OverlapUnion.h

/**********************************************************************
 *
 * GEOS - Geometry Engine Open Source
 * http://geos.osgeo.org
 *
 * Copyright (C) 2011 Sandro Santilli <strk@kbt.io>
 *
 * 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.
 *
 **********************************************************************
 *
 * Last port: ORIGINAL WORK, generalization of CascadedPolygonUnion
 *
 **********************************************************************/
 
#pragma once
 
#include <geos/export.h>
 
#include <vector>
#include <algorithm>
#include <unordered_set>
 
#include <geos/geom/Geometry.h>
#include <geos/operation/union/UnionStrategy.h>
#include <geos/operation/union/CascadedPolygonUnion.h>
 
// Forward declarations
namespace geos {
namespace geom {
class Envelope;
class LineSegment;
}
}
 
namespace geos {
namespace operation { // geos::operation
namespace geounion {  // geos::operation::geounion
 
class GEOS_DLL OverlapUnion {
 
public:
 
    OverlapUnion(const geom::Geometry* p_g0, const geom::Geometry* p_g1, geounion::UnionStrategy* unionFun)
        : g0(p_g0)
        , g1(p_g1)
        , unionFunction(unionFun)
        , geomFactory(p_g0->getFactory())
        , isUnionSafe(false)
        {};
 
    OverlapUnion(const geom::Geometry* p_g0, const geom::Geometry* p_g1)
        : OverlapUnion(p_g0, p_g1, &defaultUnionFunction)
        {};
 
 
    std::unique_ptr<geom::Geometry> doUnion();
 
private:
 
    const geom::Geometry* g0;
    const geom::Geometry* g1;
    geounion::UnionStrategy* unionFunction;
    const geom::GeometryFactory* geomFactory;
    bool isUnionSafe;
 
    geounion::ClassicUnionStrategy defaultUnionFunction;
 
    static geom::Envelope overlapEnvelope(const geom::Geometry* geom0, const geom::Geometry* geom1);
    std::unique_ptr<geom::Geometry> extractByEnvelope(const geom::Envelope& env, const geom::Geometry* geom, std::vector<std::unique_ptr<geom::Geometry>>& disjointGeoms);
    static std::unique_ptr<geom::Geometry> combine(std::unique_ptr<geom::Geometry>& unionGeom, std::vector<std::unique_ptr<geom::Geometry>>& disjointPolys);
    std::unique_ptr<geom::Geometry> unionFull(const geom::Geometry* geom0, const geom::Geometry* geom1);
    static std::unique_ptr<geom::Geometry> unionBuffer(const geom::Geometry* geom0, const geom::Geometry* geom1);
    bool isBorderSegmentsSame(const geom::Geometry* result, const geom::Envelope& env);
    static bool isEqual(std::vector<geom::LineSegment>& segs0, std::vector<geom::LineSegment>& segs1);
    std::vector<geom::LineSegment> extractBorderSegments(const geom::Geometry* geom0, const geom::Geometry* geom1, const geom::Envelope& env);
    void extractBorderSegments(const geom::Geometry* geom, const geom::Envelope& penv, std::vector<geom::LineSegment>& psegs);
 
};
 
} // namespace geos::operation::union
} // namespace geos::operation
} // namespace geos