//
// SPDX-License-Identifier: BSD-3-Clause
// Copyright (c) Contributors to the OpenEXR Project.
//
#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).
//
static 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.
//
static const int VERSION_NUMBER_FIELD = 0x000000ff;
static const int VERSION_FLAGS_FIELD = 0xffffff00;
//
// Value that goes into VERSION_NUMBER_FIELD.
//
static const int EXR_VERSION = 2;
//
// Flags that can go into VERSION_FLAGS_FIELD.
// Flags can only occupy the 1 bits in VERSION_FLAGS_FIELD.
//
static const int TILED_FLAG = 0x00000200; // File is tiled
static
const int LONG_NAMES_FLAG = 0x00000400; // File contains long
// attribute or channel
// names
static
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)
static
const int MULTI_PART_FILE_FLAG = 0x00001000; // File has multiple parts
//
// Bitwise OR of all known flags.
//
static
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
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