/*

    SDL - Simple DirectMedia Layer

    Copyright (C) 1997-2006 Sam Lantinga

    This library is free software; you can redistribute it and/or

    modify it under the terms of the GNU Lesser General Public

    License as published by the Free Software Foundation; either

    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,

    but WITHOUT ANY WARRANTY; without even the implied warranty of

    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public

    License along with this library; if not, write to the Free Software

    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga

    slouken@libsdl.org

*/

/**

 * \file SDL_rwops.h

 *

 * This file provides a general interface for SDL to read and write

 * data sources.  It can easily be extended to files, memory, etc.

 */

#ifndef _SDL_rwops_h

#define _SDL_rwops_h

#include "SDL_stdinc.h"

#include "SDL_error.h"

#include "begin_code.h"

/* Set up for C function definitions, even when using C++ */

#ifdef __cplusplus

/* *INDENT-OFF* */

extern "C" {

/* *INDENT-ON* */

#endif

/* This is the read/write operation structure -- very basic */

typedef struct SDL_RWops

{

    /* Seek to 'offset' relative to whence, one of stdio's whence values:

       RW_SEEK_SET, RW_SEEK_CUR, RW_SEEK_END

       Returns the final offset in the data source.

     */

    long (SDLCALL * seek) (struct SDL_RWops * context, long offset,

                           int whence);

    /* Read up to 'num' objects each of size 'objsize' from the data

       source to the area pointed at by 'ptr'.

       Returns the number of objects read, or 0 at error or end of file.

     */

      size_t(SDLCALL * read) (struct SDL_RWops * context, void *ptr,

                              size_t size, size_t maxnum);

    /* Write exactly 'num' objects each of size 'objsize' from the area

       pointed at by 'ptr' to data source.

       Returns the number of objects written, or 0 at error or end of file.

     */

      size_t(SDLCALL * write) (struct SDL_RWops * context, const void *ptr,

                               size_t size, size_t num);

    /* Close and free an allocated SDL_RWops structure.

       Returns 0 if successful or -1 on write error when flushing data.

     */

    int (SDLCALL * close) (struct SDL_RWops * context);

    Uint32 type;

    union

    {

#ifdef __WIN32__

        struct

        {

            SDL_bool append;

            void *h;

            struct

            {

                void *data;

                int size;

                int left;

            } buffer;

        } win32io;

#endif

#ifdef HAVE_STDIO_H

        struct

        {

            SDL_bool autoclose;

            FILE *fp;

        } stdio;

#endif

        struct

        {

            Uint8 *base;

            Uint8 *here;

            Uint8 *stop;

        } mem;

        struct

        {

            void *data1;

        } unknown;

    } hidden;

} SDL_RWops;

/* Functions to create SDL_RWops structures from various data sources */

extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromFile(const char *file,

                                                  const char *mode);

#ifdef HAVE_STDIO_H

extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromFP(FILE * fp,

                                                SDL_bool autoclose);

#endif

extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromMem(void *mem, int size);

extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromConstMem(const void *mem,

                                                      int size);

extern DECLSPEC SDL_RWops *SDLCALL SDL_AllocRW(void);

extern DECLSPEC void SDLCALL SDL_FreeRW(SDL_RWops * area);

#define RW_SEEK_SET	0       /* Seek from the beginning of data */

#define RW_SEEK_CUR	1       /* Seek relative to current read point */

#define RW_SEEK_END	2       /* Seek relative to the end of data */

/* Macros to easily read and write from an SDL_RWops structure */

#define SDL_RWseek(ctx, offset, whence)	(ctx)->seek(ctx, offset, whence)

#define SDL_RWtell(ctx)			(ctx)->seek(ctx, 0, RW_SEEK_CUR)

#define SDL_RWread(ctx, ptr, size, n)	(ctx)->read(ctx, ptr, size, n)

#define SDL_RWwrite(ctx, ptr, size, n)	(ctx)->write(ctx, ptr, size, n)

#define SDL_RWclose(ctx)		(ctx)->close(ctx)

/* Read an item of the specified endianness and return in native format */

extern DECLSPEC Uint16 SDLCALL SDL_ReadLE16(SDL_RWops * src);

extern DECLSPEC Uint16 SDLCALL SDL_ReadBE16(SDL_RWops * src);

extern DECLSPEC Uint32 SDLCALL SDL_ReadLE32(SDL_RWops * src);

extern DECLSPEC Uint32 SDLCALL SDL_ReadBE32(SDL_RWops * src);

extern DECLSPEC Uint64 SDLCALL SDL_ReadLE64(SDL_RWops * src);

extern DECLSPEC Uint64 SDLCALL SDL_ReadBE64(SDL_RWops * src);

/* Write an item of native format to the specified endianness */

extern DECLSPEC int SDLCALL SDL_WriteLE16(SDL_RWops * dst, Uint16 value);

extern DECLSPEC int SDLCALL SDL_WriteBE16(SDL_RWops * dst, Uint16 value);

extern DECLSPEC int SDLCALL SDL_WriteLE32(SDL_RWops * dst, Uint32 value);

extern DECLSPEC int SDLCALL SDL_WriteBE32(SDL_RWops * dst, Uint32 value);

extern DECLSPEC int SDLCALL SDL_WriteLE64(SDL_RWops * dst, Uint64 value);

extern DECLSPEC int SDLCALL SDL_WriteBE64(SDL_RWops * dst, Uint64 value);

/* Ends C function definitions when using C++ */

#ifdef __cplusplus

/* *INDENT-OFF* */

}

/* *INDENT-ON* */

#endif

#include "close_code.h"

#endif /* _SDL_rwops_h */

/* vi: set ts=4 sw=4 expandtab: */