assimp/include/assimp/cfileio.h

/*
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Open Asset Import Library (assimp)
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*/

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

#ifdef __GNUC__
#   pragma GCC system_header
#endif

#include <assimp/types.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 C_ENUM aiReturn (*aiFileSeek)      (C_STRUCT aiFile*, size_t, C_ENUM aiOrigin);

// aiFileIO callbacks
typedef C_STRUCT 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