This repository has been archived by the owner on Aug 8, 2023. It is now read-only.
-
Notifications
You must be signed in to change notification settings - Fork 1.3k
/
geometry_tile_data.cpp
193 lines (158 loc) · 5.78 KB
/
geometry_tile_data.cpp
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
#include <mbgl/tile/geometry_tile_data.hpp>
#include <mbgl/tile/tile_id.hpp>
#include <mapbox/geometry/wagyu/wagyu.hpp>
namespace mbgl {
static double signedArea(const GeometryCoordinates& ring) {
double sum = 0;
for (std::size_t i = 0, len = ring.size(), j = len - 1; i < len; j = i++) {
const GeometryCoordinate& p1 = ring[i];
const GeometryCoordinate& p2 = ring[j];
sum += (p2.x - p1.x) * (p1.y + p2.y);
}
return sum;
}
static LinearRing<int32_t> toWagyuPath(const GeometryCoordinates& ring) {
LinearRing<int32_t> result;
result.reserve(ring.size());
for (const auto& p : ring) {
result.emplace_back(p.x, p.y);
}
return result;
}
static GeometryCollection toGeometryCollection(MultiPolygon<int16_t>&& multipolygon) {
GeometryCollection result;
for (auto& polygon : multipolygon) {
for (auto& ring : polygon) {
result.emplace_back(std::move(ring));
}
}
return result;
}
GeometryCollection fixupPolygons(const GeometryCollection& rings) {
using namespace mapbox::geometry::wagyu;
wagyu<int32_t> clipper;
for (const auto& ring : rings) {
clipper.add_ring(toWagyuPath(ring));
}
MultiPolygon<int16_t> multipolygon;
clipper.execute(clip_type_union, multipolygon, fill_type_even_odd, fill_type_even_odd);
return toGeometryCollection(std::move(multipolygon));
}
std::vector<GeometryCollection> classifyRings(const GeometryCollection& rings) {
std::vector<GeometryCollection> polygons;
std::size_t len = rings.size();
if (len <= 1) {
polygons.emplace_back(rings.clone());
return polygons;
}
GeometryCollection polygon;
int8_t ccw = 0;
for (const auto& ring : rings) {
double area = signedArea(ring);
if (area == 0) continue;
if (ccw == 0) {
ccw = (area < 0 ? -1 : 1);
}
if (ccw == (area < 0 ? -1 : 1) && !polygon.empty()) {
polygons.emplace_back(std::move(polygon));
polygon = GeometryCollection();
}
polygon.emplace_back(ring);
}
if (!polygon.empty()) {
polygons.emplace_back(std::move(polygon));
}
return polygons;
}
void limitHoles(GeometryCollection& polygon, uint32_t maxHoles) {
if (polygon.size() > 1 + maxHoles) {
std::nth_element(polygon.begin() + 1,
polygon.begin() + 1 + maxHoles,
polygon.end(),
[] (const auto& a, const auto& b) {
return std::fabs(signedArea(a)) > std::fabs(signedArea(b));
});
polygon.resize(1 + maxHoles);
}
}
static Feature::geometry_type convertGeometry(const GeometryTileFeature& geometryTileFeature, const CanonicalTileID& tileID) {
const double size = util::EXTENT * std::pow(2, tileID.z);
const double x0 = util::EXTENT * static_cast<double>(tileID.x);
const double y0 = util::EXTENT * static_cast<double>(tileID.y);
auto tileCoordinatesToLatLng = [&] (const Point<int16_t>& p) {
double y2 = 180 - (p.y + y0) * 360 / size;
return Point<double>(
(p.x + x0) * 360 / size - 180,
360.0 / M_PI * std::atan(std::exp(y2 * M_PI / 180)) - 90.0
);
};
const GeometryCollection& geometries = geometryTileFeature.getGeometries();
switch (geometryTileFeature.getType()) {
case FeatureType::Unknown: {
assert(false);
return Point<double>(NAN, NAN);
}
case FeatureType::Point: {
MultiPoint<double> multiPoint;
for (const auto& p : geometries.at(0)) {
multiPoint.push_back(tileCoordinatesToLatLng(p));
}
if (multiPoint.size() == 1) {
return multiPoint[0];
} else {
return multiPoint;
}
}
case FeatureType::LineString: {
MultiLineString<double> multiLineString;
for (const auto& g : geometries) {
LineString<double> lineString;
for (const auto& p : g) {
lineString.push_back(tileCoordinatesToLatLng(p));
}
multiLineString.push_back(std::move(lineString));
}
if (multiLineString.size() == 1) {
return multiLineString[0];
} else {
return multiLineString;
}
}
case FeatureType::Polygon: {
MultiPolygon<double> multiPolygon;
for (const auto& pg : classifyRings(geometries)) {
Polygon<double> polygon;
for (const auto& r : pg) {
LinearRing<double> linearRing;
for (const auto& p : r) {
linearRing.push_back(tileCoordinatesToLatLng(p));
}
polygon.push_back(std::move(linearRing));
}
multiPolygon.push_back(std::move(polygon));
}
if (multiPolygon.size() == 1) {
return multiPolygon[0];
} else {
return multiPolygon;
}
}
}
// Unreachable, but placate GCC.
return Point<double>();
}
Feature convertFeature(const GeometryTileFeature& geometryTileFeature, const CanonicalTileID& tileID) {
Feature feature { convertGeometry(geometryTileFeature, tileID) };
feature.properties = geometryTileFeature.getProperties();
feature.id = geometryTileFeature.getID();
return feature;
}
const PropertyMap& GeometryTileFeature::getProperties() const {
static const PropertyMap dummy;
return dummy;
}
const GeometryCollection& GeometryTileFeature::getGeometries() const {
static const GeometryCollection dummy;
return dummy;
}
} // namespace mbgl