source: NonGTP/OpenEXR/include/IlmImf/ImfVersion.h @ 855

///////////////////////////////////////////////////////////////////////////
//
// Copyright (c) 2004, Industrial Light & Magic, a division of Lucas
// Digital Ltd. LLC
// 
// All rights reserved.
// 
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// modification, are permitted provided that the following conditions are
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///////////////////////////////////////////////////////////////////////////


#ifndef INCLUDED_IMF_VERSION_H
#define INCLUDED_IMF_VERSION_H

//-----------------------------------------------------------------------------
//
//      Magic and version number.
//
//-----------------------------------------------------------------------------


namespace Imf {


//
// The MAGIC number is stored in the first four bytes of every
// OpenEXR image file.  This can be used to quickly test whether
// a given file is an OpenEXR image file (see isImfMagic(), below).
//

const int MAGIC = 20000630;


//
// The second item in each OpenEXR image file, right after the
// magic number, is a four-byte file version identifier.  Depending
// on a file's version identifier, a file reader can enable various
// backwards-compatibility switches, or it can quickly reject files
// that it cannot read.
//
// The version identifier is split into an 8-bit version number,
// and a 24-bit flags field.
//

const int VERSION_NUMBER_FIELD  = 0x000000ff;
const int VERSION_FLAGS_FIELD   = 0xffffff00;


//
// Value that goes into VERSION_NUMBER_FIELD.
//

const int EXR_VERSION           = 2;


//
// Flags that can go into VERSION_FLAGS_FIELD.
// Flags can only occupy the 1 bits in VERSION_FLAGS_FIELD.
//

const int TILED_FLAG            = 0x00000200;


//
// Bitwise OR of all known flags.
//

const int ALL_FLAGS             = TILED_FLAG;


//
// Utility functions
//

inline bool  isTiled (int version)      {return !!(version & TILED_FLAG);}
inline int   makeTiled (int version)    {return version | TILED_FLAG;}
inline int   makeNotTiled (int version) {return version & ~TILED_FLAG;}
inline int   getVersion (int version)   {return version & VERSION_NUMBER_FIELD;}
inline int   getFlags (int version)     {return version & VERSION_FLAGS_FIELD;}
inline bool  supportsFlags (int flags)  {return !(flags & ~ALL_FLAGS);}


//
// Given the first four bytes of a file, returns true if the
// file is probably an OpenEXR image file, false if not.
//

bool         isImfMagic (const char bytes[4]);


} // namespace Imf

#endif