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SDL_rwops.h
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/*
SDL - Simple DirectMedia Layer
Copyright (C) 1997, 1998, 1999, 2000, 2001 Sam Lantinga
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the Free
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
Sam Lantinga
slouken@devolution.com
*/
#ifdef SAVE_RCSID
static char rcsid =
"@(#) $Id$";
#endif
/* 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 <stdio.h>
#include "SDL_types.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 (*seek)(struct SDL_RWops *context, int 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 -1 if the read failed.
*/
int (*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 (*write)(struct SDL_RWops *context, const void *ptr, int size, int num);
/* Close and free an allocated SDL_FSops structure */
int (*close)(struct SDL_RWops *context);
Uint32 type;
union {
struct {
int autoclose;
FILE *fp;
} stdio;
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 * SDL_RWFromFile(const char *file, const char *mode);
extern DECLSPEC SDL_RWops * SDL_RWFromFP(FILE *fp, int autoclose);
extern DECLSPEC SDL_RWops * SDL_RWFromMem(void *mem, int size);
extern DECLSPEC SDL_RWops * SDL_AllocRW(void);
extern DECLSPEC void SDL_FreeRW(SDL_RWops *area);
/* 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, 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)
/* Ends C function definitions when using C++ */
#ifdef __cplusplus
}
#endif
#include "close_code.h"
#endif /* _SDL_RWops_h */