/********************************************************************** * * GEOS - Geometry Engine Open Source * http://geos.osgeo.org * * 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: geomgraph/Quadrant.java rev. 1.8 (JTS-1.10) * **********************************************************************/ #ifndef GEOS_GEOMGRAPH_QUADRANT_INL #define GEOS_GEOMGRAPH_QUADRANT_INL #include #include #include #include namespace geos { namespace geomgraph { /* public static */ INLINE int Quadrant::quadrant(double dx, double dy) { if(dx == 0.0 && dy == 0.0) { std::ostringstream s; s << "Cannot compute the quadrant for point "; s << "(" << dx << "," << dy << ")" << std::endl; throw util::IllegalArgumentException(s.str()); } if(dx >= 0) { if(dy >= 0) { return NE; } else { return SE; } } else { if(dy >= 0) { return NW; } else { return SW; } } } /* public static */ INLINE int Quadrant::quadrant(const geom::Coordinate& p0, const geom::Coordinate& p1) { if(p1.x == p0.x && p1.y == p0.y) { throw util::IllegalArgumentException("Cannot compute the quadrant for two identical points " + p0.toString()); } if(p1.x >= p0.x) { if(p1.y >= p0.y) { return NE; } else { return SE; } } else { if(p1.y >= p0.y) { return NW; } else { return SW; } } } /* public static */ INLINE bool Quadrant::isOpposite(int quad1, int quad2) { if(quad1 == quad2) { return false; } int diff = (quad1 - quad2 + 4) % 4; // if quadrants are not adjacent, they are opposite if(diff == 2) { return true; } return false; } /* public static */ INLINE bool Quadrant::isNorthern(int quad) { return quad == NE || quad == NW; } } } #endif