g/PolygonBuilder.h

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/**********************************************************************
 *
 * 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.
 *
 **********************************************************************/

#pragma once

#include <geos/export.h>

#include <geos/geom/Polygon.h>
#include <geos/operation/overlayng/OverlayEdge.h>
#include <geos/operation/overlayng/OverlayEdgeRing.h>
#include <geos/operation/overlayng/MaximalEdgeRing.h>

#include <vector>


// Forward declarations
namespace geos {
namespace geom {
class GeometryFactory;
class Geometry;
class Polygon;
}
namespace operation {
namespace overlayng {
class Edge;
}
}
}

namespace geos {      // geos.
namespace operation { // geos.operation
namespace overlayng { // geos.operation.overlayng

class GEOS_DLL PolygonBuilder {

private:

    // Members
    const geom::GeometryFactory* geometryFactory;
    std::vector<OverlayEdgeRing*> shellList;
    std::vector<OverlayEdgeRing*> freeHoleList;
    bool isEnforcePolygonal;

    // Storage
    std::vector<std::unique_ptr<OverlayEdgeRing>> vecOER;

    std::vector<std::unique_ptr<geom::Polygon>> computePolygons(std::vector<OverlayEdgeRing*> shellList);

    void buildRings(std::vector<OverlayEdge*>& resultAreaEdges);

    void linkResultAreaEdgesMax(std::vector<OverlayEdge*>& resultEdges);

    std::vector<std::unique_ptr<MaximalEdgeRing>>
        buildMaximalRings(std::vector<OverlayEdge*>& edges);

    std::vector<OverlayEdgeRing*> storeMinimalRings(std::vector<std::unique_ptr<OverlayEdgeRing>>& minRings);

    void buildMinimalRings(std::vector<std::unique_ptr<MaximalEdgeRing>>& maxRings);

    void assignShellsAndHoles(std::vector<OverlayEdgeRing*>& minRings);

    OverlayEdgeRing* findSingleShell(std::vector<OverlayEdgeRing*>& edgeRings) const;

    void assignHoles(OverlayEdgeRing* shell, std::vector<OverlayEdgeRing*>& edgeRings);


    void placeFreeHoles(std::vector<OverlayEdgeRing*> shellList, std::vector<OverlayEdgeRing*> freeHoleList);



public:

    PolygonBuilder(std::vector<OverlayEdge*>& resultAreaEdges, const geom::GeometryFactory* geomFact)
        : geometryFactory(geomFact)
        , isEnforcePolygonal(true)
    {
        buildRings(resultAreaEdges);
    }

    PolygonBuilder(std::vector<OverlayEdge*>& resultAreaEdges, const geom::GeometryFactory* geomFact, bool p_isEnforcePolygonal)
        : geometryFactory(geomFact)
        , isEnforcePolygonal(p_isEnforcePolygonal)
    {
        buildRings(resultAreaEdges);
    }

    PolygonBuilder(const PolygonBuilder&) = delete;
    PolygonBuilder& operator=(const PolygonBuilder&) = delete;

    // Methods
    std::vector<std::unique_ptr<geom::Polygon>> getPolygons();
    std::vector<OverlayEdgeRing*> getShellRings();


};


} // namespace geos.operation.overlayng
} // namespace geos.operation
} // namespace geos