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 // 38 // Routines for converting between pixel data types, 39 // with well-defined behavior for exceptional cases. 40 // 41 //----------------------------------------------------------------------------- 42 43 #include <ImfConvert.h> 44 #include <limits.h> 45 46 namespace Imf { 47 namespace { 48 49 inline bool 50 isNegative (float f) 51 { 52 union {float f; int i;} u; 53 u.f = f; 54 return (u.i & 0x80000000) != 0; 55 } 56 57 58 inline bool 59 isNan (float f) 60 { 61 union {float f; int i;} u; 62 u.f = f; 63 return (u.i & 0x7fffffff) > 0x7f800000; 64 } 65 66 67 inline bool 68 isInfinity (float f) 69 { 70 union {float f; int i;} u; 71 u.f = f; 72 return (u.i & 0x7fffffff) == 0x7f800000; 73 } 74 75 76 inline bool 77 isFinite (float f) 78 { 79 union {float f; int i;} u; 80 u.f = f; 81 return (u.i & 0x7f800000) != 0x7f800000; 82 } 83 84 } // namespace 85 86 87 unsigned int 88 halfToUint (half h) 89 { 90 if (h.isNegative() || h.isNan()) 91 return 0; 92 93 if (h.isInfinity()) 94 return UINT_MAX; 95 96 return (unsigned int) h; 97 } 98 99 100 unsigned int 101 floatToUint (float f) 102 { 103 if (isNegative (f) || isNan (f)) 104 return 0; 105 106 if (isInfinity (f) || f > UINT_MAX) 107 return UINT_MAX; 108 109 return (unsigned int) f; 110 } 111 112 113 half 114 uintToHalf (unsigned int ui) 115 { 116 if (ui > HALF_MAX) 117 return half::posInf(); 118 119 return half (ui); 120 } 121 122 123 half 124 floatToHalf (float f) 125 { 126 if (isFinite (f)) 127 { 128 if (f > HALF_MAX) 129 return half::posInf(); 130 131 if (f < -HALF_MAX) 132 return half::negInf(); 133 } 134 135 return half (f); 136 } 137 138 139 } // namespace Imf 140
