1 | /* -*- C++ -*- |
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2 | * src/lemon/xy.h - Part of LEMON, a generic C++ optimization library |
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3 | * |
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4 | * Copyright (C) 2004 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
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5 | * (Egervary Combinatorial Optimization Research Group, EGRES). |
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6 | * |
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7 | * Permission to use, modify and distribute this software is granted |
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8 | * provided that this copyright notice appears in all copies. For |
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9 | * precise terms see the accompanying LICENSE file. |
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10 | * |
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11 | * This software is provided "AS IS" with no warranty of any kind, |
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12 | * express or implied, and with no claim as to its suitability for any |
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13 | * purpose. |
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14 | * |
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15 | */ |
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16 | |
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17 | #ifndef LEMON_XY_H |
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18 | #define LEMON_XY_H |
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19 | |
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20 | #include <iostream> |
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21 | |
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22 | ///\ingroup misc |
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23 | ///\file |
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24 | ///\brief A simple two dimensional vector and a bounding box implementation |
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25 | /// |
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26 | /// The class \ref lemon::xy "xy" implements |
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27 | ///a two dimensional vector with the usual |
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28 | /// operations. |
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29 | /// |
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30 | /// The class \ref lemon::BoundingBox "BoundingBox" can be used to determine |
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31 | /// the rectangular bounding box a set of \ref lemon::xy "xy"'s. |
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32 | /// |
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33 | ///\author Attila Bernath |
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34 | |
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35 | |
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36 | namespace lemon { |
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37 | |
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38 | /// \addtogroup misc |
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39 | /// @{ |
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40 | |
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41 | /// A two dimensional vector (plainvector) implementation |
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42 | |
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43 | /// A two dimensional vector (plainvector) implementation |
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44 | ///with the usual vector |
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45 | /// operators. |
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46 | /// |
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47 | ///\author Attila Bernath |
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48 | template<typename T> |
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49 | class xy { |
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50 | |
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51 | public: |
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52 | |
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53 | T x,y; |
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54 | |
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55 | ///Default constructor: both coordinates become 0 |
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56 | xy() : x(0), y(0) {} |
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57 | |
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58 | ///Constructing the instance from coordinates |
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59 | xy(T a, T b) : x(a), y(b) { } |
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60 | |
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61 | |
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62 | ///Gives back the square of the norm of the vector |
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63 | T normSquare(){ |
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64 | return x*x+y*y; |
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65 | }; |
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66 | |
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67 | ///Increments the left hand side by u |
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68 | xy<T>& operator +=(const xy<T>& u){ |
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69 | x += u.x; |
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70 | y += u.y; |
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71 | return *this; |
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72 | }; |
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73 | |
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74 | ///Decrements the left hand side by u |
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75 | xy<T>& operator -=(const xy<T>& u){ |
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76 | x -= u.x; |
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77 | y -= u.y; |
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78 | return *this; |
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79 | }; |
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80 | |
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81 | ///Multiplying the left hand side with a scalar |
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82 | xy<T>& operator *=(const T &u){ |
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83 | x *= u; |
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84 | y *= u; |
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85 | return *this; |
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86 | }; |
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87 | |
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88 | ///Dividing the left hand side by a scalar |
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89 | xy<T>& operator /=(const T &u){ |
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90 | x /= u; |
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91 | y /= u; |
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92 | return *this; |
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93 | }; |
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94 | |
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95 | ///Returns the scalar product of two vectors |
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96 | T operator *(const xy<T>& u){ |
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97 | return x*u.x+y*u.y; |
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98 | }; |
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99 | |
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100 | ///Returns the sum of two vectors |
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101 | xy<T> operator+(const xy<T> &u) const { |
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102 | xy<T> b=*this; |
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103 | return b+=u; |
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104 | }; |
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105 | |
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106 | ///Returns the difference of two vectors |
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107 | xy<T> operator-(const xy<T> &u) const { |
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108 | xy<T> b=*this; |
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109 | return b-=u; |
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110 | }; |
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111 | |
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112 | ///Returns a vector multiplied by a scalar |
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113 | xy<T> operator*(const T &u) const { |
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114 | xy<T> b=*this; |
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115 | return b*=u; |
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116 | }; |
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117 | |
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118 | ///Returns a vector divided by a scalar |
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119 | xy<T> operator/(const T &u) const { |
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120 | xy<T> b=*this; |
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121 | return b/=u; |
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122 | }; |
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123 | |
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124 | ///Testing equality |
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125 | bool operator==(const xy<T> &u){ |
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126 | return (x==u.x) && (y==u.y); |
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127 | }; |
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128 | |
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129 | ///Testing inequality |
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130 | bool operator!=(xy u){ |
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131 | return (x!=u.x) || (y!=u.y); |
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132 | }; |
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133 | |
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134 | }; |
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135 | |
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136 | ///Read a plainvector from a stream |
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137 | |
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138 | ///\relates xy |
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139 | /// |
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140 | template<typename T> |
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141 | inline |
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142 | std::istream& operator>>(std::istream &is, xy<T> &z) |
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143 | { |
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144 | |
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145 | is >> z.x >> z.y; |
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146 | return is; |
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147 | } |
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148 | |
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149 | ///Write a plainvector to a stream |
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150 | |
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151 | ///\relates xy |
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152 | /// |
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153 | template<typename T> |
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154 | inline |
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155 | std::ostream& operator<<(std::ostream &os, xy<T> z) |
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156 | { |
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157 | os << "(" << z.x << ", " << z.y << ")"; |
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158 | return os; |
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159 | } |
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160 | |
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161 | |
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162 | /// A class to calculate or store the bounding box of plainvectors. |
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163 | |
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164 | /// A class to calculate or store the bounding box of plainvectors. |
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165 | /// |
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166 | ///\author Attila Bernath |
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167 | template<typename T> |
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168 | class BoundingBox { |
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169 | xy<T> bottom_left, top_right; |
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170 | bool _empty; |
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171 | public: |
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172 | |
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173 | ///Default constructor: an empty bounding box |
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174 | BoundingBox() { _empty = true; } |
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175 | |
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176 | ///Constructing the instance from one point |
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177 | BoundingBox(xy<T> a) { bottom_left=top_right=a; _empty = false; } |
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178 | |
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179 | ///Is there any point added |
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180 | bool empty() const { |
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181 | return _empty; |
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182 | } |
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183 | |
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184 | ///Gives back the bottom left corner (if the bounding box is empty, then the return value is not defined) |
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185 | xy<T> bottomLeft() const { |
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186 | return bottom_left; |
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187 | }; |
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188 | |
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189 | ///Gives back the top right corner (if the bounding box is empty, then the return value is not defined) |
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190 | xy<T> topRight() const { |
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191 | return top_right; |
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192 | }; |
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193 | |
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194 | ///Checks whether a point is inside a bounding box |
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195 | bool inside(const xy<T>& u){ |
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196 | if (_empty) |
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197 | return false; |
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198 | else{ |
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199 | return ((u.x-bottom_left.x)*(top_right.x-u.x) >= 0 && |
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200 | (u.y-bottom_left.y)*(top_right.y-u.y) >= 0 ); |
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201 | } |
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202 | } |
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203 | |
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204 | ///Increments a bounding box with a point |
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205 | BoundingBox& operator +=(const xy<T>& u){ |
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206 | if (_empty){ |
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207 | bottom_left=top_right=u; |
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208 | _empty = false; |
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209 | } |
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210 | else{ |
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211 | if (bottom_left.x > u.x) bottom_left.x = u.x; |
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212 | if (bottom_left.y > u.y) bottom_left.y = u.y; |
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213 | if (top_right.x < u.x) top_right.x = u.x; |
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214 | if (top_right.y < u.y) top_right.y = u.y; |
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215 | } |
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216 | return *this; |
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217 | }; |
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218 | |
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219 | ///Sums a bounding box and a point |
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220 | BoundingBox operator +(const xy<T>& u){ |
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221 | BoundingBox b = *this; |
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222 | return b += u; |
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223 | }; |
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224 | |
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225 | ///Increments a bounding box with an other bounding box |
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226 | BoundingBox& operator +=(const BoundingBox &u){ |
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227 | if ( !u.empty() ){ |
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228 | *this += u.bottomLeft(); |
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229 | *this += u.topRight(); |
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230 | } |
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231 | return *this; |
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232 | }; |
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233 | |
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234 | ///Sums two bounding boxes |
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235 | BoundingBox operator +(const BoundingBox& u){ |
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236 | BoundingBox b = *this; |
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237 | return b += u; |
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238 | }; |
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239 | |
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240 | };//class Boundingbox |
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241 | |
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242 | |
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243 | /// @} |
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244 | |
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245 | |
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246 | } //namespace lemon |
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247 | |
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248 | #endif //LEMON_XY_H |
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