assimp/code/IFF.h

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// Definitions for the Interchange File Format (IFF)
// Alexander Gessler, 2006
// Adapted to Assimp August 2008
#ifndef AI_IFF_H_INCLUDED
#define AI_IFF_H_INCLUDED
#include "ByteSwapper.h"
namespace Assimp {
namespace IFF {
/////////////////////////////////////////////////////////////////////////////////
//! Describes an IFF chunk header
/////////////////////////////////////////////////////////////////////////////////
struct ChunkHeader
{
//! Type of the chunk header - FourCC
uint32_t type;
//! Length of the chunk data, in bytes
uint32_t length;
};
/////////////////////////////////////////////////////////////////////////////////
//! Describes an IFF sub chunk header
/////////////////////////////////////////////////////////////////////////////////
struct SubChunkHeader
{
//! Type of the chunk header - FourCC
uint32_t type;
//! Length of the chunk data, in bytes
uint16_t length;
};
#define AI_IFF_FOURCC(a,b,c,d) ((uint32_t) (((uint8_t)a << 24u) | \
((uint8_t)b << 16u) | ((uint8_t)c << 8u) | ((uint8_t)d)))
#define AI_IFF_FOURCC_FORM AI_IFF_FOURCC('F','O','R','M')
/////////////////////////////////////////////////////////////////////////////////
//! Load a chunk header
//! @param outFile Pointer to the file data - points to the chunk data afterwards
//! @return Copy of the chunk header
/////////////////////////////////////////////////////////////////////////////////
inline ChunkHeader LoadChunk(uint8_t*& outFile)
{
ChunkHeader head;
::memcpy(&head.type, outFile, 4);
outFile += 4;
::memcpy(&head.length, outFile, 4);
outFile += 4;
AI_LSWAP4(head.length);
AI_LSWAP4(head.type);
return head;
}
/////////////////////////////////////////////////////////////////////////////////
//! Load a sub chunk header
//! @param outFile Pointer to the file data - points to the chunk data afterwards
//! @return Copy of the sub chunk header
/////////////////////////////////////////////////////////////////////////////////
inline SubChunkHeader LoadSubChunk(uint8_t*& outFile)
{
SubChunkHeader head;
::memcpy(&head.type, outFile, 4);
outFile += 4;
::memcpy(&head.length, outFile, 2);
outFile += 2;
AI_LSWAP2(head.length);
AI_LSWAP4(head.type);
return head;
}
/////////////////////////////////////////////////////////////////////////////////
//! Read the file header and return the type of the file and its size
//! @param outFile Pointer to the file data. The buffer must at
//! least be 12 bytes large.
//! @param fileType Receives the type of the file
//! @return 0 if everything was OK, otherwise an error message
/////////////////////////////////////////////////////////////////////////////////
inline const char* ReadHeader(uint8_t* outFile, uint32_t& fileType)
{
ChunkHeader head = LoadChunk(outFile);
if(AI_IFF_FOURCC_FORM != head.type)
{
return "The file is not an IFF file: FORM chunk is missing";
}
::memcpy(&fileType, outFile, 4);
AI_LSWAP4(fileType);
return 0;
}
}}
#endif // !! AI_IFF_H_INCLUDED