1 | // -*- c++ -*- |
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2 | #ifndef HUGO_XY_H |
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3 | #define HUGO_XY_H |
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4 | |
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5 | #include <iostream> |
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6 | |
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7 | namespace hugo { |
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8 | |
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9 | ///\file |
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10 | ///\brief A simple two dimensional vector and a bounding box implementation |
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11 | /// |
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12 | /// The class \ref hugo::xy "xy" implements |
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13 | ///a two dimensional vector with the usual |
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14 | /// operations. |
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15 | /// |
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16 | /// The class \ref hugo::BoundingBox "BoundingBox" can be used to determine |
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17 | /// the rectangular bounding box a set of \ref hugo::xy "xy"'s. |
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18 | |
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19 | |
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20 | /** \brief |
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21 | 2 dimensional vector (plainvector) implementation |
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22 | |
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23 | */ |
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24 | template<typename T> |
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25 | class xy { |
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26 | |
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27 | public: |
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28 | |
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29 | T x,y; |
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30 | |
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31 | ///Default constructor: both coordinates become 0 |
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32 | xy() : x(0), y(0) {} |
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33 | |
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34 | ///Constructing the instance from coordinates |
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35 | xy(T a, T b) : x(a), y(a) { } |
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36 | |
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37 | |
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38 | ///Gives back the square of the norm of the vector |
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39 | T normSquare(){ |
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40 | return x*x+y*y; |
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41 | }; |
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42 | |
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43 | ///Increments the left hand side by u |
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44 | xy<T>& operator +=(const xy<T>& u){ |
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45 | x += u.x; |
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46 | y += u.y; |
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47 | return *this; |
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48 | }; |
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49 | |
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50 | ///Decrements the left hand side by u |
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51 | xy<T>& operator -=(const xy<T>& u){ |
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52 | x -= u.x; |
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53 | y -= u.y; |
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54 | return *this; |
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55 | }; |
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56 | |
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57 | ///Multiplying the left hand side with a scalar |
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58 | xy<T>& operator *=(const T &u){ |
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59 | x *= u; |
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60 | y *= u; |
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61 | return *this; |
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62 | }; |
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63 | |
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64 | ///Dividing the left hand side by a scalar |
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65 | xy<T>& operator /=(const T &u){ |
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66 | x /= u; |
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67 | y /= u; |
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68 | return *this; |
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69 | }; |
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70 | |
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71 | ///Returns the scalar product of two vectors |
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72 | T operator *(const xy<T>& u){ |
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73 | return x*u.x+y*u.y; |
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74 | }; |
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75 | |
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76 | ///Returns the sum of two vectors |
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77 | xy<T> operator+(const xy<T> &u) const { |
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78 | xy<T> b=*this; |
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79 | return b+=u; |
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80 | }; |
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81 | |
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82 | ///Returns the difference of two vectors |
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83 | xy<T> operator-(const xy<T> &u) const { |
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84 | xy<T> b=*this; |
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85 | return b-=u; |
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86 | }; |
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87 | |
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88 | ///Returns a vector multiplied by a scalar |
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89 | xy<T> operator*(const T &u) const { |
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90 | xy<T> b=*this; |
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91 | return b*=u; |
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92 | }; |
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93 | |
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94 | ///Returns a vector divided by a scalar |
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95 | xy<T> operator/(const T &u) const { |
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96 | xy<T> b=*this; |
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97 | return b/=u; |
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98 | }; |
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99 | |
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100 | ///Testing equality |
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101 | bool operator==(const xy<T> &u){ |
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102 | return (x==u.x) && (y==u.y); |
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103 | }; |
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104 | |
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105 | ///Testing inequality |
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106 | bool operator!=(xy u){ |
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107 | return (x!=u.x) || (y!=u.y); |
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108 | }; |
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109 | |
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110 | }; |
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111 | |
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112 | ///Reading a plainvector from a stream |
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113 | template<typename T> |
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114 | inline |
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115 | std::istream& operator>>(std::istream &is, xy<T> &z) |
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116 | { |
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117 | |
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118 | is >> z.x >> z.y; |
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119 | return is; |
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120 | } |
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121 | |
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122 | ///Outputting a plainvector to a stream |
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123 | template<typename T> |
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124 | inline |
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125 | std::ostream& operator<<(std::ostream &os, xy<T> z) |
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126 | { |
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127 | os << "(" << z.x << ", " << z.y << ")"; |
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128 | return os; |
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129 | } |
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130 | |
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131 | |
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132 | /** \brief |
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133 | Implementation of a bounding box of plainvectors. |
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134 | |
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135 | */ |
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136 | template<typename T> |
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137 | class BoundingBox { |
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138 | xy<T> bottom_left, top_right; |
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139 | bool _empty; |
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140 | public: |
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141 | |
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142 | ///Default constructor: an empty bounding box |
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143 | BoundingBox() { _empty = true; } |
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144 | |
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145 | ///Constructing the instance from one point |
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146 | BoundingBox(xy<T> a) { bottom_left=top_right=a; _empty = false; } |
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147 | |
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148 | ///Is there any point added |
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149 | bool empty() const { |
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150 | return _empty; |
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151 | } |
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152 | |
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153 | ///Gives back the bottom left corner (if the bounding box is empty, then the return value is not defined) |
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154 | xy<T> bottomLeft() const { |
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155 | return bottom_left; |
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156 | }; |
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157 | |
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158 | ///Gives back the top right corner (if the bounding box is empty, then the return value is not defined) |
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159 | xy<T> topRight() const { |
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160 | return top_right; |
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161 | }; |
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162 | |
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163 | ///Checks whether a point is inside a bounding box |
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164 | bool inside(const xy<T>& u){ |
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165 | if (_empty) |
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166 | return false; |
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167 | else{ |
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168 | return ((u.x-bottom_left.x)*(top_right.x-u.x) >= 0 && |
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169 | (u.y-bottom_left.y)*(top_right.y-u.y) >= 0 ); |
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170 | } |
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171 | } |
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172 | |
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173 | ///Increments a bounding box with a point |
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174 | BoundingBox& operator +=(const xy<T>& u){ |
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175 | if (_empty){ |
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176 | bottom_left=top_right=u; |
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177 | _empty = false; |
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178 | } |
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179 | else{ |
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180 | if (bottom_left.x > u.x) bottom_left.x = u.x; |
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181 | if (bottom_left.y > u.y) bottom_left.y = u.y; |
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182 | if (top_right.x < u.x) top_right.x = u.x; |
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183 | if (top_right.y < u.y) top_right.y = u.y; |
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184 | } |
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185 | return *this; |
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186 | }; |
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187 | |
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188 | ///Sums a bounding box and a point |
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189 | BoundingBox operator +(const xy<T>& u){ |
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190 | BoundingBox b = *this; |
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191 | return b += u; |
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192 | }; |
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193 | |
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194 | ///Increments a bounding box with an other bounding box |
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195 | BoundingBox& operator +=(const BoundingBox &u){ |
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196 | if ( !u.empty() ){ |
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197 | *this += u.bottomLeft(); |
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198 | *this += u.topRight(); |
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199 | } |
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200 | return *this; |
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201 | }; |
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202 | |
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203 | ///Sums two bounding boxes |
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204 | BoundingBox operator +(const BoundingBox& u){ |
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205 | BoundingBox b = *this; |
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206 | return b += u; |
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207 | }; |
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208 | |
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209 | };//class Boundingbox |
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210 | |
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211 | |
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212 | |
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213 | |
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214 | } //namespace hugo |
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215 | |
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216 | #endif //HUGO_XY_H |
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