PBRT
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00001 00002 // 00003 // Copyright (c) 2004, 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 #ifndef INCLUDED_IMF_VERSION_H 00037 #define INCLUDED_IMF_VERSION_H 00038 00039 //----------------------------------------------------------------------------- 00040 // 00041 // Magic and version number. 00042 // 00043 //----------------------------------------------------------------------------- 00044 00045 00046 namespace Imf { 00047 00048 00049 // 00050 // The MAGIC number is stored in the first four bytes of every 00051 // OpenEXR image file. This can be used to quickly test whether 00052 // a given file is an OpenEXR image file (see isImfMagic(), below). 00053 // 00054 00055 const int MAGIC = 20000630; 00056 00057 00058 // 00059 // The second item in each OpenEXR image file, right after the 00060 // magic number, is a four-byte file version identifier. Depending 00061 // on a file's version identifier, a file reader can enable various 00062 // backwards-compatibility switches, or it can quickly reject files 00063 // that it cannot read. 00064 // 00065 // The version identifier is split into an 8-bit version number, 00066 // and a 24-bit flags field. 00067 // 00068 00069 const int VERSION_NUMBER_FIELD = 0x000000ff; 00070 const int VERSION_FLAGS_FIELD = 0xffffff00; 00071 00072 00073 // 00074 // Value that goes into VERSION_NUMBER_FIELD. 00075 // 00076 00077 const int EXR_VERSION = 2; 00078 00079 00080 // 00081 // Flags that can go into VERSION_FLAGS_FIELD. 00082 // Flags can only occupy the 1 bits in VERSION_FLAGS_FIELD. 00083 // 00084 00085 const int TILED_FLAG = 0x00000200; // File is tiled 00086 00087 const int LONG_NAMES_FLAG = 0x00000400; // File contains long 00088 // attribute or channel 00089 // names 00090 00091 // 00092 // Bitwise OR of all known flags. 00093 // 00094 00095 const int ALL_FLAGS = TILED_FLAG | LONG_NAMES_FLAG; 00096 00097 00098 // 00099 // Utility functions 00100 // 00101 00102 inline bool isTiled (int version) {return !!(version & TILED_FLAG);} 00103 inline int makeTiled (int version) {return version | TILED_FLAG;} 00104 inline int makeNotTiled (int version) {return version & ~TILED_FLAG;} 00105 inline int getVersion (int version) {return version & VERSION_NUMBER_FIELD;} 00106 inline int getFlags (int version) {return version & VERSION_FLAGS_FIELD;} 00107 inline bool supportsFlags (int flags) {return !(flags & ~ALL_FLAGS);} 00108 00109 00110 // 00111 // Given the first four bytes of a file, returns true if the 00112 // file is probably an OpenEXR image file, false if not. 00113 // 00114 00115 bool isImfMagic (const char bytes[4]); 00116 00117 00118 } // namespace Imf 00119 00120 #endif