GEOS  3.13.0dev
Orientation.h
1 /**********************************************************************
2  *
3  * GEOS - Geometry Engine Open Source
4  * http://geos.osgeo.org
5  *
6  * Copyright (C) 2018 Paul Ramsey <pramsey@cleverlephant.ca>
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  * Last port: algorithm/Orientation.java @ 2017-09-04
16  *
17  **********************************************************************/
18 
19 #pragma once
20 
21 #include <geos/export.h>
22 #include <geos/geom/Coordinate.h>
23 #include <geos/geom/CoordinateSequence.h>
24 
25 namespace geos {
26 namespace algorithm { // geos::algorithm
27 
42 class GEOS_DLL Orientation {
43 public:
44 
45  /* A value that indicates an orientation or turn */
46  enum {
47  CLOCKWISE = -1,
48  COLLINEAR = 0,
49  COUNTERCLOCKWISE = 1,
50  RIGHT = -1,
51  LEFT = 1,
52  STRAIGHT = 0
53  };
54 
67  static int index(const geom::CoordinateXY& p1, const geom::CoordinateXY& p2,
68  const geom::CoordinateXY& q);
69 
89  static bool isCCW(const geom::CoordinateSequence* ring);
90 
115  static bool isCCWArea(const geom::CoordinateSequence* ring);
116 
117 };
118 
119 
120 } // namespace geos::algorithm
121 } // namespace geos
122 
Functions to compute the orientation of basic geometric structures including point triplets (triangle...
Definition: Orientation.h:42
static int index(const geom::CoordinateXY &p1, const geom::CoordinateXY &p2, const geom::CoordinateXY &q)
Returns the orientation index of the direction of the point q relative to a directed infinite line sp...
static bool isCCWArea(const geom::CoordinateSequence *ring)
static bool isCCW(const geom::CoordinateSequence *ring)
The internal representation of a list of coordinates inside a Geometry.
Definition: CoordinateSequence.h:56
Basic namespace for all GEOS functionalities.
Definition: Angle.h:25