ImfVersion.h 4.7 KB

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  1. ///////////////////////////////////////////////////////////////////////////
  2. //
  3. // Copyright (c) 2004, 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. #ifndef INCLUDED_IMF_VERSION_H
  35. #define INCLUDED_IMF_VERSION_H
  36. //-----------------------------------------------------------------------------
  37. //
  38. // Magic and version number.
  39. //
  40. //-----------------------------------------------------------------------------
  41. #include "ImfExport.h"
  42. #include "ImfNamespace.h"
  43. OPENEXR_IMF_INTERNAL_NAMESPACE_HEADER_ENTER
  44. //
  45. // The MAGIC number is stored in the first four bytes of every
  46. // OpenEXR image file. This can be used to quickly test whether
  47. // a given file is an OpenEXR image file (see isImfMagic(), below).
  48. //
  49. const int MAGIC = 20000630;
  50. //
  51. // The second item in each OpenEXR image file, right after the
  52. // magic number, is a four-byte file version identifier. Depending
  53. // on a file's version identifier, a file reader can enable various
  54. // backwards-compatibility switches, or it can quickly reject files
  55. // that it cannot read.
  56. //
  57. // The version identifier is split into an 8-bit version number,
  58. // and a 24-bit flags field.
  59. //
  60. const int VERSION_NUMBER_FIELD = 0x000000ff;
  61. const int VERSION_FLAGS_FIELD = 0xffffff00;
  62. //
  63. // Value that goes into VERSION_NUMBER_FIELD.
  64. //
  65. const int EXR_VERSION = 2;
  66. //
  67. // Flags that can go into VERSION_FLAGS_FIELD.
  68. // Flags can only occupy the 1 bits in VERSION_FLAGS_FIELD.
  69. //
  70. const int TILED_FLAG = 0x00000200; // File is tiled
  71. const int LONG_NAMES_FLAG = 0x00000400; // File contains long
  72. // attribute or channel
  73. // names
  74. const int NON_IMAGE_FLAG = 0x00000800; // File has at least one part
  75. // which is not a regular
  76. // scanline image or regular tiled image
  77. // (that is, it is a deep format)
  78. const int MULTI_PART_FILE_FLAG = 0x00001000; // File has multiple parts
  79. //
  80. // Bitwise OR of all known flags.
  81. //
  82. const int ALL_FLAGS = TILED_FLAG | LONG_NAMES_FLAG |
  83. NON_IMAGE_FLAG | MULTI_PART_FILE_FLAG;
  84. //
  85. // Utility functions
  86. //
  87. inline bool isTiled (int version) {return !!(version & TILED_FLAG);}
  88. inline bool isMultiPart (int version) {return !!(version & MULTI_PART_FILE_FLAG); }
  89. inline bool isNonImage(int version) {return !!(version & NON_IMAGE_FLAG); }
  90. inline int makeTiled (int version) {return version | TILED_FLAG;}
  91. inline int makeNotTiled (int version) {return version & ~TILED_FLAG;}
  92. inline int getVersion (int version) {return version & VERSION_NUMBER_FIELD;}
  93. inline int getFlags (int version) {return version & VERSION_FLAGS_FIELD;}
  94. inline bool supportsFlags (int flags) {return !(flags & ~ALL_FLAGS);}
  95. //
  96. // Given the first four bytes of a file, returns true if the
  97. // file is probably an OpenEXR image file, false if not.
  98. //
  99. IMF_EXPORT
  100. bool isImfMagic (const char bytes[4]);
  101. OPENEXR_IMF_INTERNAL_NAMESPACE_HEADER_EXIT
  102. #endif