union/CoverageUnion.h

/**********************************************************************
 *
 * GEOS - Geometry Engine Open Source
 * http://geos.osgeo.org
 *
 * Copyright (C) 2019 Daniel Baston <dbaston@gmail.com>
 *
 * 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.
 *
 **********************************************************************/
 
#pragma once
 
#include <geos/geom/LineSegment.h>
#include <geos/geom/Geometry.h>
 
#include <memory>
#include <unordered_set>
 
namespace geos {
    namespace geom {
        class Polygon;
        class LineString;
        class GeometryFactory;
    }
}
 
namespace geos {
namespace operation {
namespace geounion {
 
    class GEOS_DLL CoverageUnion {
    public:
        static std::unique_ptr<geom::Geometry> Union(const geom::Geometry* geom);
 
    private:
        CoverageUnion() = default;
 
        void extractSegments(const geom::Polygon* geom);
        void extractSegments(const geom::Geometry* geom);
        void extractSegments(const geom::LineString* geom);
 
        std::unique_ptr<geom::Geometry> polygonize(const geom::GeometryFactory* gf);
        std::unordered_set<geos::geom::LineSegment, geos::geom::LineSegment::HashCode> segments;
        static constexpr double AREA_PCT_DIFF_TOL = 1e-6;
    };
 
}
}
}