GEOS  3.8.0dev
Rectangle.h
1 /**********************************************************************
2  *
3  * GEOS - Geometry Engine Open Source
4  * http://geos.osgeo.org
5  *
6  * Copyright (C) 2014 Mika Heiskanen <mika.heiskanen@fmi.fi>
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_OP_INTERSECTION_RECTANGLE_H
16 #define GEOS_OP_INTERSECTION_RECTANGLE_H
17 
18 #include <geos/export.h>
19 
20 #ifdef _MSC_VER
21 #pragma warning(push)
22 #pragma warning(disable: 4251) // warning C4251: needs to have dll-interface to be used by clients of class
23 #endif
24 
25 // Forward declarations
26 namespace geos {
27 namespace geom {
28 class GeometryFactory;
29 class Geometry;
30 class Polygon;
31 class LinearRing;
32 }
33 }
34 
35 namespace geos {
36 namespace operation { // geos::operation
37 namespace intersection { // geos::operation::intersection
38 
51 class GEOS_DLL Rectangle {
52 public:
53 
64  Rectangle(double x1, double y1, double x2, double y2);
65 
69  double
70  xmin() const
71  {
72  return xMin;
73  }
74 
79  double
80  ymin() const
81  {
82  return yMin;
83  }
84 
85 
90  double
91  xmax() const
92  {
93  return xMax;
94  }
95 
96 
101  double
102  ymax() const
103  {
104  return yMax;
105  }
106 
112  geom::Polygon* toPolygon(const geom::GeometryFactory& f) const;
113 
114  geom::LinearRing* toLinearRing(const geom::GeometryFactory& f) const;
115 
120  enum Position {
121  Inside = 1,
122  Outside = 2,
123 
124  Left = 4,
125  Top = 8,
126  Right = 16,
127  Bottom = 32,
128 
129  TopLeft = Top | Left, // 12
130  TopRight = Top | Right, // 24
131  BottomLeft = Bottom | Left, // 36
132  BottomRight = Bottom | Right // 48
133  };
134 
141  static bool
143  {
144  return (pos > Outside);
145  }
146 
154  static bool
156  {
157  return onEdge(Position(pos1 & pos2));
158  }
159 
167  Position
168  position(double x, double y) const
169  {
170  // We assume the point to be inside and test it first
171  if(x > xMin && x < xMax && y > yMin && y < yMax) {
172  return Inside;
173  }
174  // Next we assume the point to be outside and test it next
175  if(x < xMin || x > xMax || y < yMin || y > yMax) {
176  return Outside;
177  }
178  // Slower cases
179  unsigned int pos = 0;
180  if(x == xMin) {
181  pos |= Left;
182  }
183  else if(x == xMax) {
184  pos |= Right;
185  }
186  if(y == yMin) {
187  pos |= Bottom;
188  }
189  else if(y == yMax) {
190  pos |= Top;
191  }
192  return Position(pos);
193  }
194 
201  static Position
203  {
204  switch(pos) {
205  case BottomLeft:
206  case Left:
207  return Top;
208  case TopLeft:
209  case Top:
210  return Right;
211  case TopRight:
212  case Right:
213  return Bottom;
214  case BottomRight:
215  case Bottom:
216  return Left;
217  /* silences compiler warnings, Inside & Outside are not handled explicitly */
218  default:
219  return pos;
220  }
221  }
222 
223 private:
224 
225  Rectangle();
226  double xMin;
227  double yMin;
228  double xMax;
229  double yMax;
230 
231 }; // class RectangleIntersection
232 
233 } // namespace geos::operation::intersection
234 } // namespace geos::operation
235 } // namespace geos
236 
237 #endif // GEOS_OP_INTERSECTION_RECTANGLE_H
static Position nextEdge(Position pos)
Next edge in clock-wise direction.
Definition: Rectangle.h:202
double ymax() const
Definition: Rectangle.h:102
static bool onSameEdge(Position pos1, Position pos2)
Test if the given positions are on the same Rectangle edge.
Definition: Rectangle.h:155
static bool onEdge(Position pos)
Test if the given position is on a edge.
Definition: Rectangle.h:142
Position position(double x, double y) const
Establish position of coordinate with respect to a Rectangle.
Definition: Rectangle.h:168
Represents a linear polygon, which may include holes.
Definition: Polygon.h:65
Supplies a set of utility methods for building Geometry objects from CoordinateSequence or other Geom...
Definition: GeometryFactory.h:67
Basic namespace for all GEOS functionalities.
Definition: IndexedNestedRingTester.h:25
Position
Position with respect to a clipping rectangle.
Definition: Rectangle.h:120
Models an OGC SFS LinearRing.
Definition: LinearRing.h:56
double ymin() const
Definition: Rectangle.h:80
Clipping rectangle.
Definition: Rectangle.h:51
double xmin() const
Definition: Rectangle.h:70
double xmax() const
Definition: Rectangle.h:91