PBRT
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00001 00002 // 00003 // Copyright (c) 2002, Industrial Light & Magic, a division of Lucas 00004 // Digital Ltd. LLC 00005 // 00006 // All rights reserved. 00007 // 00008 // Redistribution and use in source and binary forms, with or without 00009 // modification, are permitted provided that the following conditions are 00010 // met: 00011 // * Redistributions of source code must retain the above copyright 00012 // notice, this list of conditions and the following disclaimer. 00013 // * Redistributions in binary form must reproduce the above 00014 // copyright notice, this list of conditions and the following disclaimer 00015 // in the documentation and/or other materials provided with the 00016 // distribution. 00017 // * Neither the name of Industrial Light & Magic nor the names of 00018 // its contributors may be used to endorse or promote products derived 00019 // from this software without specific prior written permission. 00020 // 00021 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 00022 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 00023 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 00024 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 00025 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 00026 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 00027 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 00028 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 00029 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 00030 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 00031 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 00032 // 00034 00035 00036 00037 #ifndef INCLUDED_IMATHVECALGO_H 00038 #define INCLUDED_IMATHVECALGO_H 00039 00040 //------------------------------------------------------------------------- 00041 // 00042 // This file contains algorithms applied to or in conjunction 00043 // with points (Imath::Vec2 and Imath::Vec3). 00044 // The assumption made is that these functions are called much 00045 // less often than the basic point functions or these functions 00046 // require more support classes. 00047 // 00048 //------------------------------------------------------------------------- 00049 00050 #include "ImathVec.h" 00051 #include "ImathLimits.h" 00052 00053 namespace Imath { 00054 00055 00056 //----------------------------------------------------------------- 00057 // Find the projection of vector t onto vector s (Vec2, Vec3, Vec4) 00058 //----------------------------------------------------------------- 00059 00060 template <class Vec> Vec project (const Vec &s, const Vec &t); 00061 00062 00063 //------------------------------------------------ 00064 // Find a vector that is perpendicular to s and 00065 // in the same plane as s and t (Vec2, Vec3, Vec4) 00066 //------------------------------------------------ 00067 00068 template <class Vec> Vec orthogonal (const Vec &s, const Vec &t); 00069 00070 00071 //----------------------------------------------- 00072 // Find the direction of a ray s after reflection 00073 // off a plane with normal t (Vec2, Vec3, Vec4) 00074 //----------------------------------------------- 00075 00076 template <class Vec> Vec reflect (const Vec &s, const Vec &t); 00077 00078 00079 //-------------------------------------------------------------------- 00080 // Find the vertex of triangle (v0, v1, v2) that is closest to point p 00081 // (Vec2, Vec3, Vec4) 00082 //-------------------------------------------------------------------- 00083 00084 template <class Vec> Vec closestVertex (const Vec &v0, 00085 const Vec &v1, 00086 const Vec &v2, 00087 const Vec &p); 00088 00089 //--------------- 00090 // Implementation 00091 //--------------- 00092 00093 template <class Vec> 00094 Vec 00095 project (const Vec &s, const Vec &t) 00096 { 00097 Vec sNormalized = s.normalized(); 00098 return sNormalized * (sNormalized ^ t); 00099 } 00100 00101 template <class Vec> 00102 Vec 00103 orthogonal (const Vec &s, const Vec &t) 00104 { 00105 return t - project (s, t); 00106 } 00107 00108 template <class Vec> 00109 Vec 00110 reflect (const Vec &s, const Vec &t) 00111 { 00112 return s - typename Vec::BaseType(2) * (s - project(t, s)); 00113 } 00114 00115 template <class Vec> 00116 Vec 00117 closestVertex(const Vec &v0, 00118 const Vec &v1, 00119 const Vec &v2, 00120 const Vec &p) 00121 { 00122 Vec nearest = v0; 00123 typename Vec::BaseType neardot = (v0 - p).length2(); 00124 typename Vec::BaseType tmp = (v1 - p).length2(); 00125 00126 if (tmp < neardot) 00127 { 00128 neardot = tmp; 00129 nearest = v1; 00130 } 00131 00132 tmp = (v2 - p).length2(); 00133 00134 if (tmp < neardot) 00135 { 00136 neardot = tmp; 00137 nearest = v2; 00138 } 00139 00140 return nearest; 00141 } 00142 00143 00144 } // namespace Imath 00145 00146 #endif