Centroid.h

/**********************************************************************
 *
 * GEOS - Geometry Engine Open Source
 * http://geos.osgeo.org
 *
 * Copyright (C) 2013 Sandro Santilli <strk@keybit.net>
 *
 * 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/Centroid.java r728 (JTS-0.13+)
 *
 **********************************************************************/
 
#ifndef GEOS_ALGORITHM_CENTROID_H
#define GEOS_ALGORITHM_CENTROID_H
 
#include <geos/export.h>
#include <geos/geom/Coordinate.h> // for composition
#include <memory> // for std::auto_ptr
 
// Forward declarations
namespace geos {
    namespace geom {
        class Geometry;
        class Polygon;
        class CoordinateSequence;
    }
}
 
 
namespace geos {
namespace algorithm { // geos::algorithm

class GEOS_DLL Centroid {
 
public:

  static bool getCentroid(const geom::Geometry& geom, geom::Coordinate& cent);

  Centroid(const geom::Geometry& geom)
    :
    areasum2(0.0),
    totalLength(0.0),
    ptCount(0)
  {
    add(geom);
  }

  bool getCentroid(geom::Coordinate& cent) const;
 
private:
 
  std::auto_ptr<geom::Coordinate> areaBasePt;
  geom::Coordinate triangleCent3;
  geom::Coordinate cg3;
  geom::Coordinate lineCentSum;
  geom::Coordinate ptCentSum;
  double areasum2;
  double totalLength;
  int ptCount;
  
  void add(const geom::Geometry& geom);
  
  void setBasePoint(const geom::Coordinate& basePt);
 
  void add(const geom::Polygon& poly);
 
  void addShell(const geom::CoordinateSequence& pts);
 
  void addHole(const geom::CoordinateSequence& pts);
 
  void addTriangle(const geom::Coordinate& p0, const geom::Coordinate& p1, const geom::Coordinate& p2, bool isPositiveArea);

  static void centroid3(const geom::Coordinate& p1, const geom::Coordinate& p2, const geom::Coordinate& p3, geom::Coordinate& c );

  static double area2(const geom::Coordinate& p1, const geom::Coordinate& p2, const geom::Coordinate& p3 );

  void addLineSegments(const geom::CoordinateSequence& pts);

  void addPoint(const geom::Coordinate& pt);
};
 
} // namespace geos::algorithm
} // namespace geos
 
#endif // GEOS_ALGORITHM_CENTROID_H