ConvexHull.h

/**********************************************************************
 *
 * GEOS - Geometry Engine Open Source
 * http://geos.osgeo.org
 *
 * Copyright (C) 2011 Sandro Santilli <strk@keybit.net>
 * 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/ConvexHull.java r407 (JTS-1.12+)
 *
 **********************************************************************/
 
#ifndef GEOS_ALGORITHM_CONVEXHULL_H
#define GEOS_ALGORITHM_CONVEXHULL_H
 
#include <geos/export.h>
#include <vector>
 
// FIXME: avoid using Cordinate:: typedefs to avoid full include
#include <geos/geom/Coordinate.h>
 
#ifdef _MSC_VER
#pragma warning(push)
#pragma warning(disable: 4251) // warning C4251: needs to have dll-interface to be used by clients of class
#endif
 
// Forward declarations
namespace geos {
        namespace geom {
                class Geometry;
                class GeometryFactory;
                class CoordinateSequence;
        }
}
 
namespace geos {
namespace algorithm { // geos::algorithm

class GEOS_DLL ConvexHull {
private:
        const geom::GeometryFactory *geomFactory;
        geom::Coordinate::ConstVect inputPts;
 
        void extractCoordinates(const geom::Geometry *geom);

        geom::CoordinateSequence *toCoordinateSequence(geom::Coordinate::ConstVect &cv);
 
        void computeOctPts(const geom::Coordinate::ConstVect &src,
                        geom::Coordinate::ConstVect &tgt);
 
        bool computeOctRing(const geom::Coordinate::ConstVect &src,
                        geom::Coordinate::ConstVect &tgt);

        void reduce(geom::Coordinate::ConstVect &pts);

        void padArray3(geom::Coordinate::ConstVect &pts);

        void preSort(geom::Coordinate::ConstVect &pts);

        int polarCompare(const geom::Coordinate &o,
                        const geom::Coordinate &p, const geom::Coordinate &q);
 
        void grahamScan(const geom::Coordinate::ConstVect &c,
                        geom::Coordinate::ConstVect &ps);

        geom::Geometry* lineOrPolygon(const geom::Coordinate::ConstVect &vertices);

        void cleanRing(const geom::Coordinate::ConstVect &input,
                        geom::Coordinate::ConstVect &cleaned);

        bool isBetween(const geom::Coordinate& c1, const geom::Coordinate& c2, const geom::Coordinate& c3);
 
public:

        ConvexHull(const geom::Geometry *newGeometry);
 
 
        ~ConvexHull();

        geom::Geometry* getConvexHull();
};
 
} // namespace geos::algorithm
} // namespace geos
 
#ifdef _MSC_VER
#pragma warning(pop)
#endif
 
#ifdef GEOS_INLINE
# include "geos/algorithm/ConvexHull.inl"
#endif
 
#endif // GEOS_ALGORITHM_CONVEXHULL_H