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Merge pull request #347 from mapbox/wagyu-quick-clip

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Use Wagyu's quick_clip
This commit is contained in:
Eric Fischer 2017-01-12 14:20:32 -08:00 committed by GitHub
commit a00903ecc6
5 changed files with 166 additions and 108 deletions
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4
CHANGELOG.md
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@ -1,3 +1,7 @@
## 1.16.4
* Use Wagyu's quick_lr_clip() instead of a separate implementation
## 1.16.3
* Upgrade Wagyu to bfbf2893

125
geometry.cpp
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@ -11,6 +11,7 @@
#include <sqlite3.h>
#include <mapbox/geometry.hpp>
#include <mapbox/geometry/wagyu/wagyu.hpp>
#include <mapbox/geometry/wagyu/quick_clip.hpp>
#include "geometry.hpp"
#include "projection.hpp"
#include "serial.hpp"
@ -423,103 +424,13 @@ 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;
@ -529,19 +440,25 @@ 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);
optional_linear_ring<long long> lr = mapbox::geometry::wagyu::quick_clip::quick_lr_clip(ring, bbox);
if (lr) {
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;

137
mapbox/geometry/wagyu/quick_clip.hpp Normal file
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@ -0,0 +1,137 @@
#pragma once
#include <mapbox/geometry/box.hpp>
#include <mapbox/geometry/multi_polygon.hpp>
#include <mapbox/geometry/polygon.hpp>
#include <mapbox/geometry/wagyu/wagyu.hpp>
#include <experimental/optional>
template <typename T>
using optional_linear_ring = std::experimental::optional<mapbox::geometry::linear_ring<T>>;
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>(
static_cast<T>(a.x + static_cast<double>(b.x - a.x) * (box.min.y - a.y) / (b.y - a.y)),
box.min.y);
case 1:
return mapbox::geometry::point<T>(
box.max.x,
static_cast<T>(a.y + static_cast<double>(b.y - a.y) * (box.max.x - a.x) / (b.x - a.x)));
case 2:
return mapbox::geometry::point<T>(
static_cast<T>(a.x + static_cast<double>(b.x - a.x) * (box.max.y - a.y) / (b.y - a.y)),
box.max.y);
default: // case 3
return mapbox::geometry::point<T>(
box.min.x,
static_cast<T>(a.y + static_cast<double>(b.y - a.y) * (box.min.x - a.x) / (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>
optional_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) {
return optional_linear_ring<T>();
}
// Close the ring if the first/last point was outside
if (out[0] != out[out.size() - 1]) {
out.push_back(out[0]);
}
return optional_linear_ring<T>(std::move(out));
}
}
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) {
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) {
clipper.add_ring(*new_lr, polygon_type_subject);
}
}
}
clipper.execute(clip_type_union, result, subject_fill_type, fill_type_even_odd);
return result;
}
}
}
}

6
mapbox/geometry/wagyu/ring_util.hpp
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@ -485,15 +485,15 @@ bool first_is_bottom_point(const_point_ptr<T> btmPt1, const_point_ptr<T> btmPt2)
template <typename T>
point_ptr<T> get_bottom_point(point_ptr<T> pp) {
point_ptr<T> dups = 0;
point_ptr<T> dups = nullptr;
point_ptr<T> p = pp->next;
while (p != pp) {
if (p->y > pp->y) {
pp = p;
dups = 0;
dups = nullptr;
} else if (p->y == pp->y && p->x <= pp->x) {
if (p->x < pp->x) {
dups = 0;
dups = nullptr;
pp = p;
} else {
if (p->next != pp && p->prev != pp) {

2
version.hpp
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@ -1 +1 @@
#define VERSION "tippecanoe v1.16.3\n"
#define VERSION "tippecanoe v1.16.4\n"