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#include <mbgl/tile/geojson_tile_source.hpp>
#include <mbgl/tile/geojson_tile.hpp>
#include <mbgl/tile/geometry_tile_data.hpp>
#include <mbgl/util/async_request.hpp>
#include <mapbox/geojsonvt.hpp>
namespace mbgl {
GeoJSONTileSource::GeoJSONTileSource(GeometryTileData& tileData_,
mapbox::geojsonvt::GeoJSONVT* geojsonvt_,
const OverscaledTileID& id)
: GeometryTileSource(tileData_), tileID(id), geojsonvt(geojsonvt_) {
update();
}
GeoJSONTileSource::~GeoJSONTileSource() = default;
// A monitor can have its GeoJSONVT object swapped out (e.g. when loading a new GeoJSON file).
// In that case, we're sending new notifications to all observers.
void GeoJSONTileSource::setGeoJSONVT(mapbox::geojsonvt::GeoJSONVT* vt) {
// Don't duplicate notifications in case of nil changes.
if (geojsonvt != vt) {
geojsonvt = vt;
update();
}
}
// Converts the geojsonvt::Tile to a a GeoJSONTile. They have a differing internal structure.
std::unique_ptr<GeoJSONTile> convertTile(const mapbox::geojsonvt::Tile& tile) {
std::shared_ptr<GeoJSONTileLayer> layer;
if (tile) {
std::vector<std::shared_ptr<const GeoJSONTileFeature>> features;
GeometryCoordinates line;
for (auto& feature : tile.features) {
const FeatureType featureType =
(feature.type == mapbox::geojsonvt::TileFeatureType::Point
? FeatureType::Point
: (feature.type == mapbox::geojsonvt::TileFeatureType::LineString
? FeatureType::LineString
: (feature.type == mapbox::geojsonvt::TileFeatureType::Polygon
? FeatureType::Polygon
: FeatureType::Unknown)));
if (featureType == FeatureType::Unknown) {
continue;
}
GeometryCollection geometry;
// Flatten the geometry; GeoJSONVT distinguishes between a Points array and Rings array
// (Points = GeoJSON types Point, MultiPoint, LineString)
// (Rings = GeoJSON types MultiLineString, Polygon, MultiPolygon)
// However, in Mapbox GL, we use one structure for both types, and just have one outer
// element for Points.
if (feature.tileGeometry.is<mapbox::geojsonvt::TilePoints>()) {
line.clear();
for (auto& point : feature.tileGeometry.get<mapbox::geojsonvt::TilePoints>()) {
line.emplace_back(point.x, point.y);
}
geometry.emplace_back(std::move(line));
} else if (feature.tileGeometry.is<mapbox::geojsonvt::TileRings>()) {
for (auto& ring : feature.tileGeometry.get<mapbox::geojsonvt::TileRings>()) {
line.clear();
for (auto& point : ring) {
line.emplace_back(point.x, point.y);
}
geometry.emplace_back(std::move(line));
}
}
// https://github.com/mapbox/geojson-vt-cpp/issues/44
if (featureType == FeatureType::Polygon) {
geometry = fixupPolygons(geometry);
}
Feature::property_map properties{ feature.tags.begin(), feature.tags.end() };
features.emplace_back(std::make_shared<GeoJSONTileFeature>(
featureType, std::move(geometry), std::move(properties)));
}
layer = std::make_unique<GeoJSONTileLayer>(std::move(features));
}
return std::make_unique<GeoJSONTile>(layer);
}
void GeoJSONTileSource::update() {
if (geojsonvt) {
auto tile = convertTile(
geojsonvt->getTile(tileID.canonical.z, tileID.canonical.x, tileID.canonical.y));
tileData.setData(nullptr, std::move(tile), {}, {});
}
}
} // namespace mbgl
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