GEOS 3.2.1
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00001 /********************************************************************** 00002 * $Id: CentroidArea.h 2556 2009-06-06 22:22:28Z strk $ 00003 * 00004 * GEOS - Geometry Engine Open Source 00005 * http://geos.refractions.net 00006 * 00007 * Copyright (C) 2005-2006 Refractions Research Inc. 00008 * Copyright (C) 2001-2002 Vivid Solutions Inc. 00009 * 00010 * This is free software; you can redistribute and/or modify it under 00011 * the terms of the GNU Lesser General Public Licence as published 00012 * by the Free Software Foundation. 00013 * See the COPYING file for more information. 00014 * 00015 **********************************************************************/ 00016 00017 #ifndef GEOS_ALGORITHM_CENTROIDAREA_H 00018 #define GEOS_ALGORITHM_CENTROIDAREA_H 00019 00020 00021 #include <geos/export.h> 00022 #include <geos/geom/Coordinate.h> 00023 00024 // Forward declarations 00025 namespace geos { 00026 namespace geom { 00027 class CoordinateSequence; 00028 class Geometry; 00029 class Polygon; 00030 } 00031 } 00032 00033 namespace geos { 00034 namespace algorithm { // geos::algorithm 00035 00050 class GEOS_DLL CentroidArea { 00051 00052 public: 00053 00054 CentroidArea() 00055 : 00056 basePt(0.0, 0.0), 00057 areasum2(0) 00058 {} 00059 00060 ~CentroidArea() {} 00061 00068 void add(const geom::Geometry *geom); 00069 00076 void add(const geom::CoordinateSequence *ring); 00077 00078 geom::Coordinate* getCentroid() const; 00079 00081 bool getCentroid(geom::Coordinate& ret) const; 00082 00083 private: 00084 00086 geom::Coordinate basePt; 00087 00088 // temporary variable to hold centroid of triangle 00089 geom::Coordinate triangleCent3; 00090 00092 double areasum2; 00093 00095 geom::Coordinate cg3; 00096 00097 void setBasePoint(const geom::Coordinate &newbasePt); 00098 00099 void add(const geom::Polygon *poly); 00100 00101 void addShell(const geom::CoordinateSequence *pts); 00102 00103 void addHole(const geom::CoordinateSequence *pts); 00104 00105 void addTriangle(const geom::Coordinate &p0, const geom::Coordinate &p1, 00106 const geom::Coordinate &p2,bool isPositiveArea); 00107 00108 static void centroid3(const geom::Coordinate &p1, const geom::Coordinate &p2, 00109 const geom::Coordinate &p3, geom::Coordinate &c); 00110 00111 static double area2(const geom::Coordinate &p1, const geom::Coordinate &p2, 00112 const geom::Coordinate &p3); 00113 00114 }; 00115 00116 } // namespace geos::algorithm 00117 } // namespace geos 00118 00119 00120 #endif // GEOS_ALGORITHM_CENTROIDAREA_H 00121 00122 /********************************************************************** 00123 * $Log$ 00124 * Revision 1.1 2006/03/09 16:46:48 strk 00125 * geos::geom namespace definition, first pass at headers split 00126 * 00127 **********************************************************************/ 00128