GEOS  3.6.2
Centroid.h
00001 /**********************************************************************
00002  *
00003  * GEOS - Geometry Engine Open Source
00004  * http://geos.osgeo.org
00005  *
00006  * Copyright (C) 2013 Sandro Santilli <strk@keybit.net>
00007  *
00008  * This is free software; you can redistribute and/or modify it under
00009  * the terms of the GNU Lesser General Public Licence as published
00010  * by the Free Software Foundation. 
00011  * See the COPYING file for more information.
00012  *
00013  **********************************************************************
00014  *
00015  * Last port: algorithm/Centroid.java r728 (JTS-0.13+)
00016  *
00017  **********************************************************************/
00018 
00019 #ifndef GEOS_ALGORITHM_CENTROID_H
00020 #define GEOS_ALGORITHM_CENTROID_H
00021 
00022 #include <geos/export.h>
00023 #include <geos/geom/Coordinate.h> // for composition
00024 #include <memory> // for std::auto_ptr
00025 
00026 // Forward declarations
00027 namespace geos {
00028     namespace geom {
00029         class Geometry;
00030         class Polygon;
00031         class CoordinateSequence;
00032     }
00033 }
00034 
00035 
00036 namespace geos {
00037 namespace algorithm { // geos::algorithm
00038 
00061 class GEOS_DLL Centroid {
00062 
00063 public:
00064 
00074   static bool getCentroid(const geom::Geometry& geom, geom::Coordinate& cent);
00075 
00079   Centroid(const geom::Geometry& geom)
00080     :
00081     areasum2(0.0),
00082     totalLength(0.0),
00083     ptCount(0)
00084   {
00085     add(geom);
00086   }
00087 
00096   bool getCentroid(geom::Coordinate& cent) const;
00097 
00098 private:
00099 
00100   std::auto_ptr<geom::Coordinate> areaBasePt;
00101   geom::Coordinate triangleCent3;
00102   geom::Coordinate cg3;
00103   geom::Coordinate lineCentSum;
00104   geom::Coordinate ptCentSum;
00105   double areasum2;
00106   double totalLength;
00107   int ptCount;
00108   
00114   void add(const geom::Geometry& geom);
00115   
00116   void setBasePoint(const geom::Coordinate& basePt);
00117 
00118   void add(const geom::Polygon& poly);
00119 
00120   void addShell(const geom::CoordinateSequence& pts);
00121 
00122   void addHole(const geom::CoordinateSequence& pts);
00123 
00124   void addTriangle(const geom::Coordinate& p0, const geom::Coordinate& p1, const geom::Coordinate& p2, bool isPositiveArea);
00125 
00131   static void centroid3(const geom::Coordinate& p1, const geom::Coordinate& p2, const geom::Coordinate& p3, geom::Coordinate& c );
00132 
00137   static double area2(const geom::Coordinate& p1, const geom::Coordinate& p2, const geom::Coordinate& p3 );
00138 
00145   void addLineSegments(const geom::CoordinateSequence& pts);
00146 
00151   void addPoint(const geom::Coordinate& pt);
00152 };
00153 
00154 } // namespace geos::algorithm
00155 } // namespace geos
00156 
00157 #endif // GEOS_ALGORITHM_CENTROID_H