COIN-OR::LEMON - Graph Library

source: lemon-0.x/src/lemon/xy.h @ 1257:7101e2c3a881

Last change on this file since 1257:7101e2c3a881 was 1257:7101e2c3a881, checked in by Alpar Juttner, 20 years ago
  • several missing 'const' added
  • value of xy is undefined by default
File size: 7.8 KB
Line 
1/* -*- C++ -*-
2 * src/lemon/xy.h - Part of LEMON, a generic C++ optimization library
3 *
4 * Copyright (C) 2005 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
5 * (Egervary Combinatorial Optimization Research Group, EGRES).
6 *
7 * Permission to use, modify and distribute this software is granted
8 * provided that this copyright notice appears in all copies. For
9 * precise terms see the accompanying LICENSE file.
10 *
11 * This software is provided "AS IS" with no warranty of any kind,
12 * express or implied, and with no claim as to its suitability for any
13 * purpose.
14 *
15 */
16
17#ifndef LEMON_XY_H
18#define LEMON_XY_H
19
20#include <iostream>
21
22///\ingroup misc
23///\file
24///\brief A simple two dimensional vector and a bounding box implementation
25///
26/// The class \ref lemon::xy "xy" implements
27///a two dimensional vector with the usual
28/// operations.
29///
30/// The class \ref lemon::BoundingBox "BoundingBox" can be used to determine
31/// the rectangular bounding box a set of \ref lemon::xy "xy"'s.
32///
33///\author Attila Bernath
34
35
36namespace lemon {
37
38  /// \addtogroup misc
39  /// @{
40
41  /// A simple two dimensional vector (plainvector) implementation
42
43  /// A simple two dimensional vector (plainvector) implementation
44  ///with the usual vector
45  /// operators.
46  ///
47  ///\author Attila Bernath
48  template<typename T>
49    class xy {
50
51    public:
52
53      typedef T Value;
54
55      T x,y;     
56     
57      ///Default constructor
58      xy() {}
59
60      ///Constructing the instance from coordinates
61      xy(T a, T b) : x(a), y(b) { }
62
63
64      ///Conversion constructor
65      template<class TT> xy(const xy<TT> &p) : x(p.x), y(p.y) {}
66
67      ///Gives back the square of the norm of the vector
68      T normSquare() const {
69        return x*x+y*y;
70      };
71 
72      ///Increments the left hand side by u
73      xy<T>& operator +=(const xy<T>& u) {
74        x += u.x;
75        y += u.y;
76        return *this;
77      };
78 
79      ///Decrements the left hand side by u
80      xy<T>& operator -=(const xy<T>& u) {
81        x -= u.x;
82        y -= u.y;
83        return *this;
84      };
85
86      ///Multiplying the left hand side with a scalar
87      xy<T>& operator *=(const T &u) {
88        x *= u;
89        y *= u;
90        return *this;
91      };
92
93      ///Dividing the left hand side by a scalar
94      xy<T>& operator /=(const T &u) {
95        x /= u;
96        y /= u;
97        return *this;
98      };
99 
100      ///Returns the scalar product of two vectors
101      T operator *(const xy<T>& u) const {
102        return x*u.x+y*u.y;
103      };
104 
105      ///Returns the sum of two vectors
106      xy<T> operator+(const xy<T> &u) const {
107        xy<T> b=*this;
108        return b+=u;
109      };
110
111      ///Returns the neg of the vectors
112      xy<T> operator-() const {
113        xy<T> b=*this;
114        b.x=-b.x; b.y=-b.y;
115        return b;
116      };
117
118      ///Returns the difference of two vectors
119      xy<T> operator-(const xy<T> &u) const {
120        xy<T> b=*this;
121        return b-=u;
122      };
123
124      ///Returns a vector multiplied by a scalar
125      xy<T> operator*(const T &u) const {
126        xy<T> b=*this;
127        return b*=u;
128      };
129
130      ///Returns a vector divided by a scalar
131      xy<T> operator/(const T &u) const {
132        xy<T> b=*this;
133        return b/=u;
134      };
135
136      ///Testing equality
137      bool operator==(const xy<T> &u) const {
138        return (x==u.x) && (y==u.y);
139      };
140
141      ///Testing inequality
142      bool operator!=(xy u) const {
143        return  (x!=u.x) || (y!=u.y);
144      };
145
146    };
147
148  ///Returns a vector multiplied by a scalar
149
150  ///Returns a vector multiplied by a scalar
151  ///\relates xy
152  template<typename T> xy<T> operator*(const T &u,const xy<T> &x) {
153    return x*u;
154  };
155
156  ///Read a plainvector from a stream
157
158  ///Read a plainvector from a stream
159  ///\relates xy
160  ///
161  template<typename T>
162  inline
163  std::istream& operator>>(std::istream &is, xy<T> &z)
164  {
165
166    is >> z.x >> z.y;
167    return is;
168  }
169
170  ///Write a plainvector to a stream
171
172  ///Write a plainvector to a stream
173  ///\relates xy
174  ///
175  template<typename T>
176  inline
177  std::ostream& operator<<(std::ostream &os, xy<T> z)
178  {
179    os << "(" << z.x << ", " << z.y << ")";
180    return os;
181  }
182
183  ///Rotate by 90 degrees
184
185  ///Returns its parameter rotated by 90 degrees in positive direction.
186  ///\relates xy
187  ///
188  template<typename T>
189  inline xy<T> rot90(const xy<T> &z)
190  {
191    return xy<T>(-z.y,z.x);
192  }
193
194  ///Rotate by 270 degrees
195
196  ///Returns its parameter rotated by 90 degrees in negative direction.
197  ///\relates xy
198  ///
199  template<typename T>
200  inline xy<T> rot270(const xy<T> &z)
201  {
202    return xy<T>(z.y,-z.x);
203  }
204
205 
206
207  /// A class to calculate or store the bounding box of plainvectors.
208
209  /// A class to calculate or store the bounding box of plainvectors.
210  ///
211  ///\author Attila Bernath
212  template<typename T>
213    class BoundingBox {
214      xy<T> bottom_left, top_right;
215      bool _empty;
216    public:
217     
218      ///Default constructor: an empty bounding box
219      BoundingBox() { _empty = true; }
220
221      ///Constructing the instance from one point
222      BoundingBox(xy<T> a) { bottom_left=top_right=a; _empty = false; }
223
224      ///Is there any point added
225      bool empty() const {
226        return _empty;
227      }
228
229      ///Gives back the bottom left corner (if the bounding box is empty, then the return value is not defined)
230      xy<T> bottomLeft() const {
231        return bottom_left;
232      };
233
234      ///Gives back the top right corner (if the bounding box is empty, then the return value is not defined)
235      xy<T> topRight() const {
236        return top_right;
237      };
238
239      ///Gives back the bottom right corner (if the bounding box is empty, then the return value is not defined)
240      xy<T> bottomRight() const {
241        return xy<T>(top_right.x,bottom_left.y);
242      };
243
244      ///Gives back the top left corner (if the bounding box is empty, then the return value is not defined)
245      xy<T> topLeft() const {
246        return xy<T>(bottom_left.x,top_right.y);
247      };
248
249      ///Gives back the bottom of the box (if the bounding box is empty, then the return value is not defined)
250      T bottom() const {
251        return bottom_left.y;
252      };
253
254      ///Gives back the top of the box (if the bounding box is empty, then the return value is not defined)
255      T top() const {
256        return top_right.y;
257      };
258
259      ///Gives back the left side of the box (if the bounding box is empty, then the return value is not defined)
260      T left() const {
261        return bottom_left.x;
262      };
263
264      ///Gives back the right side of the box (if the bounding box is empty, then the return value is not defined)
265      T right() const {
266        return top_right.x;
267      };
268
269      ///Gives back the height of the box (if the bounding box is empty, then the return value is not defined)
270      T height() const {
271        return top_right.y-bottom_left.y;
272      };
273
274      ///Gives back the width of the box (if the bounding box is empty, then the return value is not defined)
275      T width() const {
276        return top_right.x-bottom_left.x;
277      };
278
279      ///Checks whether a point is inside a bounding box
280      bool inside(const xy<T>& u){
281        if (_empty)
282          return false;
283        else{
284          return ((u.x-bottom_left.x)*(top_right.x-u.x) >= 0 &&
285                  (u.y-bottom_left.y)*(top_right.y-u.y) >= 0 );
286        }
287      }
288 
289      ///Increments a bounding box with a point
290      BoundingBox& operator +=(const xy<T>& u){
291        if (_empty){
292          bottom_left=top_right=u;
293          _empty = false;
294        }
295        else{
296          if (bottom_left.x > u.x) bottom_left.x = u.x;
297          if (bottom_left.y > u.y) bottom_left.y = u.y;
298          if (top_right.x < u.x) top_right.x = u.x;
299          if (top_right.y < u.y) top_right.y = u.y;
300        }
301        return *this;
302      };
303 
304      ///Sums a bounding box and a point
305      BoundingBox operator +(const xy<T>& u){
306        BoundingBox b = *this;
307        return b += u;
308      };
309
310      ///Increments a bounding box with an other bounding box
311      BoundingBox& operator +=(const BoundingBox &u){
312        if ( !u.empty() ){
313          *this += u.bottomLeft();
314          *this += u.topRight();
315        }
316        return *this;
317      };
318 
319      ///Sums two bounding boxes
320      BoundingBox operator +(const BoundingBox& u){
321        BoundingBox b = *this;
322        return b += u;
323      };
324
325    };//class Boundingbox
326
327
328  /// @}
329
330
331} //namespace lemon
332
333#endif //LEMON_XY_H
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