1 | /************************************************************** ggt-head beg |
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2 | * |
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3 | * GGT: Generic Graphics Toolkit |
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4 | * |
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5 | * Original Authors: |
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6 | * Allen Bierbaum |
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7 | * |
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8 | * ----------------------------------------------------------------- |
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9 | * File: PlaneOps.h,v |
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10 | * Date modified: 2005/06/04 18:40:46 |
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11 | * Version: 1.13 |
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12 | * ----------------------------------------------------------------- |
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13 | * |
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14 | *********************************************************** ggt-head end */ |
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15 | /*************************************************************** ggt-cpr beg |
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16 | * |
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17 | * GGT: The Generic Graphics Toolkit |
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18 | * Copyright (C) 2001,2002 Allen Bierbaum |
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19 | * |
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20 | * This library is free software; you can redistribute it and/or |
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21 | * modify it under the terms of the GNU Lesser General Public |
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22 | * License as published by the Free Software Foundation; either |
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23 | * version 2.1 of the License, or (at your option) any later version. |
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24 | * |
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25 | * This library is distributed in the hope that it will be useful, |
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26 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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27 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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28 | * Lesser General Public License for more details. |
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29 | * |
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30 | * You should have received a copy of the GNU Lesser General Public |
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31 | * License along with this library; if not, write to the Free Software |
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32 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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33 | * |
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34 | ************************************************************ ggt-cpr end */ |
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35 | #ifndef _GMTL_PLANEOPS_H_ |
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36 | #define _GMTL_PLANEOPS_H_ |
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37 | |
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38 | #include <gmtl/Defines.h> |
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39 | #include <gmtl/Plane.h> |
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40 | #include <gmtl/Math.h> |
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41 | |
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42 | namespace gmtl |
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43 | { |
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44 | |
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45 | /** @ingroup Ops Plane |
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46 | * @name Plane Operations |
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47 | * @{ |
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48 | */ |
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49 | |
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50 | /** |
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51 | * Computes the distance from the plane to the point. |
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52 | * |
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53 | * @param plane the plane to compare the point to it |
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54 | * @param pt a point in space |
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55 | * |
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56 | * @return the distance from the point to the plane |
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57 | */ |
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58 | template< class DATA_TYPE > |
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59 | DATA_TYPE distance( const Plane<DATA_TYPE>& plane, const Point<DATA_TYPE, 3>& pt ) |
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60 | { |
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61 | return ( dot(plane.mNorm, static_cast< Vec<DATA_TYPE, 3> >(pt)) - plane.mOffset ); |
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62 | } |
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63 | |
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64 | /** |
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65 | * Determines which side of the plane the given point lies. This operation is |
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66 | * done with ZERO tolerance. |
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67 | * |
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68 | * @param plane the plane to compare the point to |
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69 | * @param pt the point to test |
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70 | * |
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71 | * @return the PlaneSide enum describing on which side of the plane the point |
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72 | * lies |
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73 | */ |
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74 | template< class DATA_TYPE > |
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75 | PlaneSide whichSide( const Plane<DATA_TYPE>& plane, |
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76 | const Point<DATA_TYPE, 3>& pt ) |
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77 | { |
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78 | DATA_TYPE dist = distance( plane, pt ); |
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79 | |
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80 | if ( dist < DATA_TYPE(0) ) |
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81 | return NEG_SIDE; |
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82 | else if ( dist > DATA_TYPE(0) ) |
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83 | return POS_SIDE; |
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84 | else |
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85 | return ON_PLANE; |
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86 | } |
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87 | |
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88 | /** |
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89 | * Determines which side of the plane the given point lies with the given |
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90 | * epsilon tolerance. |
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91 | * |
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92 | * @param plane the plane to compare the point to |
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93 | * @param pt the point to test |
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94 | * @param eps the epsilon tolerance to use while testing |
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95 | * |
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96 | * @return the PlaneSide enum describing on which side of the plane the point |
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97 | * lies |
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98 | */ |
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99 | template< class DATA_TYPE > |
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100 | PlaneSide whichSide( const Plane<DATA_TYPE>& plane, |
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101 | const Point<DATA_TYPE, 3>& pt, |
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102 | const DATA_TYPE& eps ) |
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103 | { |
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104 | DATA_TYPE dist = distance( plane, pt ); |
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105 | |
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106 | if ( dist < eps ) |
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107 | return NEG_SIDE; |
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108 | else if ( dist > eps ) |
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109 | return POS_SIDE; |
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110 | else |
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111 | return ON_PLANE; |
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112 | } |
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113 | |
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114 | /** |
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115 | * Finds the point on the plane that is nearest to the given point. As a |
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116 | * convenience, the distance between pt and result is returned. |
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117 | * |
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118 | * @param plane [in] the plane to compare the point to |
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119 | * @param pt [in] the point to test |
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120 | * @param result [out] the point on plane closest to pt |
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121 | * |
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122 | * @return the distance between pt and result |
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123 | */ |
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124 | template< class DATA_TYPE > |
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125 | DATA_TYPE findNearestPt( const Plane<DATA_TYPE>& plane, |
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126 | const Point<DATA_TYPE, 3>& pt, |
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127 | Point<DATA_TYPE, 3>& result ) |
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128 | { |
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129 | // GGI: p297 |
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130 | // GGII: p223 |
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131 | gmtlASSERT( isNormalized(plane.mNorm) ); // Assert: Normalized |
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132 | DATA_TYPE dist_to_plane(0); |
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133 | dist_to_plane = plane.mOffset + dot( plane.mNorm, static_cast< Vec<DATA_TYPE, 3> >(pt) ); |
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134 | result = pt - (plane.mNorm * dist_to_plane); |
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135 | return dist_to_plane; |
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136 | } |
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137 | |
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138 | /** |
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139 | * Mirror the point by the plane |
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140 | */ |
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141 | template< class DATA_TYPE, unsigned SIZE> |
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142 | void reflect( Point<DATA_TYPE, SIZE>& result, |
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143 | const Plane<DATA_TYPE>& plane, |
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144 | const Point<DATA_TYPE, SIZE>& point ) |
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145 | { |
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146 | gmtl::Point<DATA_TYPE, SIZE> point_on_plane; |
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147 | findNearestPt( plane, point, point_on_plane ); |
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148 | gmtl::Vec<DATA_TYPE, SIZE> dir = point_on_plane - point; |
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149 | result = point + (dir * DATA_TYPE(2.0f)); |
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150 | } |
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151 | /** @} */ |
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152 | |
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153 | /** @ingroup Compare Plane |
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154 | * @name Plane Comparitors |
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155 | * @{ |
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156 | */ |
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157 | |
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158 | /** |
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159 | * Compare two planes to see if they are EXACTLY the same. In other words, this |
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160 | * comparison is done with zero tolerance. |
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161 | * |
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162 | * @param p1 the first plane to compare |
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163 | * @param p2 the second plane to compare |
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164 | * |
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165 | * @return true if they are equal, false otherwise |
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166 | */ |
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167 | template< class DATA_TYPE > |
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168 | inline bool operator==( const Plane<DATA_TYPE>& p1, const Plane<DATA_TYPE>& p2 ) |
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169 | { |
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170 | return ( (p1.mNorm == p2.mNorm) && (p1.mOffset == p2.mOffset) ); |
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171 | } |
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172 | |
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173 | /** |
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174 | * Compare two planes to see if they are not EXACTLY the same. In other words, |
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175 | * this comparison is done with zero tolerance. |
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176 | * |
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177 | * @param p1 the first plane to compare |
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178 | * @param p2 the second plane to compare |
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179 | * |
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180 | * @return true if they are not equal, false otherwise |
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181 | */ |
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182 | template< class DATA_TYPE > |
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183 | inline bool operator!=( const Plane<DATA_TYPE>& p1, const Plane<DATA_TYPE>& p2 ) |
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184 | { |
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185 | return (! (p1 == p2)); |
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186 | } |
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187 | |
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188 | /** |
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189 | * Compare two planes to see if they are the same within the given tolerance. |
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190 | * |
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191 | * @param p1 the first plane to compare |
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192 | * @param p2 the second plane to compare |
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193 | * @param eps the tolerance value to use |
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194 | * |
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195 | * @pre eps must be >= 0 |
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196 | * |
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197 | * @return true if they are equal within a tolerance, false otherwise |
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198 | */ |
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199 | template< class DATA_TYPE > |
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200 | inline bool isEqual( const Plane<DATA_TYPE>& p1, const Plane<DATA_TYPE>& p2, |
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201 | const DATA_TYPE& eps ) |
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202 | { |
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203 | gmtlASSERT( eps >= 0 ); |
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204 | return ( (isEqual(p1.mNorm, p2.mNorm, eps)) && |
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205 | (Math::isEqual(p1.mOffset, p2.mOffset, eps)) ); |
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206 | } |
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207 | /** @} */ |
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208 | |
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209 | |
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210 | } // namespace gmtl |
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211 | |
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212 | #endif |
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213 | |
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