///////////////////////////////////////////////////////////////////////////

//

// Copyright (c) 2004, Industrial Light & Magic, a division of Lucas

// Digital Ltd. LLC

// 

// All rights reserved.

// 

// Redistribution and use in source and binary forms, with or without

// modification, are permitted provided that the following conditions are

// met:

// *       Redistributions of source code must retain the above copyright

// notice, this list of conditions and the following disclaimer.

// *       Redistributions in binary form must reproduce the above

// copyright notice, this list of conditions and the following disclaimer

// in the documentation and/or other materials provided with the

// distribution.

// *       Neither the name of Industrial Light & Magic nor the names of

// its contributors may be used to endorse or promote products derived

// from this software without specific prior written permission. 

// 

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

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// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

//

///////////////////////////////////////////////////////////////////////////

#ifndef INCLUDED_IMF_VERSION_H

#define INCLUDED_IMF_VERSION_H

//-----------------------------------------------------------------------------

//

//  Magic and version number.

//

//-----------------------------------------------------------------------------

#include "ImfExport.h"

#include "ImfNamespace.h"

OPENEXR_IMF_INTERNAL_NAMESPACE_HEADER_ENTER

//

// 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;   // File is tiled

const int LONG_NAMES_FLAG       = 0x00000400;   // File contains long

                                                // attribute or channel

                                                // names

const int NON_IMAGE_FLAG        = 0x00000800;   // File has at least one part

                                                // which is not a regular

                                                // scanline image or regular tiled image

                                                // (that is, it is a deep format)

const int MULTI_PART_FILE_FLAG  = 0x00001000;   // File has multiple parts

//

// Bitwise OR of all known flags.

//

const int ALL_FLAGS   = TILED_FLAG | LONG_NAMES_FLAG |

                                  NON_IMAGE_FLAG | MULTI_PART_FILE_FLAG;

//

// Utility functions

//

inline bool  isTiled (int version)  {return !!(version & TILED_FLAG);}

inline bool  isMultiPart (int version)  {return version & MULTI_PART_FILE_FLAG; }

inline bool  isNonImage(int version)    {return version & NON_IMAGE_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.

//

IMF_EXPORT 

bool       isImfMagic (const char bytes[4]);

OPENEXR_IMF_INTERNAL_NAMESPACE_HEADER_EXIT

#endif