COIN-OR::LEMON - Graph Library

source: lemon-0.x/src/lemon/xy.h @ 967:6563019430ba

Last change on this file since 967:6563019430ba was 967:6563019430ba, checked in by Alpar Juttner, 16 years ago

Several changes in doc.

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1/* -*- C++ -*-
2 * src/lemon/xy.h - Part of LEMON, a generic C++ optimization library
3 *
4 * Copyright (C) 2004 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 two dimensional vector (plainvector) implementation
42
43  /// A 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 ValueType;
54
55      T x,y;     
56     
57      ///Default constructor: both coordinates become 0
58      xy() : x(0), y(0) {}
59
60      ///Constructing the instance from coordinates
61      xy(T a, T b) : x(a), y(b) { }
62
63
64      ///Gives back the square of the norm of the vector
65      T normSquare(){
66        return x*x+y*y;
67      };
68 
69      ///Increments the left hand side by u
70      xy<T>& operator +=(const xy<T>& u){
71        x += u.x;
72        y += u.y;
73        return *this;
74      };
75 
76      ///Decrements the left hand side by u
77      xy<T>& operator -=(const xy<T>& u){
78        x -= u.x;
79        y -= u.y;
80        return *this;
81      };
82
83      ///Multiplying the left hand side with a scalar
84      xy<T>& operator *=(const T &u){
85        x *= u;
86        y *= u;
87        return *this;
88      };
89
90      ///Dividing the left hand side by a scalar
91      xy<T>& operator /=(const T &u){
92        x /= u;
93        y /= u;
94        return *this;
95      };
96 
97      ///Returns the scalar product of two vectors
98      T operator *(const xy<T>& u){
99        return x*u.x+y*u.y;
100      };
101 
102      ///Returns the sum of two vectors
103      xy<T> operator+(const xy<T> &u) const {
104        xy<T> b=*this;
105        return b+=u;
106      };
107
108      ///Returns the difference of two vectors
109      xy<T> operator-(const xy<T> &u) const {
110        xy<T> b=*this;
111        return b-=u;
112      };
113
114      ///Returns a vector multiplied by a scalar
115      xy<T> operator*(const T &u) const {
116        xy<T> b=*this;
117        return b*=u;
118      };
119
120      ///Returns a vector divided by a scalar
121      xy<T> operator/(const T &u) const {
122        xy<T> b=*this;
123        return b/=u;
124      };
125
126      ///Testing equality
127      bool operator==(const xy<T> &u){
128        return (x==u.x) && (y==u.y);
129      };
130
131      ///Testing inequality
132      bool operator!=(xy u){
133        return  (x!=u.x) || (y!=u.y);
134      };
135
136    };
137
138  ///Read a plainvector from a stream
139
140  ///Read a plainvector from a stream
141  ///\relates xy
142  ///
143  template<typename T>
144  inline
145  std::istream& operator>>(std::istream &is, xy<T> &z)
146  {
147
148    is >> z.x >> z.y;
149    return is;
150  }
151
152  ///Write a plainvector to a stream
153
154  ///Write a plainvector to a stream
155  ///\relates xy
156  ///
157  template<typename T>
158  inline
159  std::ostream& operator<<(std::ostream &os, xy<T> z)
160  {
161    os << "(" << z.x << ", " << z.y << ")";
162    return os;
163  }
164
165
166  /// A class to calculate or store the bounding box of plainvectors.
167
168  /// A class to calculate or store the bounding box of plainvectors.
169  ///
170  ///\author Attila Bernath
171  template<typename T>
172    class BoundingBox {
173      xy<T> bottom_left, top_right;
174      bool _empty;
175    public:
176     
177      ///Default constructor: an empty bounding box
178      BoundingBox() { _empty = true; }
179
180      ///Constructing the instance from one point
181      BoundingBox(xy<T> a) { bottom_left=top_right=a; _empty = false; }
182
183      ///Is there any point added
184      bool empty() const {
185        return _empty;
186      }
187
188      ///Gives back the bottom left corner (if the bounding box is empty, then the return value is not defined)
189      xy<T> bottomLeft() const {
190        return bottom_left;
191      };
192
193      ///Gives back the top right corner (if the bounding box is empty, then the return value is not defined)
194      xy<T> topRight() const {
195        return top_right;
196      };
197
198      ///Checks whether a point is inside a bounding box
199      bool inside(const xy<T>& u){
200        if (_empty)
201          return false;
202        else{
203          return ((u.x-bottom_left.x)*(top_right.x-u.x) >= 0 &&
204                  (u.y-bottom_left.y)*(top_right.y-u.y) >= 0 );
205        }
206      }
207 
208      ///Increments a bounding box with a point
209      BoundingBox& operator +=(const xy<T>& u){
210        if (_empty){
211          bottom_left=top_right=u;
212          _empty = false;
213        }
214        else{
215          if (bottom_left.x > u.x) bottom_left.x = u.x;
216          if (bottom_left.y > u.y) bottom_left.y = u.y;
217          if (top_right.x < u.x) top_right.x = u.x;
218          if (top_right.y < u.y) top_right.y = u.y;
219        }
220        return *this;
221      };
222 
223      ///Sums a bounding box and a point
224      BoundingBox operator +(const xy<T>& u){
225        BoundingBox b = *this;
226        return b += u;
227      };
228
229      ///Increments a bounding box with an other bounding box
230      BoundingBox& operator +=(const BoundingBox &u){
231        if ( !u.empty() ){
232          *this += u.bottomLeft();
233          *this += u.topRight();
234        }
235        return *this;
236      };
237 
238      ///Sums two bounding boxes
239      BoundingBox operator +(const BoundingBox& u){
240        BoundingBox b = *this;
241        return b += u;
242      };
243
244    };//class Boundingbox
245
246
247  /// @}
248
249
250} //namespace lemon
251
252#endif //LEMON_XY_H
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