MinimumDiameter.h

/**********************************************************************
 *
 * GEOS - Geometry Engine Open Source
 * http://geos.osgeo.org
 *
 * Copyright (C) 2023 Paul Ramsey <pramsey@cleverelephant.ca>
 * 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.
 *
 **********************************************************************/
 
#pragma once
 
#include <geos/geom/Coordinate.h>
#include <geos/geom/LineSegment.h>
 
#include <memory>
#include <geos/export.h>
 
// Forward declarations
namespace geos {
namespace geom {
class GeometryFactory;
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;
    std::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);
 
    static std::unique_ptr<geom::Geometry> computeMaximumLine(
                        const geom::CoordinateSequence* pts,
                        const geom::GeometryFactory* factory);
 
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