PolygonRing.h

/**********************************************************************
 *
 * GEOS - Geometry Engine Open Source
 * http://geos.osgeo.org
 *
 * Copyright (C) 2021 Paul Ramsey <pramsey@cleverelephant.ca>
 * Copyright (C) 2021 Martin Davis
 *
 * 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/operation/valid/PolygonRingTouch.h>
#include <geos/operation/valid/PolygonRingSelfNode.h>
 
#include <geos/export.h>
 
 
#include <map>
 
// Forward declarations
namespace geos {
namespace geom {
class LinearRing;
}
}
 
namespace geos {      // geos.
namespace operation { // geos.operation
namespace valid {     // geos.operation.valid
 
class GEOS_DLL PolygonRing {
    using CoordinateXY = geos::geom::CoordinateXY;
    using LinearRing = geos::geom::LinearRing;
 
private:
 
    int id = -1;
    PolygonRing* shell = nullptr;
    const LinearRing* ring = nullptr;
 
    PolygonRing* touchSetRoot = nullptr;
 
    std::map<int, PolygonRingTouch> touches;
 
    std::vector<PolygonRingSelfNode> selfNodes;
 
    /* METHODS */
 
    bool isOnlyTouch(const PolygonRing* polyRing, const CoordinateXY& pt) const;
 
    const CoordinateXY* findHoleCycleLocation();
 
    static void init(PolygonRing* root, std::stack<PolygonRingTouch*>& touchStack);
 
    static const CoordinateXY* scanForHoleCycle(const PolygonRingTouch* currentTouch,
        PolygonRing* root,
        std::stack<PolygonRingTouch*>& touchStack);
 
 
    bool isInTouchSet() const
    {
        return touchSetRoot != nullptr;
    };
 
    void setTouchSetRoot(PolygonRing* polyRing)
    {
        touchSetRoot = polyRing;
    };
 
    PolygonRing* getTouchSetRoot() const
    {
        return touchSetRoot;
    };
 
    bool hasTouches() const
    {
        return ! touches.empty();
    };
 
    std::vector<PolygonRingTouch*> getTouches() const;
 
    void addTouch(PolygonRing* polyRing, const CoordinateXY& pt);
 
 
public:
 
    PolygonRing(const LinearRing* p_ring, int p_index, PolygonRing* p_shell)
        : id(p_index)
        , shell(p_shell)
        , ring(p_ring)
        {};
 
    PolygonRing(const LinearRing* p_ring)
        : PolygonRing(p_ring, -1, this)
        {};
 
    static bool isShell(const PolygonRing* polyRing);
 
    static bool addTouch(PolygonRing* ring0, PolygonRing* ring1, const CoordinateXY& pt);
 
    static const CoordinateXY* findHoleCycleLocation(const std::vector<PolygonRing*>& polyRings);
 
    static const CoordinateXY* findInteriorSelfNode(const std::vector<PolygonRing*>& polyRings);
 
    bool isSamePolygon(const PolygonRing* polyRing) const
    {
        return shell == polyRing->shell;
    };
 
    bool isShell() const
    {
        return shell == this;
    };
 
    void addSelfTouch(const CoordinateXY& origin,
        const CoordinateXY* e00, const CoordinateXY* e01,
        const CoordinateXY* e10, const CoordinateXY* e11);
 
    const CoordinateXY* findInteriorSelfNode() const;
 
 
};
 
 
 
} // namespace geos.operation.valid
} // namespace geos.operation
} // namespace geos