include/geos/noding/Octant.h

   1 /**********************************************************************
   2  *
   3  * GEOS - Geometry Engine Open Source
   4  * http://geos.osgeo.org
   5  *
   6  * Copyright (C) 2006      Refractions Research Inc.
   7  *
   8  * This is free software; you can redistribute and/or modify it under
   9  * the terms of the GNU Lesser General Public Licence as published
  10  * by the Free Software Foundation.
  11  * See the COPYING file for more information.
  12  *
  13  **********************************************************************/
  14
  15 #ifndef GEOS_NODING_OCTANT_H
  16 #define GEOS_NODING_OCTANT_H
  17
  18 #include <geos/export.h>
  19
  20 #include <geos/inline.h>
  21 #include <geos/util.h>
  22
  23 // Forward declarations
  24 namespace geos {
  25         namespace geom {
  26                 class Coordinate;
  27         }
  28 }
  29
  30 namespace geos {
  31 namespace noding { // geos.noding
  32
  33 /** \brief
  34  * Methods for computing and working with octants of the Cartesian plane.
  35  *
  36  * Octants are numbered as follows:
  37  *
  38  *   2|1
  39  * 3  |  0
  40  * ---+--
  41  * 4  |  7
  42  *   5|6
  43  *
  44  * If line segments lie along a coordinate axis, the octant is the lower of the two
  45  * possible values.
  46  *
  47  * Last port: noding/Octant.java rev. 1.2 (JTS-1.7)
  48  */
  49 class GEOS_DLL Octant {
  50 private:
  51         Octant() {} // Can't instanciate it
  52 public:
  53
  54         /**
  55          * Returns the octant of a directed line segment (specified
  56          * as x and y displacements, which cannot both be 0).
  57          */
  58         static int octant(double dx, double dy);
  59
  60         /**
  61          * Returns the octant of a directed line segment from p0 to p1.
  62          */
  63         static int octant(const geom::Coordinate& p0, const geom::Coordinate& p1);
  64
  65     static int octant(const geom::Coordinate* p0, const geom::Coordinate* p1)
  66     {
  67         ::geos::ignore_unused_variable_warning(p0);
  68                 return octant(*p0, *p1);
  69         }
  70 };
  71
  72
  73 } // namespace geos.noding
  74 } // namespace geos
  75
  76 //#ifdef GEOS_INLINE
  77 //# include "geos/noding/Octant.inl"
  78 //#endif
  79
  80 #endif
  81
  82 /**********************************************************************
  83  * $Log$
  84  * Revision 1.2  2006/03/24 09:52:41  strk
  85  * USE_INLINE => GEOS_INLINE
  86  *
  87  * Revision 1.1  2006/03/09 16:46:49  strk
  88  * geos::geom namespace definition, first pass at headers split
  89  *
  90  **********************************************************************/
  91