MinimumDiameter.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/MinimumDiameter.java r966
 *
 **********************************************************************/

#ifndef GEOS_ALGORITHM_MINIMUMDIAMETER_H
#define GEOS_ALGORITHM_MINIMUMDIAMETER_H

#include <geos/geom/Coordinate.h>
#include <geos/geom/LineSegment.h>

#include <memory>
#include <geos/export.h>

// Forward declarations
namespace geos {
namespace geom {
class Geometry;
class LineString;
class CoordinateSequence;
}
}


namespace geos {
namespace algorithm { // geos::algorithm

class GEOS_DLL MinimumDiameter {
private:
    const geom::Geometry* inputGeom;
    bool isConvex;

    std::unique_ptr<geom::CoordinateSequence> convexHullPts;

    geom::LineSegment minBaseSeg;
    geom::Coordinate minWidthPt;
    size_t minPtIndex;
    double minWidth;
    void computeMinimumDiameter();
    void computeWidthConvex(const geom::Geometry* geom);

    void computeConvexRingMinDiameter(const geom::CoordinateSequence* pts);

    unsigned int findMaxPerpDistance(const geom::CoordinateSequence* pts,
                                     const geom::LineSegment* seg, unsigned int startIndex);

    static unsigned int getNextIndex(const geom::CoordinateSequence* pts,
                                     unsigned int index);

    static double computeC(double a, double b, const geom::Coordinate& p);

    static geom::LineSegment computeSegmentForLine(double a, double b, double c);

public:
    ~MinimumDiameter() = default;

    MinimumDiameter(const geom::Geometry* newInputGeom);

    MinimumDiameter(const geom::Geometry* newInputGeom,
                    const bool newIsConvex);

    double getLength();

    const geom::Coordinate& getWidthCoordinate();

    std::unique_ptr<geom::LineString> getSupportingSegment();

    std::unique_ptr<geom::LineString> getDiameter();

    std::unique_ptr<geom::Geometry> getMinimumRectangle();

    static std::unique_ptr<geom::Geometry> getMinimumRectangle(geom::Geometry* geom);

    static std::unique_ptr<geom::Geometry> getMinimumDiameter(geom::Geometry* geom);

};

} // namespace geos::algorithm
} // namespace geos

#endif // GEOS_ALGORITHM_MINIMUMDIAMETER_H