static bool parseGeoJSONPolygonCoordinates(const vector<BSONElement>& coordinates,
const BSONObj &sourceObject,
S2Polygon *out) {
const vector<BSONElement>& exteriorRing = coordinates[0].Array();
vector<S2Point> exteriorVertices;
if (!parsePoints(exteriorRing, &exteriorVertices)) { return false; }
eraseDuplicatePoints(&exteriorVertices);
// The last point is duplicated. We drop it, since S2Loop expects no
// duplicate points
exteriorVertices.resize(exteriorVertices.size() - 1);
// S2 Polygon loops must have 3 vertices
if (exteriorVertices.size() < 3) { return false; }
S2PolygonBuilderOptions polyOptions;
polyOptions.set_validate(true);
// Don't silently eliminate duplicate edges.
polyOptions.set_xor_edges(false);
S2PolygonBuilder polyBuilder(polyOptions);
S2Loop exteriorLoop(exteriorVertices);
exteriorLoop.Normalize();
if (exteriorLoop.is_hole()) {
exteriorLoop.Invert();
}
if (!exteriorLoop.IsValid()) { return false; }
polyBuilder.AddLoop(&exteriorLoop);
// Subsequent arrays of coordinates are interior rings/holes.
for (size_t i = 1; i < coordinates.size(); ++i) {
vector<S2Point> holePoints;
if (!parsePoints(coordinates[i].Array(), &holePoints)) { return false; }
eraseDuplicatePoints(&holePoints);
// Drop the duplicated last point.
holePoints.resize(holePoints.size() - 1);
// S2 Polygon loops must have 3 vertices
if (holePoints.size() < 3) { return false; }
// Interior rings are clockwise.
S2Loop holeLoop(holePoints);
holeLoop.Normalize();
if (!holeLoop.IsValid()) { return false; }
if (!holeLoop.is_hole()) {
if (!exteriorLoop.Contains(&holeLoop)) { return false; }
holeLoop.Invert();
} else {
// It's already clockwise; we need to invert once to check that it's contained in
// the shell, then invert again.
holeLoop.Invert();
if (!exteriorLoop.Contains(&holeLoop)) { return false; }
holeLoop.Invert();
}
polyBuilder.AddLoop(&holeLoop);
}
return polyBuilder.AssemblePolygon(out, NULL);
}
void GeoParser::parseGeoJSONPolygon(const BSONObj& obj, S2Polygon* out) {
const vector<BSONElement>& coordinates =
obj.getFieldDotted(GEOJSON_COORDINATES).Array();
const vector<BSONElement>& exteriorRing = coordinates[0].Array();
vector<S2Point> exteriorVertices;
parsePoints(exteriorRing, &exteriorVertices);
// The last point is duplicated. We drop it, since S2Loop expects no
// duplicate points
exteriorVertices.resize(exteriorVertices.size() - 1);
S2PolygonBuilderOptions polyOptions;
polyOptions.set_validate(true);
// Don't silently eliminate duplicate edges.
polyOptions.set_xor_edges(false);
S2PolygonBuilder polyBuilder(polyOptions);
S2Loop exteriorLoop(exteriorVertices);
exteriorLoop.Normalize();
if (exteriorLoop.is_hole()) {
exteriorLoop.Invert();
}
uassert(16693, "Exterior shell of polygon is invalid: " + obj.toString(),
exteriorLoop.IsValid());
polyBuilder.AddLoop(&exteriorLoop);
// Subsequent arrays of coordinates are interior rings/holes.
for (size_t i = 1; i < coordinates.size(); ++i) {
vector<S2Point> holePoints;
parsePoints(coordinates[i].Array(), &holePoints);
// Drop the duplicated last point.
holePoints.resize(holePoints.size() - 1);
// Interior rings are clockwise.
S2Loop holeLoop(holePoints);
holeLoop.Normalize();
uassert(16694, "Interior hole of polygon is invalid: " + obj.toString(),
holeLoop.IsValid());
if (!holeLoop.is_hole()) {
holeLoop.Invert();
}
polyBuilder.AddLoop(&holeLoop);
}
uassert(16695, "Couldn't assemble polygon: " + obj.toString(),
polyBuilder.AssemblePolygon(out, NULL));
}