LineIntersector.h

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/**********************************************************************
 *
 * 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/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);

    LineIntersector(const geom::PrecisionModel* initialPrecisionModel = nullptr)
        :
        precisionModel(initialPrecisionModel),
        result(0),
        isProperVar(false)
    {}

    ~LineIntersector() {}

    bool isInteriorIntersection();

    bool isInteriorIntersection(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;
    }

    size_t
    getIntersectionNum() const
    {
        return result;
    }


    const geom::Coordinate&
    getIntersection(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(size_t segmentIndex, size_t intIndex);

    size_t getIndexAlongSegment(size_t segmentIndex, size_t intIndex);

    double getEdgeDistance(size_t geomIndex, size_t intIndex) const;

private:

    const geom::PrecisionModel* precisionModel;

    size_t result;

    const geom::Coordinate* inputLines[2][2];

    geom::Coordinate intPt[2];

    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(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


#endif // GEOS_ALGORITHM_LINEINTERSECTOR_H