static VALUE method_geometry_intersection(VALUE self, VALUE rhs)
{
VALUE result = Qnil;
RGeo_GeometryData* self_data = RGEO_GEOMETRY_DATA_PTR(self);
const GEOSGeometry* self_geom = self_data->geom;
if (self_geom) {
VALUE factory = self_data->factory;
const GEOSGeometry* rhs_geom = rgeo_convert_to_geos_geometry(factory, rhs, Qnil);
if (rhs_geom) {
result = rgeo_wrap_geos_geometry(factory, GEOSIntersection_r(self_data->geos_context, self_geom, rhs_geom), Qnil);
}
}
return result;
}
int LabelPosition::polygonIntersectionCost( PointSet *polygon ) const
{
if ( !mGeos )
createGeosGeom();
if ( !polygon->mGeos )
polygon->createGeosGeom();
GEOSContextHandle_t geosctxt = geosContext();
int cost = 0;
//check the label center. if covered by polygon, initial cost of 4
if ( polygon->containsPoint(( x[0] + x[2] ) / 2.0, ( y[0] + y[2] ) / 2.0 ) )
cost += 4;
try
{
//calculate proportion of label candidate which is covered by polygon
GEOSGeometry* intersectionGeom = GEOSIntersection_r( geosctxt, mGeos, polygon->mGeos );
if ( !intersectionGeom )
return cost;
double positionArea = 0;
if ( GEOSArea_r( geosctxt, mGeos, &positionArea ) != 1 )
{
GEOSGeom_destroy_r( geosctxt, intersectionGeom );
return cost;
}
double intersectionArea = 0;
if ( GEOSArea_r( geosctxt, intersectionGeom, &intersectionArea ) != 1 )
{
intersectionArea = 0;
}
GEOSGeom_destroy_r( geosctxt, intersectionGeom );
double portionCovered = intersectionArea / positionArea;
cost += ceil( portionCovered * 8.0 ); //cost of 8 if totally covered
return cost;
}
catch ( GEOSException &e )
{
QgsMessageLog::logMessage( QObject::tr( "Exception: %1" ).arg( e.what() ), QObject::tr( "GEOS" ) );
return cost;
}
}
