LineIntersector.h

/**********************************************************************
 *
 * GEOS - Geometry Engine Open Source
 * http://geos.osgeo.org
 *
 * Copyright (C) 2005-2006 Refractions Research Inc.
 * Copyright (C) 2001-2002 Vivid Solutions Inc.
 *
 * 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: algorithm/RobustLineIntersector.java r785 (JTS-1.13+)
 *
 **********************************************************************/
 
#ifndef GEOS_ALGORITHM_LINEINTERSECTOR_H
#define GEOS_ALGORITHM_LINEINTERSECTOR_H
 
#include <geos/inline.h>
#include <geos/export.h>
#include <string>
 
#include <geos/geom/Coordinate.h>
 
// Forward declarations
namespace geos {
namespace geom {
class PrecisionModel;
}
}
 
namespace geos {
namespace algorithm { // geos::algorithm
 
class GEOS_DLL LineIntersector {
public:
 
    static double interpolateZ(const geom::Coordinate& p, const geom::Coordinate& p0, const geom::Coordinate& p1);
 
 
    static double computeEdgeDistance(const geom::Coordinate& p, const geom::Coordinate& p0, const geom::Coordinate& p1);
 
    static double nonRobustComputeEdgeDistance(const geom::Coordinate& p, const geom::Coordinate& p1,
            const geom::Coordinate& p2);
 
    explicit LineIntersector(const geom::PrecisionModel* initialPrecisionModel = nullptr)
        :
        precisionModel(initialPrecisionModel),
        result(0),
        isProperVar(false)
    {}
 
    ~LineIntersector() = default;
 
    bool isInteriorIntersection();
 
    bool isInteriorIntersection(std::size_t inputLineIndex);
 
    void
    setPrecisionModel(const geom::PrecisionModel* newPM)
    {
        precisionModel = newPM;
    }
 
    void computeIntersection(const geom::Coordinate& p, const geom::Coordinate& p1, const geom::Coordinate& p2);
 
    static bool hasIntersection(const geom::Coordinate& p, const geom::Coordinate& p1, const geom::Coordinate& p2);
 
    enum intersection_type : uint8_t {
        NO_INTERSECTION = 0,
 
        POINT_INTERSECTION = 1,
 
        COLLINEAR_INTERSECTION = 2
    };
 
    void computeIntersection(const geom::Coordinate& p1, const geom::Coordinate& p2,
                             const geom::Coordinate& p3, const geom::Coordinate& p4);
 
    std::string toString() const;
 
    bool
    hasIntersection() const
    {
        return result != NO_INTERSECTION;
    }
 
 
    const geom::Coordinate*
    getEndpoint(std::size_t segmentIndex, std::size_t ptIndex) const
    {
        return inputLines[segmentIndex][ptIndex];
    }
 
    size_t
    getIntersectionNum() const
    {
        return result;
    }
 
 
    const geom::Coordinate&
    getIntersection(std::size_t intIndex) const
    {
        return intPt[intIndex];
    }
 
    static bool isSameSignAndNonZero(double a, double b);
 
    bool isIntersection(const geom::Coordinate& pt) const;
 
    bool
    isProper() const
    {
        return hasIntersection() && isProperVar;
    }
 
    const geom::Coordinate& getIntersectionAlongSegment(std::size_t segmentIndex, std::size_t intIndex);
 
    std::size_t getIndexAlongSegment(std::size_t segmentIndex, std::size_t intIndex);
 
    double getEdgeDistance(std::size_t geomIndex, std::size_t intIndex) const;
 
private:
 
    const geom::PrecisionModel* precisionModel;
 
    std::size_t result;
 
    const geom::Coordinate* inputLines[2][2];
 
    geom::Coordinate intPt[2];
 
    std::size_t intLineIndex[2][2];
 
    bool isProperVar;
    //Coordinate &pa;
    //Coordinate &pb;
 
    bool
    isCollinear() const
    {
        return result == COLLINEAR_INTERSECTION;
    }
 
    uint8_t computeIntersect(const geom::Coordinate& p1, const geom::Coordinate& p2,
                             const geom::Coordinate& q1, const geom::Coordinate& q2);
 
    bool
    isEndPoint() const
    {
        return hasIntersection() && !isProperVar;
    }
 
    void computeIntLineIndex();
 
    void computeIntLineIndex(std::size_t segmentIndex);
 
    uint8_t computeCollinearIntersection(const geom::Coordinate& p1, const geom::Coordinate& p2,
                                         const geom::Coordinate& q1, const geom::Coordinate& q2);
 
    geom::Coordinate intersection(const geom::Coordinate& p1,
                                  const geom::Coordinate& p2,
                                  const geom::Coordinate& q1,
                                  const geom::Coordinate& q2) const;
 
    bool isInSegmentEnvelopes(const geom::Coordinate& intPt) const;
 
 
    geom::Coordinate intersectionSafe(const geom::Coordinate& p1, const geom::Coordinate& p2,
                                      const geom::Coordinate& q1, const geom::Coordinate& q2) const;
 
    static geom::Coordinate nearestEndpoint(const geom::Coordinate& p1,
                                            const geom::Coordinate& p2,
                                            const geom::Coordinate& q1,
                                            const geom::Coordinate& q2);
 
    static double zGet(const geom::Coordinate& p, const geom::Coordinate& q);
 
    static double zGetOrInterpolate(const geom::Coordinate& p,
                                    const geom::Coordinate& p0,
                                    const geom::Coordinate& p1);
 
    static geom::Coordinate zGetOrInterpolateCopy(const geom::Coordinate& p,
                                                  const geom::Coordinate& p0,
                                                  const geom::Coordinate& p1);
 
    static double zInterpolate(const geom::Coordinate& p,
                               const geom::Coordinate& p0,
                               const geom::Coordinate& p1);
 
    static double zInterpolate(const geom::Coordinate& p,
                               const geom::Coordinate& p1,
                               const geom::Coordinate& p2,
                               const geom::Coordinate& q1,
                               const geom::Coordinate& q2);
 
};
 
 
} // namespace geos::algorithm
} // namespace geos
 
#ifdef GEOS_INLINE
# include "geos/algorithm/LineIntersector.inl"
#endif
 
#endif // GEOS_ALGORITHM_LINEINTERSECTOR_H