GEOS
3.4.2
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00001 /********************************************************************** 00002 * 00003 * GEOS - Geometry Engine Open Source 00004 * http://geos.osgeo.org 00005 * 00006 * Copyright (C) 2005-2006 Refractions Research Inc. 00007 * Copyright (C) 2001-2002 Vivid Solutions Inc. 00008 * 00009 * This is free software; you can redistribute and/or modify it under 00010 * the terms of the GNU Lesser General Public Licence as published 00011 * by the Free Software Foundation. 00012 * See the COPYING file for more information. 00013 * 00014 ********************************************************************** 00015 * 00016 * Last port: geomgraph/Quadrant.java rev. 1.8 (JTS-1.10) 00017 * 00018 **********************************************************************/ 00019 00020 00021 #ifndef GEOS_GEOMGRAPH_QUADRANT_H 00022 #define GEOS_GEOMGRAPH_QUADRANT_H 00023 00024 #include <geos/export.h> 00025 #include <string> 00026 00027 #include <geos/inline.h> 00028 00029 // Forward declarations 00030 namespace geos { 00031 namespace geom { 00032 class Coordinate; 00033 } 00034 } 00035 00036 namespace geos { 00037 namespace geomgraph { // geos.geomgraph 00038 00048 class GEOS_DLL Quadrant { 00049 00050 public: 00051 00052 static const int NE = 0; 00053 static const int NW = 1; 00054 static const int SW = 2; 00055 static const int SE = 3; 00056 00063 static int quadrant(double dx, double dy); 00064 00070 static int quadrant(const geom::Coordinate& p0, 00071 const geom::Coordinate& p1); 00072 00076 static bool isOpposite(int quad1, int quad2); 00077 00078 /* 00079 * Returns the right-hand quadrant of the halfplane defined by 00080 * the two quadrants, 00081 * or -1 if the quadrants are opposite, or the quadrant if they 00082 * are identical. 00083 */ 00084 static int commonHalfPlane(int quad1, int quad2); 00085 00090 static bool isInHalfPlane(int quad, int halfPlane); 00091 00095 static bool isNorthern(int quad); 00096 }; 00097 00098 00099 } // namespace geos.geomgraph 00100 } // namespace geos 00101 00102 #endif // ifndef GEOS_GEOMGRAPH_QUADRANT_H 00103