geos/src/triangulate/polygon/PolygonTriangulator.cpp

76 lines
1.9 KiB
C++

/**********************************************************************
*
* GEOS - Geometry Engine Open Source
* http://geos.osgeo.org
*
* Copyright (C) 2020 Paul Ramsey <pramsey@cleverelephant.ca>
*
* This is free software; you can redistribute and/or modify it under
* the terms of the GNU Lesser General Public Licence as published
* by the Free Software Foundation.
* See the COPYING file for more information.
*
**********************************************************************/
#include <geos/geom/GeometryFactory.h>
#include <geos/geom/util/PolygonExtracter.h>
#include <geos/triangulate/tri/TriList.h>
#include <geos/triangulate/polygon/PolygonTriangulator.h>
#include <geos/triangulate/polygon/PolygonHoleJoiner.h>
#include <geos/triangulate/polygon/PolygonEarClipper.h>
namespace geos {
namespace triangulate {
namespace polygon {
/* public static */
std::unique_ptr<Geometry>
PolygonTriangulator::triangulate(const Geometry* geom)
{
PolygonTriangulator clipper(geom);
return clipper.compute();
}
/* private */
std::unique_ptr<Geometry>
PolygonTriangulator::compute()
{
// Short circuit empty case
if(inputGeom->isEmpty()) {
auto gf = inputGeom->getFactory();
return gf->createGeometryCollection();
}
std::vector<const Polygon*> polys;
geom::util::PolygonExtracter::getPolygons(*inputGeom, polys);
TriList<Tri> triList;
for (const Polygon* poly : polys) {
// Skip empty component polygons
if (poly->isEmpty())
continue;
triangulatePolygon(poly, triList);
}
return triList.toGeometry(geomFact);
}
/* private */
void
PolygonTriangulator::triangulatePolygon(const Polygon* poly, TriList<Tri>& triList)
{
auto polyShell = PolygonHoleJoiner::join(poly);
PolygonEarClipper::triangulate(*polyShell, triList);
//Tri::validate(triList);
return;
}
} // namespace geos.triangulate.polygon
} // namespace geos.triangulate
} // namespace geos