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 46namespace Imf { 47namespace { 48 49inline bool 50isNegative (float f) 51{ 52 union {float f; int i;} u; 53 u.f = f; 54 return (u.i & 0x80000000) != 0; 55} 56 57 58inline bool 59isNan (float f) 60{ 61 union {float f; int i;} u; 62 u.f = f; 63 return (u.i & 0x7fffffff) > 0x7f800000; 64} 65 66 67inline bool 68isInfinity (float f) 69{ 70 union {float f; int i;} u; 71 u.f = f; 72 return (u.i & 0x7fffffff) == 0x7f800000; 73} 74 75 76inline bool 77isFinite (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 87unsigned int 88halfToUint (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 100unsigned int 101floatToUint (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 113half 114uintToHalf (unsigned int ui) 115{ 116 if (ui > HALF_MAX) 117 return half::posInf(); 118 119 return half (ui); 120} 121 122 123half 124floatToHalf (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