/********************************************************************** * $Id: Quadrant.h 1820 2006-09-06 16:54:23Z mloskot $ * * GEOS - Geometry Engine Open Source * http://geos.refractions.net * * 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. * **********************************************************************/#ifndef GEOS_GEOMGRAPH_QUADRANT_H#define GEOS_GEOMGRAPH_QUADRANT_H#include <string>#include <geos/inline.h>// Forward declarationsnamespace geos {	namespace geom {		class Coordinate;	}}namespace geos {namespace geomgraph { // geos.geomgraph/** * Utility functions for working with quadrants, which are numbered as follows: * <pre> * 1 | 0 * --+-- * 2 | 3 * <pre> * */class Quadrant {public:	/**	 * Returns the quadrant of a directed line segment	 * (specified as x and y displacements, which cannot both be 0).	 */	static int quadrant(double dx, double dy);	/**	 * Returns the quadrant of a directed line segment from p0 to p1.	 */	static int quadrant(const geom::Coordinate& p0, const geom::Coordinate& p1);	/**	 * Returns true if the quadrants are 1 and 3, or 2 and 4	 */	static bool isOpposite(int quad1, int quad2);	/* 	 * Returns the right-hand quadrant of the halfplane defined by	 * the two quadrants,	 * or -1 if the quadrants are opposite, or the quadrant if they	 * are identical.	 */	static int commonHalfPlane(int quad1, int quad2);	/**	 * Returns whether the given quadrant lies within the given halfplane	 * (specified by its right-hand quadrant).	 */	static bool isInHalfPlane(int quad, int halfPlane);	/**	 * Returns true if the given quadrant is 0 or 1.	 */	static bool isNorthern(int quad);};} // namespace geos.geomgraph} // namespace geos//#ifdef GEOS_INLINE//# include "geos/geomgraph/Quadrant.inl"//#endif#endif // ifndef GEOS_GEOMGRAPH_QUADRANT_H/********************************************************************** * $Log$ * Revision 1.2  2006/03/24 09:52:41  strk * USE_INLINE => GEOS_INLINE * * Revision 1.1  2006/03/09 16:46:49  strk * geos::geom namespace definition, first pass at headers split * **********************************************************************/