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
194
195
196
197
198
199
200
201
202
|
#include <mbgl/style/expression/within.hpp>
#include <mapbox/geojson.hpp>
#include <mapbox/geometry.hpp>
#include <mbgl/style/conversion_impl.hpp>
#include <mbgl/tile/geometry_tile_data.hpp>
#include <mbgl/util/logging.hpp>
#include <mbgl/util/string.hpp>
#include <rapidjson/document.h>
#include <mbgl/style/conversion/json.hpp>
namespace mbgl {
namespace {
class PolygonFeature : public GeometryTileFeature {
public:
const Feature& feature;
mutable optional<GeometryCollection> geometry;
PolygonFeature(const Feature& feature_, const CanonicalTileID& canonical) : feature(feature_) {
geometry = convertGeometry(feature.geometry, canonical);
assert(geometry);
geometry = fixupPolygons(*geometry);
}
FeatureType getType() const override { return FeatureType::Polygon; }
const PropertyMap& getProperties() const override { return feature.properties; }
FeatureIdentifier getID() const override { return feature.id; }
optional<mbgl::Value> getValue(const std::string& /*key*/) const override { return optional<mbgl::Value>(); }
const GeometryCollection& getGeometries() const override {
assert(geometry);
return *geometry;
}
};
bool rayIntersect(const mbgl::Point<double>& p, const mbgl::Point<double>& p1, const mbgl::Point<double>& p2) {
return ((p1.y > p.y) != (p2.y > p.y)) && (p.x < (p2.x - p1.x) * (p.y - p1.y) / (p2.y - p1.y) + p1.x);
}
// ray casting algorithm for detecting if point is in polygon
bool pointWithinPolygon(const mbgl::Point<double>& point, const mapbox::geometry::polygon<double>& polygon) {
bool within = false;
for (auto ring : polygon) {
auto size = ring.size();
// loop through every edge of the ring
for (std::size_t i = 0; i < size - 1; ++i) {
if (rayIntersect(point, ring[i], ring[i + 1])) {
within = !within;
}
}
}
return within;
}
bool pointWithinPolygons(const mbgl::Point<double>& point, const mapbox::geometry::multi_polygon<double>& polygons) {
for (auto polygon : polygons) {
if (pointWithinPolygon(point, polygon)) return true;
}
return false;
}
bool pointsWithinPolygons(const mbgl::GeometryTileFeature& feature,
const mbgl::CanonicalTileID& canonical,
const mbgl::GeoJSON& geoJson) {
return geoJson.match(
[&feature, &canonical](const mapbox::geometry::geometry<double>& geometrySet) -> bool {
mbgl::Feature f(geometrySet);
PolygonFeature polyFeature(f, canonical);
auto refinedGeoSet = convertGeometry(polyFeature, canonical);
return refinedGeoSet.match(
[&feature, &canonical](const mapbox::geometry::multi_polygon<double>& polygons) -> bool {
return convertGeometry(feature, canonical)
.match(
[&polygons](const mapbox::geometry::point<double>& point) -> bool {
return pointWithinPolygons(point, polygons);
},
[&polygons](const mapbox::geometry::multi_point<double>& points) -> bool {
return std::all_of(points.begin(), points.end(), [&polygons](const auto& p) {
return pointWithinPolygons(p, polygons);
});
},
[](const auto&) -> bool { return false; });
},
[&feature, &canonical](const mapbox::geometry::polygon<double>& polygon) -> bool {
return convertGeometry(feature, canonical)
.match(
[&polygon](const mapbox::geometry::point<double>& point) -> bool {
return pointWithinPolygon(point, polygon);
},
[&polygon](const mapbox::geometry::multi_point<double>& points) -> bool {
return std::all_of(points.begin(), points.end(), [&polygon](const auto& p) {
return pointWithinPolygon(p, polygon);
});
},
[](const auto&) -> bool { return false; });
},
[](const auto&) -> bool { return false; });
},
[](const auto&) -> bool { return false; });
}
mbgl::optional<mbgl::GeoJSON> parseValue(const mbgl::style::conversion::Convertible& value_,
mbgl::style::expression::ParsingContext& ctx) {
if (isObject(value_)) {
const auto geometryType = objectMember(value_, "type");
if (geometryType) {
const auto type = toString(*geometryType);
if (type && *type == "Polygon") {
mbgl::style::conversion::Error error;
auto geojson = toGeoJSON(value_, error);
if (geojson && error.message.empty()) {
return geojson;
}
ctx.error(error.message);
}
}
}
ctx.error("'Within' expression requires valid geojson source that contains polygon geometry type.");
return nullopt;
}
} // namespace
namespace style {
namespace expression {
Within::Within(GeoJSON geojson) : Expression(Kind::Within, type::Boolean), geoJSONSource(std::move(geojson)) {}
Within::~Within() = default;
using namespace mbgl::style::conversion;
EvaluationResult Within::evaluate(const EvaluationContext& params) const {
if (!params.feature || !params.canonical) {
return false;
}
auto geometryType = params.feature->getType();
// Currently only support Point/Points in Polygon/Polygons
if (geometryType == FeatureType::Point) {
return pointsWithinPolygons(*params.feature, *params.canonical, geoJSONSource);
}
mbgl::Log::Warning(mbgl::Event::General, "within expression currently only support 'Point' geometry type");
return false;
}
ParseResult Within::parse(const Convertible& value, ParsingContext& ctx) {
if (isArray(value)) {
// object value, quoted with ["within", value]
if (arrayLength(value) != 2) {
ctx.error("'within' expression requires exactly one argument, but found " +
util::toString(arrayLength(value) - 1) + " instead.");
return ParseResult();
}
auto parsedValue = parseValue(arrayMember(value, 1), ctx);
if (!parsedValue) {
return ParseResult();
}
return ParseResult(std::make_unique<Within>(*parsedValue));
}
return ParseResult();
}
Value valueConverter(const mapbox::geojson::rapidjson_value& v) {
if (v.IsDouble()) {
return v.GetDouble();
}
if (v.IsString()) {
return std::string(v.GetString());
}
if (v.IsArray()) {
std::vector<Value> result;
result.reserve(v.Size());
for (const auto& m : v.GetArray()) {
result.push_back(valueConverter(m));
}
return result;
}
// Ignore other types as valid geojson only contains above types.
return Null;
}
mbgl::Value Within::serialize() const {
std::unordered_map<std::string, Value> serialized;
rapidjson::CrtAllocator allocator;
const mapbox::geojson::rapidjson_value value = mapbox::geojson::convert(geoJSONSource, allocator);
if (value.IsObject()) {
for (const auto& m : value.GetObject()) {
serialized.emplace(m.name.GetString(), valueConverter(m.value));
}
} else {
mbgl::Log::Error(mbgl::Event::General,
"Failed to serialize 'within' expression, converted rapidJSON is not an object");
}
return std::vector<mbgl::Value>{{getOperator(), *fromExpressionValue<mbgl::Value>(serialized)}};
}
} // namespace expression
} // namespace style
} // namespace mbgl
|
