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
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
|
#include <mbgl/style/expression/distance.hpp>
#include <mapbox/geojson.hpp>
#include <mapbox/geometry.hpp>
#include <mapbox/cheap_ruler.hpp>
#include <mbgl/style/conversion/json.hpp>
#include <mbgl/tile/geometry_tile_data.hpp>
#include <mbgl/util/logging.hpp>
#include <mbgl/util/string.hpp>
#include <mbgl/util/geometry_distance.hpp>
#include <rapidjson/document.h>
namespace mbgl {
namespace {
//
////Returns the distance between a point P on a segment AB.
//double distanceToLineSegment(const mapbox::geometry::point<double>& p, const mapbox::geometry::point<double>& a,const mapbox::geometry::point<double>& b) {
// mapbox::geometry::point<double> vectorAB{(b.x - a.x), (b.y - a.y)};
// mapbox::geometry::point<double> vectorAP{(p.x - a.x), (p.y - a.y)};
// const auto dotProduct = [](const mapbox::geometry::point<double>& v,const mapbox::geometry::point<double>& w) {
// return v.x * w.x + v.y * w.y;
// };
//
// mapbox::cheap_ruler::CheapRuler ruler(p.y, mapbox::cheap_ruler::CheapRuler::Unit::Meters);
// // dotProduct equals to |vectorAB| * |vectorAP| * cos();
// const double dot1 = dotProduct(vectorAB, vectorAP);
// if (dot1 < 0) return ruler.distance(p, a);
//
// const double dot2 = dotProduct(vectorAB, vectorAB);
// if (dot1 >= dot2) return ruler.distance(p, b);
//
// const double ratio = dot1 / dot2;
// const mapbox::geometry::point<double> pointOnAB = {(a.x + vectorAB.x * ratio), (a.y + vectorAB.y * ratio)};
// return ruler.distance(p, pointOnAB);
//}
//
//double distanceToLineInMeters(const mapbox::geometry::point<double>& point, const mapbox::geometry::line_string<double>& line){
// double ret = std::numeric_limits<double>::infinity();
// for (size_t i = 0; i < line.size() - 1; ++i){
// ret = std::min(ret, distanceToLineSegment(point, line[i], line[i+1]));
// }
// return ret;
//}
//
//double distanceToLinesInMeters(const mapbox::geometry::point<double>& point, const mapbox::geometry::multi_line_string<double>& lines){
// double ret = std::numeric_limits<double>::infinity();
// for (const auto& line: lines) {
// ret = std::min(ret, distanceToLineInMeters(point, line));
// }
// return ret;
//}
double calculateDistance(const mbgl::GeometryTileFeature& feature,
const mbgl::CanonicalTileID& canonical,
const Feature::geometry_type& geoSet) {
return convertGeometry(feature, canonical).match(
[&geoSet](const mapbox::geometry::point<double>& point) -> double {
mapbox::cheap_ruler::CheapRuler ruler(point.y, mapbox::cheap_ruler::CheapRuler::Unit::Meters);
return geoSet.match(
[&point, &ruler](const mapbox::geometry::point<double>& point2) {
return ruler.distance(point, point2);
},
[&point, &ruler](const mapbox::geometry::multi_point<double>& points) {
double ret = std::numeric_limits<double>::infinity();
for (size_t i = 0; i < points.size() - 1; ++i){
ret = std::min(ret, ruler.distance(point, points[i]));
}
return ret;
},
[&point, &ruler](const mapbox::geometry::line_string<double>& line) {
double ret = std::numeric_limits<double>::infinity();
for (size_t i = 0; i < line.size() - 1; ++i){
ret = std::min(ret, ruler.distanceToLineSegment(point, line[i], line[i+1]));
}
return ret;
},
[&point,&ruler](const mapbox::geometry::multi_line_string<double>& lines) {
double ret = std::numeric_limits<double>::infinity();
for (const auto& line: lines) {
for (size_t i = 0; i < line.size() - 1; ++i){
ret = std::min(ret, ruler.distanceToLineSegment(point, line[i], line[i+1]));
}
}
return ret;
},
[](const auto&) -> double { return -1.0; });
},
[](const auto&) -> double { return -1.0; });
}
optional<mbgl::GeoJSON> parseValue(const mbgl::style::conversion::Convertible& value_,
mbgl::style::expression::ParsingContext& ctx) {
if (isObject(value_)) {
mbgl::style::conversion::Error error;
auto geojson = toGeoJSON(value_, error);
if (geojson && error.message.empty()) {
return geojson;
}
ctx.error(error.message);
}
ctx.error("'distance' expression requires valid geojson source that contains polygon geometry type.");
return nullopt;
}
optional<Feature::geometry_type> getGeometry(const Feature& feature, mbgl::style::expression::ParsingContext& ctx) {
const auto type = apply_visitor(ToFeatureType(), feature.geometry);
if (type == FeatureType::Point || type == FeatureType::LineString) {
return feature.geometry;
}
ctx.error("'distance' expression requires valid geojson source that contains Point/LineString geometry type.");
return nullopt;
}
} // namespace
namespace style {
namespace expression {
Distance::Distance(GeoJSON geojson, Feature::geometry_type geometries_)
: Expression(Kind::Distance, type::Number),
geoJSONSource(std::move(geojson)),
geometries(std::move(geometries_)){}
Distance::~Distance() = default;
using namespace mbgl::style::conversion;
EvaluationResult Distance::evaluate(const EvaluationContext& params) const {
if (!params.feature || !params.canonical) {
return -1.0;
}
auto geometryType = params.feature->getType();
// Currently only support Point/Points distance to LineString
if (geometryType == FeatureType::Point) {
auto distance = calculateDistance(*params.feature, *params.canonical, geometries);
return distance;
}
mbgl::Log::Warning(mbgl::Event::General,
"distance expression currently only support feature with Point geometry.");
return -1.0;
}
ParseResult Distance::parse(const Convertible& value, ParsingContext& ctx) {
if (isArray(value)) {
// object value, quoted with ["Distance", value]
if (arrayLength(value) != 2) {
ctx.error("'distance' 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 parsedValue->match(
[&parsedValue, &ctx](const mapbox::geometry::geometry<double>& geometrySet) {
if (auto ret = getGeometry(mbgl::Feature(geometrySet), ctx)) {
return ParseResult(std::make_unique<Distance>(*parsedValue, std::move(*ret)));
}
return ParseResult();
},
[&parsedValue, &ctx](const mapbox::feature::feature<double>& feature) {
if (auto ret = getGeometry(mbgl::Feature(feature), ctx)) {
return ParseResult(std::make_unique<Distance>(*parsedValue, std::move(*ret)));
}
return ParseResult();
},
[&parsedValue, &ctx](const mapbox::feature::feature_collection<double>& features) {
for (const auto& feature : features) {
if (auto ret = getGeometry(mbgl::Feature(feature), ctx)) {
return ParseResult(std::make_unique<Distance>(*parsedValue, std::move(*ret)));
}
}
return ParseResult();
},
[&ctx](const auto&) {
ctx.error("'distance' expression requires valid geojson that contains LineString/Point geometries.");
return ParseResult();
});
}
ctx.error("'distance' expression needs to be an array with exactly one argument.");
return ParseResult();
}
Value convertValue(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(convertValue(m));
}
return result;
}
if (v.IsObject()) {
std::unordered_map<std::string, Value> result;
for (const auto& m : v.GetObject()) {
result.emplace(m.name.GetString(), convertValue(m.value));
}
return result;
}
// Ignore other types as valid geojson only contains above types.
return Null;
}
mbgl::Value Distance::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(), convertValue(m.value));
}
} else {
mbgl::Log::Error(mbgl::Event::General,
"Failed to serialize 'distance' expression, converted rapidJSON is not an object");
}
return std::vector<mbgl::Value>{{getOperator(), *fromExpressionValue<mbgl::Value>(serialized)}};
}
bool Distance::operator==(const Expression& e) const {
if (e.getKind() == Kind::Distance) {
auto rhs = static_cast<const Distance*>(&e);
return geoJSONSource == rhs->geoJSONSource && geometries == rhs->geometries;
}
return false;
}
std::vector<optional<Value>> Distance::possibleOutputs() const {
return { nullopt };
}
std::string Distance::getOperator() const {
return "distance";
}
} // namespace expression
} // namespace style
} // namespace mbgl
|
