SDL_rwops.h
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/*
SDL - Simple DirectMedia Layer
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Copyright (C) 1997-2006 Sam Lantinga
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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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
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Lesser General Public License for more details.
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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
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Sam Lantinga
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slouken@libsdl.org
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*/
/* 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
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#include "SDL_config.h"
#ifdef HAVE_STDIO_H
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#include <stdio.h>
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#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.
*/
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int (SDLCALL *seek)(struct SDL_RWops *context, int offset, int whence);
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/* 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.
*/
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int (SDLCALL *read)(struct SDL_RWops *context, void *ptr, int size, int maxnum);
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/* 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.
*/
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int (SDLCALL *write)(struct SDL_RWops *context, const void *ptr, int size, int num);
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/* Close and free an allocated SDL_FSops structure */
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int (SDLCALL *close)(struct SDL_RWops *context);
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Uint32 type;
union {
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#ifdef HAVE_STDIO_H
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struct {
int autoclose;
FILE *fp;
} stdio;
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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 */
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extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromFile(const char *file, const char *mode);
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#ifdef HAVE_STDIO_H
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extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromFP(FILE *fp, int autoclose);
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extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromMem(void *mem, int size);
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extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromConstMem(const void *mem, int size);
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extern DECLSPEC SDL_RWops * SDLCALL SDL_AllocRW(void);
extern DECLSPEC void SDLCALL SDL_FreeRW(SDL_RWops *area);
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#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 */
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/* Macros to easily read and write from an SDL_RWops structure */
#define SDL_RWseek(ctx, offset, whence) (ctx)->seek(ctx, offset, whence)
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#define SDL_RWtell(ctx) (ctx)->seek(ctx, 0, RW_SEEK_CUR)
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#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 */