        auto new_lr = quick_clip::quick_lr_clip(lr, b);
+        if (!new_lr.empty()) {
+            clipper.add_ring(new_lr, polygon_type_subject);
+        }
+    }
+    clipper.execute(clip_type_union, result, subject_fill_type, fill_type_even_odd);
+    return result;
+}
+
+template <typename T>
+mapbox::geometry::multi_polygon<T>
+clip(mapbox::geometry::multi_polygon<T> const& mp, mapbox::geometry::box<T> const& b, fill_type subject_fill_type) {
+    mapbox::geometry::multi_polygon<T> result;
+    wagyu<T> clipper;
+    for (auto const& poly : mp) {
+        for (auto const& lr : poly) {
+            auto new_lr = quick_clip::quick_lr_clip(lr, b);
+            if (!new_lr.empty()) {
+                clipper.add_ring(new_lr, polygon_type_subject);
+            }
+        }
+    }
+    clipper.execute(clip_type_union, result, subject_fill_type, fill_type_even_odd);
+    return result;
+}
+} // namespace wagyu
+} // namespace geometry
+} // namespace mapbox

mapbox/geometry/wagyu/ring.hpp

@@ -0,0 +1,633 @@
+#pragma once
+
+#include <assert.h>
+#include <cmath>
+#include <deque>
+#include <list>
+#include <map>
+#include <mapbox/geometry/box.hpp>
+#include <mapbox/geometry/wagyu/point.hpp>
+#include <set>
+#include <sstream>
+#include <vector>
+
+#ifdef DEBUG
+#include <execinfo.h>
+#include <iostream>
+#include <sstream>
+#include <stdio.h>
+//
+// void* callstack[128];
+// int i, frames = backtrace(callstack, 128);
+// char** strs = backtrace_symbols(callstack, frames);
+// for (i = 0; i < frames; ++i) {
+//     printf("%s\n", strs[i]);
+// }
+// free(strs);
+#endif
+
+namespace mapbox {
+namespace geometry {
+namespace wagyu {
+
+template <typename T>
+double area_from_point(point_ptr<T> op, std::size_t& size, mapbox::geometry::box<T>& bbox) {
+    point_ptr<T> startOp = op;
+    size = 0;
+    double a = 0.0;
+    T min_x = op->x;
+    T max_x = op->x;
+    T min_y = op->y;
+    T max_y = op->y;
+    do {
+        ++size;
+        if (op->x > max_x) {
+            max_x = op->x;
+        } else if (op->x < min_x) {
+            min_x = op->x;
+        }
+        if (op->y > max_y) {
+            max_y = op->y;
+        } else if (op->y < min_y) {
+            min_y = op->y;
+        }
+        a += static_cast<double>(op->prev->x + op->x) * static_cast<double>(op->prev->y - op->y);
+        op = op->next;
+    } while (op != startOp);
+    bbox.min.x = min_x;
+    bbox.max.x = max_x;
+    bbox.min.y = min_y;
+    bbox.max.y = max_y;
+    return a * 0.5;
+}
+
+// NOTE: ring and ring_ptr are forward declared in wagyu/point.hpp
+
+template <typename T>
+using ring_vector = std::vector<ring_ptr<T>>;
+
+template <typename T>
+struct ring {
+    std::size_t ring_index; // To support unset 0 is undefined and indexes offset by 1
+
+    std::size_t size_;             // number of points in the ring
+    double area_;                  // area of the ring
+    mapbox::geometry::box<T> bbox; // bounding box of the ring
+
+    ring_ptr<T> parent;
+    ring_vector<T> children;
+
+    point_ptr<T> points;
+    point_ptr<T> bottom_point;
+    bool is_hole_;
+    bool corrected;
+
+    ring(ring const&) = delete;
+    ring& operator=(ring const&) = delete;
+
+    ring()
+        : ring_index(0),
+          size_(0),
+          area_(std::numeric_limits<double>::quiet_NaN()),
+          bbox({ 0, 0 }, { 0, 0 }),
+          parent(nullptr),
+          children(),
+          points(nullptr),
+          bottom_point(nullptr),
+          is_hole_(false),
+          corrected(false) {
+    }
+
+    void reset_stats() {
+        area_ = std::numeric_limits<double>::quiet_NaN();
+        is_hole_ = false;
+        bbox.min.x = 0;
+        bbox.min.y = 0;
+        bbox.max.x = 0;
+        bbox.max.y = 0;
+        size_ = 0;
+    }
+
+    void recalculate_stats() {
+        if (points != nullptr) {
+            area_ = area_from_point(points, size_, bbox);
+            is_hole_ = !(area_ > 0.0);
+        }
+    }
+
+    void set_stats(double a, std::size_t s, mapbox::geometry::box<T> const& b) {
+        bbox = b;
+        area_ = a;
+        size_ = s;
+        is_hole_ = !(area_ > 0.0);
+    }
+
+    double area() {
+        if (std::isnan(area_)) {
+            recalculate_stats();
+        }
+        return area_;
+    }
+
+    bool is_hole() {
+        if (std::isnan(area_)) {
+            recalculate_stats();
+        }
+        return is_hole_;
+    }
+
+    std::size_t size() {
+        if (std::isnan(area_)) {
+            recalculate_stats();
+        }
+        return size_;
+    }
+};
+
+template <typename T>
+using hot_pixel_vector = std::vector<mapbox::geometry::point<T>>;
+
+template <typename T>
+using hot_pixel_itr = typename hot_pixel_vector<T>::iterator;
+
+template <typename T>
+using hot_pixel_rev_itr = typename hot_pixel_vector<T>::reverse_iterator;
+
+template <typename T>
+struct ring_manager {
+
+    ring_vector<T> children;
+    point_vector<T> all_points;
+    hot_pixel_vector<T> hot_pixels;
+    hot_pixel_itr<T> current_hp_itr;
+    std::deque<point<T>> points;
+    std::deque<ring<T>> rings;
+    std::vector<point<T>> storage;
+    std::size_t index;
+
+    ring_manager(ring_manager const&) = delete;
+    ring_manager& operator=(ring_manager const&) = delete;
+
+    ring_manager()
+        : children(),
+          all_points(),
+          hot_pixels(),
+          current_hp_itr(hot_pixels.end()),
+          points(),
+          rings(),
+          storage(),
+          index(0) {
+    }
+};
+
+template <typename T>
+void preallocate_point_memory(ring_manager<T>& rings, std::size_t size) {
+    rings.storage.reserve(size);
+    rings.all_points.reserve(size);
+}
+
+template <typename T>
+ring_ptr<T> create_new_ring(ring_manager<T>& manager) {
+    manager.rings.emplace_back();
+    ring_ptr<T> result = &manager.rings.back();
+    result->ring_index = manager.index++;
+    return result;
+}
+
+template <typename T>
+point_ptr<T> create_new_point(ring_ptr<T> r, mapbox::geometry::point<T> const& pt, ring_manager<T>& rings) {
+    point_ptr<T> point;
+    if (rings.storage.size() < rings.storage.capacity()) {
+        rings.storage.emplace_back(r, pt);
+        point = &rings.storage.back();
+    } else {
+        rings.points.emplace_back(r, pt);
+        point = &rings.points.back();
+    }
+    rings.all_points.push_back(point);
+    return point;
+}
+
+template <typename T>
+point_ptr<T> create_new_point(ring_ptr<T> r,
+                              mapbox::geometry::point<T> const& pt,
+                              point_ptr<T> before_this_point,
+                              ring_manager<T>& rings) {
+    point_ptr<T> point;
+    if (rings.storage.size() < rings.storage.capacity()) {
+        rings.storage.emplace_back(r, pt, before_this_point);
+        point = &rings.storage.back();
+    } else {
+        rings.points.emplace_back(r, pt, before_this_point);
+        point = &rings.points.back();
+    }
+    rings.all_points.push_back(point);
+    return point;
+}
+
+template <typename T>
+void set_to_children(ring_ptr<T> r, ring_vector<T>& children) {
+    for (auto& c : children) {
+        if (c == nullptr) {
+            c = r;
+            return;
+        }
+    }
+    children.push_back(r);
+}
+
+template <typename T>
+void remove_from_children(ring_ptr<T> r, ring_vector<T>& children) {
+    for (auto& c : children) {
+        if (c == r) {
+            c = nullptr;
+            return;
+        }
+    }
+}
+
+template <typename T>
+void assign_as_child(ring_ptr<T> new_ring, ring_ptr<T> parent, ring_manager<T>& manager) {
+    // Assigning as a child assumes that this is
+    // a brand new ring. Therefore it does
+    // not have any existing relationships
+    if ((parent == nullptr && new_ring->is_hole()) || (parent != nullptr && new_ring->is_hole() == parent->is_hole())) {
+        throw std::runtime_error("Trying to assign a child that is the same orientation as the parent");
+    }
+    auto& children = parent == nullptr ? manager.children : parent->children;
+    set_to_children(new_ring, children);
+    new_ring->parent = parent;
+}
+
+template <typename T>
+void reassign_as_child(ring_ptr<T> ring, ring_ptr<T> parent, ring_manager<T>& manager) {
+    // Reassigning a ring assumes it already
+    // has an existing parent
+    if ((parent == nullptr && ring->is_hole()) || (parent != nullptr && ring->is_hole() == parent->is_hole())) {
+        throw std::runtime_error("Trying to re-assign a child that is the same orientation as the parent");
+    }
+
+    // Remove the old child relationship
+    auto& old_children = ring->parent == nullptr ? manager.children : ring->parent->children;
+    remove_from_children(ring, old_children);
+
+    // Add new child relationship
+    auto& children = parent == nullptr ? manager.children : parent->children;
+    set_to_children(ring, children);
+    ring->parent = parent;
+}
+
+template <typename T>
+void assign_as_sibling(ring_ptr<T> new_ring, ring_ptr<T> sibling, ring_manager<T>& manager) {
+    // Assigning as a sibling assumes that this is
+    // a brand new ring. Therefore it does
+    // not have any existing relationships
+    if (new_ring->is_hole() != sibling->is_hole()) {
+        throw std::runtime_error("Trying to assign to be a sibling that is not the same orientation as the sibling");
+    }
+    auto& children = sibling->parent == nullptr ? manager.children : sibling->parent->children;
+    set_to_children(new_ring, children);
+    new_ring->parent = sibling->parent;
+}
+
+template <typename T>
+void reassign_as_sibling(ring_ptr<T> ring, ring_ptr<T> sibling, ring_manager<T>& manager) {
+    if (ring->parent == sibling->parent) {
+        return;
+    }
+    // Assigning as a sibling assumes that this is
+    // a brand new ring. Therefore it does
+    // not have any existing relationships
+    if (ring->is_hole() != sibling->is_hole()) {
+        throw std::runtime_error("Trying to assign to be a sibling that is not the same orientation as the sibling");
+    }
+    // Remove the old child relationship
+    auto& old_children = ring->parent == nullptr ? manager.children : ring->parent->children;
+    remove_from_children(ring, old_children);
+    // Add new relationship
+    auto& children = sibling->parent == nullptr ? manager.children : sibling->parent->children;
+    set_to_children(ring, children);
+    ring->parent = sibling->parent;
+}
+
+template <typename T>
+void ring1_replaces_ring2(ring_ptr<T> ring1, ring_ptr<T> ring2, ring_manager<T>& manager) {
+    assert(ring1 != ring2);
+    auto& ring1_children = ring1 == nullptr ? manager.children : ring1->children;
+    for (auto& c : ring2->children) {
+        if (c == nullptr) {
+            continue;
+        }
+        c->parent = ring1;
+        set_to_children(c, ring1_children);
+        c = nullptr;
+    }
+    // Remove the old child relationship
+    auto& old_children = ring2->parent == nullptr ? manager.children : ring2->parent->children;
+    remove_from_children(ring2, old_children);
+    ring2->points = nullptr;
+    ring2->reset_stats();
+}
+
+template <typename T>
+void remove_points(point_ptr<T> pt) {
+    if (pt != nullptr) {
+        pt->prev->next = nullptr;
+        while (pt != nullptr) {
+            point_ptr<T> tmp = pt;
+            pt = pt->next;
+            tmp->next = nullptr;
+            tmp->prev = nullptr;
+            tmp->ring = nullptr;
+        }
+    }
+}
+
+template <typename T>
+void remove_ring_and_points(ring_ptr<T> r,
+                            ring_manager<T>& manager,
+                            bool remove_children = true,
+                            bool remove_from_parent = true) {
+    // Removes a ring and any children that might be
+    // under that ring.
+    for (auto& c : r->children) {
+        if (c == nullptr) {
+            continue;
+        }
+        if (remove_children) {
+            remove_ring_and_points(c, manager, true, false);
+        }
+        c = nullptr;
+    }
+    if (remove_from_parent) {
+        // Remove the old child relationship
+        auto& old_children = r->parent == nullptr ? manager.children : r->parent->children;
+        remove_from_children(r, old_children);
+    }
+    point_ptr<T> pt = r->points;
+    if (pt != nullptr) {
+        pt->prev->next = nullptr;
+        while (pt != nullptr) {
+            point_ptr<T> tmp = pt;
+            pt = pt->next;
+            tmp->next = nullptr;
+            tmp->prev = nullptr;
+            tmp->ring = nullptr;
+        }
+    }
+    r->points = nullptr;
+    r->reset_stats();
+}
+
+template <typename T>
+void remove_ring(ring_ptr<T> r, ring_manager<T>& manager, bool remove_children = true, bool remove_from_parent = true) {
+    // Removes a ring and any children that might be
+    // under that ring.
+    for (auto& c : r->children) {
+        if (c == nullptr) {
+            continue;
+        }
+        if (remove_children) {
+            remove_ring(c, manager, true, false);
+        }
+        c = nullptr;
+    }
+    if (remove_from_parent) {
+        // Remove the old child relationship
+        auto& old_children = r->parent == nullptr ? manager.children : r->parent->children;
+        remove_from_children(r, old_children);
+    }
+    r->points = nullptr;
+    r->reset_stats();
+}
+
+template <typename T>
+inline std::size_t ring_depth(ring_ptr<T> r) {
+    std::size_t depth = 0;
+    if (!r) {
+        return depth;
+    }
+    while (r->parent) {
+        depth++;
+        r = r->parent;
+    }
+    return depth;
+}
+
+template <typename T>
+inline bool ring_is_hole(ring_ptr<T> r) {
+    // This is different then the "normal" way of determing if
+    // a ring is a hole or not because it uses the depth of the
+    // the ring to determine if it is a hole or not. This is only done
+    // intially when rings are output from Vatti.
+    return ring_depth(r) & 1;
+}
+
+template <typename T>
+void set_next(const_point_ptr<T>& node, const const_point_ptr<T>& next_node) {
+    node->next = next_node;
+}
+
+template <typename T>
+point_ptr<T> get_next(const_point_ptr<T>& node) {
+    return node->next;
+}
+
+template <typename T>
+point_ptr<T> get_prev(const_point_ptr<T>& node) {
+    return node->prev;
+}
+
+template <typename T>
+void set_prev(const_point_ptr<T>& node, const const_point_ptr<T>& prev_node) {
+    node->prev = prev_node;
+}
+
+template <typename T>
+void init(const_point_ptr<T>& node) {
+    set_next(node, node);
+    set_prev(node, node);
+}
+
+template <typename T>
+void link_before(point_ptr<T>& node, point_ptr<T>& new_node) {
+    point_ptr<T> prev_node = get_prev(node);
+    set_prev(new_node, prev_node);
+    set_next(new_node, node);
+    set_prev(node, new_node);
+    set_next(prev_node, new_node);
+}
+
+template <typename T>
+void link_after(point_ptr<T>& node, point_ptr<T>& new_node) {
+    point_ptr<T> next_node = get_next(node);
+    set_prev(new_node, node);
+    set_next(new_node, next_node);
+    set_next(node, new_node);
+    set_prev(next_node, new_node);
+}
+
+template <typename T>
+void transfer_point(point_ptr<T>& p, point_ptr<T>& b, point_ptr<T>& e) {
+    if (b != e) {
+        point_ptr<T> prev_p = get_prev(p);
+        point_ptr<T> prev_b = get_prev(b);
+        point_ptr<T> prev_e = get_prev(e);
+        set_next(prev_e, p);
+        set_prev(p, prev_e);
+        set_next(prev_b, e);
+        set_prev(e, prev_b);
+        set_next(prev_p, b);
+        set_prev(b, prev_p);
+    } else {
+        link_before(p, b);
+    }
+}
+
+template <typename T>
+void reverse_ring(point_ptr<T> pp) {
+    if (!pp) {
+        return;
+    }
+    point_ptr<T> pp1;
+    point_ptr<T> pp2;
+    pp1 = pp;
+    do {
+        pp2 = pp1->next;
+        pp1->next = pp1->prev;
+        pp1->prev = pp2;
+        pp1 = pp2;
+    } while (pp1 != pp);
+}
+
+#ifdef DEBUG
+
+template <class charT, class traits, typename T>
+inline std::basic_ostream<charT, traits>& operator<<(std::basic_ostream<charT, traits>& out, ring<T>& r) {
+    out << "  ring_index: " << r.ring_index << std::endl;
+    if (!r.parent) {
+        // out << "  parent_ring ptr: nullptr" << std::endl;
+        out << "  parent_index: -----" << std::endl;
+    } else {
+        // out << "  parent_ring ptr: " << r.parent << std::endl;
+        out << "  parent_ring idx: " << r.parent->ring_index << std::endl;
+    }
+    ring_ptr<T> n = const_cast<ring_ptr<T>>(&r);
+    if (ring_is_hole(n)) {
+        out << "  is_hole: true " << std::endl;
+    } else {
+        out << "  is_hole: false " << std::endl;
+    }
+    auto pt_itr = r.points;
+    if (pt_itr) {
+        out << "  area: " << r.area() << std::endl;
+        out << "  points:" << std::endl;
+        out << "      [[[" << pt_itr->x << "," << pt_itr->y << "],";
+        pt_itr = pt_itr->next;
+        while (pt_itr != r.points) {
+            out << "[" << pt_itr->x << "," << pt_itr->y << "],";
+            pt_itr = pt_itr->next;
+        }
+        out << "[" << pt_itr->x << "," << pt_itr->y << "]]]" << std::endl;
+    } else {
+        out << "  area: NONE" << std::endl;
+        out << "  points: NONE" << std::endl;
+    }
+    return out;
+}
+
+template <typename T>
+std::string debug_ring_addresses(ring_ptr<T> r) {
+    std::ostringstream out;
+    out << "Ring: " << r->ring_index << std::endl;
+    if (r->points == nullptr) {
+        out << "   Ring has no points" << std::endl;
+        return out.str();
+    }
+    auto pt_itr = r->points;
+    do {
+        out << "    [" << pt_itr->x << "," << pt_itr->y << "] - " << pt_itr << std::endl;
+        pt_itr = pt_itr->next;
+    } while (pt_itr != r->points);
+    return out.str();
+}
+
+template <typename T>
+std::string output_as_polygon(ring_ptr<T> r) {
+    std::ostringstream out;
+
+    auto pt_itr = r->points;
+    if (pt_itr) {
+        out << "[";
+        out << "[[" << pt_itr->x << "," << pt_itr->y << "],";
+        pt_itr = pt_itr->next;
+        while (pt_itr != r->points) {
+            out << "[" << pt_itr->x << "," << pt_itr->y << "],";
+            pt_itr = pt_itr->next;
+        }
+        out << "[" << pt_itr->x << "," << pt_itr->y << "]]";
+        for (auto const& c : r->children) {
+            if (c == nullptr) {
+                continue;
+            }
+            pt_itr = c->points;
+            if (pt_itr) {
+                out << ",[[" << pt_itr->x << "," << pt_itr->y << "],";
+                pt_itr = pt_itr->next;
+                while (pt_itr != c->points) {
+                    out << "[" << pt_itr->x << "," << pt_itr->y << "],";
+                    pt_itr = pt_itr->next;
+                }
+                out << "[" << pt_itr->x << "," << pt_itr->y << "]]";
+            }
+        }
+        out << "]" << std::endl;
+    } else {
+        out << "[]" << std::endl;
+    }
+
+    return out.str();
+}
+
+template <class charT, class traits, typename T>
+inline std::basic_ostream<charT, traits>& operator<<(std::basic_ostream<charT, traits>& out, ring_vector<T>& rings) {
+    out << "START RING VECTOR" << std::endl;
+    for (auto& r : rings) {
+        if (r == nullptr || !r->points) {
+            continue;
+        }
+        out << " ring: " << r->ring_index << " - " << r << std::endl;
+        out << *r;
+    }
+    out << "END RING VECTOR" << std::endl;
+    return out;
+}
+
+template <class charT, class traits, typename T>
+inline std::basic_ostream<charT, traits>& operator<<(std::basic_ostream<charT, traits>& out,
+                                                     std::deque<ring<T>>& rings) {
+    out << "START RING VECTOR" << std::endl;
+    for (auto& r : rings) {
+        if (!r.points) {
+            continue;
+        }
+        out << " ring: " << r.ring_index << std::endl;
+        out << r;
+    }
+    out << "END RING VECTOR" << std::endl;
+    return out;
+}
+
+template <class charT, class traits, typename T>
+inline std::basic_ostream<charT, traits>& operator<<(std::basic_ostream<charT, traits>& out,
+                                                     hot_pixel_vector<T>& hp_vec) {
+    out << "Hot Pixels: " << std::endl;
+    for (auto& hp : hp_vec) {
+        out << hp << std::endl;
+    }
+    return out;
+}
+#endif
+} // namespace wagyu
+} // namespace geometry
+} // namespace mapbox

mapbox/geometry/wagyu/ring_util.hpp

@@ -0,0 +1,836 @@
+#pragma once
+
+#ifdef DEBUG
+#include <iostream>
+// Example debug print for backtrace - only works on IOS
+#include <execinfo.h>
+#include <stdio.h>
+//
+// void* callstack[128];
+// int i, frames = backtrace(callstack, 128);
+// char** strs = backtrace_symbols(callstack, frames);
+// for (i = 0; i < frames; ++i) {
+//     printf("%s\n", strs[i]);
+// }
+// free(strs);
+#endif
+
+#include <algorithm>
+
+#include <mapbox/geometry/wagyu/active_bound_list.hpp>
+#include <mapbox/geometry/wagyu/config.hpp>
+#include <mapbox/geometry/wagyu/edge.hpp>
+#include <mapbox/geometry/wagyu/ring.hpp>
+#include <mapbox/geometry/wagyu/util.hpp>
+
+namespace mapbox {
+namespace geometry {
+namespace wagyu {
+
+template <typename T>
+void set_hole_state(bound<T>& bnd, active_bound_list<T> const& active_bounds, ring_manager<T>& rings) {
+    auto bnd_itr = std::find(active_bounds.rbegin(), active_bounds.rend(), &bnd);
+    ++bnd_itr;
+    bound_ptr<T> bndTmp = nullptr;
+    // Find first non line ring to the left of current bound.
+    while (bnd_itr != active_bounds.rend()) {
+        if (*bnd_itr == nullptr) {
+            ++bnd_itr;
+            continue;
+        }
+        if ((*bnd_itr)->ring) {
+            if (!bndTmp) {
+                bndTmp = (*bnd_itr);
+            } else if (bndTmp->ring == (*bnd_itr)->ring) {
+                bndTmp = nullptr;
+            }
+        }
+        ++bnd_itr;
+    }
+    if (!bndTmp) {
+        bnd.ring->parent = nullptr;
+        rings.children.push_back(bnd.ring);
+    } else {
+        bnd.ring->parent = bndTmp->ring;
+        bndTmp->ring->children.push_back(bnd.ring);
+    }
+}
+
+template <typename T>
+void update_current_hp_itr(T scanline_y, ring_manager<T>& rings) {
+    while (rings.current_hp_itr->y > scanline_y) {
+        ++rings.current_hp_itr;
+    }
+}
+
+template <typename T>
+struct hot_pixel_sorter {
+    inline bool operator()(mapbox::geometry::point<T> const& pt1, mapbox::geometry::point<T> const& pt2) {
+        if (pt1.y == pt2.y) {
+            return pt1.x < pt2.x;
+        } else {
+            return pt1.y > pt2.y;
+        }
+    }
+};
+
+template <typename T>
+T round_towards_min(double val) {
+    // 0.5 rounds to 0
+    // 0.0 rounds to 0
+    // -0.5 rounds to -1
+    double half = std::floor(val) + 0.5;
+    if (values_are_equal(val, half)) {
+        return static_cast<T>(std::floor(val));
+    } else {
+        return static_cast<T>(std::llround(val));
+    }
+}
+
+template <typename T>
+T round_towards_max(double val) {
+    // 0.5 rounds to 1
+    // 0.0 rounds to 0
+    // -0.5 rounds to 0
+    double half = std::floor(val) + 0.5;
+    if (values_are_equal(val, half)) {
+        return static_cast<T>(std::ceil(val));
+    } else {
+        return static_cast<T>(std::llround(val));
+    }
+}
+
+template <typename T>
+inline T get_edge_min_x(edge<T> const& edge, const T current_y) {
+    if (is_horizontal(edge)) {
+        if (edge.bot.x < edge.top.x) {
+            return edge.bot.x;
+        } else {
+            return edge.top.x;
+        }
+    } else if (edge.dx > 0.0) {
+        if (current_y == edge.top.y) {
+            return edge.top.x;
+        } else {
+            double lower_range_y = static_cast<double>(current_y - edge.bot.y) - 0.5;
+            double return_val = static_cast<double>(edge.bot.x) + edge.dx * lower_range_y;
+            T value = round_towards_min<T>(return_val);
+            return value;
+        }
+    } else {
+        if (current_y == edge.bot.y) {
+            return edge.bot.x;
+        } else {
+            double return_val =
+                static_cast<double>(edge.bot.x) + edge.dx * (static_cast<double>(current_y - edge.bot.y) + 0.5);
+            T value = round_towards_min<T>(return_val);
+            return value;
+        }
+    }
+}
+
+template <typename T>
+inline T get_edge_max_x(edge<T> const& edge, const T current_y) {
+    if (is_horizontal(edge)) {
+        if (edge.bot.x > edge.top.x) {
+            return edge.bot.x;
+        } else {
+            return edge.top.x;
+        }
+    } else if (edge.dx < 0.0) {
+        if (current_y == edge.top.y) {
+            return edge.top.x;
+        } else {
+            double lower_range_y = static_cast<double>(current_y - edge.bot.y) - 0.5;
+            double return_val = static_cast<double>(edge.bot.x) + edge.dx * lower_range_y;
+            T value = round_towards_max<T>(return_val);
+            return value;
+        }
+    } else {
+        if (current_y == edge.bot.y) {
+            return edge.bot.x;
+        } else {
+            double return_val =
+                static_cast<double>(edge.bot.x) + edge.dx * (static_cast<double>(current_y - edge.bot.y) + 0.5);
+            T value = round_towards_max<T>(return_val);
+            return value;
+        }
+    }
+}
+
+template <typename T>
+void hot_pixel_set_left_to_right(T y,
+                                 T start_x,
+                                 T end_x,
+                                 bound<T>& bnd,
+                                 ring_manager<T>& rings,
+                                 hot_pixel_itr<T>& itr,
+                                 hot_pixel_itr<T>& end,
+                                 bool add_end_point) {
+    T x_min = get_edge_min_x(*(bnd.current_edge), y);
+    x_min = std::max(x_min, start_x);
+    T x_max = get_edge_max_x(*(bnd.current_edge), y);
+    x_max = std::min(x_max, end_x);
+    for (; itr != end; ++itr) {
+        if (itr->x < x_min) {
+            continue;
+        }
+        if (itr->x > x_max) {
+            break;
+        }
+        if (!add_end_point && itr->x == end_x) {
+            continue;
+        }
+        point_ptr<T> op = bnd.ring->points;
+        bool to_front = (bnd.side == edge_left);
+        if (to_front && (*itr == *op)) {
+            continue;
+        } else if (!to_front && (*itr == *op->prev)) {
+            continue;
+        }
+        point_ptr<T> new_point = create_new_point(bnd.ring, *itr, op, rings);
+        if (to_front) {
+            bnd.ring->points = new_point;
+        }
+    }
+}
+
+template <typename T>
+void hot_pixel_set_right_to_left(T y,
+                                 T start_x,
+                                 T end_x,
+                                 bound<T>& bnd,
+                                 ring_manager<T>& rings,
+                                 hot_pixel_rev_itr<T>& itr,
+                                 hot_pixel_rev_itr<T>& end,
+                                 bool add_end_point) {
+    T x_min = get_edge_min_x(*(bnd.current_edge), y);
+    x_min = std::max(x_min, end_x);
+    T x_max = get_edge_max_x(*(bnd.current_edge), y);
+    x_max = std::min(x_max, start_x);
+    for (; itr != end; ++itr) {
+        if (itr->x > x_max) {
+            continue;
+        }
+        if (itr->x < x_min) {
+            break;
+        }
+        if (!add_end_point && itr->x == end_x) {
+            continue;
+        }
+        point_ptr<T> op = bnd.ring->points;
+        bool to_front = (bnd.side == edge_left);
+        if (to_front && (*itr == *op)) {
+            continue;
+        } else if (!to_front && (*itr == *op->prev)) {
+            continue;
+        }
+        point_ptr<T> new_point = create_new_point(bnd.ring, *itr, op, rings);
+        if (to_front) {
+            bnd.ring->points = new_point;
+        }
+    }
+}
+
+template <typename T>
+void sort_hot_pixels(ring_manager<T>& rings) {
+    std::sort(rings.hot_pixels.begin(), rings.hot_pixels.end(), hot_pixel_sorter<T>());
+    auto last = std::unique(rings.hot_pixels.begin(), rings.hot_pixels.end());
+    rings.hot_pixels.erase(last, rings.hot_pixels.end());
+}
+
+template <typename T>
+void insert_hot_pixels_in_path(bound<T>& bnd,
+                               mapbox::geometry::point<T> const& end_pt,
+                               ring_manager<T>& rings,
+                               bool add_end_point) {
+    if (end_pt == bnd.last_point) {
+        return;
+    }
+
+    T start_y = bnd.last_point.y;
+    T start_x = bnd.last_point.x;
+    T end_y = end_pt.y;
+    T end_x = end_pt.x;
+
+    auto itr = rings.current_hp_itr;
+    while (itr->y <= start_y && itr != rings.hot_pixels.begin()) {
+        --itr;
+    }
+    if (start_x > end_x) {
+        for (; itr != rings.hot_pixels.end();) {
+            if (itr->y > start_y) {
+                ++itr;
+                continue;
+            }
+            if (itr->y < end_y) {
+                break;
+            }
+            T y = itr->y;
+            auto last_itr = hot_pixel_rev_itr<T>(itr);
+            while (itr != rings.hot_pixels.end() && itr->y == y) {
+                ++itr;
+            }
+            auto first_itr = hot_pixel_rev_itr<T>(itr);
+            bool add_end_point_itr = (y != end_pt.y || add_end_point);
+            hot_pixel_set_right_to_left(y, start_x, end_x, bnd, rings, first_itr, last_itr, add_end_point_itr);
+        }
+    } else {
+        for (; itr != rings.hot_pixels.end();) {
+            if (itr->y > start_y) {
+                ++itr;
+                continue;
+            }
+            if (itr->y < end_y) {
+                break;
+            }
+            T y = itr->y;
+            auto first_itr = itr;
+            while (itr != rings.hot_pixels.end() && itr->y == y) {
+                ++itr;
+            }
+            auto last_itr = itr;
+            bool add_end_point_itr = (y != end_pt.y || add_end_point);
+            hot_pixel_set_left_to_right(y, start_x, end_x, bnd, rings, first_itr, last_itr, add_end_point_itr);
+        }
+    }
+    bnd.last_point = end_pt;
+}
+
+template <typename T>
+void add_to_hot_pixels(mapbox::geometry::point<T> const& pt, ring_manager<T>& rings) {
+    rings.hot_pixels.push_back(pt);
+}
+
+template <typename T>
+void add_first_point(bound<T>& bnd,
+                     active_bound_list<T>& active_bounds,
+                     mapbox::geometry::point<T> const& pt,
+                     ring_manager<T>& rings) {
+
+    ring_ptr<T> r = create_new_ring(rings);
+    bnd.ring = r;
+    r->points = create_new_point(r, pt, rings);
+    set_hole_state(bnd, active_bounds, rings);
+    bnd.last_point = pt;
+}
+
+template <typename T>
+void add_point_to_ring(bound<T>& bnd, mapbox::geometry::point<T> const& pt, ring_manager<T>& rings) {
+    assert(bnd.ring);
+    // Handle hot pixels
+    insert_hot_pixels_in_path(bnd, pt, rings, false);
+
+    // bnd.ring->points is the 'Left-most' point & bnd.ring->points->prev is the
+    // 'Right-most'
+    point_ptr<T> op = bnd.ring->points;
+    bool to_front = (bnd.side == edge_left);
+    if (to_front && (pt == *op)) {
+        return;
+    } else if (!to_front && (pt == *op->prev)) {
+        return;
+    }
+    point_ptr<T> new_point = create_new_point(bnd.ring, pt, bnd.ring->points, rings);
+    if (to_front) {
+        bnd.ring->points = new_point;
+    }
+}
+
+template <typename T>
+void add_point(bound<T>& bnd,
+               active_bound_list<T>& active_bounds,
+               mapbox::geometry::point<T> const& pt,
+               ring_manager<T>& rings) {
+    if (bnd.ring == nullptr) {
+        add_first_point(bnd, active_bounds, pt, rings);
+    } else {
+        add_point_to_ring(bnd, pt, rings);
+    }
+}
+
+template <typename T>
+void add_local_minimum_point(bound<T>& b1,
+                             bound<T>& b2,
+                             active_bound_list<T>& active_bounds,
+                             mapbox::geometry::point<T> const& pt,
+                             ring_manager<T>& rings) {
+    if (is_horizontal(*b2.current_edge) || (b1.current_edge->dx > b2.current_edge->dx)) {
+        add_point(b1, active_bounds, pt, rings);
+        b2.last_point = pt;
+        b2.ring = b1.ring;
+        b1.side = edge_left;
+        b2.side = edge_right;
+    } else {
+        add_point(b2, active_bounds, pt, rings);
+        b1.last_point = pt;
+        b1.ring = b2.ring;
+        b1.side = edge_right;
+        b2.side = edge_left;
+    }
+}
+
+template <typename T>
+inline double get_dx(point<T> const& pt1, point<T> const& pt2) {
+    if (pt1.y == pt2.y) {
+        return std::numeric_limits<double>::infinity();
+    } else {
+        return static_cast<double>(pt2.x - pt1.x) / static_cast<double>(pt2.y - pt1.y);
+    }
+}
+
+template <typename T>
+bool first_is_bottom_point(const_point_ptr<T> btmPt1, const_point_ptr<T> btmPt2) {
+    point_ptr<T> p = btmPt1->prev;
+    while ((*p == *btmPt1) && (p != btmPt1)) {
+        p = p->prev;
+    }
+    double dx1p = std::fabs(get_dx(*btmPt1, *p));
+
+    p = btmPt1->next;
+    while ((*p == *btmPt1) && (p != btmPt1)) {
+        p = p->next;
+    }
+    double dx1n = std::fabs(get_dx(*btmPt1, *p));
+
+    p = btmPt2->prev;
+    while ((*p == *btmPt2) && (p != btmPt2)) {
+        p = p->prev;
+    }
+    double dx2p = std::fabs(get_dx(*btmPt2, *p));
+
+    p = btmPt2->next;
+    while ((*p == *btmPt2) && (p != btmPt2)) {
+        p = p->next;
+    }
+    double dx2n = std::fabs(get_dx(*btmPt2, *p));
+
+    if (values_are_equal(std::max(dx1p, dx1n), std::max(dx2p, dx2n)) &&
+        values_are_equal(std::min(dx1p, dx1n), std::min(dx2p, dx2n))) {
+        std::size_t s = 0;
+        mapbox::geometry::box<T> bbox({ 0, 0 }, { 0, 0 });
+        return area_from_point(btmPt1, s, bbox) > 0.0; // if otherwise identical use orientation
+    } else {
+        return (greater_than_or_equal(dx1p, dx2p) && greater_than_or_equal(dx1p, dx2n)) ||
+               (greater_than_or_equal(dx1n, dx2p) && greater_than_or_equal(dx1n, dx2n));
+    }
+}
+
+template <typename T>
+point_ptr<T> get_bottom_point(point_ptr<T> pp) {
+    point_ptr<T> dups = nullptr;
+    point_ptr<T> p = pp->next;
+    while (p != pp) {
+        if (p->y > pp->y) {
+            pp = p;
+            dups = nullptr;
+        } else if (p->y == pp->y && p->x <= pp->x) {
+            if (p->x < pp->x) {
+                dups = nullptr;
+                pp = p;
+            } else {
+                if (p->next != pp && p->prev != pp) {
+                    dups = p;
+                }
+            }
+        }
+        p = p->next;
+    }
+    if (dups) {
+        // there appears to be at least 2 vertices at bottom_point so ...
+        while (dups != p) {
+            if (!first_is_bottom_point(p, dups)) {
+                pp = dups;
+            }
+            dups = dups->next;
+            while (*dups != *pp) {
+                dups = dups->next;
+            }
+        }
+    }
+    return pp;
+}
+
+template <typename T>
+ring_ptr<T> get_lower_most_ring(ring_ptr<T> ring1, ring_ptr<T> ring2) {
+    // work out which polygon fragment has the correct hole state ...
+    if (!ring1->bottom_point) {
+        ring1->bottom_point = get_bottom_point(ring1->points);
+    }
+    if (!ring2->bottom_point) {
+        ring2->bottom_point = get_bottom_point(ring2->points);
+    }
+    point_ptr<T> pt1 = ring1->bottom_point;
+    point_ptr<T> pt2 = ring2->bottom_point;
+    if (pt1->y > pt2->y) {
+        return ring1;
+    } else if (pt1->y < pt2->y) {
+        return ring2;
+    } else if (pt1->x < pt2->x) {
+        return ring1;
+    } else if (pt1->x > pt2->x) {
+        return ring2;
+    } else if (pt1->next == pt1) {
+        return ring2;
+    } else if (pt2->next == pt2) {
+        return ring1;
+    } else if (first_is_bottom_point(pt1, pt2)) {
+        return ring1;
+    } else {
+        return ring2;
+    }
+}
+
+template <typename T>
+bool ring1_child_below_ring2(ring_ptr<T> ring1, ring_ptr<T> ring2) {
+    do {
+        ring1 = ring1->parent;
+        if (ring1 == ring2) {
+            return true;
+        }
+    } while (ring1);
+    return false;
+}
+
+template <typename T>
+void update_points_ring(ring_ptr<T> ring) {
+    point_ptr<T> op = ring->points;
+    do {
+        op->ring = ring;
+        op = op->prev;
+    } while (op != ring->points);
+}
+
+template <typename T>
+void append_ring(bound<T>& b1, bound<T>& b2, active_bound_list<T>& active_bounds, ring_manager<T>& manager) {
+    // get the start and ends of both output polygons ...
+    ring_ptr<T> outRec1 = b1.ring;
+    ring_ptr<T> outRec2 = b2.ring;
+
+    ring_ptr<T> keep_ring;
+    bound_ptr<T> keep_bound;
+    ring_ptr<T> remove_ring;
+    bound_ptr<T> remove_bound;
+    if (ring1_child_below_ring2(outRec1, outRec2)) {
+        keep_ring = outRec2;
+        keep_bound = &b2;
+        remove_ring = outRec1;
+        remove_bound = &b1;
+    } else if (ring1_child_below_ring2(outRec2, outRec1)) {
+        keep_ring = outRec1;
+        keep_bound = &b1;
+        remove_ring = outRec2;
+        remove_bound = &b2;
+    } else if (outRec1 == get_lower_most_ring(outRec1, outRec2)) {
+        keep_ring = outRec1;
+        keep_bound = &b1;
+        remove_ring = outRec2;
+        remove_bound = &b2;
+    } else {
+        keep_ring = outRec2;
+        keep_bound = &b2;
+        remove_ring = outRec1;
+        remove_bound = &b1;
+    }
+
+    // get the start and ends of both output polygons and
+    // join b2 poly onto b1 poly and delete pointers to b2 ...
+
+    point_ptr<T> p1_lft = keep_ring->points;
+    point_ptr<T> p1_rt = p1_lft->prev;
+    point_ptr<T> p2_lft = remove_ring->points;
+    point_ptr<T> p2_rt = p2_lft->prev;
+
+    // join b2 poly onto b1 poly and delete pointers to b2 ...
+    if (keep_bound->side == edge_left) {
+        if (remove_bound->side == edge_left) {
+            // z y x a b c
+            reverse_ring(p2_lft);
+            p2_lft->next = p1_lft;
+            p1_lft->prev = p2_lft;
+            p1_rt->next = p2_rt;
+            p2_rt->prev = p1_rt;
+            keep_ring->points = p2_rt;
+        } else {
+            // x y z a b c
+            p2_rt->next = p1_lft;
+            p1_lft->prev = p2_rt;
+            p2_lft->prev = p1_rt;
+            p1_rt->next = p2_lft;
+            keep_ring->points = p2_lft;
+        }
+    } else {
+        if (remove_bound->side == edge_right) {
+            // a b c z y x
+            reverse_ring(p2_lft);
+            p1_rt->next = p2_rt;
+            p2_rt->prev = p1_rt;
+            p2_lft->next = p1_lft;
+            p1_lft->prev = p2_lft;
+        } else {
+            // a b c x y z
+            p1_rt->next = p2_lft;
+            p2_lft->prev = p1_rt;
+            p1_lft->prev = p2_rt;
+            p2_rt->next = p1_lft;
+        }
+    }
+
+    keep_ring->bottom_point = nullptr;
+    bool keep_is_hole = ring_is_hole(keep_ring);
+    bool remove_is_hole = ring_is_hole(remove_ring);
+
+    remove_ring->points = nullptr;
+    remove_ring->bottom_point = nullptr;
+    if (keep_is_hole != remove_is_hole) {
+        ring1_replaces_ring2(keep_ring->parent, remove_ring, manager);
+    } else {
+        ring1_replaces_ring2(keep_ring, remove_ring, manager);
+    }
+
+    update_points_ring(keep_ring);
+
+    // nb: safe because we only get here via AddLocalMaxPoly
+    keep_bound->ring = nullptr;
+    remove_bound->ring = nullptr;
+
+    for (auto& b : active_bounds) {
+        if (b == nullptr) {
+            continue;
+        }
+        if (b->ring == remove_ring) {
+            b->ring = keep_ring;
+            b->side = keep_bound->side;
+            break; // Not sure why there is a break here but was transfered logic from angus
+        }
+    }
+}
+
+template <typename T>
+void add_local_maximum_point(bound<T>& b1,
+                             bound<T>& b2,
+                             mapbox::geometry::point<T> const& pt,
+                             ring_manager<T>& rings,
+                             active_bound_list<T>& active_bounds) {
+    insert_hot_pixels_in_path(b2, pt, rings, false);
+    add_point(b1, active_bounds, pt, rings);
+    if (b1.ring == b2.ring) {
+        b1.ring = nullptr;
+        b2.ring = nullptr;
+        // I am not certain that order is important here?
+    } else if (b1.ring->ring_index < b2.ring->ring_index) {
+        append_ring(b1, b2, active_bounds, rings);
+    } else {
+        append_ring(b2, b1, active_bounds, rings);
+    }
+}
+
+enum point_in_polygon_result : std::int8_t {
+    point_on_polygon = -1,
+    point_inside_polygon = 0,
+    point_outside_polygon = 1
+};
+
+template <typename T>
+point_in_polygon_result point_in_polygon(point<T> const& pt, point_ptr<T> op) {
+    // returns 0 if false, +1 if true, -1 if pt ON polygon boundary
+    point_in_polygon_result result = point_outside_polygon;
+    point_ptr<T> startOp = op;
+    do {
+        if (op->next->y == pt.y) {
+            if ((op->next->x == pt.x) || (op->y == pt.y && ((op->next->x > pt.x) == (op->x < pt.x)))) {
+                return point_on_polygon;
+            }
+        }
+        if ((op->y < pt.y) != (op->next->y < pt.y)) {
+            if (op->x >= pt.x) {
+                if (op->next->x > pt.x) {
+                    // Switch between point outside polygon and point inside
+                    // polygon
+                    if (result == point_outside_polygon) {
+                        result = point_inside_polygon;
+                    } else {
+                        result = point_outside_polygon;
+                    }
+                } else {
+                    double d = static_cast<double>(op->x - pt.x) * static_cast<double>(op->next->y - pt.y) -
+                               static_cast<double>(op->next->x - pt.x) * static_cast<double>(op->y - pt.y);
+                    if (value_is_zero(d)) {
+                        return point_on_polygon;
+                    }
+                    if ((d > 0) == (op->next->y > op->y)) {
+                        // Switch between point outside polygon and point inside
+                        // polygon
+                        if (result == point_outside_polygon) {
+                            result = point_inside_polygon;
+                        } else {
+                            result = point_outside_polygon;
+                        }
+                    }
+                }
+            } else {
+                if (op->next->x > pt.x) {
+                    double d = static_cast<double>(op->x - pt.x) * static_cast<double>(op->next->y - pt.y) -
+                               static_cast<double>(op->next->x - pt.x) * static_cast<double>(op->y - pt.y);
+                    if (value_is_zero(d)) {
+                        return point_on_polygon;
+                    }
+                    if ((d > 0) == (op->next->y > op->y)) {
+                        // Switch between point outside polygon and point inside
+                        // polygon
+                        if (result == point_outside_polygon) {
+                            result = point_inside_polygon;
+                        } else {
+                            result = point_outside_polygon;
+                        }
+                    }
+                }
+            }
+        }
+        op = op->next;
+    } while (startOp != op);
+    return result;
+}
+
+template <typename T>
+point_in_polygon_result point_in_polygon(mapbox::geometry::point<double> const& pt, point_ptr<T> op) {
+    // returns 0 if false, +1 if true, -1 if pt ON polygon boundary
+    point_in_polygon_result result = point_outside_polygon;
+    point_ptr<T> startOp = op;
+    do {
+        double op_x = static_cast<double>(op->x);
+        double op_y = static_cast<double>(op->y);
+        double op_next_x = static_cast<double>(op->next->x);
+        double op_next_y = static_cast<double>(op->next->y);
+        if (values_are_equal(op_next_y, pt.y)) {
+            if (values_are_equal(op_next_x, pt.x) ||
+                (values_are_equal(op_y, pt.y) && ((op_next_x > pt.x) == (op_x < pt.x)))) {
+                return point_on_polygon;
+            }
+        }
+        if ((op_y < pt.y) != (op_next_y < pt.y)) {
+            if (greater_than_or_equal(op_x, pt.x)) {
+                if (op_next_x > pt.x) {
+                    // Switch between point outside polygon and point inside
+                    // polygon
+                    if (result == point_outside_polygon) {
+                        result = point_inside_polygon;
+                    } else {
+                        result = point_outside_polygon;
+                    }
+                } else {
+                    double d = (op_x - pt.x) * (op_next_y - pt.y) - (op_next_x - pt.x) * (op_y - pt.y);
+                    if (value_is_zero(d)) {
+                        return point_on_polygon;
+                    }
+                    if ((d > 0.0) == (op_next_y > op_y)) {
+                        // Switch between point outside polygon and point inside
+                        // polygon
+                        if (result == point_outside_polygon) {
+                            result = point_inside_polygon;
+                        } else {
+                            result = point_outside_polygon;
+                        }
+                    }
+                }
+            } else {
+                if (op_next_x > pt.x) {
+                    double d = (op_x - pt.x) * (op_next_y - pt.y) - (op_next_x - pt.x) * (op_y - pt.y);
+                    if (value_is_zero(d)) {
+                        return point_on_polygon;
+                    }
+                    if ((d > 0.0) == (op_next_y > op_y)) {
+                        // Switch between point outside polygon and point inside
+                        // polygon
+                        if (result == point_outside_polygon) {
+                            result = point_inside_polygon;
+                        } else {
+                            result = point_outside_polygon;
+                        }
+                    }
+                }
+            }
+        }
+        op = op->next;
+    } while (startOp != op);
+    return result;
+}
+
+template <typename T>
+bool is_convex(point_ptr<T> edge) {
+    point_ptr<T> prev = edge->prev;
+    point_ptr<T> next = edge->next;
+    T v1x = edge->x - prev->x;
+    T v1y = edge->y - prev->y;
+    T v2x = next->x - edge->x;
+    T v2y = next->y - edge->y;
+    T cross = v1x * v2y - v2x * v1y;
+    if (cross < 0 && edge->ring->area() > 0) {
+        return true;
+    } else if (cross > 0 && edge->ring->area() < 0) {
+        return true;
+    } else {
+        return false;
+    }
+}
+
+template <typename T>
+mapbox::geometry::point<double> centroid_of_points(point_ptr<T> edge) {
+    point_ptr<T> prev = edge->prev;
+    point_ptr<T> next = edge->next;
+    return { static_cast<double>(prev->x + edge->x + next->x) / 3.0,
+             static_cast<double>(prev->y + edge->y + next->y) / 3.0 };
+}
+
+template <typename T>
+point_in_polygon_result inside_or_outside_special(point_ptr<T> first_pt, point_ptr<T> other_poly) {
+
+    // We are going to loop through all the points
+    // of the original triangle. The goal is to find a convex edge
+    // that with its next and previous forms a triangle with its centroid
+    // that is within the first ring. Then we will check the other polygon
+    // to see if it is within this polygon.
+    point_ptr<T> itr = first_pt;
+    do {
+        if (is_convex(itr)) {
+            auto pt = centroid_of_points(itr);
+            if (point_inside_polygon == point_in_polygon(pt, first_pt)) {
+                return point_in_polygon(pt, other_poly);
+            }
+        }
+        itr = itr->next;
+    } while (itr != first_pt);
+
+    throw std::runtime_error("Could not find a point within the polygon to test");
+}
+
+template <typename T>
+bool box2_contains_box1(mapbox::geometry::box<T> const& box1, mapbox::geometry::box<T> const& box2) {
+    return (box2.max.x >= box1.max.x && box2.max.y >= box1.max.y && box2.min.x <= box1.min.x &&
+            box2.min.y <= box1.min.y);
+}
+
+template <typename T>
+bool poly2_contains_poly1(ring_ptr<T> ring1, ring_ptr<T> ring2) {
+    if (!box2_contains_box1(ring1->bbox, ring2->bbox)) {
+        return false;
+    }
+    if (std::fabs(ring2->area()) < std::fabs(ring1->area())) {
+        return false;
+    }
+    point_ptr<T> outpt1 = ring1->points->next;
+    point_ptr<T> outpt2 = ring2->points->next;
+    point_ptr<T> op = outpt1;
+    do {
+        // nb: PointInPolygon returns 0 if false, +1 if true, -1 if pt on polygon
+        point_in_polygon_result res = point_in_polygon(*op, outpt2);
+        if (res != point_on_polygon) {
+            return res == point_inside_polygon;
+        }
+        op = op->next;
+    } while (op != outpt1);
+    point_in_polygon_result res = inside_or_outside_special(outpt1, outpt2);
+    return res == point_inside_polygon;
+}
+} // namespace wagyu
+} // namespace geometry
+} // namespace mapbox

mapbox/geometry/wagyu/scanbeam.hpp

@@ -0,0 +1,45 @@
+#pragma once
+
+#include <mapbox/geometry/wagyu/config.hpp>
+#include <mapbox/geometry/wagyu/local_minimum.hpp>
+
+#include <algorithm>
+
+namespace mapbox {
+namespace geometry {
+namespace wagyu {
+
+template <typename T>
+using scanbeam_list = std::vector<T>;
+
+template <typename T>
+void insert_sorted_scanbeam(scanbeam_list<T>& scanbeam, T& t) {
+    typename scanbeam_list<T>::iterator i = std::lower_bound(scanbeam.begin(), scanbeam.end(), t);
+    if (i == scanbeam.end() || t < *i) {
+        scanbeam.insert(i, t);
+    }
+}
+
+template <typename T>
+bool pop_from_scanbeam(T& Y, scanbeam_list<T>& scanbeam) {
+    if (scanbeam.empty()) {
+        return false;
+    }
+
+    Y = scanbeam.back();
+    scanbeam.pop_back();
+    return true;
+}
+
+template <typename T>
+void setup_scanbeam(local_minimum_list<T>& minima_list, scanbeam_list<T>& scanbeam) {
+
+    scanbeam.reserve(minima_list.size());
+    for (auto lm = minima_list.begin(); lm != minima_list.end(); ++lm) {
+        scanbeam.push_back(lm->y);
+    }
+    std::sort(scanbeam.begin(), scanbeam.end());
+}
+} // namespace wagyu
+} // namespace geometry
+} // namespace mapbox

mapbox/geometry/wagyu/snap_rounding.hpp

@@ -0,0 +1,191 @@
+#pragma once
+
+#include <mapbox/geometry/wagyu/active_bound_list.hpp>
+#include <mapbox/geometry/wagyu/bound.hpp>
+#include <mapbox/geometry/wagyu/bubble_sort.hpp>
+#include <mapbox/geometry/wagyu/config.hpp>
+#include <mapbox/geometry/wagyu/edge.hpp>
+#include <mapbox/geometry/wagyu/intersect.hpp>
+#include <mapbox/geometry/wagyu/intersect_util.hpp>
+#include <mapbox/geometry/wagyu/ring.hpp>
+#include <mapbox/geometry/wagyu/ring_util.hpp>
+#include <mapbox/geometry/wagyu/util.hpp>
+
+namespace mapbox {
+namespace geometry {
+namespace wagyu {
+
+template <typename T>
+struct hp_intersection_swap {
+
+    ring_manager<T>& manager;
+
+    hp_intersection_swap(ring_manager<T>& m) : manager(m) {
+    }
+
+    void operator()(bound_ptr<T> const& b1, bound_ptr<T> const& b2) {
+        mapbox::geometry::point<double> pt;
+        if (!get_edge_intersection<T, double>(*(b1->current_edge), *(b2->current_edge), pt)) {
+            // LCOV_EXCL_START
+            throw std::runtime_error("Trying to find intersection of lines that do not intersect");
+            // LCOV_EXCL_END
+        }
+        add_to_hot_pixels(round_point<T>(pt), manager);
+    }
+};
+
+template <typename T>
+void process_hot_pixel_intersections(T top_y, active_bound_list<T>& active_bounds, ring_manager<T>& manager) {
+    if (active_bounds.empty()) {
+        return;
+    }
+    update_current_x(active_bounds, top_y);
+    bubble_sort(active_bounds.begin(), active_bounds.end(), intersection_compare<T>(),
+                hp_intersection_swap<T>(manager));
+}
+
+template <typename T>
+bool horizontals_at_top_scanbeam(T top_y,
+                                 active_bound_list_itr<T>& bnd_curr,
+                                 active_bound_list<T>& active_bounds,
+                                 ring_manager<T>& manager) {
+    bool shifted = false;
+    auto& current_edge = (*bnd_curr)->current_edge;
+    (*bnd_curr)->current_x = static_cast<double>(current_edge->top.x);
+    if (current_edge->bot.x < current_edge->top.x) {
+        // left to right
+        auto bnd_next = std::next(bnd_curr);
+        while (bnd_next != active_bounds.end() &&
+               (*bnd_next == nullptr || (*bnd_next)->current_x < (*bnd_curr)->current_x)) {
+            if (*bnd_next != nullptr && (*bnd_next)->current_edge->top.y != top_y &&
+                (*bnd_next)->current_edge->bot.y != top_y) {
+                mapbox::geometry::point<T> pt(wround<T>((*bnd_next)->current_x), top_y);
+                add_to_hot_pixels(pt, manager);
+            }
+            std::iter_swap(bnd_curr, bnd_next);
+            ++bnd_curr;
+            ++bnd_next;
+            shifted = true;
+        }
+    } else {
+        // right to left
+        if (bnd_curr != active_bounds.begin()) {
+            auto bnd_prev = std::prev(bnd_curr);
+            while (bnd_curr != active_bounds.begin() &&
+                   (*bnd_prev == nullptr || (*bnd_prev)->current_x > (*bnd_curr)->current_x)) {
+                if (*bnd_prev != nullptr && (*bnd_prev)->current_edge->top.y != top_y &&
+                    (*bnd_prev)->current_edge->bot.y != top_y) {
+                    mapbox::geometry::point<T> pt(wround<T>((*bnd_prev)->current_x), top_y);
+                    add_to_hot_pixels(pt, manager);
+                }
+                std::iter_swap(bnd_curr, bnd_prev);
+                --bnd_curr;
+                if (bnd_curr != active_bounds.begin()) {
+                    --bnd_prev;
+                }
+            }
+        }
+    }
+    return shifted;
+}
+
+template <typename T>
+void process_hot_pixel_edges_at_top_of_scanbeam(T top_y,
+                                                scanbeam_list<T>& scanbeam,
+                                                active_bound_list<T>& active_bounds,
+                                                ring_manager<T>& manager) {
+    for (auto bnd = active_bounds.begin(); bnd != active_bounds.end();) {
+        if (*bnd == nullptr) {
+            ++bnd;
+            continue;
+        }
+        bound<T>& current_bound = *(*bnd);
+        auto bnd_curr = bnd;
+        bool shifted = false;
+        auto& current_edge = current_bound.current_edge;
+        while (current_edge != current_bound.edges.end() && current_edge->top.y == top_y) {
+            add_to_hot_pixels(current_edge->top, manager);
+            if (is_horizontal(*current_edge)) {
+                if (horizontals_at_top_scanbeam(top_y, bnd_curr, active_bounds, manager)) {
+                    shifted = true;
+                }
+            }
+            next_edge_in_bound(current_bound, scanbeam);
+        }
+        if (current_edge == current_bound.edges.end()) {
+            *bnd_curr = nullptr;
+        }
+        if (!shifted) {
+            ++bnd;
+        }
+    }
+    active_bounds.erase(std::remove(active_bounds.begin(), active_bounds.end(), nullptr), active_bounds.end());
+}
+
+template <typename T>
+void insert_local_minima_into_ABL_hot_pixel(T top_y,
+                                            local_minimum_ptr_list<T>& minima_sorted,
+                                            local_minimum_ptr_list_itr<T>& lm,
+                                            active_bound_list<T>& active_bounds,
+                                            ring_manager<T>& manager,
+                                            scanbeam_list<T>& scanbeam) {
+    while (lm != minima_sorted.end() && (*lm)->y == top_y) {
+        add_to_hot_pixels((*lm)->left_bound.edges.front().bot, manager);
+        auto& left_bound = (*lm)->left_bound;
+        auto& right_bound = (*lm)->right_bound;
+        left_bound.current_edge = left_bound.edges.begin();
+        left_bound.next_edge = std::next(left_bound.current_edge);
+        left_bound.current_x = static_cast<double>(left_bound.current_edge->bot.x);
+        right_bound.current_edge = right_bound.edges.begin();
+        right_bound.next_edge = std::next(right_bound.current_edge);
+        right_bound.current_x = static_cast<double>(right_bound.current_edge->bot.x);
+        auto lb_abl_itr = insert_bound_into_ABL(left_bound, right_bound, active_bounds);
+        if (!current_edge_is_horizontal<T>(lb_abl_itr)) {
+            insert_sorted_scanbeam(scanbeam, (*lb_abl_itr)->current_edge->top.y);
+        }
+        auto rb_abl_itr = std::next(lb_abl_itr);
+        if (!current_edge_is_horizontal<T>(rb_abl_itr)) {
+            insert_sorted_scanbeam(scanbeam, (*rb_abl_itr)->current_edge->top.y);
+        }
+        ++lm;
+    }
+}
+
+template <typename T>
+void build_hot_pixels(local_minimum_list<T>& minima_list, ring_manager<T>& manager) {
+    active_bound_list<T> active_bounds;
+    scanbeam_list<T> scanbeam;
+    T scanline_y = std::numeric_limits<T>::max();
+
+    local_minimum_ptr_list<T> minima_sorted;
+    minima_sorted.reserve(minima_list.size());
+    for (auto& lm : minima_list) {
+        minima_sorted.push_back(&lm);
+    }
+    std::stable_sort(minima_sorted.begin(), minima_sorted.end(), local_minimum_sorter<T>());
+    local_minimum_ptr_list_itr<T> current_lm = minima_sorted.begin();
+
+    setup_scanbeam(minima_list, scanbeam);
+
+    // Estimate size for reserving hot pixels
+    std::size_t reserve = 0;
+    for (auto& lm : minima_list) {
+        reserve += lm.left_bound.edges.size() + 2;
+        reserve += lm.right_bound.edges.size() + 2;
+    }
+    manager.hot_pixels.reserve(reserve);
+
+    while (pop_from_scanbeam(scanline_y, scanbeam) || current_lm != minima_sorted.end()) {
+
+        process_hot_pixel_intersections(scanline_y, active_bounds, manager);
+
+        insert_local_minima_into_ABL_hot_pixel(scanline_y, minima_sorted, current_lm, active_bounds, manager, scanbeam);
+
+        process_hot_pixel_edges_at_top_of_scanbeam(scanline_y, scanbeam, active_bounds, manager);
+    }
+    preallocate_point_memory(manager, manager.hot_pixels.size());
+    sort_hot_pixels(manager);
+}
+} // namespace wagyu
+} // namespace geometry
+} // namespace mapbox

mapbox/geometry/wagyu/util.hpp

@@ -0,0 +1,98 @@
+#pragma once
+
+#include <cmath>
+
+#include <mapbox/geometry/point.hpp>
+#include <mapbox/geometry/polygon.hpp>
+#include <mapbox/geometry/wagyu/almost_equal.hpp>
+#include <mapbox/geometry/wagyu/point.hpp>
+
+namespace mapbox {
+namespace geometry {
+namespace wagyu {
+
+template <typename T>
+double area(mapbox::geometry::linear_ring<T> const& poly) {
+    std::size_t size = poly.size();
+    if (size < 3) {
+        return 0.0;
+    }
+
+    double a = 0.0;
+    auto itr = poly.begin();
+    auto itr_prev = poly.end();
+    --itr_prev;
+    a += static_cast<double>(itr_prev->x + itr->x) * static_cast<double>(itr_prev->y - itr->y);
+    ++itr;
+    itr_prev = poly.begin();
+    for (; itr != poly.end(); ++itr, ++itr_prev) {
+        a += static_cast<double>(itr_prev->x + itr->x) * static_cast<double>(itr_prev->y - itr->y);
+    }
+    return -a * 0.5;
+}
+
+inline bool values_are_equal(double x, double y) {
+    return util::FloatingPoint<double>(x).AlmostEquals(util::FloatingPoint<double>(y));
+}
+
+inline bool value_is_zero(double val) {
+    return values_are_equal(val, static_cast<double>(0.0));
+}
+
+inline bool greater_than_or_equal(double x, double y) {
+    return x > y || values_are_equal(x, y);
+}
+
+inline bool greater_than(double x, double y) {
+    return (!values_are_equal(x, y) && x > y);
+}
+
+inline bool less_than(double x, double y) {
+    return (!values_are_equal(x, y) && x < y);
+}
+
+template <typename T>
+bool slopes_equal(mapbox::geometry::point<T> const& pt1,
+                  mapbox::geometry::point<T> const& pt2,
+                  mapbox::geometry::point<T> const& pt3) {
+    return static_cast<std::int64_t>(pt1.y - pt2.y) * static_cast<std::int64_t>(pt2.x - pt3.x) ==
+           static_cast<std::int64_t>(pt1.x - pt2.x) * static_cast<std::int64_t>(pt2.y - pt3.y);
+}
+
+template <typename T>
+bool slopes_equal(mapbox::geometry::wagyu::point<T> const& pt1,
+                  mapbox::geometry::wagyu::point<T> const& pt2,
+                  mapbox::geometry::point<T> const& pt3) {
+    return static_cast<std::int64_t>(pt1.y - pt2.y) * static_cast<std::int64_t>(pt2.x - pt3.x) ==
+           static_cast<std::int64_t>(pt1.x - pt2.x) * static_cast<std::int64_t>(pt2.y - pt3.y);
+}
+
+template <typename T>
+bool slopes_equal(mapbox::geometry::wagyu::point<T> const& pt1,
+                  mapbox::geometry::wagyu::point<T> const& pt2,
+                  mapbox::geometry::wagyu::point<T> const& pt3) {
+    return static_cast<std::int64_t>(pt1.y - pt2.y) * static_cast<std::int64_t>(pt2.x - pt3.x) ==
+           static_cast<std::int64_t>(pt1.x - pt2.x) * static_cast<std::int64_t>(pt2.y - pt3.y);
+}
+
+template <typename T>
+bool slopes_equal(mapbox::geometry::point<T> const& pt1,
+                  mapbox::geometry::point<T> const& pt2,
+                  mapbox::geometry::point<T> const& pt3,
+                  mapbox::geometry::point<T> const& pt4) {
+    return static_cast<std::int64_t>(pt1.y - pt2.y) * static_cast<std::int64_t>(pt3.x - pt4.x) ==
+           static_cast<std::int64_t>(pt1.x - pt2.x) * static_cast<std::int64_t>(pt3.y - pt4.y);
+}
+
+template <typename T>
+inline T wround(double value) {
+    return static_cast<T>(::llround(value));
+}
+
+template <>
+inline std::int64_t wround<std::int64_t>(double value) {
+    return ::llround(value);
+}
+} // namespace wagyu
+} // namespace geometry
+} // namespace mapbox

mapbox/geometry/wagyu/vatti.hpp

@@ -0,0 +1,64 @@
+#pragma once
+
+#include <algorithm>
+#include <set>
+
+#include <mapbox/geometry/wagyu/active_bound_list.hpp>
+#include <mapbox/geometry/wagyu/config.hpp>
+#include <mapbox/geometry/wagyu/intersect_util.hpp>
+#include <mapbox/geometry/wagyu/local_minimum.hpp>
+#include <mapbox/geometry/wagyu/local_minimum_util.hpp>
+#include <mapbox/geometry/wagyu/process_horizontal.hpp>
+#include <mapbox/geometry/wagyu/process_maxima.hpp>
+#include <mapbox/geometry/wagyu/ring.hpp>
+#include <mapbox/geometry/wagyu/ring_util.hpp>
+#include <mapbox/geometry/wagyu/util.hpp>
+
+namespace mapbox {
+namespace geometry {
+namespace wagyu {
+
+template <typename T>
+void execute_vatti(local_minimum_list<T>& minima_list,
+                   ring_manager<T>& manager,
+                   clip_type cliptype,
+                   fill_type subject_fill_type,
+                   fill_type clip_fill_type) {
+    active_bound_list<T> active_bounds;
+    scanbeam_list<T> scanbeam;
+    T scanline_y = std::numeric_limits<T>::max();
+
+    local_minimum_ptr_list<T> minima_sorted;
+    minima_sorted.reserve(minima_list.size());
+    for (auto& lm : minima_list) {
+        minima_sorted.push_back(&lm);
+    }
+    std::stable_sort(minima_sorted.begin(), minima_sorted.end(), local_minimum_sorter<T>());
+    local_minimum_ptr_list_itr<T> current_lm = minima_sorted.begin();
+    // std::clog << output_all_edges(minima_sorted) << std::endl;
+
+    setup_scanbeam(minima_list, scanbeam);
+    manager.current_hp_itr = manager.hot_pixels.begin();
+
+    while (pop_from_scanbeam(scanline_y, scanbeam) || current_lm != minima_sorted.end()) {
+
+        process_intersections(scanline_y, active_bounds, cliptype, subject_fill_type, clip_fill_type, manager);
+
+        update_current_hp_itr(scanline_y, manager);
+
+        // First we process bounds that has already been added to the active bound list --
+        // if the active bound list is empty local minima that are at this scanline_y and
+        // have a horizontal edge at the local minima will be processed
+        process_edges_at_top_of_scanbeam(scanline_y, active_bounds, scanbeam, minima_sorted, current_lm, manager,
+                                         cliptype, subject_fill_type, clip_fill_type);
+
+        // Next we will add local minima bounds to the active bounds list that are on the local
+        // minima queue at
+        // this current scanline_y
+        insert_local_minima_into_ABL(scanline_y, minima_sorted, current_lm, active_bounds, manager, scanbeam, cliptype,
+                                     subject_fill_type, clip_fill_type);
+    }
+}
+} // namespace wagyu
+} // namespace geometry
+} // namespace mapbox

mapbox/geometry/wagyu/wagyu.hpp

@@ -0,0 +1,145 @@
+#pragma once
+
+#include <list>
+
+#include <mapbox/geometry/box.hpp>
+#include <mapbox/geometry/line_string.hpp>
+#include <mapbox/geometry/multi_polygon.hpp>
+#include <mapbox/geometry/polygon.hpp>
+
+#include <mapbox/geometry/wagyu/build_local_minima_list.hpp>
+#include <mapbox/geometry/wagyu/build_result.hpp>
+#include <mapbox/geometry/wagyu/config.hpp>
+#include <mapbox/geometry/wagyu/interrupt.hpp>
+#include <mapbox/geometry/wagyu/local_minimum.hpp>
+#include <mapbox/geometry/wagyu/snap_rounding.hpp>
+#include <mapbox/geometry/wagyu/topology_correction.hpp>
+#include <mapbox/geometry/wagyu/vatti.hpp>
+
+#define WAGYU_MAJOR_VERSION 0
+#define WAGYU_MINOR_VERSION 5
+#define WAGYU_PATCH_VERSION 0
+
+#define WAGYU_VERSION (WAGYU_MAJOR_VERSION * 100000) + (WAGYU_MINOR_VERSION * 100) + (WAGYU_PATCH_VERSION)
+
+namespace mapbox {
+namespace geometry {
+namespace wagyu {
+
+template <typename T>
+class wagyu {
+private:
+    local_minimum_list<T> minima_list;
+    bool reverse_output;
+
+    wagyu(wagyu const&) = delete;
+    wagyu& operator=(wagyu const&) = delete;
+
+public:
+    wagyu() : minima_list(), reverse_output(false) {
+    }
+
+    ~wagyu() {
+        clear();
+    }
+
+    template <typename T2>
+    bool add_ring(mapbox::geometry::linear_ring<T2> const& pg, polygon_type p_type = polygon_type_subject) {
+        return add_linear_ring(pg, minima_list, p_type);
+    }
+
+    template <typename T2>
+    bool add_polygon(mapbox::geometry::polygon<T2> const& ppg, polygon_type p_type = polygon_type_subject) {
+        bool result = false;
+        for (auto const& r : ppg) {
+            if (add_ring(r, p_type)) {
+                result = true;
+            }
+        }
+        return result;
+    }
+
+    void reverse_rings(bool value) {
+        reverse_output = value;
+    }
+
+    void clear() {
+        minima_list.clear();
+    }
+
+    mapbox::geometry::box<T> get_bounds() {
+        mapbox::geometry::point<T> min = { 0, 0 };
+        mapbox::geometry::point<T> max = { 0, 0 };
+        if (minima_list.empty()) {
+            return mapbox::geometry::box<T>(min, max);
+        }
+        bool first_set = false;
+        for (auto const& lm : minima_list) {
+            if (!lm.left_bound.edges.empty()) {
+                if (!first_set) {
+                    min = lm.left_bound.edges.front().top;
+                    max = lm.left_bound.edges.back().bot;
+                    first_set = true;
+                } else {
+                    min.y = std::min(min.y, lm.left_bound.edges.front().top.y);
+                    max.y = std::max(max.y, lm.left_bound.edges.back().bot.y);
+                    max.x = std::max(max.x, lm.left_bound.edges.back().top.x);
+                    min.x = std::min(min.x, lm.left_bound.edges.back().top.x);
+                }
+                for (auto const& e : lm.left_bound.edges) {
+                    max.x = std::max(max.x, e.bot.x);
+                    min.x = std::min(min.x, e.bot.x);
+                }
+            }
+            if (!lm.right_bound.edges.empty()) {
+                if (!first_set) {
+                    min = lm.right_bound.edges.front().top;
+                    max = lm.right_bound.edges.back().bot;
+                    first_set = true;
+                } else {
+                    min.y = std::min(min.y, lm.right_bound.edges.front().top.y);
+                    max.y = std::max(max.y, lm.right_bound.edges.back().bot.y);
+                    max.x = std::max(max.x, lm.right_bound.edges.back().top.x);
+                    min.x = std::min(min.x, lm.right_bound.edges.back().top.x);
+                }
+                for (auto const& e : lm.right_bound.edges) {
+                    max.x = std::max(max.x, e.bot.x);
+                    min.x = std::min(min.x, e.bot.x);
+                }
+            }
+        }
+        return mapbox::geometry::box<T>(min, max);
+    }
+
+    template <typename T2>
+    bool execute(clip_type cliptype,
+                 mapbox::geometry::multi_polygon<T2>& solution,
+                 fill_type subject_fill_type,
+                 fill_type clip_fill_type) {
+
+        if (minima_list.empty()) {
+            return false;
+        }
+
+        ring_manager<T> manager;
+
+        interrupt_check(); // Check for interruptions
+
+        build_hot_pixels(minima_list, manager);
+
+        interrupt_check(); // Check for interruptions
+
+        execute_vatti(minima_list, manager, cliptype, subject_fill_type, clip_fill_type);
+
+        interrupt_check(); // Check for interruptions
+
+        correct_topology(manager);
+
+        build_result(solution, manager, reverse_output);
+
+        return true;
+    }
+};
+} // namespace wagyu
+} // namespace geometry
+} // namespace mapbox

mapbox/optional.hpp

@@ -0,0 +1,74 @@
+#ifndef MAPBOX_UTIL_OPTIONAL_HPP
+#define MAPBOX_UTIL_OPTIONAL_HPP
+
+#pragma message("This implementation of optional is deprecated. See https://github.com/mapbox/variant/issues/64.")
+
+#include <type_traits>
+#include <utility>
+
+#include <mapbox/variant.hpp>
+
+namespace mapbox {
+namespace util {
+
+template <typename T>
+class optional
+{
+    static_assert(!std::is_reference<T>::value, "optional doesn't support references");
+
+    struct none_type
+    {
+    };
+
+    variant<none_type, T> variant_;
+
+public:
+    optional() = default;
+
+    optional(optional const& rhs)
+    {
+        if (this != &rhs)
+        { // protect against invalid self-assignment
+            variant_ = rhs.variant_;
+        }
+    }
+
+    optional(T const& v) { variant_ = v; }
+
+    explicit operator bool() const noexcept { return variant_.template is<T>(); }
+
+    T const& get() const { return variant_.template get<T>(); }
+    T& get() { return variant_.template get<T>(); }
+
+    T const& operator*() const { return this->get(); }
+    T operator*() { return this->get(); }
+
+    optional& operator=(T const& v)
+    {
+        variant_ = v;
+        return *this;
+    }
+
+    optional& operator=(optional const& rhs)
+    {
+        if (this != &rhs)
+        {
+            variant_ = rhs.variant_;
+        }
+        return *this;
+    }
+
+    template <typename... Args>
+    void emplace(Args&&... args)
+    {
+        variant_ = T{std::forward<Args>(args)...};
+    }
+
+    void reset() { variant_ = none_type{}; }
+
+}; // class optional
+
+} // namespace util
+} // namespace mapbox
+
+#endif // MAPBOX_UTIL_OPTIONAL_HPP

mapbox/recursive_wrapper.hpp

@@ -0,0 +1,122 @@
+#ifndef MAPBOX_UTIL_RECURSIVE_WRAPPER_HPP
+#define MAPBOX_UTIL_RECURSIVE_WRAPPER_HPP
+
+// Based on variant/recursive_wrapper.hpp from boost.
+//
+// Original license:
+//
+// Copyright (c) 2002-2003
+// Eric Friedman, Itay Maman
+//
+// Distributed under the Boost Software License, Version 1.0. (See
+// accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+
+#include <cassert>
+#include <utility>
+
+namespace mapbox {
+namespace util {
+
+template <typename T>
+class recursive_wrapper
+{
+
+    T* p_;
+
+    void assign(T const& rhs)
+    {
+        this->get() = rhs;
+    }
+
+public:
+    using type = T;
+
+    /**
+     * Default constructor default initializes the internally stored value.
+     * For POD types this means nothing is done and the storage is
+     * uninitialized.
+     *
+     * @throws std::bad_alloc if there is insufficient memory for an object
+     *         of type T.
+     * @throws any exception thrown by the default constructur of T.
+     */
+    recursive_wrapper()
+        : p_(new T){}
+
+    ~recursive_wrapper() noexcept { delete p_; }
+
+    recursive_wrapper(recursive_wrapper const& operand)
+        : p_(new T(operand.get())) {}
+
+    recursive_wrapper(T const& operand)
+        : p_(new T(operand)) {}
+
+    recursive_wrapper(recursive_wrapper&& operand)
+        : p_(new T(std::move(operand.get()))) {}
+
+    recursive_wrapper(T&& operand)
+        : p_(new T(std::move(operand))) {}
+
+    inline recursive_wrapper& operator=(recursive_wrapper const& rhs)
+    {
+        assign(rhs.get());
+        return *this;
+    }
+
+    inline recursive_wrapper& operator=(T const& rhs)
+    {
+        assign(rhs);
+        return *this;
+    }
+
+    inline void swap(recursive_wrapper& operand) noexcept
+    {
+        T* temp = operand.p_;
+        operand.p_ = p_;
+        p_ = temp;
+    }
+
+    recursive_wrapper& operator=(recursive_wrapper&& rhs) noexcept
+    {
+        swap(rhs);
+        return *this;
+    }
+
+    recursive_wrapper& operator=(T&& rhs)
+    {
+        get() = std::move(rhs);
+        return *this;
+    }
+
+    T& get()
+    {
+        assert(p_);
+        return *get_pointer();
+    }
+
+    T const& get() const
+    {
+        assert(p_);
+        return *get_pointer();
+    }
+
+    T* get_pointer() { return p_; }
+
+    const T* get_pointer() const { return p_; }
+
+    operator T const&() const { return this->get(); }
+
+    operator T&() { return this->get(); }
+
+}; // class recursive_wrapper
+
+template <typename T>
+inline void swap(recursive_wrapper<T>& lhs, recursive_wrapper<T>& rhs) noexcept
+{
+    lhs.swap(rhs);
+}
+} // namespace util
+} // namespace mapbox
+
+#endif // MAPBOX_UTIL_RECURSIVE_WRAPPER_HPP

mapbox/variant_io.hpp

@@ -0,0 +1,45 @@
+#ifndef MAPBOX_UTIL_VARIANT_IO_HPP
+#define MAPBOX_UTIL_VARIANT_IO_HPP
+
+#include <iosfwd>
+
+#include <mapbox/variant.hpp>
+
+namespace mapbox {
+namespace util {
+
+namespace detail {
+// operator<< helper
+template <typename Out>
+class printer
+{
+public:
+    explicit printer(Out& out)
+        : out_(out) {}
+    printer& operator=(printer const&) = delete;
+
+    // visitor
+    template <typename T>
+    void operator()(T const& operand) const
+    {
+        out_ << operand;
+    }
+
+private:
+    Out& out_;
+};
+}
+
+// operator<<
+template <typename CharT, typename Traits, typename... Types>
+VARIANT_INLINE std::basic_ostream<CharT, Traits>&
+operator<<(std::basic_ostream<CharT, Traits>& out, variant<Types...> const& rhs)
+{
+    detail::printer<std::basic_ostream<CharT, Traits>> visitor(out);
+    apply_visitor(visitor, rhs);
+    return out;
+}
+} // namespace util
+} // namespace mapbox
+
+#endif // MAPBOX_UTIL_VARIANT_IO_HPP

mapbox/variant_visitor.hpp

@@ -0,0 +1,38 @@
+#ifndef MAPBOX_UTIL_VARIANT_VISITOR_HPP
+#define MAPBOX_UTIL_VARIANT_VISITOR_HPP
+
+namespace mapbox {
+namespace util {
+
+template <typename... Fns>
+struct visitor;
+
+template <typename Fn>
+struct visitor<Fn> : Fn
+{
+    using type = Fn;
+    using Fn::operator();
+
+    visitor(Fn fn) : Fn(fn) {}
+};
+
+template <typename Fn, typename... Fns>
+struct visitor<Fn, Fns...> : Fn, visitor<Fns...>
+{
+    using type = visitor;
+    using Fn::operator();
+    using visitor<Fns...>::operator();
+
+    visitor(Fn fn, Fns... fns) : Fn(fn), visitor<Fns...>(fns...) {}
+};
+
+template <typename... Fns>
+visitor<Fns...> make_visitor(Fns... fns)
+{
+    return visitor<Fns...>(fns...);
+}
+
+} // namespace util
+} // namespace mapbox
+
+#endif // MAPBOX_UTIL_VARIANT_VISITOR_HPP

mbtiles.cpp

@@ -11,10 +11,17 @@
 #include <string>
 #include <set>
 #include <map>
-#include "main.hpp"
-#include "pool.hpp"
+#include <sys/stat.h>
+#include "mvt.hpp"
 #include "mbtiles.hpp"
-#include "geometry.hpp"
+#include "text.hpp"
+#include "milo/dtoa_milo.h"
+#include "write_json.hpp"
+#include "version.hpp"
+
+size_t max_tilestats_attributes = 1000;
+size_t max_tilestats_sample_values = 1000;
+size_t max_tilestats_values = 100;
 
 sqlite3 *mbtiles_open(char *dbname, char **argv, int forcetable) {
 	sqlite3 *outdb;
@@ -38,7 +45,8 @@ sqlite3 *mbtiles_open(char *dbname, char **argv, int forcetable) {
 		exit(EXIT_FAILURE);
 	}
 	if (sqlite3_exec(outdb, "CREATE TABLE metadata (name text, value text);", NULL, NULL, &err) != SQLITE_OK) {
-		fprintf(stderr, "%s: create metadata table: %s\n", argv[0], err);
+		fprintf(stderr, "%s: Tileset \"%s\" already exists. You can use --force if you want to delete the old tileset.\n", argv[0], dbname);
+		fprintf(stderr, "%s: %s\n", argv[0], err);
 		if (!forcetable) {
 			exit(EXIT_FAILURE);
 		}
@@ -86,43 +94,6 @@ void mbtiles_write_tile(sqlite3 *outdb, int z, int tx, int ty, const char *data,
 	}
 }
 
-static void quote(std::string *buf, const char *s) {
-	char tmp[strlen(s) * 8 + 1];
-	char *out = tmp;
-
-	for (; *s != '\0'; s++) {
-		unsigned char ch = (unsigned char) *s;
-
-		if (ch == '\\' || ch == '\"') {
-			*out++ = '\\';
-			*out++ = ch;
-		} else if (ch < ' ') {
-			sprintf(out, "\\u%04x", ch);
-			out = out + strlen(out);
-		} else {
-			*out++ = ch;
-		}
-	}
-
-	*out = '\0';
-	buf->append(tmp, strlen(tmp));
-}
-
-void aprintf(std::string *buf, const char *format, ...) {
-	va_list ap;
-	char *tmp;
-
-	va_start(ap, format);
-	if (vasprintf(&tmp, format, ap) < 0) {
-		fprintf(stderr, "memory allocation failure\n");
-		exit(EXIT_FAILURE);
-	}
-	va_end(ap);
-
-	buf->append(tmp, strlen(tmp));
-	free(tmp);
-}
-
 bool type_and_string::operator<(const type_and_string &o) const {
 	if (string < o.string) {
 		return true;
@@ -133,11 +104,189 @@ bool type_and_string::operator<(const type_and_string &o) const {
 	return false;
 }
 
-void mbtiles_write_metadata(sqlite3 *outdb, const char *fname, int minzoom, int maxzoom, double minlat, double minlon, double maxlat, double maxlon, double midlat, double midlon, int forcetable, const char *attribution, std::map<std::string, layermap_entry> const &layermap) {
+bool type_and_string::operator!=(const type_and_string &o) const {
+	if (type != o.type) {
+		return true;
+	}
+	if (string != o.string) {
+		return true;
+	}
+	return false;
+}
+
+void tilestats(std::map<std::string, layermap_entry> const &layermap1, size_t elements, json_writer &state) {
+	// Consolidate layers/attributes whose names are truncated
+	std::vector<std::map<std::string, layermap_entry>> lmv;
+	lmv.push_back(layermap1);
+	std::map<std::string, layermap_entry> layermap = merge_layermaps(lmv, true);
+
+	state.json_write_hash();
+
+	state.nospace = true;
+	state.json_write_string("layerCount");
+	state.json_write_unsigned(layermap.size());
+
+	state.nospace = true;
+	state.json_write_string("layers");
+	state.json_write_array();
+
+	bool first = true;
+	for (auto layer : layermap) {
+		first = false;
+
+		state.nospace = true;
+		state.json_write_hash();
+
+		state.nospace = true;
+		state.json_write_string("layer");
+		state.json_write_string(layer.first);
+
+		state.nospace = true;
+		state.json_write_string("count");
+		state.json_write_unsigned(layer.second.points + layer.second.lines + layer.second.polygons);
+
+		std::string geomtype = "Polygon";
+		if (layer.second.points >= layer.second.lines && layer.second.points >= layer.second.polygons) {
+			geomtype = "Point";
+		} else if (layer.second.lines >= layer.second.polygons && layer.second.lines >= layer.second.points) {
+			geomtype = "LineString";
+		}
+
+		state.nospace = true;
+		state.json_write_string("geometry");
+		state.json_write_string(geomtype);
+
+		size_t attrib_count = layer.second.file_keys.size();
+		if (attrib_count > max_tilestats_attributes) {
+			attrib_count = max_tilestats_attributes;
+		}
+
+		state.nospace = true;
+		state.json_write_string("attributeCount");
+		state.json_write_unsigned(attrib_count);
+
+		state.nospace = true;
+		state.json_write_string("attributes");
+		state.nospace = true;
+		state.json_write_array();
+
+		size_t attrs = 0;
+		for (auto attribute : layer.second.file_keys) {
+			if (attrs == elements) {
+				break;
+			}
+			attrs++;
+
+			state.nospace = true;
+			state.json_write_hash();
+
+			state.nospace = true;
+			state.json_write_string("attribute");
+			state.json_write_string(attribute.first);
+
+			size_t val_count = attribute.second.sample_values.size();
+			if (val_count > max_tilestats_sample_values) {
+				val_count = max_tilestats_sample_values;
+			}
+
+			state.nospace = true;
+			state.json_write_string("count");
+			state.json_write_unsigned(val_count);
+
+			int type = 0;
+			for (auto s : attribute.second.sample_values) {
+				type |= (1 << s.type);
+			}
+
+			std::string type_str;
+			// No "null" because null attributes are dropped
+			if (type == (1 << mvt_double)) {
+				type_str = "number";
+			} else if (type == (1 << mvt_bool)) {
+				type_str = "boolean";
+			} else if (type == (1 << mvt_string)) {
+				type_str = "string";
+			} else {
+				type_str = "mixed";
+			}
+
+			state.nospace = true;
+			state.json_write_string("type");
+			state.json_write_string(type_str);
+
+			state.nospace = true;
+			state.json_write_string("values");
+			state.json_write_array();
+
+			size_t vals = 0;
+			for (auto value : attribute.second.sample_values) {
+				if (vals == elements) {
+					break;
+				}
+
+				state.nospace = true;
+
+				if (value.type == mvt_double || value.type == mvt_bool) {
+					vals++;
+
+					state.json_write_stringified(value.string);
+				} else {
+					std::string trunc = truncate16(value.string, 256);
+
+					if (trunc.size() == value.string.size()) {
+						vals++;
+
+						state.json_write_string(value.string);
+					}
+				}
+			}
+
+			state.nospace = true;
+			state.json_end_array();
+
+			if ((type & (1 << mvt_double)) != 0) {
+				state.nospace = true;
+				state.json_write_string("min");
+				state.json_write_number(attribute.second.min);
+
+				state.nospace = true;
+				state.json_write_string("max");
+				state.json_write_number(attribute.second.max);
+			}
+
+			state.nospace = true;
+			state.json_end_hash();
+		}
+
+		state.nospace = true;
+		state.json_end_array();
+		state.nospace = true;
+		state.json_end_hash();
+	}
+
+	state.nospace = true;
+	state.json_end_array();
+	state.nospace = true;
+	state.json_end_hash();
+}
+
+void mbtiles_write_metadata(sqlite3 *outdb, const char *outdir, const char *fname, int minzoom, int maxzoom, double minlat, double minlon, double maxlat, double maxlon, double midlat, double midlon, int forcetable, const char *attribution, std::map<std::string, layermap_entry> const &layermap, bool vector, const char *description, bool do_tilestats, std::map<std::string, std::string> const &attribute_descriptions, std::string const &program, std::string const &commandline) {
 	char *sql, *err;
 
+	sqlite3 *db = outdb;
+	if (outdb == NULL) {
+		if (sqlite3_open("", &db) != SQLITE_OK) {
+			fprintf(stderr, "Temporary db: %s\n", sqlite3_errmsg(db));
+			exit(EXIT_FAILURE);
+		}
+		if (sqlite3_exec(db, "CREATE TABLE metadata (name text, value text);", NULL, NULL, &err) != SQLITE_OK) {
+			fprintf(stderr, "Create metadata table: %s\n", err);
+			exit(EXIT_FAILURE);
+		}
+	}
+
 	sql = sqlite3_mprintf("INSERT INTO metadata (name, value) VALUES ('name', %Q);", fname);
-	if (sqlite3_exec(outdb, sql, NULL, NULL, &err) != SQLITE_OK) {
+	if (sqlite3_exec(db, sql, NULL, NULL, &err) != SQLITE_OK) {
 		fprintf(stderr, "set name in metadata: %s\n", err);
 		if (!forcetable) {
 			exit(EXIT_FAILURE);
@@ -145,8 +294,8 @@ void mbtiles_write_metadata(sqlite3 *outdb, const char *fname, int minzoom, int
 	}
 	sqlite3_free(sql);
 
-	sql = sqlite3_mprintf("INSERT INTO metadata (name, value) VALUES ('description', %Q);", fname);
-	if (sqlite3_exec(outdb, sql, NULL, NULL, &err) != SQLITE_OK) {
+	sql = sqlite3_mprintf("INSERT INTO metadata (name, value) VALUES ('description', %Q);", description != NULL ? description : fname);
+	if (sqlite3_exec(db, sql, NULL, NULL, &err) != SQLITE_OK) {
 		fprintf(stderr, "set description in metadata: %s\n", err);
 		if (!forcetable) {
 			exit(EXIT_FAILURE);
@@ -155,7 +304,7 @@ void mbtiles_write_metadata(sqlite3 *outdb, const char *fname, int minzoom, int
 	sqlite3_free(sql);
 
 	sql = sqlite3_mprintf("INSERT INTO metadata (name, value) VALUES ('version', %d);", 2);
-	if (sqlite3_exec(outdb, sql, NULL, NULL, &err) != SQLITE_OK) {
+	if (sqlite3_exec(db, sql, NULL, NULL, &err) != SQLITE_OK) {
 		fprintf(stderr, "set version : %s\n", err);
 		if (!forcetable) {
 			exit(EXIT_FAILURE);
@@ -164,7 +313,7 @@ void mbtiles_write_metadata(sqlite3 *outdb, const char *fname, int minzoom, int
 	sqlite3_free(sql);
 
 	sql = sqlite3_mprintf("INSERT INTO metadata (name, value) VALUES ('minzoom', %d);", minzoom);
-	if (sqlite3_exec(outdb, sql, NULL, NULL, &err) != SQLITE_OK) {
+	if (sqlite3_exec(db, sql, NULL, NULL, &err) != SQLITE_OK) {
 		fprintf(stderr, "set minzoom: %s\n", err);
 		if (!forcetable) {
 			exit(EXIT_FAILURE);
@@ -173,7 +322,7 @@ void mbtiles_write_metadata(sqlite3 *outdb, const char *fname, int minzoom, int
 	sqlite3_free(sql);
 
 	sql = sqlite3_mprintf("INSERT INTO metadata (name, value) VALUES ('maxzoom', %d);", maxzoom);
-	if (sqlite3_exec(outdb, sql, NULL, NULL, &err) != SQLITE_OK) {
+	if (sqlite3_exec(db, sql, NULL, NULL, &err) != SQLITE_OK) {
 		fprintf(stderr, "set maxzoom: %s\n", err);
 		if (!forcetable) {
 			exit(EXIT_FAILURE);
@@ -182,7 +331,7 @@ void mbtiles_write_metadata(sqlite3 *outdb, const char *fname, int minzoom, int
 	sqlite3_free(sql);
 
 	sql = sqlite3_mprintf("INSERT INTO metadata (name, value) VALUES ('center', '%f,%f,%d');", midlon, midlat, maxzoom);
-	if (sqlite3_exec(outdb, sql, NULL, NULL, &err) != SQLITE_OK) {
+	if (sqlite3_exec(db, sql, NULL, NULL, &err) != SQLITE_OK) {
 		fprintf(stderr, "set center: %s\n", err);
 		if (!forcetable) {
 			exit(EXIT_FAILURE);
@@ -191,7 +340,7 @@ void mbtiles_write_metadata(sqlite3 *outdb, const char *fname, int minzoom, int
 	sqlite3_free(sql);
 
 	sql = sqlite3_mprintf("INSERT INTO metadata (name, value) VALUES ('bounds', '%f,%f,%f,%f');", minlon, minlat, maxlon, maxlat);
-	if (sqlite3_exec(outdb, sql, NULL, NULL, &err) != SQLITE_OK) {
+	if (sqlite3_exec(db, sql, NULL, NULL, &err) != SQLITE_OK) {
 		fprintf(stderr, "set bounds: %s\n", err);
 		if (!forcetable) {
 			exit(EXIT_FAILURE);
@@ -200,7 +349,7 @@ void mbtiles_write_metadata(sqlite3 *outdb, const char *fname, int minzoom, int
 	sqlite3_free(sql);
 
 	sql = sqlite3_mprintf("INSERT INTO metadata (name, value) VALUES ('type', %Q);", "overlay");
-	if (sqlite3_exec(outdb, sql, NULL, NULL, &err) != SQLITE_OK) {
+	if (sqlite3_exec(db, sql, NULL, NULL, &err) != SQLITE_OK) {
 		fprintf(stderr, "set type: %s\n", err);
 		if (!forcetable) {
 			exit(EXIT_FAILURE);
@@ -210,7 +359,7 @@ void mbtiles_write_metadata(sqlite3 *outdb, const char *fname, int minzoom, int
 
 	if (attribution != NULL) {
 		sql = sqlite3_mprintf("INSERT INTO metadata (name, value) VALUES ('attribution', %Q);", attribution);
-		if (sqlite3_exec(outdb, sql, NULL, NULL, &err) != SQLITE_OK) {
+		if (sqlite3_exec(db, sql, NULL, NULL, &err) != SQLITE_OK) {
 			fprintf(stderr, "set type: %s\n", err);
 			if (!forcetable) {
 				exit(EXIT_FAILURE);
@@ -219,8 +368,8 @@ void mbtiles_write_metadata(sqlite3 *outdb, const char *fname, int minzoom, int
 		sqlite3_free(sql);
 	}
 
-	sql = sqlite3_mprintf("INSERT INTO metadata (name, value) VALUES ('format', %Q);", "pbf");
-	if (sqlite3_exec(outdb, sql, NULL, NULL, &err) != SQLITE_OK) {
+	sql = sqlite3_mprintf("INSERT INTO metadata (name, value) VALUES ('format', %Q);", vector ? "pbf" : "png");
+	if (sqlite3_exec(db, sql, NULL, NULL, &err) != SQLITE_OK) {
 		fprintf(stderr, "set format: %s\n", err);
 		if (!forcetable) {
 			exit(EXIT_FAILURE);
@@ -228,93 +377,249 @@ void mbtiles_write_metadata(sqlite3 *outdb, const char *fname, int minzoom, int
 	}
 	sqlite3_free(sql);
 
-	std::string buf("{");
-	aprintf(&buf, "\"vector_layers\": [ ");
-
-	std::vector<std::string> lnames;
-	for (auto ai = layermap.begin(); ai != layermap.end(); ++ai) {
-		lnames.push_back(ai->first);
-	}
-
-	for (size_t i = 0; i < lnames.size(); i++) {
-		if (i != 0) {
-			aprintf(&buf, ", ");
-		}
-
-		auto fk = layermap.find(lnames[i]);
-		aprintf(&buf, "{ \"id\": \"");
-		quote(&buf, lnames[i].c_str());
-		aprintf(&buf, "\", \"description\": \"\", \"minzoom\": %d, \"maxzoom\": %d, \"fields\": {", fk->second.minzoom, fk->second.maxzoom);
-
-		std::set<type_and_string>::iterator j;
-		bool first = true;
-		for (j = fk->second.file_keys.begin(); j != fk->second.file_keys.end(); ++j) {
-			if (first) {
-				first = false;
-			} else {
-				aprintf(&buf, ", ");
-			}
-
-			aprintf(&buf, "\"");
-			quote(&buf, j->string.c_str());
-
-			if (j->type == VT_NUMBER) {
-				aprintf(&buf, "\": \"Number\"");
-			} else if (j->type == VT_BOOLEAN) {
-				aprintf(&buf, "\": \"Boolean\"");
-			} else {
-				aprintf(&buf, "\": \"String\"");
-			}
-		}
-
-		aprintf(&buf, "} }");
-	}
-
-	aprintf(&buf, " ] }");
-
-	sql = sqlite3_mprintf("INSERT INTO metadata (name, value) VALUES ('json', %Q);", buf.c_str());
-	if (sqlite3_exec(outdb, sql, NULL, NULL, &err) != SQLITE_OK) {
-		fprintf(stderr, "set json: %s\n", err);
+	std::string version = program + " " + VERSION;
+	sql = sqlite3_mprintf("INSERT INTO metadata (name, value) VALUES ('generator', %Q);", version.c_str());
+	if (sqlite3_exec(db, sql, NULL, NULL, &err) != SQLITE_OK) {
+		fprintf(stderr, "set version: %s\n", err);
 		if (!forcetable) {
 			exit(EXIT_FAILURE);
 		}
 	}
 	sqlite3_free(sql);
+
+	sql = sqlite3_mprintf("INSERT INTO metadata (name, value) VALUES ('generator_options', %Q);", commandline.c_str());
+	if (sqlite3_exec(db, sql, NULL, NULL, &err) != SQLITE_OK) {
+		fprintf(stderr, "set commandline: %s\n", err);
+		if (!forcetable) {
+			exit(EXIT_FAILURE);
+		}
+	}
+	sqlite3_free(sql);
+
+	if (vector) {
+		size_t elements = max_tilestats_values;
+		std::string buf;
+
+		{
+			json_writer state(&buf);
+
+			state.json_write_hash();
+			state.nospace = true;
+
+			state.json_write_string("vector_layers");
+			state.json_write_array();
+
+			std::vector<std::string> lnames;
+			for (auto ai = layermap.begin(); ai != layermap.end(); ++ai) {
+				lnames.push_back(ai->first);
+			}
+
+			for (size_t i = 0; i < lnames.size(); i++) {
+				auto fk = layermap.find(lnames[i]);
+				state.json_write_hash();
+
+				state.json_write_string("id");
+				state.json_write_string(lnames[i]);
+
+				state.json_write_string("description");
+				state.json_write_string(fk->second.description);
+
+				state.json_write_string("minzoom");
+				state.json_write_signed(fk->second.minzoom);
+
+				state.json_write_string("maxzoom");
+				state.json_write_signed(fk->second.maxzoom);
+
+				state.json_write_string("fields");
+				state.json_write_hash();
+				state.nospace = true;
+
+				bool first = true;
+				for (auto j = fk->second.file_keys.begin(); j != fk->second.file_keys.end(); ++j) {
+					if (first) {
+						first = false;
+					}
+
+					state.json_write_string(j->first);
+
+					auto f = attribute_descriptions.find(j->first);
+					if (f == attribute_descriptions.end()) {
+						int type = 0;
+						for (auto s : j->second.sample_values) {
+							type |= (1 << s.type);
+						}
+
+						if (type == (1 << mvt_double)) {
+							state.json_write_string("Number");
+						} else if (type == (1 << mvt_bool)) {
+							state.json_write_string("Boolean");
+						} else if (type == (1 << mvt_string)) {
+							state.json_write_string("String");
+						} else {
+							state.json_write_string("Mixed");
+						}
+					} else {
+						state.json_write_string(f->second);
+					}
+				}
+
+				state.nospace = true;
+				state.json_end_hash();
+				state.json_end_hash();
+			}
+
+			state.json_end_array();
+
+			if (do_tilestats && elements > 0) {
+				state.nospace = true;
+				state.json_write_string("tilestats");
+				tilestats(layermap, elements, state);
+			}
+
+			state.nospace = true;
+			state.json_end_hash();
+		}
+
+		sql = sqlite3_mprintf("INSERT INTO metadata (name, value) VALUES ('json', %Q);", buf.c_str());
+		if (sqlite3_exec(db, sql, NULL, NULL, &err) != SQLITE_OK) {
+			fprintf(stderr, "set json: %s\n", err);
+			if (!forcetable) {
+				exit(EXIT_FAILURE);
+			}
+		}
+		sqlite3_free(sql);
+	}
+
+	if (outdir != NULL) {
+		std::string metadata = std::string(outdir) + "/metadata.json";
+
+		struct stat st;
+		if (stat(metadata.c_str(), &st) == 0) {
+			// Leave existing metadata in place with --allow-existing
+		} else {
+			FILE *fp = fopen(metadata.c_str(), "w");
+			if (fp == NULL) {
+				perror(metadata.c_str());
+				exit(EXIT_FAILURE);
+			}
+
+			json_writer state(fp);
+
+			state.json_write_hash();
+			state.json_write_newline();
+
+			sqlite3_stmt *stmt;
+			bool first = true;
+			if (sqlite3_prepare_v2(db, "SELECT name, value from metadata;", -1, &stmt, NULL) == SQLITE_OK) {
+				while (sqlite3_step(stmt) == SQLITE_ROW) {
+					std::string key, value;
+
+					const char *k = (const char *) sqlite3_column_text(stmt, 0);
+					const char *v = (const char *) sqlite3_column_text(stmt, 1);
+					if (k == NULL || v == NULL) {
+						fprintf(stderr, "Corrupt mbtiles file: null metadata\n");
+						exit(EXIT_FAILURE);
+					}
+
+					state.json_comma_newline();
+					state.json_write_string(k);
+					state.json_write_string(v);
+					first = false;
+				}
+				sqlite3_finalize(stmt);
+			}
+
+			state.json_write_newline();
+			state.json_end_hash();
+			state.json_write_newline();
+			fclose(fp);
+		}
+	}
+
+	if (outdb == NULL) {
+		if (sqlite3_close(db) != SQLITE_OK) {
+			fprintf(stderr, "Could not close temp database: %s\n", sqlite3_errmsg(db));
+			exit(EXIT_FAILURE);
+		}
+	}
 }
 
-void mbtiles_close(sqlite3 *outdb, char **argv) {
+void mbtiles_close(sqlite3 *outdb, const char *pgm) {
 	char *err;
 
 	if (sqlite3_exec(outdb, "ANALYZE;", NULL, NULL, &err) != SQLITE_OK) {
-		fprintf(stderr, "%s: ANALYZE failed: %s\n", argv[0], err);
+		fprintf(stderr, "%s: ANALYZE failed: %s\n", pgm, err);
 		exit(EXIT_FAILURE);
 	}
 	if (sqlite3_close(outdb) != SQLITE_OK) {
-		fprintf(stderr, "%s: could not close database: %s\n", argv[0], sqlite3_errmsg(outdb));
+		fprintf(stderr, "%s: could not close database: %s\n", pgm, sqlite3_errmsg(outdb));
 		exit(EXIT_FAILURE);
 	}
 }
 
-std::map<std::string, layermap_entry> merge_layermaps(std::vector<std::map<std::string, layermap_entry> > const &maps) {
+std::map<std::string, layermap_entry> merge_layermaps(std::vector<std::map<std::string, layermap_entry>> const &maps) {
+	return merge_layermaps(maps, false);
+}
+
+std::map<std::string, layermap_entry> merge_layermaps(std::vector<std::map<std::string, layermap_entry>> const &maps, bool trunc) {
 	std::map<std::string, layermap_entry> out;
 
 	for (size_t i = 0; i < maps.size(); i++) {
 		for (auto map = maps[i].begin(); map != maps[i].end(); ++map) {
-			if (out.count(map->first) == 0) {
-				out.insert(std::pair<std::string, layermap_entry>(map->first, layermap_entry(out.size())));
-				auto out_entry = out.find(map->first);
-				out_entry->second.minzoom = map->second.minzoom;
-				out_entry->second.maxzoom = map->second.maxzoom;
+			if (map->second.points + map->second.lines + map->second.polygons + map->second.retain == 0) {
+				continue;
 			}
 
-			auto out_entry = out.find(map->first);
+			std::string layername = map->first;
+			if (trunc) {
+				layername = truncate16(layername, 256);
+			}
+
+			if (out.count(layername) == 0) {
+				out.insert(std::pair<std::string, layermap_entry>(layername, layermap_entry(out.size())));
+				auto out_entry = out.find(layername);
+				out_entry->second.minzoom = map->second.minzoom;
+				out_entry->second.maxzoom = map->second.maxzoom;
+				out_entry->second.description = map->second.description;
+			}
+
+			auto out_entry = out.find(layername);
 			if (out_entry == out.end()) {
 				fprintf(stderr, "Internal error merging layers\n");
 				exit(EXIT_FAILURE);
 			}
 
 			for (auto fk = map->second.file_keys.begin(); fk != map->second.file_keys.end(); ++fk) {
-				out_entry->second.file_keys.insert(*fk);
+				std::string attribname = fk->first;
+				if (trunc) {
+					attribname = truncate16(attribname, 256);
+				}
+
+				auto fk2 = out_entry->second.file_keys.find(attribname);
+
+				if (fk2 == out_entry->second.file_keys.end()) {
+					out_entry->second.file_keys.insert(std::pair<std::string, type_and_string_stats>(attribname, fk->second));
+				} else {
+					for (auto val : fk->second.sample_values) {
+						auto pt = std::lower_bound(fk2->second.sample_values.begin(), fk2->second.sample_values.end(), val);
+						if (pt == fk2->second.sample_values.end() || *pt != val) {  // not found
+							fk2->second.sample_values.insert(pt, val);
+
+							if (fk2->second.sample_values.size() > max_tilestats_sample_values) {
+								fk2->second.sample_values.pop_back();
+							}
+						}
+					}
+
+					fk2->second.type |= fk->second.type;
+
+					if (fk->second.min < fk2->second.min) {
+						fk2->second.min = fk->second.min;
+					}
+					if (fk->second.max > fk2->second.max) {
+						fk2->second.max = fk->second.max;
+					}
+				}
 			}
 
 			if (map->second.minzoom < out_entry->second.minzoom) {
@@ -323,8 +628,51 @@ std::map<std::string, layermap_entry> merge_layermaps(std::vector<std::map<std::
 			if (map->second.maxzoom > out_entry->second.maxzoom) {
 				out_entry->second.maxzoom = map->second.maxzoom;
 			}
+
+			out_entry->second.points += map->second.points;
+			out_entry->second.lines += map->second.lines;
+			out_entry->second.polygons += map->second.polygons;
 		}
 	}
 
 	return out;
 }
+
+void add_to_file_keys(std::map<std::string, type_and_string_stats> &file_keys, std::string const &attrib, type_and_string const &val) {
+	if (val.type == mvt_null) {
+		return;
+	}
+
+	auto fka = file_keys.find(attrib);
+	if (fka == file_keys.end()) {
+		file_keys.insert(std::pair<std::string, type_and_string_stats>(attrib, type_and_string_stats()));
+		fka = file_keys.find(attrib);
+	}
+
+	if (fka == file_keys.end()) {
+		fprintf(stderr, "Can't happen (tilestats)\n");
+		exit(EXIT_FAILURE);
+	}
+
+	if (val.type == mvt_double) {
+		double d = atof(val.string.c_str());
+
+		if (d < fka->second.min) {
+			fka->second.min = d;
+		}
+		if (d > fka->second.max) {
+			fka->second.max = d;
+		}
+	}
+
+	auto pt = std::lower_bound(fka->second.sample_values.begin(), fka->second.sample_values.end(), val);
+	if (pt == fka->second.sample_values.end() || *pt != val) {  // not found
+		fka->second.sample_values.insert(pt, val);
+
+		if (fka->second.sample_values.size() > max_tilestats_sample_values) {
+			fka->second.sample_values.pop_back();
+		}
+	}
+
+	fka->second.type |= (1 << val.type);
+}

mbtiles.hpp

@@ -1,15 +1,40 @@
+#ifndef MBTILES_HPP
+#define MBTILES_HPP
+
+#include <math.h>
+#include <map>
+#include "mvt.hpp"
+
+extern size_t max_tilestats_attributes;
+extern size_t max_tilestats_sample_values;
+extern size_t max_tilestats_values;
+
 struct type_and_string {
-	int type;
-	std::string string;
+	int type = 0;
+	std::string string = "";
 
 	bool operator<(const type_and_string &o) const;
+	bool operator!=(const type_and_string &o) const;
+};
+
+struct type_and_string_stats {
+	std::vector<type_and_string> sample_values = std::vector<type_and_string>();  // sorted
+	double min = INFINITY;
+	double max = -INFINITY;
+	int type = 0;
 };
 
 struct layermap_entry {
-	size_t id;
-	std::set<type_and_string> file_keys;
-	int minzoom;
-	int maxzoom;
+	size_t id = 0;
+	std::map<std::string, type_and_string_stats> file_keys{};
+	int minzoom = 0;
+	int maxzoom = 0;
+	std::string description = "";
+
+	size_t points = 0;
+	size_t lines = 0;
+	size_t polygons = 0;
+	size_t retain = 0;  // keep for tilestats, even if no features directly here
 
 	layermap_entry(size_t _id) {
 		id = _id;
@@ -20,10 +45,13 @@ sqlite3 *mbtiles_open(char *dbname, char **argv, int forcetable);
 
 void mbtiles_write_tile(sqlite3 *outdb, int z, int tx, int ty, const char *data, int size);
 
-void mbtiles_write_metadata(sqlite3 *outdb, const char *fname, int minzoom, int maxzoom, double minlat, double minlon, double maxlat, double maxlon, double midlat, double midlon, int forcetable, const char *attribution, std::map<std::string, layermap_entry> const &layermap);
+void mbtiles_write_metadata(sqlite3 *outdb, const char *outdir, const char *fname, int minzoom, int maxzoom, double minlat, double minlon, double maxlat, double maxlon, double midlat, double midlon, int forcetable, const char *attribution, std::map<std::string, layermap_entry> const &layermap, bool vector, const char *description, bool do_tilestats, std::map<std::string, std::string> const &attribute_descriptions, std::string const &program, std::string const &commandline);
 
-void mbtiles_close(sqlite3 *outdb, char **argv);
-
-void aprintf(std::string *buf, const char *format, ...);
+void mbtiles_close(sqlite3 *outdb, const char *pgm);
 
 std::map<std::string, layermap_entry> merge_layermaps(std::vector<std::map<std::string, layermap_entry> > const &maps);
+std::map<std::string, layermap_entry> merge_layermaps(std::vector<std::map<std::string, layermap_entry> > const &maps, bool trunc);
+
+void add_to_file_keys(std::map<std::string, type_and_string_stats> &file_keys, std::string const &layername, type_and_string const &val);
+
+#endif

memfile.cpp

@@ -53,7 +53,7 @@ int memfile_write(struct memfile *file, void *s, long long len) {
 			return -1;
 		}
 
-		file->len += INCREMENT;
+		file->len += (len + INCREMENT + 1) / INCREMENT * INCREMENT;
 
 		if (ftruncate(file->fd, file->len) != 0) {
 			return -1;

memfile.hpp

@@ -1,11 +1,22 @@
+#ifndef MEMFILE_HPP
+#define MEMFILE_HPP
+
+#include <atomic>
+
 struct memfile {
-	int fd;
-	char *map;
-	long long len;
-	long long off;
-	long long tree;
+	int fd = 0;
+	char *map = NULL;
+	std::atomic<long long> len;
+	long long off = 0;
+	unsigned long tree = 0;
+
+	memfile()
+	    : len(0) {
+	}
 };
 
 struct memfile *memfile_open(int fd);
 int memfile_close(struct memfile *file);
 int memfile_write(struct memfile *file, void *s, long long len);
+
+#endif

milo/LICENSE.txt

@@ -0,0 +1,19 @@
+Copyright (C) 2014 Milo Yip
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.

milo/dtoa_milo.h

@@ -0,0 +1,415 @@
+#pragma once
+#include <assert.h>
+#include <math.h>
+#include <cmath>
+
+#if defined(_MSC_VER)
+#include "msinttypes/stdint.h"
+#include <intrin.h>
+#else
+#include <stdint.h>
+#endif
+
+namespace milo {
+
+#define UINT64_C2(h, l) ((static_cast<uint64_t>(h) << 32) | static_cast<uint64_t>(l))
+
+struct DiyFp {
+	DiyFp() {}
+
+	DiyFp(uint64_t ff, int ee) : f(ff), e(ee) {}
+
+	DiyFp(double d) {
+		union {
+			double d;
+			uint64_t u64;
+		} u = { d };
+
+		int biased_e = (u.u64 & kDpExponentMask) >> kDpSignificandSize;
+		uint64_t significand = (u.u64 & kDpSignificandMask);
+		if (biased_e != 0) {
+			f = significand + kDpHiddenBit;
+			e = biased_e - kDpExponentBias;
+		} 
+		else {
+			f = significand;
+			e = kDpMinExponent + 1;
+		}
+	}
+
+	DiyFp operator-(const DiyFp& rhs) const {
+		assert(e == rhs.e);
+		assert(f >= rhs.f);
+		return DiyFp(f - rhs.f, e);
+	}
+
+	DiyFp operator*(const DiyFp& rhs) const {
+#if defined(_MSC_VER) && defined(_M_AMD64)
+		uint64_t h;
+		uint64_t l = _umul128(f, rhs.f, &h);
+		if (l & (uint64_t(1) << 63)) // rounding
+			h++;
+		return DiyFp(h, e + rhs.e + 64);
+#elif (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6)) && defined(__x86_64__)
+		unsigned __int128 p = static_cast<unsigned __int128>(f) * static_cast<unsigned __int128>(rhs.f);
+		uint64_t h = p >> 64;
+		uint64_t l = static_cast<uint64_t>(p);
+		if (l & (uint64_t(1) << 63)) // rounding
+			h++;
+		return DiyFp(h, e + rhs.e + 64);
+#else
+		const uint64_t M32 = 0xFFFFFFFF;
+		const uint64_t a = f >> 32;
+		const uint64_t b = f & M32;
+		const uint64_t c = rhs.f >> 32;
+		const uint64_t d = rhs.f & M32;
+		const uint64_t ac = a * c;
+		const uint64_t bc = b * c;
+		const uint64_t ad = a * d;
+		const uint64_t bd = b * d;
+		uint64_t tmp = (bd >> 32) + (ad & M32) + (bc & M32);
+		tmp += 1U << 31;  /// mult_round
+		return DiyFp(ac + (ad >> 32) + (bc >> 32) + (tmp >> 32), e + rhs.e + 64);
+#endif
+	}
+
+	DiyFp Normalize() const {
+#if defined(_MSC_VER) && defined(_M_AMD64)
+		unsigned long index;
+		_BitScanReverse64(&index, f);
+		return DiyFp(f << (63 - index), e - (63 - index));
+#elif defined(__GNUC__)
+		int s = __builtin_clzll(f);
+		return DiyFp(f << s, e - s);
+#else
+		DiyFp res = *this;
+		while (!(res.f & kDpHiddenBit)) {
+			res.f <<= 1;
+			res.e--;
+		}
+		res.f <<= (kDiySignificandSize - kDpSignificandSize - 1);
+		res.e = res.e - (kDiySignificandSize - kDpSignificandSize - 1);
+		return res;
+#endif
+	}
+
+	DiyFp NormalizeBoundary() const {
+#if defined(_MSC_VER) && defined(_M_AMD64)
+		unsigned long index;
+		_BitScanReverse64(&index, f);
+		return DiyFp (f << (63 - index), e - (63 - index));
+#else
+		DiyFp res = *this;
+		while (!(res.f & (kDpHiddenBit << 1))) {
+			res.f <<= 1;
+			res.e--;
+		}
+		res.f <<= (kDiySignificandSize - kDpSignificandSize - 2);
+		res.e = res.e - (kDiySignificandSize - kDpSignificandSize - 2);
+		return res;
+#endif
+	}
+
+	void NormalizedBoundaries(DiyFp* minus, DiyFp* plus) const {
+		DiyFp pl = DiyFp((f << 1) + 1, e - 1).NormalizeBoundary();
+		DiyFp mi = (f == kDpHiddenBit) ? DiyFp((f << 2) - 1, e - 2) : DiyFp((f << 1) - 1, e - 1);
+		mi.f <<= mi.e - pl.e;
+		mi.e = pl.e;
+		*plus = pl;
+		*minus = mi;
+	}
+
+	static const int kDiySignificandSize = 64;
+	static const int kDpSignificandSize = 52;
+	static const int kDpExponentBias = 0x3FF + kDpSignificandSize;
+	static const int kDpMinExponent = -kDpExponentBias;
+	static const uint64_t kDpExponentMask = UINT64_C2(0x7FF00000, 0x00000000);
+	static const uint64_t kDpSignificandMask = UINT64_C2(0x000FFFFF, 0xFFFFFFFF);
+	static const uint64_t kDpHiddenBit = UINT64_C2(0x00100000, 0x00000000);
+
+	uint64_t f;
+	int e;
+};
+
+inline DiyFp GetCachedPower(int e, int* K) {
+	// 10^-348, 10^-340, ..., 10^340
+	static const uint64_t kCachedPowers_F[] = {
+		UINT64_C2(0xfa8fd5a0, 0x081c0288), UINT64_C2(0xbaaee17f, 0xa23ebf76),
+		UINT64_C2(0x8b16fb20, 0x3055ac76), UINT64_C2(0xcf42894a, 0x5dce35ea),
+		UINT64_C2(0x9a6bb0aa, 0x55653b2d), UINT64_C2(0xe61acf03, 0x3d1a45df),
+		UINT64_C2(0xab70fe17, 0xc79ac6ca), UINT64_C2(0xff77b1fc, 0xbebcdc4f),
+		UINT64_C2(0xbe5691ef, 0x416bd60c), UINT64_C2(0x8dd01fad, 0x907ffc3c),
+		UINT64_C2(0xd3515c28, 0x31559a83), UINT64_C2(0x9d71ac8f, 0xada6c9b5),
+		UINT64_C2(0xea9c2277, 0x23ee8bcb), UINT64_C2(0xaecc4991, 0x4078536d),
+		UINT64_C2(0x823c1279, 0x5db6ce57), UINT64_C2(0xc2109436, 0x4dfb5637),
+		UINT64_C2(0x9096ea6f, 0x3848984f), UINT64_C2(0xd77485cb, 0x25823ac7),
+		UINT64_C2(0xa086cfcd, 0x97bf97f4), UINT64_C2(0xef340a98, 0x172aace5),
+		UINT64_C2(0xb23867fb, 0x2a35b28e), UINT64_C2(0x84c8d4df, 0xd2c63f3b),
+		UINT64_C2(0xc5dd4427, 0x1ad3cdba), UINT64_C2(0x936b9fce, 0xbb25c996),
+		UINT64_C2(0xdbac6c24, 0x7d62a584), UINT64_C2(0xa3ab6658, 0x0d5fdaf6),
+		UINT64_C2(0xf3e2f893, 0xdec3f126), UINT64_C2(0xb5b5ada8, 0xaaff80b8),
+		UINT64_C2(0x87625f05, 0x6c7c4a8b), UINT64_C2(0xc9bcff60, 0x34c13053),
+		UINT64_C2(0x964e858c, 0x91ba2655), UINT64_C2(0xdff97724, 0x70297ebd),
+		UINT64_C2(0xa6dfbd9f, 0xb8e5b88f), UINT64_C2(0xf8a95fcf, 0x88747d94),
+		UINT64_C2(0xb9447093, 0x8fa89bcf), UINT64_C2(0x8a08f0f8, 0xbf0f156b),
+		UINT64_C2(0xcdb02555, 0x653131b6), UINT64_C2(0x993fe2c6, 0xd07b7fac),
+		UINT64_C2(0xe45c10c4, 0x2a2b3b06), UINT64_C2(0xaa242499, 0x697392d3),
+		UINT64_C2(0xfd87b5f2, 0x8300ca0e), UINT64_C2(0xbce50864, 0x92111aeb),
+		UINT64_C2(0x8cbccc09, 0x6f5088cc), UINT64_C2(0xd1b71758, 0xe219652c),
+		UINT64_C2(0x9c400000, 0x00000000), UINT64_C2(0xe8d4a510, 0x00000000),
+		UINT64_C2(0xad78ebc5, 0xac620000), UINT64_C2(0x813f3978, 0xf8940984),
+		UINT64_C2(0xc097ce7b, 0xc90715b3), UINT64_C2(0x8f7e32ce, 0x7bea5c70),
+		UINT64_C2(0xd5d238a4, 0xabe98068), UINT64_C2(0x9f4f2726, 0x179a2245),
+		UINT64_C2(0xed63a231, 0xd4c4fb27), UINT64_C2(0xb0de6538, 0x8cc8ada8),
+		UINT64_C2(0x83c7088e, 0x1aab65db), UINT64_C2(0xc45d1df9, 0x42711d9a),
+		UINT64_C2(0x924d692c, 0xa61be758), UINT64_C2(0xda01ee64, 0x1a708dea),
+		UINT64_C2(0xa26da399, 0x9aef774a), UINT64_C2(0xf209787b, 0xb47d6b85),
+		UINT64_C2(0xb454e4a1, 0x79dd1877), UINT64_C2(0x865b8692, 0x5b9bc5c2),
+		UINT64_C2(0xc83553c5, 0xc8965d3d), UINT64_C2(0x952ab45c, 0xfa97a0b3),
+		UINT64_C2(0xde469fbd, 0x99a05fe3), UINT64_C2(0xa59bc234, 0xdb398c25),
+		UINT64_C2(0xf6c69a72, 0xa3989f5c), UINT64_C2(0xb7dcbf53, 0x54e9bece),
+		UINT64_C2(0x88fcf317, 0xf22241e2), UINT64_C2(0xcc20ce9b, 0xd35c78a5),
+		UINT64_C2(0x98165af3, 0x7b2153df), UINT64_C2(0xe2a0b5dc, 0x971f303a),
+		UINT64_C2(0xa8d9d153, 0x5ce3b396), UINT64_C2(0xfb9b7cd9, 0xa4a7443c),
+		UINT64_C2(0xbb764c4c, 0xa7a44410), UINT64_C2(0x8bab8eef, 0xb6409c1a),
+		UINT64_C2(0xd01fef10, 0xa657842c), UINT64_C2(0x9b10a4e5, 0xe9913129),
+		UINT64_C2(0xe7109bfb, 0xa19c0c9d), UINT64_C2(0xac2820d9, 0x623bf429),
+		UINT64_C2(0x80444b5e, 0x7aa7cf85), UINT64_C2(0xbf21e440, 0x03acdd2d),
+		UINT64_C2(0x8e679c2f, 0x5e44ff8f), UINT64_C2(0xd433179d, 0x9c8cb841),
+		UINT64_C2(0x9e19db92, 0xb4e31ba9), UINT64_C2(0xeb96bf6e, 0xbadf77d9),
+		UINT64_C2(0xaf87023b, 0x9bf0ee6b)
+	};
+	static const int16_t kCachedPowers_E[] = {
+		-1220, -1193, -1166, -1140, -1113, -1087, -1060, -1034, -1007,  -980,
+		 -954,  -927,  -901,  -874,  -847,  -821,  -794,  -768,  -741,  -715,
+		 -688,  -661,  -635,  -608,  -582,  -555,  -529,  -502,  -475,  -449,
+		 -422,  -396,  -369,  -343,  -316,  -289,  -263,  -236,  -210,  -183,
+		 -157,  -130,  -103,   -77,   -50,   -24,     3,    30,    56,    83,
+		  109,   136,   162,   189,   216,   242,   269,   295,   322,   348,
+		  375,   402,   428,   455,   481,   508,   534,   561,   588,   614,
+		  641,   667,   694,   720,   747,   774,   800,   827,   853,   880,
+		  907,   933,   960,   986,  1013,  1039,  1066
+	};
+
+	//int k = static_cast<int>(ceil((-61 - e) * 0.30102999566398114)) + 374;
+	double dk = (-61 - e) * 0.30102999566398114 + 347;	// dk must be positive, so can do ceiling in positive
+	int k = static_cast<int>(dk);
+	if (k != dk)
+		k++;
+
+	unsigned index = static_cast<unsigned>((k >> 3) + 1);
+	*K = -(-348 + static_cast<int>(index << 3));	// decimal exponent no need lookup table
+
+	assert(index < sizeof(kCachedPowers_F) / sizeof(kCachedPowers_F[0]));
+	return DiyFp(kCachedPowers_F[index], kCachedPowers_E[index]);
+}
+
+inline void GrisuRound(std::string &buffer, int len, uint64_t delta, uint64_t rest, uint64_t ten_kappa, uint64_t wp_w) {
+	while (rest < wp_w && delta - rest >= ten_kappa &&
+		   (rest + ten_kappa < wp_w ||  /// closer
+			wp_w - rest > rest + ten_kappa - wp_w)) {
+		buffer[len - 1]--;
+		rest += ten_kappa;
+	}
+}
+
+inline unsigned CountDecimalDigit32(uint32_t n) {
+	// Simple pure C++ implementation was faster than __builtin_clz version in this situation.
+	if (n < 10) return 1;
+	if (n < 100) return 2;
+	if (n < 1000) return 3;
+	if (n < 10000) return 4;
+	if (n < 100000) return 5;
+	if (n < 1000000) return 6;
+	if (n < 10000000) return 7;
+	if (n < 100000000) return 8;
+	if (n < 1000000000) return 9;
+	return 10;
+}
+
+inline void DigitGen(const DiyFp& W, const DiyFp& Mp, uint64_t delta, std::string &buffer, int* len, int* K) {
+	static const uint32_t kPow10[] = { 1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000, 1000000000 };
+	const DiyFp one(uint64_t(1) << -Mp.e, Mp.e);
+	const DiyFp wp_w = Mp - W;
+	uint32_t p1 = static_cast<uint32_t>(Mp.f >> -one.e);
+	uint64_t p2 = Mp.f & (one.f - 1);
+	int kappa = static_cast<int>(CountDecimalDigit32(p1));
+	*len = 0;
+
+	while (kappa > 0) {
+		uint32_t d;
+		switch (kappa) {
+			case 10: d = p1 / 1000000000; p1 %= 1000000000; break;
+			case  9: d = p1 /  100000000; p1 %=  100000000; break;
+			case  8: d = p1 /   10000000; p1 %=   10000000; break;
+			case  7: d = p1 /    1000000; p1 %=    1000000; break;
+			case  6: d = p1 /     100000; p1 %=     100000; break;
+			case  5: d = p1 /      10000; p1 %=      10000; break;
+			case  4: d = p1 /       1000; p1 %=       1000; break;
+			case  3: d = p1 /        100; p1 %=        100; break;
+			case  2: d = p1 /         10; p1 %=         10; break;
+			case  1: d = p1;              p1 =           0; break;
+			default: 
+#if defined(_MSC_VER)
+				__assume(0);
+#elif __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5)
+				__builtin_unreachable();
+#else
+				d = 0;
+#endif
+		}
+		if (d || *len) {
+			buffer.push_back('0' + static_cast<char>(d));
+			(*len)++;
+		}
+		kappa--;
+		uint64_t tmp = (static_cast<uint64_t>(p1) << -one.e) + p2;
+		if (tmp <= delta) {
+			*K += kappa;
+			GrisuRound(buffer, *len, delta, tmp, static_cast<uint64_t>(kPow10[kappa]) << -one.e, wp_w.f);
+			return;
+		}
+	}
+
+	// kappa = 0
+	for (;;) {
+		p2 *= 10;
+		delta *= 10;
+		char d = static_cast<char>(p2 >> -one.e);
+		if (d || *len) {
+			buffer.push_back('0' + d);
+			(*len)++;
+		}
+		p2 &= one.f - 1;
+		kappa--;
+		if (p2 < delta) {
+			*K += kappa;
+			int index = -static_cast<int>(kappa);
+			GrisuRound(buffer, *len, delta, p2, one.f, wp_w.f * (index < 9 ? kPow10[-static_cast<int>(kappa)] : 0));
+			return;
+		}
+	}
+}
+
+inline void Grisu2(double value, std::string &buffer, int* length, int* K) {
+	const DiyFp v(value);
+	DiyFp w_m, w_p;
+	v.NormalizedBoundaries(&w_m, &w_p);
+
+	const DiyFp c_mk = GetCachedPower(w_p.e, K);
+	const DiyFp W = v.Normalize() * c_mk;
+	DiyFp Wp = w_p * c_mk;
+	DiyFp Wm = w_m * c_mk;
+	Wm.f++;
+	Wp.f--;
+	DigitGen(W, Wp, Wp.f - Wm.f, buffer, length, K);
+}
+
+inline const char* GetDigitsLut() {
+	static const char cDigitsLut[200] = {
+		'0', '0', '0', '1', '0', '2', '0', '3', '0', '4', '0', '5', '0', '6', '0', '7', '0', '8', '0', '9',
+		'1', '0', '1', '1', '1', '2', '1', '3', '1', '4', '1', '5', '1', '6', '1', '7', '1', '8', '1', '9',
+		'2', '0', '2', '1', '2', '2', '2', '3', '2', '4', '2', '5', '2', '6', '2', '7', '2', '8', '2', '9',
+		'3', '0', '3', '1', '3', '2', '3', '3', '3', '4', '3', '5', '3', '6', '3', '7', '3', '8', '3', '9',
+		'4', '0', '4', '1', '4', '2', '4', '3', '4', '4', '4', '5', '4', '6', '4', '7', '4', '8', '4', '9',
+		'5', '0', '5', '1', '5', '2', '5', '3', '5', '4', '5', '5', '5', '6', '5', '7', '5', '8', '5', '9',
+		'6', '0', '6', '1', '6', '2', '6', '3', '6', '4', '6', '5', '6', '6', '6', '7', '6', '8', '6', '9',
+		'7', '0', '7', '1', '7', '2', '7', '3', '7', '4', '7', '5', '7', '6', '7', '7', '7', '8', '7', '9',
+		'8', '0', '8', '1', '8', '2', '8', '3', '8', '4', '8', '5', '8', '6', '8', '7', '8', '8', '8', '9',
+		'9', '0', '9', '1', '9', '2', '9', '3', '9', '4', '9', '5', '9', '6', '9', '7', '9', '8', '9', '9'
+	};
+	return cDigitsLut;
+}
+
+inline void WriteExponent(int K, std::string &buffer) {
+	if (K < 0) {
+		buffer.push_back('-');
+		K = -K;
+	} else {
+		buffer.push_back('+');
+	}
+
+	if (K >= 100) {
+		buffer.push_back('0' + static_cast<char>(K / 100));
+		K %= 100;
+		const char* d = GetDigitsLut() + K * 2;
+		buffer.push_back(d[0]);
+		buffer.push_back(d[1]);
+	}
+	else if (K >= 10) {
+		const char* d = GetDigitsLut() + K * 2;
+		buffer.push_back(d[0]);
+		buffer.push_back(d[1]);
+	}
+	else
+		buffer.push_back('0' + static_cast<char>(K));
+}
+
+inline void Prettify(std::string &buffer, int length, int k) {
+	const int kk = length + k;	// 10^(kk-1) <= v < 10^kk
+
+	if (length <= kk && kk <= 21) {
+		// 1234e7 -> 12340000000
+		for (int i = length; i < kk; i++)
+			buffer.push_back('0');
+	}
+	else if (0 < kk && kk <= 21) {
+		// 1234e-2 -> 12.34
+		buffer.insert(buffer.begin() + kk, '.');
+	}
+	else if (-6 < kk && kk <= 0) {
+		// 1234e-6 -> 0.001234
+		const int offset = 2 - kk;
+		buffer.insert(buffer.begin(), '0');
+		buffer.insert(buffer.begin() + 1, '.');
+		for (int i = 2; i < offset; i++)
+			buffer.insert(buffer.begin() + 2, '0');
+	}
+	else if (length == 1) {
+		// 1e30
+		buffer.push_back('e');
+		WriteExponent(kk - 1, buffer);
+	}
+	else {
+		// 1234e30 -> 1.234e33
+		buffer.insert(buffer.begin() + 1, '.');
+		buffer.push_back('e');
+		WriteExponent(kk - 1, buffer);
+	}
+}
+
+inline std::string dtoa_milo(double value) {
+	std::string buffer;
+
+	if (std::isnan(value)) {
+		return "nan";
+	}
+	if (std::isinf(value)) {
+		if (value < 0) {
+			return "-inf";
+		} else {
+			return "inf";
+		}
+	}
+
+	if (value == 0) {
+		buffer = "0";
+	}
+	else {
+		bool minus = false;
+		if (value < 0) {
+			minus = true;
+			value = -value;
+		}
+		int length, K;
+		Grisu2(value, buffer, &length, &K);
+		Prettify(buffer, length, K);
+		if (minus) {
+			buffer.insert(buffer.begin(), '-');
+		}
+	}
+
+	return buffer;
+}
+
+}

mvt.cpp

@@ -4,10 +4,15 @@
 #include <vector>
 #include <map>
 #include <zlib.h>
+#include <errno.h>
+#include <limits.h>
+#include <ctype.h>
 #include "mvt.hpp"
+#include "geometry.hpp"
 #include "protozero/varint.hpp"
 #include "protozero/pbf_reader.hpp"
 #include "protozero/pbf_writer.hpp"
+#include "milo/dtoa_milo.h"
 
 mvt_geometry::mvt_geometry(int nop, long long nx, long long ny) {
 	this->op = nop;
@@ -29,25 +34,49 @@ int decompress(std::string const &input, std::string &output) {
 	inflate_s.avail_in = 0;
 	inflate_s.next_in = Z_NULL;
 	if (inflateInit2(&inflate_s, 32 + 15) != Z_OK) {
-		fprintf(stderr, "error: %s\n", inflate_s.msg);
+		fprintf(stderr, "Decompression error: %s\n", inflate_s.msg);
 	}
 	inflate_s.next_in = (Bytef *) input.data();
 	inflate_s.avail_in = input.size();
-	size_t length = 0;
-	do {
-		output.resize(length + 2 * input.size());
-		inflate_s.avail_out = 2 * input.size();
-		inflate_s.next_out = (Bytef *) (output.data() + length);
-		int ret = inflate(&inflate_s, Z_FINISH);
-		if (ret != Z_STREAM_END && ret != Z_OK && ret != Z_BUF_ERROR) {
-			fprintf(stderr, "error: %s\n", inflate_s.msg);
+	inflate_s.next_out = (Bytef *) output.data();
+	inflate_s.avail_out = output.size();
+
+	while (true) {
+		size_t existing_output = inflate_s.next_out - (Bytef *) output.data();
+
+		output.resize(existing_output + 2 * inflate_s.avail_in + 100);
+		inflate_s.next_out = (Bytef *) output.data() + existing_output;
+		inflate_s.avail_out = output.size() - existing_output;
+
+		int ret = inflate(&inflate_s, 0);
+		if (ret < 0) {
+			fprintf(stderr, "Decompression error: ");
+			if (ret == Z_DATA_ERROR) {
+				fprintf(stderr, "data error");
+			}
+			if (ret == Z_STREAM_ERROR) {
+				fprintf(stderr, "stream error");
+			}
+			if (ret == Z_MEM_ERROR) {
+				fprintf(stderr, "out of memory");
+			}
+			if (ret == Z_BUF_ERROR) {
+				fprintf(stderr, "no data in buffer");
+			}
+			fprintf(stderr, "\n");
 			return 0;
 		}
 
-		length += (2 * input.size() - inflate_s.avail_out);
-	} while (inflate_s.avail_out == 0);
+		if (ret == Z_STREAM_END) {
+			break;
+		}
+
+		// ret must be Z_OK or Z_NEED_DICT;
+		// continue decompresing
+	}
+
+	output.resize(inflate_s.next_out - (Bytef *) output.data());
 	inflateEnd(&inflate_s);
-	output.resize(length);
 	return 1;
 }
 
@@ -79,16 +108,20 @@ int compress(std::string const &input, std::string &output) {
 	return 0;
 }
 
-bool mvt_tile::decode(std::string &message) {
+bool mvt_tile::decode(std::string &message, bool &was_compressed) {
 	layers.clear();
 	std::string src;
 
 	if (is_compressed(message)) {
 		std::string uncompressed;
-		decompress(message, uncompressed);
+		if (decompress(message, uncompressed) == 0) {
+			exit(EXIT_FAILURE);
+		}
 		src = uncompressed;
+		was_compressed = true;
 	} else {
 		src = message;
+		was_compressed = false;
 	}
 
 	protozero::pbf_reader reader(src);
@@ -115,6 +148,9 @@ bool mvt_tile::decode(std::string &message) {
 					protozero::pbf_reader value_reader(layer_reader.get_message());
 					mvt_value value;
 
+					value.type = mvt_null;
+					value.numeric_value.null_value = 0;
+
 					while (value_reader.next()) {
 						switch (value_reader.tag()) {
 						case 1: /* string */
@@ -296,6 +332,12 @@ std::string mvt_tile::encode() {
 				value_writer.add_sint64(6, pbv.numeric_value.sint_value);
 			} else if (pbv.type == mvt_bool) {
 				value_writer.add_bool(7, pbv.numeric_value.bool_value);
+			} else if (pbv.type == mvt_null) {
+				fprintf(stderr, "Internal error: trying to write null attribute to tile\n");
+				exit(EXIT_FAILURE);
+			} else {
+				fprintf(stderr, "Internal error: trying to write undefined attribute type to tile\n");
+				exit(EXIT_FAILURE);
 			}
 
 			layer_writer.add_message(4, value_string);
@@ -314,7 +356,7 @@ std::string mvt_tile::encode() {
 
 			std::vector<uint32_t> geometry;
 
-			int px = 0, py = 0;
+			long long px = 0, py = 0;
 			int cmd_idx = -1;
 			int cmd = -1;
 			int length = 0;
@@ -339,8 +381,13 @@ std::string mvt_tile::encode() {
 					long long wwx = geom[g].x;
 					long long wwy = geom[g].y;
 
-					int dx = wwx - px;
-					int dy = wwy - py;
+					long long dx = wwx - px;
+					long long dy = wwy - py;
+
+					if (dx < INT_MIN || dx > INT_MAX || dy < INT_MIN || dy > INT_MAX) {
+						fprintf(stderr, "Internal error: Geometry delta is too big: %lld,%lld\n", dx, dy);
+						exit(EXIT_FAILURE);
+					}
 
 					geometry.push_back(protozero::encode_zigzag32(dx));
 					geometry.push_back(protozero::encode_zigzag32(dy));
@@ -367,10 +414,7 @@ std::string mvt_tile::encode() {
 		writer.add_message(3, layer_string);
 	}
 
-	std::string compressed;
-	compress(data, compressed);
-
-	return compressed;
+	return data;
 }
 
 bool mvt_value::operator<(const mvt_value &o) const {
@@ -384,7 +428,8 @@ bool mvt_value::operator<(const mvt_value &o) const {
 		    (type == mvt_int && numeric_value.int_value < o.numeric_value.int_value) ||
 		    (type == mvt_uint && numeric_value.uint_value < o.numeric_value.uint_value) ||
 		    (type == mvt_sint && numeric_value.sint_value < o.numeric_value.sint_value) ||
-		    (type == mvt_bool && numeric_value.bool_value < o.numeric_value.bool_value)) {
+		    (type == mvt_bool && numeric_value.bool_value < o.numeric_value.bool_value) ||
+		    (type == mvt_null && numeric_value.null_value < o.numeric_value.null_value)) {
 			return true;
 		}
 	}
@@ -392,6 +437,59 @@ bool mvt_value::operator<(const mvt_value &o) const {
 	return false;
 }
 
+static std::string quote(std::string const &s) {
+	std::string buf;
+
+	for (size_t i = 0; i < s.size(); i++) {
+		unsigned char ch = s[i];
+
+		if (ch == '\\' || ch == '\"') {
+			buf.push_back('\\');
+			buf.push_back(ch);
+		} else if (ch < ' ') {
+			char tmp[7];
+			sprintf(tmp, "\\u%04x", ch);
+			buf.append(std::string(tmp));
+		} else {
+			buf.push_back(ch);
+		}
+	}
+
+	return buf;
+}
+
+std::string mvt_value::toString() {
+	if (type == mvt_string) {
+		return quote(string_value);
+	} else if (type == mvt_int) {
+		return std::to_string(numeric_value.int_value);
+	} else if (type == mvt_double) {
+		double v = numeric_value.double_value;
+		if (v == (long long) v) {
+			return std::to_string((long long) v);
+		} else {
+			return milo::dtoa_milo(v);
+		}
+	} else if (type == mvt_float) {
+		double v = numeric_value.float_value;
+		if (v == (long long) v) {
+			return std::to_string((long long) v);
+		} else {
+			return milo::dtoa_milo(v);
+		}
+	} else if (type == mvt_sint) {
+		return std::to_string(numeric_value.sint_value);
+	} else if (type == mvt_uint) {
+		return std::to_string(numeric_value.uint_value);
+	} else if (type == mvt_bool) {
+		return numeric_value.bool_value ? "true" : "false";
+	} else if (type == mvt_null) {
+		return "null";
+	} else {
+		return "unknown";
+	}
+}
+
 void mvt_layer::tag(mvt_feature &feature, std::string key, mvt_value value) {
 	size_t ko, vo;
 
@@ -417,3 +515,130 @@ void mvt_layer::tag(mvt_feature &feature, std::string key, mvt_value value) {
 	feature.tags.push_back(ko);
 	feature.tags.push_back(vo);
 }
+
+bool is_integer(const char *s, long long *v) {
+	errno = 0;
+	char *endptr;
+
+	*v = strtoll(s, &endptr, 0);
+	if (*v == 0 && errno != 0) {
+		return 0;
+	}
+	if ((*v == LLONG_MIN || *v == LLONG_MAX) && (errno == ERANGE || errno == EINVAL)) {
+		return 0;
+	}
+	if (*endptr != '\0') {
+		// Special case: If it is an integer followed by .0000 or similar,
+		// it is still an integer
+
+		if (*endptr != '.') {
+			return 0;
+		}
+		endptr++;
+		for (; *endptr != '\0'; endptr++) {
+			if (*endptr != '0') {
+				return 0;
+			}
+		}
+
+		return 1;
+	}
+
+	return 1;
+}
+
+bool is_unsigned_integer(const char *s, unsigned long long *v) {
+	errno = 0;
+	char *endptr;
+
+	// Special check because MacOS stroull() returns 1
+	// for -18446744073709551615
+	while (isspace(*s)) {
+		s++;
+	}
+	if (*s == '-') {
+		return 0;
+	}
+
+	*v = strtoull(s, &endptr, 0);
+	if (*v == 0 && errno != 0) {
+		return 0;
+	}
+	if ((*v == ULLONG_MAX) && (errno == ERANGE || errno == EINVAL)) {
+		return 0;
+	}
+	if (*endptr != '\0') {
+		// Special case: If it is an integer followed by .0000 or similar,
+		// it is still an integer
+
+		if (*endptr != '.') {
+			return 0;
+		}
+		endptr++;
+		for (; *endptr != '\0'; endptr++) {
+			if (*endptr != '0') {
+				return 0;
+			}
+		}
+
+		return 1;
+	}
+
+	return 1;
+}
+
+mvt_value stringified_to_mvt_value(int type, const char *s) {
+	mvt_value tv;
+
+	if (type == mvt_double) {
+		long long v;
+		unsigned long long uv;
+		if (is_unsigned_integer(s, &uv)) {
+			if (uv <= LLONG_MAX) {
+				tv.type = mvt_int;
+				tv.numeric_value.int_value = uv;
+			} else {
+				tv.type = mvt_uint;
+				tv.numeric_value.uint_value = uv;
+			}
+		} else if (is_integer(s, &v)) {
+			tv.type = mvt_sint;
+			tv.numeric_value.sint_value = v;
+		} else {
+			errno = 0;
+			char *endptr;
+
+			float f = strtof(s, &endptr);
+
+			if (endptr == s || ((f == HUGE_VAL || f == HUGE_VALF || f == HUGE_VALL) && errno == ERANGE)) {
+				double d = strtod(s, &endptr);
+				if (endptr == s || ((d == HUGE_VAL || d == HUGE_VALF || d == HUGE_VALL) && errno == ERANGE)) {
+					fprintf(stderr, "Warning: numeric value %s could not be represented\n", s);
+				}
+				tv.type = mvt_double;
+				tv.numeric_value.double_value = d;
+			} else {
+				double d = atof(s);
+				if (f == d) {
+					tv.type = mvt_float;
+					tv.numeric_value.float_value = f;
+				} else {
+					// Conversion succeeded, but lost precision, so use double
+					tv.type = mvt_double;
+					tv.numeric_value.double_value = d;
+				}
+			}
+		}
+	} else if (type == mvt_bool) {
+		tv.type = mvt_bool;
+		tv.numeric_value.bool_value = (s[0] == 't');
+	} else if (type == mvt_null) {
+		tv.type = mvt_null;
+		tv.numeric_value.null_value = 0;
+	} else {
+		tv.type = mvt_string;
+		tv.string_value = s;
+	}
+
+	return tv;
+}

mvt.hpp

@@ -1,3 +1,12 @@
+#ifndef MVT_HPP
+#define MVT_HPP
+
+#include <sqlite3.h>
+#include <string>
+#include <map>
+#include <set>
+#include <vector>
+
 struct mvt_value;
 struct mvt_layer;
 
@@ -8,11 +17,23 @@ enum mvt_operation {
 };
 
 struct mvt_geometry {
-	int x;
-	int y;
-	int /* mvt_operation */ op;
+	long long x = 0;
+	long long y = 0;
+	int /* mvt_operation */ op = 0;
 
 	mvt_geometry(int op, long long x, long long y);
+
+	bool operator<(mvt_geometry const &s) const {
+		if (y < s.y || (y == s.y && x < s.x)) {
+			return true;
+		} else {
+			return false;
+		}
+	}
+
+	bool operator==(mvt_geometry const &s) const {
+		return y == s.y && x == s.x;
+	}
 };
 
 enum mvt_geometry_type {
@@ -22,11 +43,12 @@ enum mvt_geometry_type {
 };
 
 struct mvt_feature {
-	std::vector<unsigned> tags;
-	std::vector<mvt_geometry> geometry;
-	int /* mvt_geometry_type */ type;
-	unsigned long long id;
-	bool has_id;
+	std::vector<unsigned> tags{};
+	std::vector<mvt_geometry> geometry{};
+	int /* mvt_geometry_type */ type = 0;
+	unsigned long long id = 0;
+	bool has_id = false;
+	bool dropped = false;
 
 	mvt_feature() {
 		has_id = false;
@@ -41,7 +63,8 @@ enum mvt_value_type {
 	mvt_int,
 	mvt_uint,
 	mvt_sint,
-	mvt_bool
+	mvt_bool,
+	mvt_null,
 };
 
 struct mvt_value {
@@ -54,35 +77,49 @@ struct mvt_value {
 		unsigned long long uint_value;
 		long long sint_value;
 		bool bool_value;
+		int null_value;
 	} numeric_value;
 
 	bool operator<(const mvt_value &o) const;
+	std::string toString();
+
+	mvt_value() {
+		this->type = mvt_double;
+		this->string_value = "";
+		this->numeric_value.double_value = 0;
+	}
 };
 
 struct mvt_layer {
-	int version;
-	std::string name;
-	std::vector<mvt_feature> features;
-	std::vector<std::string> keys;
-	std::vector<mvt_value> values;
-	int extent;
+	int version = 0;
+	std::string name = "";
+	std::vector<mvt_feature> features{};
+	std::vector<std::string> keys{};
+	std::vector<mvt_value> values{};
+	long long extent = 0;
 
 	// Add a key-value pair to a feature, using this layer's constant pool
 	void tag(mvt_feature &feature, std::string key, mvt_value value);
 
 	// For tracking the key-value constants already used in this layer
-	std::map<std::string, size_t> key_map;
-	std::map<mvt_value, size_t> value_map;
+	std::map<std::string, size_t> key_map{};
+	std::map<mvt_value, size_t> value_map{};
 };
 
 struct mvt_tile {
-	std::vector<mvt_layer> layers;
+	std::vector<mvt_layer> layers{};
 
 	std::string encode();
-	bool decode(std::string &message);
+	bool decode(std::string &message, bool &was_compressed);
 };
 
 bool is_compressed(std::string const &data);
 int decompress(std::string const &input, std::string &output);
 int compress(std::string const &input, std::string &output);
 int dezig(unsigned n);
+
+mvt_value stringified_to_mvt_value(int type, const char *s);
+
+bool is_integer(const char *s, long long *v);
+bool is_unsigned_integer(const char *s, unsigned long long *v);
+#endif

options.hpp

@@ -1,8 +1,11 @@
+#ifndef OPTIONS_HPP
+#define OPTIONS_HPP
+
 #define A_COALESCE ((int) 'c')
 #define A_REVERSE ((int) 'r')
 #define A_REORDER ((int) 'o')
 #define A_LINE_DROP ((int) 'l')
-#define A_DEBUG_POLYGON ((int) 'D')
+#define A_DEBUG_POLYGON ((int) '@')
 #define A_POLYGON_DROP ((int) 'p')
 #define A_DETECT_SHARED_BORDERS ((int) 'b')
 #define A_PREFER_RADIX_SORT ((int) 'R')
@@ -12,10 +15,20 @@
 #define A_DROP_DENSEST_AS_NEEDED ((int) 's')
 #define A_DROP_FRACTION_AS_NEEDED ((int) 'd')
 #define A_DROP_SMALLEST_AS_NEEDED ((int) 'n')
+#define A_COALESCE_DENSEST_AS_NEEDED ((int) 'S')
+#define A_COALESCE_SMALLEST_AS_NEEDED ((int) 'N')
+#define A_COALESCE_FRACTION_AS_NEEDED ((int) 'D')
 #define A_GRID_LOW_ZOOMS ((int) 'L')
+#define A_DETECT_WRAPAROUND ((int) 'w')
+#define A_EXTEND_ZOOMS ((int) 'e')
+#define A_CLUSTER_DENSEST_AS_NEEDED ((int) 'C')
+#define A_GENERATE_IDS ((int) 'i')
+#define A_CONVERT_NUMERIC_IDS ((int) 'I')
+#define A_HILBERT ((int) 'h')
 
 #define P_SIMPLIFY ((int) 's')
 #define P_SIMPLIFY_LOW ((int) 'S')
+#define P_SIMPLIFY_SHARED_NODES ((int) 'n')
 #define P_FEATURE_LIMIT ((int) 'f')
 #define P_KILOBYTE_LIMIT ((int) 'k')
 #define P_DYNAMIC_DROP ((int) 'd')
@@ -24,6 +37,13 @@
 #define P_CLIPPING ((int) 'c')
 #define P_DUPLICATION ((int) 'D')
 #define P_TINY_POLYGON_REDUCTION ((int) 't')
+#define P_TILE_COMPRESSION ((int) 'C')
+#define P_TILE_STATS ((int) 'g')
+#define P_USE_SOURCE_POLYGON_WINDING ((int) 'w')
+#define P_REVERSE_SOURCE_POLYGON_WINDING ((int) 'W')
+#define P_EMPTY_CSV_COLUMNS ((int) 'e')
 
 extern int prevent[256];
 extern int additional[256];
+
+#endif

plugin.cpp

@@ -0,0 +1,660 @@
+#ifdef __APPLE__
+#define _DARWIN_UNLIMITED_STREAMS
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <vector>
+#include <string>
+#include <map>
+#include <set>
+#include <pthread.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <cmath>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <sqlite3.h>
+#include <limits.h>
+#include "main.hpp"
+#include "mvt.hpp"
+#include "mbtiles.hpp"
+#include "projection.hpp"
+#include "geometry.hpp"
+#include "serial.hpp"
+
+extern "C" {
+#include "jsonpull/jsonpull.h"
+}
+
+#include "plugin.hpp"
+#include "write_json.hpp"
+#include "read_json.hpp"
+
+struct writer_arg {
+	int write_to;
+	std::vector<mvt_layer> *layers;
+	unsigned z;
+	unsigned x;
+	unsigned y;
+	int extent;
+};
+
+void *run_writer(void *a) {
+	writer_arg *wa = (writer_arg *) a;
+
+	FILE *fp = fdopen(wa->write_to, "w");
+	if (fp == NULL) {
+		perror("fdopen (pipe writer)");
+		exit(EXIT_FAILURE);
+	}
+
+	json_writer state(fp);
+	for (size_t i = 0; i < wa->layers->size(); i++) {
+		layer_to_geojson((*(wa->layers))[i], wa->z, wa->x, wa->y, false, true, false, true, 0, 0, 0, true, state);
+	}
+
+	if (fclose(fp) != 0) {
+		if (errno == EPIPE) {
+			static bool warned = false;
+			if (!warned) {
+				fprintf(stderr, "Warning: broken pipe in postfilter\n");
+				warned = true;
+			}
+		} else {
+			perror("fclose output to filter");
+			exit(EXIT_FAILURE);
+		}
+	}
+
+	return NULL;
+}
+
+// XXX deduplicate
+static std::vector<mvt_geometry> to_feature(drawvec &geom) {
+	std::vector<mvt_geometry> out;
+
+	for (size_t i = 0; i < geom.size(); i++) {
+		out.push_back(mvt_geometry(geom[i].op, geom[i].x, geom[i].y));
+	}
+
+	return out;
+}
+
+// Reads from the postfilter
+std::vector<mvt_layer> parse_layers(int fd, int z, unsigned x, unsigned y, std::vector<std::map<std::string, layermap_entry>> *layermaps, size_t tiling_seg, std::vector<std::vector<std::string>> *layer_unmaps, int extent) {
+	std::map<std::string, mvt_layer> ret;
+
+	FILE *f = fdopen(fd, "r");
+	if (f == NULL) {
+		perror("fdopen filter output");
+		exit(EXIT_FAILURE);
+	}
+	json_pull *jp = json_begin_file(f);
+
+	while (1) {
+		json_object *j = json_read(jp);
+		if (j == NULL) {
+			if (jp->error != NULL) {
+				fprintf(stderr, "Filter output:%d: %s\n", jp->line, jp->error);
+				if (jp->root != NULL) {
+					json_context(jp->root);
+				}
+				exit(EXIT_FAILURE);
+			}
+
+			json_free(jp->root);
+			break;
+		}
+
+		json_object *type = json_hash_get(j, "type");
+		if (type == NULL || type->type != JSON_STRING) {
+			continue;
+		}
+		if (strcmp(type->string, "Feature") != 0) {
+			continue;
+		}
+
+		json_object *geometry = json_hash_get(j, "geometry");
+		if (geometry == NULL) {
+			fprintf(stderr, "Filter output:%d: filtered feature with no geometry\n", jp->line);
+			json_context(j);
+			json_free(j);
+			exit(EXIT_FAILURE);
+		}
+
+		json_object *properties = json_hash_get(j, "properties");
+		if (properties == NULL || (properties->type != JSON_HASH && properties->type != JSON_NULL)) {
+			fprintf(stderr, "Filter output:%d: feature without properties hash\n", jp->line);
+			json_context(j);
+			json_free(j);
+			exit(EXIT_FAILURE);
+		}
+
+		json_object *geometry_type = json_hash_get(geometry, "type");
+		if (geometry_type == NULL) {
+			fprintf(stderr, "Filter output:%d: null geometry (additional not reported)\n", jp->line);
+			json_context(j);
+			exit(EXIT_FAILURE);
+		}
+
+		if (geometry_type->type != JSON_STRING) {
+			fprintf(stderr, "Filter output:%d: geometry type is not a string\n", jp->line);
+			json_context(j);
+			exit(EXIT_FAILURE);
+		}
+
+		json_object *coordinates = json_hash_get(geometry, "coordinates");
+		if (coordinates == NULL || coordinates->type != JSON_ARRAY) {
+			fprintf(stderr, "Filter output:%d: feature without coordinates array\n", jp->line);
+			json_context(j);
+			exit(EXIT_FAILURE);
+		}
+
+		int t;
+		for (t = 0; t < GEOM_TYPES; t++) {
+			if (strcmp(geometry_type->string, geometry_names[t]) == 0) {
+				break;
+			}
+		}
+		if (t >= GEOM_TYPES) {
+			fprintf(stderr, "Filter output:%d: Can't handle geometry type %s\n", jp->line, geometry_type->string);
+			json_context(j);
+			exit(EXIT_FAILURE);
+		}
+
+		std::string layername = "unknown";
+		json_object *tippecanoe = json_hash_get(j, "tippecanoe");
+		json_object *layer = NULL;
+		if (tippecanoe != NULL) {
+			layer = json_hash_get(tippecanoe, "layer");
+			if (layer != NULL && layer->type == JSON_STRING) {
+				layername = std::string(layer->string);
+			}
+		}
+
+		if (ret.count(layername) == 0) {
+			mvt_layer l;
+			l.name = layername;
+			l.version = 2;
+			l.extent = extent;
+
+			ret.insert(std::pair<std::string, mvt_layer>(layername, l));
+		}
+		auto l = ret.find(layername);
+
+		drawvec dv;
+		parse_geometry(t, coordinates, dv, VT_MOVETO, "Filter output", jp->line, j);
+		if (mb_geometry[t] == VT_POLYGON) {
+			dv = fix_polygon(dv);
+		}
+
+		// Scale and offset geometry from global to tile
+		for (size_t i = 0; i < dv.size(); i++) {
+			long long scale = 1LL << (32 - z);
+			dv[i].x = std::round((dv[i].x - scale * x) * extent / (double) scale);
+			dv[i].y = std::round((dv[i].y - scale * y) * extent / (double) scale);
+		}
+
+		if (mb_geometry[t] == VT_POLYGON) {
+			dv = clean_or_clip_poly(dv, 0, 0, false);
+			if (dv.size() < 3) {
+				dv.clear();
+			}
+		}
+		dv = remove_noop(dv, mb_geometry[t], 0);
+		if (mb_geometry[t] == VT_POLYGON) {
+			dv = close_poly(dv);
+		}
+
+		if (dv.size() > 0) {
+			mvt_feature feature;
+			feature.type = mb_geometry[t];
+			feature.geometry = to_feature(dv);
+
+			json_object *id = json_hash_get(j, "id");
+			if (id != NULL) {
+				feature.id = atoll(id->string);
+				feature.has_id = true;
+			}
+
+			std::map<std::string, layermap_entry> &layermap = (*layermaps)[tiling_seg];
+			if (layermap.count(layername) == 0) {
+				layermap_entry lme = layermap_entry(layermap.size());
+				lme.minzoom = z;
+				lme.maxzoom = z;
+
+				layermap.insert(std::pair<std::string, layermap_entry>(layername, lme));
+
+				if (lme.id >= (*layer_unmaps)[tiling_seg].size()) {
+					(*layer_unmaps)[tiling_seg].resize(lme.id + 1);
+					(*layer_unmaps)[tiling_seg][lme.id] = layername;
+				}
+			}
+
+			auto fk = layermap.find(layername);
+			if (fk == layermap.end()) {
+				fprintf(stderr, "Internal error: layer %s not found\n", layername.c_str());
+				exit(EXIT_FAILURE);
+			}
+			if (z < fk->second.minzoom) {
+				fk->second.minzoom = z;
+			}
+			if (z > fk->second.maxzoom) {
+				fk->second.maxzoom = z;
+			}
+
+			if (feature.type == mvt_point) {
+				fk->second.points++;
+			} else if (feature.type == mvt_linestring) {
+				fk->second.lines++;
+			} else if (feature.type == mvt_polygon) {
+				fk->second.polygons++;
+			}
+
+			for (size_t i = 0; i < properties->length; i++) {
+				int tp = -1;
+				std::string s;
+
+				stringify_value(properties->values[i], tp, s, "Filter output", jp->line, j);
+
+				// Nulls can be excluded here because this is the postfilter
+				// and it is nearly time to create the vector representation
+
+				if (tp >= 0 && tp != mvt_null) {
+					mvt_value v = stringified_to_mvt_value(tp, s.c_str());
+					l->second.tag(feature, std::string(properties->keys[i]->string), v);
+
+					type_and_string attrib;
+					attrib.type = tp;
+					attrib.string = s;
+
+					add_to_file_keys(fk->second.file_keys, std::string(properties->keys[i]->string), attrib);
+				}
+			}
+
+			l->second.features.push_back(feature);
+		}
+
+		json_free(j);
+	}
+
+	json_end(jp);
+	if (fclose(f) != 0) {
+		perror("fclose postfilter output");
+		exit(EXIT_FAILURE);
+	}
+
+	std::vector<mvt_layer> final;
+	for (auto a : ret) {
+		final.push_back(a.second);
+	}
+	return final;
+}
+
+// Reads from the prefilter
+serial_feature parse_feature(json_pull *jp, int z, unsigned x, unsigned y, std::vector<std::map<std::string, layermap_entry>> *layermaps, size_t tiling_seg, std::vector<std::vector<std::string>> *layer_unmaps, bool postfilter) {
+	serial_feature sf;
+
+	while (1) {
+		json_object *j = json_read(jp);
+		if (j == NULL) {
+			if (jp->error != NULL) {
+				fprintf(stderr, "Filter output:%d: %s\n", jp->line, jp->error);
+				if (jp->root != NULL) {
+					json_context(jp->root);
+				}
+				exit(EXIT_FAILURE);
+			}
+
+			json_free(jp->root);
+			sf.t = -1;
+			return sf;
+		}
+
+		json_object *type = json_hash_get(j, "type");
+		if (type == NULL || type->type != JSON_STRING) {
+			continue;
+		}
+		if (strcmp(type->string, "Feature") != 0) {
+			continue;
+		}
+
+		json_object *geometry = json_hash_get(j, "geometry");
+		if (geometry == NULL) {
+			fprintf(stderr, "Filter output:%d: filtered feature with no geometry\n", jp->line);
+			json_context(j);
+			json_free(j);
+			exit(EXIT_FAILURE);
+		}
+
+		json_object *properties = json_hash_get(j, "properties");
+		if (properties == NULL || (properties->type != JSON_HASH && properties->type != JSON_NULL)) {
+			fprintf(stderr, "Filter output:%d: feature without properties hash\n", jp->line);
+			json_context(j);
+			json_free(j);
+			exit(EXIT_FAILURE);
+		}
+
+		json_object *geometry_type = json_hash_get(geometry, "type");
+		if (geometry_type == NULL) {
+			fprintf(stderr, "Filter output:%d: null geometry (additional not reported)\n", jp->line);
+			json_context(j);
+			exit(EXIT_FAILURE);
+		}
+
+		if (geometry_type->type != JSON_STRING) {
+			fprintf(stderr, "Filter output:%d: geometry type is not a string\n", jp->line);
+			json_context(j);
+			exit(EXIT_FAILURE);
+		}
+
+		json_object *coordinates = json_hash_get(geometry, "coordinates");
+		if (coordinates == NULL || coordinates->type != JSON_ARRAY) {
+			fprintf(stderr, "Filter output:%d: feature without coordinates array\n", jp->line);
+			json_context(j);
+			exit(EXIT_FAILURE);
+		}
+
+		int t;
+		for (t = 0; t < GEOM_TYPES; t++) {
+			if (strcmp(geometry_type->string, geometry_names[t]) == 0) {
+				break;
+			}
+		}
+		if (t >= GEOM_TYPES) {
+			fprintf(stderr, "Filter output:%d: Can't handle geometry type %s\n", jp->line, geometry_type->string);
+			json_context(j);
+			exit(EXIT_FAILURE);
+		}
+
+		drawvec dv;
+		parse_geometry(t, coordinates, dv, VT_MOVETO, "Filter output", jp->line, j);
+		if (mb_geometry[t] == VT_POLYGON) {
+			dv = fix_polygon(dv);
+		}
+
+		// Scale and offset geometry from global to tile
+		double scale = 1LL << geometry_scale;
+		for (size_t i = 0; i < dv.size(); i++) {
+			unsigned sx = 0, sy = 0;
+			if (z != 0) {
+				sx = x << (32 - z);
+				sy = y << (32 - z);
+			}
+			dv[i].x = std::round(dv[i].x / scale) * scale - sx;
+			dv[i].y = std::round(dv[i].y / scale) * scale - sy;
+		}
+
+		if (dv.size() > 0) {
+			sf.t = mb_geometry[t];
+			sf.segment = tiling_seg;
+			sf.geometry = dv;
+			sf.seq = 0;
+			sf.index = 0;
+			sf.bbox[0] = sf.bbox[1] = LLONG_MAX;
+			sf.bbox[2] = sf.bbox[3] = LLONG_MIN;
+			sf.extent = 0;
+			sf.metapos = 0;
+			sf.has_id = false;
+
+			std::string layername = "unknown";
+			json_object *tippecanoe = json_hash_get(j, "tippecanoe");
+			if (tippecanoe != NULL) {
+				json_object *layer = json_hash_get(tippecanoe, "layer");
+				if (layer != NULL && layer->type == JSON_STRING) {
+					layername = std::string(layer->string);
+				}
+
+				json_object *index = json_hash_get(tippecanoe, "index");
+				if (index != NULL && index->type == JSON_NUMBER) {
+					sf.index = index->number;
+				}
+
+				json_object *sequence = json_hash_get(tippecanoe, "sequence");
+				if (sequence != NULL && sequence->type == JSON_NUMBER) {
+					sf.seq = sequence->number;
+				}
+
+				json_object *extent = json_hash_get(tippecanoe, "extent");
+				if (extent != NULL && extent->type == JSON_NUMBER) {
+					sf.extent = extent->number;
+				}
+
+				json_object *dropped = json_hash_get(tippecanoe, "dropped");
+				if (dropped != NULL && dropped->type == JSON_TRUE) {
+					sf.dropped = true;
+				}
+			}
+
+			for (size_t i = 0; i < dv.size(); i++) {
+				if (dv[i].op == VT_MOVETO || dv[i].op == VT_LINETO) {
+					if (dv[i].x < sf.bbox[0]) {
+						sf.bbox[0] = dv[i].x;
+					}
+					if (dv[i].y < sf.bbox[1]) {
+						sf.bbox[1] = dv[i].y;
+					}
+					if (dv[i].x > sf.bbox[2]) {
+						sf.bbox[2] = dv[i].x;
+					}
+					if (dv[i].y > sf.bbox[3]) {
+						sf.bbox[3] = dv[i].y;
+					}
+				}
+			}
+
+			json_object *id = json_hash_get(j, "id");
+			if (id != NULL) {
+				sf.id = atoll(id->string);
+				sf.has_id = true;
+			}
+
+			std::map<std::string, layermap_entry> &layermap = (*layermaps)[tiling_seg];
+
+			if (layermap.count(layername) == 0) {
+				layermap_entry lme = layermap_entry(layermap.size());
+				lme.minzoom = z;
+				lme.maxzoom = z;
+
+				layermap.insert(std::pair<std::string, layermap_entry>(layername, lme));
+
+				if (lme.id >= (*layer_unmaps)[tiling_seg].size()) {
+					(*layer_unmaps)[tiling_seg].resize(lme.id + 1);
+					(*layer_unmaps)[tiling_seg][lme.id] = layername;
+				}
+			}
+
+			auto fk = layermap.find(layername);
+			if (fk == layermap.end()) {
+				fprintf(stderr, "Internal error: layer %s not found\n", layername.c_str());
+				exit(EXIT_FAILURE);
+			}
+			sf.layer = fk->second.id;
+
+			if (z < fk->second.minzoom) {
+				fk->second.minzoom = z;
+			}
+			if (z > fk->second.maxzoom) {
+				fk->second.maxzoom = z;
+			}
+
+			if (!postfilter) {
+				if (sf.t == mvt_point) {
+					fk->second.points++;
+				} else if (sf.t == mvt_linestring) {
+					fk->second.lines++;
+				} else if (sf.t == mvt_polygon) {
+					fk->second.polygons++;
+				}
+			}
+
+			for (size_t i = 0; i < properties->length; i++) {
+				serial_val v;
+				v.type = -1;
+
+				stringify_value(properties->values[i], v.type, v.s, "Filter output", jp->line, j);
+
+				// Nulls can be excluded here because the expression evaluation filter
+				// would have already run before prefiltering
+
+				if (v.type >= 0 && v.type != mvt_null) {
+					sf.full_keys.push_back(std::string(properties->keys[i]->string));
+					sf.full_values.push_back(v);
+
+					type_and_string attrib;
+					attrib.string = v.s;
+					attrib.type = v.type;
+
+					if (!postfilter) {
+						add_to_file_keys(fk->second.file_keys, std::string(properties->keys[i]->string), attrib);
+					}
+				}
+			}
+
+			json_free(j);
+			return sf;
+		}
+
+		json_free(j);
+	}
+}
+
+static pthread_mutex_t pipe_lock = PTHREAD_MUTEX_INITIALIZER;
+
+void setup_filter(const char *filter, int *write_to, int *read_from, pid_t *pid, unsigned z, unsigned x, unsigned y) {
+	// This will create two pipes, a new thread, and a new process.
+	//
+	// The new process will read from one pipe and write to the other, and execute the filter.
+	// The new thread will write the GeoJSON to the pipe that leads to the filter.
+	// The original thread will read the GeoJSON from the filter and convert it back into vector tiles.
+
+	if (pthread_mutex_lock(&pipe_lock) != 0) {
+		perror("pthread_mutex_lock (pipe)");
+		exit(EXIT_FAILURE);
+	}
+
+	int pipe_orig[2], pipe_filtered[2];
+	if (pipe(pipe_orig) < 0) {
+		perror("pipe (original features)");
+		exit(EXIT_FAILURE);
+	}
+	if (pipe(pipe_filtered) < 0) {
+		perror("pipe (filtered features)");
+		exit(EXIT_FAILURE);
+	}
+
+	std::string z_str = std::to_string(z);
+	std::string x_str = std::to_string(x);
+	std::string y_str = std::to_string(y);
+
+	*pid = fork();
+	if (*pid < 0) {
+		perror("fork");
+		exit(EXIT_FAILURE);
+	} else if (*pid == 0) {
+		// child
+
+		if (dup2(pipe_orig[0], 0) < 0) {
+			perror("dup child stdin");
+			exit(EXIT_FAILURE);
+		}
+		if (dup2(pipe_filtered[1], 1) < 0) {
+			perror("dup child stdout");
+			exit(EXIT_FAILURE);
+		}
+		if (close(pipe_orig[1]) != 0) {
+			perror("close output to filter");
+			exit(EXIT_FAILURE);
+		}
+		if (close(pipe_filtered[0]) != 0) {
+			perror("close input from filter");
+			exit(EXIT_FAILURE);
+		}
+		if (close(pipe_orig[0]) != 0) {
+			perror("close dup input of filter");
+			exit(EXIT_FAILURE);
+		}
+		if (close(pipe_filtered[1]) != 0) {
+			perror("close dup output of filter");
+			exit(EXIT_FAILURE);
+		}
+
+		// XXX close other fds?
+
+		if (execlp("sh", "sh", "-c", filter, "sh", z_str.c_str(), x_str.c_str(), y_str.c_str(), NULL) != 0) {
+			perror("exec");
+			exit(EXIT_FAILURE);
+		}
+	} else {
+		// parent
+
+		if (close(pipe_orig[0]) != 0) {
+			perror("close filter-side reader");
+			exit(EXIT_FAILURE);
+		}
+		if (close(pipe_filtered[1]) != 0) {
+			perror("close filter-side writer");
+			exit(EXIT_FAILURE);
+		}
+		if (fcntl(pipe_orig[1], F_SETFD, FD_CLOEXEC) != 0) {
+			perror("cloxec output to filter");
+			exit(EXIT_FAILURE);
+		}
+		if (fcntl(pipe_filtered[0], F_SETFD, FD_CLOEXEC) != 0) {
+			perror("cloxec input from filter");
+			exit(EXIT_FAILURE);
+		}
+
+		if (pthread_mutex_unlock(&pipe_lock) != 0) {
+			perror("pthread_mutex_unlock (pipe_lock)");
+			exit(EXIT_FAILURE);
+		}
+
+		*write_to = pipe_orig[1];
+		*read_from = pipe_filtered[0];
+	}
+}
+
+std::vector<mvt_layer> filter_layers(const char *filter, std::vector<mvt_layer> &layers, unsigned z, unsigned x, unsigned y, std::vector<std::map<std::string, layermap_entry>> *layermaps, size_t tiling_seg, std::vector<std::vector<std::string>> *layer_unmaps, int extent) {
+	int write_to, read_from;
+	pid_t pid;
+	setup_filter(filter, &write_to, &read_from, &pid, z, x, y);
+
+	writer_arg wa;
+	wa.write_to = write_to;
+	wa.layers = &layers;
+	wa.z = z;
+	wa.x = x;
+	wa.y = y;
+	wa.extent = extent;
+
+	pthread_t writer;
+	if (pthread_create(&writer, NULL, run_writer, &wa) != 0) {
+		perror("pthread_create (filter writer)");
+		exit(EXIT_FAILURE);
+	}
+
+	std::vector<mvt_layer> nlayers = parse_layers(read_from, z, x, y, layermaps, tiling_seg, layer_unmaps, extent);
+
+	while (1) {
+		int stat_loc;
+		if (waitpid(pid, &stat_loc, 0) < 0) {
+			perror("waitpid for filter\n");
+			exit(EXIT_FAILURE);
+		}
+		if (WIFEXITED(stat_loc) || WIFSIGNALED(stat_loc)) {
+			break;
+		}
+	}
+
+	void *ret;
+	if (pthread_join(writer, &ret) != 0) {
+		perror("pthread_join filter writer");
+		exit(EXIT_FAILURE);
+	}
+
+	return nlayers;
+}

plugin.hpp

@@ -0,0 +1,3 @@
+std::vector<mvt_layer> filter_layers(const char *filter, std::vector<mvt_layer> &layer, unsigned z, unsigned x, unsigned y, std::vector<std::map<std::string, layermap_entry>> *layermaps, size_t tiling_seg, std::vector<std::vector<std::string>> *layer_unmaps, int extent);
+void setup_filter(const char *filter, int *write_to, int *read_from, pid_t *pid, unsigned z, unsigned x, unsigned y);
+serial_feature parse_feature(json_pull *jp, int z, unsigned x, unsigned y, std::vector<std::map<std::string, layermap_entry>> *layermaps, size_t tiling_seg, std::vector<std::vector<std::string>> *layer_unmaps, bool filters);

pool.cpp

@@ -2,47 +2,43 @@
 #include <stdlib.h>
 #include <string.h>
 #include <limits.h>
+#include <math.h>
 #include "memfile.hpp"
 #include "pool.hpp"
 
-static unsigned char swizzle[256] = {
-	0x00, 0xBF, 0x18, 0xDE, 0x93, 0xC9, 0xB1, 0x5E, 0xDF, 0xBE, 0x72, 0x5A, 0xBB, 0x42, 0x64, 0xC6,
-	0xD8, 0xB7, 0x15, 0x74, 0x1C, 0x8B, 0x91, 0xF5, 0x29, 0x46, 0xEC, 0x6F, 0xCA, 0x20, 0xF0, 0x06,
-	0x27, 0x61, 0x87, 0xE0, 0x6E, 0x43, 0x50, 0xC5, 0x1B, 0xB4, 0x37, 0xC3, 0x69, 0xA6, 0xEE, 0x80,
-	0xAF, 0x9B, 0xA1, 0x76, 0x23, 0x24, 0x53, 0xF3, 0x5B, 0x65, 0x19, 0xF4, 0xFC, 0xDD, 0x26, 0xE8,
-	0x10, 0xF7, 0xCE, 0x92, 0x48, 0xF6, 0x94, 0x60, 0x07, 0xC4, 0xB9, 0x97, 0x6D, 0xA4, 0x11, 0x0D,
-	0x1F, 0x4D, 0x13, 0xB0, 0x5D, 0xBA, 0x31, 0xD5, 0x8D, 0x51, 0x36, 0x96, 0x7A, 0x03, 0x7F, 0xDA,
-	0x17, 0xDB, 0xD4, 0x83, 0xE2, 0x79, 0x6A, 0xE1, 0x95, 0x38, 0xFF, 0x28, 0xB2, 0xB3, 0xA7, 0xAE,
-	0xF8, 0x54, 0xCC, 0xDC, 0x9A, 0x6B, 0xFB, 0x3F, 0xD7, 0xBC, 0x21, 0xC8, 0x71, 0x09, 0x16, 0xAC,
-	0x3C, 0x8A, 0x62, 0x05, 0xC2, 0x8C, 0x32, 0x4E, 0x35, 0x9C, 0x5F, 0x75, 0xCD, 0x2E, 0xA2, 0x3E,
-	0x1A, 0xC1, 0x8E, 0x14, 0xA0, 0xD3, 0x7D, 0xD9, 0xEB, 0x5C, 0x70, 0xE6, 0x9E, 0x12, 0x3B, 0xEF,
-	0x1E, 0x49, 0xD2, 0x98, 0x39, 0x7E, 0x44, 0x4B, 0x6C, 0x88, 0x02, 0x2C, 0xAD, 0xE5, 0x9F, 0x40,
-	0x7B, 0x4A, 0x3D, 0xA9, 0xAB, 0x0B, 0xD6, 0x2F, 0x90, 0x2A, 0xB6, 0x1D, 0xC7, 0x22, 0x55, 0x34,
-	0x0A, 0xD0, 0xB5, 0x68, 0xE3, 0x59, 0xFD, 0xFA, 0x57, 0x77, 0x25, 0xA3, 0x04, 0xB8, 0x33, 0x89,
-	0x78, 0x82, 0xE4, 0xC0, 0x0E, 0x8F, 0x85, 0xD1, 0x84, 0x08, 0x67, 0x47, 0x9D, 0xCB, 0x58, 0x4C,
-	0xAA, 0xED, 0x52, 0xF2, 0x4F, 0xF1, 0x66, 0xCF, 0xA5, 0x56, 0xEA, 0x7C, 0xE9, 0x63, 0xE7, 0x01,
-	0xF9, 0xFE, 0x0C, 0x99, 0x2D, 0x0F, 0x3A, 0x41, 0x45, 0xA8, 0x30, 0x2B, 0x73, 0xBD, 0x86, 0x81,
-};
-
 int swizzlecmp(const char *a, const char *b) {
-	while (*a || *b) {
-		int aa = swizzle[(unsigned char) *a];
-		int bb = swizzle[(unsigned char) *b];
+	ssize_t alen = strlen(a);
+	ssize_t blen = strlen(b);
 
-		int cmp = aa - bb;
-		if (cmp != 0) {
-			return cmp;
-		}
-
-		a++;
-		b++;
+	if (strcmp(a, b) == 0) {
+		return 0;
 	}
 
-	return 0;
+	long long hash1 = 0, hash2 = 0;
+	for (ssize_t i = alen - 1; i >= 0; i--) {
+		hash1 = (hash1 * 37 + a[i]) & INT_MAX;
+	}
+	for (ssize_t i = blen - 1; i >= 0; i--) {
+		hash2 = (hash2 * 37 + b[i]) & INT_MAX;
+	}
+
+	int h1 = hash1, h2 = hash2;
+	if (h1 == h2) {
+		return strcmp(a, b);
+	}
+
+	return h1 - h2;
 }
 
 long long addpool(struct memfile *poolfile, struct memfile *treefile, const char *s, char type) {
-	long long *sp = &treefile->tree;
+	unsigned long *sp = &treefile->tree;
+	size_t depth = 0;
+
+	// In typical data, traversal depth generally stays under 2.5x
+	size_t max = 3 * log(treefile->off / sizeof(struct stringpool)) / log(2);
+	if (max < 30) {
+		max = 30;
+	}
 
 	while (*sp != 0) {
 		int cmp = swizzlecmp(s, poolfile->map + ((struct stringpool *) (treefile->map + *sp))->off + 1);
@@ -58,6 +54,23 @@ long long addpool(struct memfile *poolfile, struct memfile *treefile, const char
 		} else {
 			return ((struct stringpool *) (treefile->map + *sp))->off;
 		}
+
+		depth++;
+		if (depth > max) {
+			// Search is very deep, so string is probably unique.
+			// Add it to the pool without adding it to the search tree.
+
+			long long off = poolfile->off;
+			if (memfile_write(poolfile, &type, 1) < 0) {
+				perror("memfile write");
+				exit(EXIT_FAILURE);
+			}
+			if (memfile_write(poolfile, (void *) s, strlen(s) + 1) < 0) {
+				perror("memfile write");
+				exit(EXIT_FAILURE);
+			}
+			return off;
+		}
 	}
 
 	// *sp is probably in the memory-mapped file, and will move if the file grows.
@@ -78,6 +91,16 @@ long long addpool(struct memfile *poolfile, struct memfile *treefile, const char
 		exit(EXIT_FAILURE);
 	}
 
+	if (off >= LONG_MAX || treefile->off >= LONG_MAX) {
+		// Tree or pool is bigger than 2GB
+		static bool warned = false;
+		if (!warned) {
+			fprintf(stderr, "Warning: string pool is very large.\n");
+			warned = true;
+		}
+		return off;
+	}
+
 	struct stringpool tsp;
 	tsp.left = 0;
 	tsp.right = 0;

pool.hpp

@@ -1,7 +1,12 @@
+#ifndef POOL_HPP
+#define POOL_HPP
+
 struct stringpool {
-	long long left;
-	long long right;
-	long long off;
+	unsigned long left = 0;
+	unsigned long right = 0;
+	unsigned long off = 0;
 };
 
 long long addpool(struct memfile *poolfile, struct memfile *treefile, const char *s, char type);
+
+#endif

projection.cpp

@@ -2,18 +2,39 @@
 #include <string.h>
 #include <stdlib.h>
 #include <math.h>
+#include <atomic>
 #include "projection.hpp"
 
+unsigned long long (*encode_index)(unsigned int wx, unsigned int wy) = NULL;
+void (*decode_index)(unsigned long long index, unsigned *wx, unsigned *wy) = NULL;
+
 struct projection projections[] = {
 	{"EPSG:4326", lonlat2tile, tile2lonlat, "urn:ogc:def:crs:OGC:1.3:CRS84"},
 	{"EPSG:3857", epsg3857totile, tiletoepsg3857, "urn:ogc:def:crs:EPSG::3857"},
-	{NULL, NULL},
+	{NULL, NULL, NULL, NULL},
 };
 
 struct projection *projection = &projections[0];
 
 // http://wiki.openstreetmap.org/wiki/Slippy_map_tilenames
 void lonlat2tile(double lon, double lat, int zoom, long long *x, long long *y) {
+	// Place infinite and NaN coordinates off the edge of the Mercator plane
+
+	int lat_class = fpclassify(lat);
+	int lon_class = fpclassify(lon);
+	bool bad_lon = false;
+
+	if (lat_class == FP_INFINITE || lat_class == FP_NAN) {
+		lat = 89.9;
+	}
+	if (lon_class == FP_INFINITE || lon_class == FP_NAN) {
+		// Keep these far enough from the plane that they don't get
+		// moved back into it by 360-degree offsetting
+
+		lon = 720;
+		bad_lon = true;
+	}
+
 	// Must limit latitude somewhere to prevent overflow.
 	// 89.9 degrees latitude is 0.621 worlds beyond the edge of the flat earth,
 	// hopefully far enough out that there are few expectations about the shape.
@@ -24,10 +45,10 @@ void lonlat2tile(double lon, double lat, int zoom, long long *x, long long *y) {
 		lat = 89.9;
 	}
 
-	if (lon < -360) {
+	if (lon < -360 && !bad_lon) {
 		lon = -360;
 	}
-	if (lon > 360) {
+	if (lon > 360 && !bad_lon) {
 		lon = 360;
 	}
 
@@ -49,6 +70,18 @@ void tile2lonlat(long long x, long long y, int zoom, double *lon, double *lat) {
 }
 
 void epsg3857totile(double ix, double iy, int zoom, long long *x, long long *y) {
+	// Place infinite and NaN coordinates off the edge of the Mercator plane
+
+	int iy_class = fpclassify(iy);
+	int ix_class = fpclassify(ix);
+
+	if (iy_class == FP_INFINITE || iy_class == FP_NAN) {
+		iy = 40000000.0;
+	}
+	if (ix_class == FP_INFINITE || ix_class == FP_NAN) {
+		ix = 40000000.0;
+	}
+
 	*x = ix * (1LL << 31) / 6378137.0 / M_PI + (1LL << 31);
 	*y = ((1LL << 32) - 1) - (iy * (1LL << 31) / 6378137.0 / M_PI + (1LL << 31));
 
@@ -68,7 +101,60 @@ void tiletoepsg3857(long long ix, long long iy, int zoom, double *ox, double *oy
 	*oy = ((1LL << 32) - 1 - iy - (1LL << 31)) * M_PI * 6378137.0 / (1LL << 31);
 }
 
-unsigned long long encode(unsigned int wx, unsigned int wy) {
+// https://en.wikipedia.org/wiki/Hilbert_curve
+
+void hilbert_rot(unsigned long long n, unsigned *x, unsigned *y, unsigned long long rx, unsigned long long ry) {
+	if (ry == 0) {
+		if (rx == 1) {
+			*x = n - 1 - *x;
+			*y = n - 1 - *y;
+		}
+
+		unsigned t = *x;
+		*x = *y;
+		*y = t;
+	}
+}
+
+unsigned long long hilbert_xy2d(unsigned long long n, unsigned x, unsigned y) {
+	unsigned long long d = 0;
+	unsigned long long rx, ry;
+
+	for (unsigned long long s = n / 2; s > 0; s /= 2) {
+		rx = (x & s) != 0;
+		ry = (y & s) != 0;
+
+		d += s * s * ((3 * rx) ^ ry);
+		hilbert_rot(s, &x, &y, rx, ry);
+	}
+
+	return d;
+}
+
+void hilbert_d2xy(unsigned long long n, unsigned long long d, unsigned *x, unsigned *y) {
+	unsigned long long rx, ry;
+	unsigned long long t = d;
+
+	*x = *y = 0;
+	for (unsigned long long s = 1; s < n; s *= 2) {
+		rx = 1 & (t / 2);
+		ry = 1 & (t ^ rx);
+		hilbert_rot(s, x, y, rx, ry);
+		*x += s * rx;
+		*y += s * ry;
+		t /= 4;
+	}
+}
+
+unsigned long long encode_hilbert(unsigned int wx, unsigned int wy) {
+	return hilbert_xy2d(1LL << 32, wx, wy);
+}
+
+void decode_hilbert(unsigned long long index, unsigned *wx, unsigned *wy) {
+	hilbert_d2xy(1LL << 32, index, wx, wy);
+}
+
+unsigned long long encode_quadkey(unsigned int wx, unsigned int wy) {
 	unsigned long long out = 0;
 
 	int i;
@@ -83,13 +169,32 @@ unsigned long long encode(unsigned int wx, unsigned int wy) {
 	return out;
 }
 
-void decode(unsigned long long index, unsigned *wx, unsigned *wy) {
+static std::atomic<unsigned char> decodex[256];
+static std::atomic<unsigned char> decodey[256];
+
+void decode_quadkey(unsigned long long index, unsigned *wx, unsigned *wy) {
+	static std::atomic<int> initialized(0);
+	if (!initialized) {
+		for (size_t ix = 0; ix < 256; ix++) {
+			size_t xx = 0, yy = 0;
+
+			for (size_t i = 0; i < 32; i++) {
+				xx |= ((ix >> (64 - 2 * (i + 1) + 1)) & 1) << (32 - (i + 1));
+				yy |= ((ix >> (64 - 2 * (i + 1) + 0)) & 1) << (32 - (i + 1));
+			}
+
+			decodex[ix] = xx;
+			decodey[ix] = yy;
+		}
+
+		initialized = 1;
+	}
+
 	*wx = *wy = 0;
 
-	int i;
-	for (i = 0; i < 32; i++) {
-		*wx |= ((index >> (64 - 2 * (i + 1) + 1)) & 1) << (32 - (i + 1));
-		*wy |= ((index >> (64 - 2 * (i + 1) + 0)) & 1) << (32 - (i + 1));
+	for (size_t i = 0; i < 8; i++) {
+		*wx |= ((unsigned) decodex[(index >> (8 * i)) & 0xFF]) << (4 * i);
+		*wy |= ((unsigned) decodey[(index >> (8 * i)) & 0xFF]) << (4 * i);
 	}
 }
 

projection.hpp

@@ -1,9 +1,10 @@
+#ifndef PROJECTION_HPP
+#define PROJECTION_HPP
+
 void lonlat2tile(double lon, double lat, int zoom, long long *x, long long *y);
 void epsg3857totile(double ix, double iy, int zoom, long long *x, long long *y);
 void tile2lonlat(long long x, long long y, int zoom, double *lon, double *lat);
 void tiletoepsg3857(long long x, long long y, int zoom, double *ox, double *oy);
-unsigned long long encode(unsigned int wx, unsigned int wy);
-void decode(unsigned long long index, unsigned *wx, unsigned *wy);
 void set_projection_or_exit(const char *optarg);
 
 struct projection {
@@ -15,3 +16,14 @@ struct projection {
 
 extern struct projection *projection;
 extern struct projection projections[];
+
+extern unsigned long long (*encode_index)(unsigned int wx, unsigned int wy);
+extern void (*decode_index)(unsigned long long index, unsigned *wx, unsigned *wy);
+
+unsigned long long encode_quadkey(unsigned int wx, unsigned int wy);
+void decode_quadkey(unsigned long long index, unsigned *wx, unsigned *wy);
+
+unsigned long long encode_hilbert(unsigned int wx, unsigned int wy);
+void decode_hilbert(unsigned long long index, unsigned *wx, unsigned *wy);
+
+#endif

protozero/byteswap.hpp

@@ -16,56 +16,69 @@ documentation.
  * @brief Contains functions to swap bytes in values (for different endianness).
  */
 
-#include <cstdint>
 #include <cassert>
+#include <cstdint>
 
 #include <protozero/config.hpp>
 
 namespace protozero {
+namespace detail {
 
-/**
- * Swap N byte value between endianness formats. This template function must
- * be specialized to actually work.
- */
-template <int N>
-inline void byteswap(const char* /*data*/, char* /*result*/) {
-    static_assert(N == 1, "Can only swap 4 or 8 byte values");
-}
-
-/**
- * Swap 4 byte value (int32_t, uint32_t, float) between endianness formats.
- */
-template <>
-inline void byteswap<4>(const char* data, char* result) {
+inline uint32_t byteswap_impl(uint32_t value) noexcept {
 #ifdef PROTOZERO_USE_BUILTIN_BSWAP
-    *reinterpret_cast<uint32_t*>(result) = __builtin_bswap32(*reinterpret_cast<const uint32_t*>(data));
+    return __builtin_bswap32(value);
 #else
-    result[3] = data[0];
-    result[2] = data[1];
-    result[1] = data[2];
-    result[0] = data[3];
+    return ((value & 0xff000000) >> 24) |
+           ((value & 0x00ff0000) >>  8) |
+           ((value & 0x0000ff00) <<  8) |
+           ((value & 0x000000ff) << 24);
 #endif
 }
 
-/**
- * Swap 8 byte value (int64_t, uint64_t, double) between endianness formats.
- */
-template <>
-inline void byteswap<8>(const char* data, char* result) {
+inline uint64_t byteswap_impl(uint64_t value) noexcept {
 #ifdef PROTOZERO_USE_BUILTIN_BSWAP
-    *reinterpret_cast<uint64_t*>(result) = __builtin_bswap64(*reinterpret_cast<const uint64_t*>(data));
+    return __builtin_bswap64(value);
 #else
-    result[7] = data[0];
-    result[6] = data[1];
-    result[5] = data[2];
-    result[4] = data[3];
-    result[3] = data[4];
-    result[2] = data[5];
-    result[1] = data[6];
-    result[0] = data[7];
+    return ((value & 0xff00000000000000ULL) >> 56) |
+           ((value & 0x00ff000000000000ULL) >> 40) |
+           ((value & 0x0000ff0000000000ULL) >> 24) |
+           ((value & 0x000000ff00000000ULL) >>  8) |
+           ((value & 0x00000000ff000000ULL) <<  8) |
+           ((value & 0x0000000000ff0000ULL) << 24) |
+           ((value & 0x000000000000ff00ULL) << 40) |
+           ((value & 0x00000000000000ffULL) << 56);
 #endif
 }
 
+inline void byteswap_inplace(uint32_t* ptr) noexcept {
+    *ptr = byteswap_impl(*ptr);
+}
+
+inline void byteswap_inplace(uint64_t* ptr) noexcept {
+    *ptr = byteswap_impl(*ptr);
+}
+
+inline void byteswap_inplace(int32_t* ptr) noexcept {
+    auto bptr = reinterpret_cast<uint32_t*>(ptr);
+    *bptr = byteswap_impl(*bptr);
+}
+
+inline void byteswap_inplace(int64_t* ptr) noexcept {
+    auto bptr = reinterpret_cast<uint64_t*>(ptr);
+    *bptr = byteswap_impl(*bptr);
+}
+
+inline void byteswap_inplace(float* ptr) noexcept {
+    auto bptr = reinterpret_cast<uint32_t*>(ptr);
+    *bptr = byteswap_impl(*bptr);
+}
+
+inline void byteswap_inplace(double* ptr) noexcept {
+    auto bptr = reinterpret_cast<uint64_t*>(ptr);
+    *bptr = byteswap_impl(*bptr);
+}
+
+} // end namespace detail
 } // end namespace protozero
 
 #endif // PROTOZERO_BYTESWAP_HPP

protozero/config.hpp

@@ -35,17 +35,6 @@ documentation.
 # define PROTOZERO_BYTE_ORDER PROTOZERO_LITTLE_ENDIAN
 #endif
 
-// On some ARM machines and depending on compiler settings access to unaligned
-// floating point values will result in a SIGBUS. Do not use the bare pointers
-// in this case.
-#if PROTOZERO_BYTE_ORDER == PROTOZERO_LITTLE_ENDIAN
-# if !defined(__arm__) && !defined(_M_ARM)
-#  ifndef PROTOZERO_DO_NOT_USE_BARE_POINTER
-#   define PROTOZERO_USE_BARE_POINTER_FOR_PACKED_FIXED
-#  endif
-# endif
-#endif
-
 // Check whether __builtin_bswap is available
 #if defined(__GNUC__) || defined(__clang__)
 # define PROTOZERO_USE_BUILTIN_BSWAP