/*

    SDL - Simple DirectMedia Layer

    Copyright (C) 1997-2009 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

extern "C" {

#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:

	 *	SEEK_SET, SEEK_CUR, SEEK_END

	 *  Returns the final offset in the data source.

	 */

	int (SDLCALL *seek)(struct SDL_RWops *context, int offset, int whence);

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

	 *  source to the area pointed at by 'ptr'.

	 *  Returns the number of objects read, or -1 if the read failed.

	 */

	int (SDLCALL *read)(struct SDL_RWops *context, void *ptr, int size, int maxnum);

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

	 *  pointed at by 'ptr' to data source.

	 *  Returns 'num', or -1 if the write failed.

	 */

	int (SDLCALL *write)(struct SDL_RWops *context, const void *ptr, int size, int num);

	/** Close and free an allocated SDL_FSops structure */

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

	Uint32 type;

	union {

#if defined(__WIN32__) && !defined(__SYMBIAN32__)

	    struct {

		int   append;

		void *h;

		struct {

		    void *data;

		    int size;

		    int left;

		} buffer;

	    } win32io;

#endif

#ifdef HAVE_STDIO_H 

	    struct {

		int autoclose;

	 	FILE *fp;

	    } stdio;

#endif

	    struct {

		Uint8 *base;

	 	Uint8 *here;

		Uint8 *stop;

	    } mem;

	    struct {

		void *data1;

	    } unknown;

	} hidden;

} SDL_RWops;

/** @name 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, int 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);

/*@}*/

/** @name Seek Reference Points */

/*@{*/

#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 */

/*@}*/

/** @name 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)

/*@}*/

/** @name 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);

/*@}*/

/** @name 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

}

#endif

#include "close_code.h"

#endif /* _SDL_rwops_h */