MinimumBoundingCircle.h

/**********************************************************************
 *
 * GEOS - Geometry Engine Open Source
 * http://geos.osgeo.org
 *
 * Copyright (C) 2019 Paul Ramsey <pramsey@cleverelephant.ca>
 *
 * 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/MinimumBoundingCircle.java 2019-01-23
 *
 **********************************************************************/
 
#pragma once
 
#include <geos/export.h>
#include <geos/geom/Coordinate.h>
#include <geos/geom/CoordinateSequence.h>
#include <geos/geom/Geometry.h>
#include <geos/geom/Point.h>
#include <geos/geom/Triangle.h>
 
#include <vector>
 
// Forward declarations
// namespace geos {
//      namespace geom {
//              class GeometryCollection;
//      }
// }
 
 
namespace geos {
namespace algorithm { // geos::algorithm
 
class GEOS_DLL MinimumBoundingCircle {
 
private:
 
    // member variables
    const geom::Geometry* input;
    std::vector<geom::CoordinateXY> extremalPts;
    geom::CoordinateXY centre;
    double radius;
 
    void computeCentre();
    void compute();
    void computeCirclePoints();
    geom::CoordinateXY lowestPoint(std::vector<geom::CoordinateXY>& pts);
    geom::CoordinateXY pointWitMinAngleWithX(std::vector<geom::CoordinateXY>& pts, geom::CoordinateXY& P);
    geom::CoordinateXY pointWithMinAngleWithSegment(std::vector<geom::CoordinateXY>& pts,
            geom::CoordinateXY& P, geom::CoordinateXY& Q);
    std::vector<geom::CoordinateXY> farthestPoints(std::vector<geom::CoordinateXY>& pts);
 
 
public:
 
    MinimumBoundingCircle(const geom::Geometry* geom):
        input(nullptr),
        radius(0.0)
    {
        input = geom;
        centre.setNull();
    }
 
    ~MinimumBoundingCircle() {};
 
    std::unique_ptr<geom::Geometry> getCircle();
 
    std::unique_ptr<geom::Geometry> getMaximumDiameter();
 
    std::unique_ptr<geom::Geometry> getDiameter();
 
    std::vector<geom::CoordinateXY> getExtremalPoints();
 
    geom::CoordinateXY getCentre();
 
    double getRadius();
 
};
 
} // namespace geos::algorithm
} // namespace geos