74 lines
1.7 KiB
C
74 lines
1.7 KiB
C
|
/**********************************************************************
|
||
|
|
*
|
||
|
|
* GEOS - Geometry Engine Open Source
|
||
|
|
* http://geos.osgeo.org
|
||
|
|
*
|
||
|
|
* Copyright (C) 2006 Refractions Research 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.
|
||
|
|
*
|
||
|
|
**********************************************************************/
|
||
|
|
|
||
|
|
#pragma once
|
||
|
|
|
||
|
|
#include <geos/export.h>
|
||
|
|
|
||
|
|
#include <geos/util.h>
|
||
|
|
|
||
|
|
// Forward declarations
|
||
|
|
namespace geos {
|
||
|
|
namespace geom {
|
||
|
|
class CoordinateXY;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
namespace geos {
|
||
|
|
namespace noding { // geos.noding
|
||
|
|
|
||
|
|
/** \brief
|
||
|
|
* Methods for computing and working with octants of the Cartesian plane.
|
||
|
|
*
|
||
|
|
* Octants are numbered as follows:
|
||
|
|
*
|
||
|
|
* 2|1
|
||
|
|
* 3 | 0
|
||
|
|
* ---+--
|
||
|
|
* 4 | 7
|
||
|
|
* 5|6
|
||
|
|
*
|
||
|
|
* If line segments lie along a coordinate axis, the octant is the lower of the two
|
||
|
|
* possible values.
|
||
|
|
*
|
||
|
|
* Last port: noding/Octant.java rev. 1.2 (JTS-1.7)
|
||
|
|
*/
|
||
|
|
class GEOS_DLL Octant {
|
||
|
|
private:
|
||
|
|
Octant() {} // Can't instantiate it
|
||
|
|
public:
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Returns the octant of a directed line segment (specified
|
||
|
|
* as x and y displacements, which cannot both be 0).
|
||
|
|
*/
|
||
|
|
static int octant(double dx, double dy);
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Returns the octant of a directed line segment from p0 to p1.
|
||
|
|
*/
|
||
|
|
static int octant(const geom::CoordinateXY& p0, const geom::CoordinateXY& p1);
|
||
|
|
|
||
|
|
static int
|
||
|
|
octant(const geom::CoordinateXY* p0, const geom::CoordinateXY* p1)
|
||
|
|
{
|
||
|
|
::geos::ignore_unused_variable_warning(p0);
|
||
|
|
return octant(*p0, *p1);
|
||
|
|
}
|
||
|
|
};
|
||
|
|
|
||
|
|
|
||
|
|
} // namespace geos.noding
|
||
|
|
} // namespace geos
|