From b68c19042ba4720cf6a5c272812d4f90725268d7 Mon Sep 17 00:00:00 2001
From: Eric Fischer <enf@pobox.com>
Date: Fri, 24 Aug 2018 16:19:47 -0700
Subject: [PATCH] Fix elevation inconsistencies

---
 geometry.cpp   |  2 ++
 mvt.cpp        | 10 +++++-----
 write_json.cpp |  2 +-
 3 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/geometry.cpp b/geometry.cpp
index f240fd2..691f8cf 100644
--- a/geometry.cpp
+++ b/geometry.cpp
@@ -1145,6 +1145,7 @@ static int clip(double *x0, double *y0, double *x1, double *y1, double xmin, dou
 				y = *y0 + (*y1 - *y0) * (xmax - *x0) / (*x1 - *x0);
 				x = xmax;
 
+				e.resize(0);
 				for (size_t i = 0; i < e0->size() && i < e1->size(); i++) {
 					e.push_back((*e0)[i] + ((*e1)[i] - (*e0)[i]) * (xmax - *x0) / (*x1 - *x0));
 				}
@@ -1152,6 +1153,7 @@ static int clip(double *x0, double *y0, double *x1, double *y1, double xmin, dou
 				y = *y0 + (*y1 - *y0) * (xmin - *x0) / (*x1 - *x0);
 				x = xmin;
 
+				e.resize(0);
 				for (size_t i = 0; i < e0->size() && i < e1->size(); i++) {
 					e.push_back((*e0)[i] + ((*e1)[i] - (*e0)[i]) * (xmin - *x0) / (*x1 - *x0));
 				}
diff --git a/mvt.cpp b/mvt.cpp
index c74f983..1d30215 100644
--- a/mvt.cpp
+++ b/mvt.cpp
@@ -314,7 +314,7 @@ bool mvt_tile::decode(std::string &message, bool &was_compressed) {
 					protozero::pbf_reader feature_reader(layer_reader.get_message());
 					mvt_feature feature;
 					std::vector<uint32_t> geoms;
-					size_t dimensions = 2;
+					size_t dimensions = 0;
 					std::vector<double> elevations;
 
 					while (feature_reader.next()) {
@@ -391,7 +391,7 @@ bool mvt_tile::decode(std::string &message, bool &was_compressed) {
 
 								mvt_geometry decoded = mvt_geometry(op, px, py);
 
-								for (size_t i = 2; i < dimensions; i++) {
+								for (size_t i = 0; i < dimensions; i++) {
 									if (elevation_index < elevations.size()) {
 										decoded.elevations.push_back(elevations[elevation_index]);
 										elevation_index++;
@@ -515,7 +515,7 @@ std::string mvt_tile::encode() {
 		for (size_t f = 0; f < layers[i].features.size(); f++) {
 			std::string feature_string;
 			protozero::pbf_writer feature_writer(feature_string);
-			size_t dimensions = 2;
+			size_t dimensions = 0;
 
 			feature_writer.add_enum(3, layers[i].features[f].type);
 			feature_writer.add_packed_uint32(2, std::begin(layers[i].features[f].tags), std::end(layers[i].features[f].tags));
@@ -562,7 +562,7 @@ std::string mvt_tile::encode() {
 					py = wwy;
 					length++;
 
-					if (geom[g].elevations.size() + 2 > dimensions) {
+					if (geom[g].elevations.size() > dimensions) {
 						dimensions = geom[g].elevations.size();
 					}
 				} else if (op == mvt_closepath) {
@@ -579,7 +579,7 @@ std::string mvt_tile::encode() {
 
 			feature_writer.add_packed_uint32(4, std::begin(geometry), std::end(geometry));
 
-			if (dimensions > 2) {
+			if (dimensions > 0) {
 				std::vector<double> elevations;
 
 				for (size_t g = 0; g < geom.size(); g++) {
diff --git a/write_json.cpp b/write_json.cpp
index d6504bc..f2f2583 100644
--- a/write_json.cpp
+++ b/write_json.cpp
@@ -379,7 +379,7 @@ void write_coordinates(json_writer &state, lonlat const &p) {
 	state.json_write_float(p.lat);
 
 	for (size_t i = 0; i < p.elevations.size(); i++) {
-		state.json_write_number(p.elevations[i]);
+		state.json_write_float(p.elevations[i]);
 	}
 
 	state.json_end_array();