assimp/include/aiFileIO.h

/*
---------------------------------------------------------------------------
Open Asset Import Library (ASSIMP)
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Copyright (c) 2006-2008, ASSIMP Development Team

All rights reserved.

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  following disclaimer.

* Redistributions in binary form must reproduce the above
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  derived from this software without specific prior
  written permission of the ASSIMP Development Team.

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

/** @file aiFileIO.h
 *  @brief Defines generic C routines to access memory-mapped files
 */
#ifndef AI_FILEIO_H_INC
#define AI_FILEIO_H_INC

#include "aiTypes.h"
#ifdef __cplusplus
extern "C" {
#endif
struct aiFileIO;
struct aiFile;

// aiFile callbacks
typedef size_t   (*aiFileWriteProc) (C_STRUCT aiFile*,   const char*, size_t, size_t);
typedef size_t   (*aiFileReadProc)  (C_STRUCT aiFile*,   char*, size_t,size_t);
typedef size_t   (*aiFileTellProc)  (C_STRUCT aiFile*);
typedef void     (*aiFileFlushProc) (C_STRUCT aiFile*);
typedef aiReturn (*aiFileSeek)(C_STRUCT aiFile*, size_t, aiOrigin);

// aiFileIO callbacks
typedef aiFile* (*aiFileOpenProc)  (C_STRUCT aiFileIO*, const char*, const char*);
typedef void    (*aiFileCloseProc) (C_STRUCT aiFileIO*, C_STRUCT aiFile*);

// Represents user-defined data
typedef char* aiUserData;

// ----------------------------------------------------------------------------------
/** @brief C-API: File system callbacks
 *
 *  Provided are functions to open and close files. Supply a custom structure to
 *  the import function. If you don't, a default implementation is used. Use custom
 *  file systems to enable reading from other sources, such as ZIPs 
 *  or memory locations. */
struct aiFileIO
{
	/** Function used to open a new file
	 */
	aiFileOpenProc OpenProc;

	/** Function used to close an existing file
	 */
	aiFileCloseProc CloseProc;

	/** User-defined, opaque data */
	aiUserData UserData;
};

// ----------------------------------------------------------------------------------
/** @brief C-API: File callbacks
 *
 *  Actually, it's a data structure to wrap a set of fXXXX (e.g fopen) 
 *  replacement functions.
 *
 *  The default implementation of the functions utilizes the fXXX functions from 
 *  the CRT. However, you can supply a custom implementation to Assimp by
 *  delivering a custom aiFileIO. Use this to enable reading from other sources, 
 *  such as ZIP archives or memory locations. */
struct aiFile
{
	/** Callback to read from a file */
	aiFileReadProc ReadProc;

	/** Callback to write to a file */
	aiFileWriteProc WriteProc;

	/** Callback to retrieve the current position of 
	 *  the file cursor (ftell())
	 */
	aiFileTellProc TellProc;

	/** Callback to retrieve the size of the file, 
	 *  in bytes
	 */
	aiFileTellProc FileSizeProc;

	/** Callback to set the current position
	 * of the file cursor (fseek())
	 */
	aiFileSeek SeekProc;

	/** Callback to flush the file contents
	 */
	aiFileFlushProc FlushProc;

	/** User-defined, opaque data
	 */
	aiUserData UserData;
};

#ifdef __cplusplus
}
#endif
#endif // AI_FILEIO_H_INC