1 /////////////////////////////////////////////////////////////////////////// 2 // 3 // Copyright (c) 2002, Industrial Light & Magic, a division of Lucas 4 // Digital Ltd. LLC 5 // 6 // All rights reserved. 7 // 8 // Redistribution and use in source and binary forms, with or without 9 // modification, are permitted provided that the following conditions are 10 // met: 11 // * Redistributions of source code must retain the above copyright 12 // notice, this list of conditions and the following disclaimer. 13 // * Redistributions in binary form must reproduce the above 14 // copyright notice, this list of conditions and the following disclaimer 15 // in the documentation and/or other materials provided with the 16 // distribution. 17 // * Neither the name of Industrial Light & Magic nor the names of 18 // its contributors may be used to endorse or promote products derived 19 // from this software without specific prior written permission. 20 // 21 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 24 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 25 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 26 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 27 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 28 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 29 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 30 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 31 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 // 33 /////////////////////////////////////////////////////////////////////////// 34 35 36 37 #ifndef INCLUDED_IMF_LUT_H 38 #define INCLUDED_IMF_LUT_H 39 40 //----------------------------------------------------------------------------- 41 // 42 // Lookup tables for efficient application 43 // of half --> half functions to pixel data, 44 // and some commonly applied functions. 45 // 46 //----------------------------------------------------------------------------- 47 48 #include <ImfRgbaFile.h> 49 #include <ImfFrameBuffer.h> 50 #include "ImathBox.h" 51 #include "halfFunction.h" 52 53 namespace Imf { 54 55 // 56 // Lookup table for individual half channels. 57 // 58 59 class HalfLut 60 { 61 public: 62 63 //------------ 64 // Constructor 65 //------------ 66 67 template <class Function> 68 HalfLut (Function f); 69 70 71 //---------------------------------------------------------------------- 72 // Apply the table to data[0], data[stride] ... data[(nData-1) * stride] 73 //---------------------------------------------------------------------- 74 75 void apply (half *data, 76 int nData, 77 int stride = 1) const; 78 79 80 //--------------------------------------------------------------- 81 // Apply the table to a frame buffer slice (see ImfFrameBuffer.h) 82 //--------------------------------------------------------------- 83 84 void apply (const Slice &data, 85 const Imath::Box2i &dataWindow) const; 86 87 private: 88 89 halfFunction <half> _lut; 90 }; 91 92 93 // 94 // Lookup table for combined RGBA data. 95 // 96 97 class RgbaLut 98 { 99 public: 100 101 //------------ 102 // Constructor 103 //------------ 104 105 template <class Function> 106 RgbaLut (Function f, RgbaChannels chn = WRITE_RGB); 107 108 109 //---------------------------------------------------------------------- 110 // Apply the table to data[0], data[stride] ... data[(nData-1) * stride] 111 //---------------------------------------------------------------------- 112 113 void apply (Rgba *data, 114 int nData, 115 int stride = 1) const; 116 117 118 //----------------------------------------------------------------------- 119 // Apply the table to a frame buffer (see RgbaOutpuFile.setFrameBuffer()) 120 //----------------------------------------------------------------------- 121 122 void apply (Rgba *base, 123 int xStride, 124 int yStride, 125 const Imath::Box2i &dataWindow) const; 126 127 private: 128 129 halfFunction <half> _lut; 130 RgbaChannels _chn; 131 }; 132 133 134 // 135 // 12bit log rounding reduces data to 20 stops with 200 steps per stop. 136 // That makes 4000 numbers. An extra 96 just come along for the ride. 137 // Zero explicitly remains zero. The first non-zero half will map to 1 138 // in the 0-4095 12log space. A nice power of two number is placed at 139 // the center [2000] and that number is near 0.18. 140 // 141 142 half round12log (half x); 143 144 145 // 146 // Round to n-bit precision (n should be between 0 and 10). 147 // After rounding, the significand's 10-n least significant 148 // bits will be zero. 149 // 150 151 struct roundNBit 152 { 153 roundNBit (int n): n(n) {} 154 half operator () (half x) {return x.round(n);} 155 int n; 156 }; 157 158 159 // 160 // Template definitions 161 // 162 163 164 template <class Function> 165 HalfLut::HalfLut (Function f): 166 _lut(f, -HALF_MAX, HALF_MAX, half (0), 167 half::posInf(), half::negInf(), half::qNan()) 168 { 169 // empty 170 } 171 172 173 template <class Function> 174 RgbaLut::RgbaLut (Function f, RgbaChannels chn): 175 _lut(f, -HALF_MAX, HALF_MAX, half (0), 176 half::posInf(), half::negInf(), half::qNan()), 177 _chn(chn) 178 { 179 // empty 180 } 181 182 183 } // namespace Imf 184 185 #endif 186