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SDL_rwops.h
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/*
SDL - Simple DirectMedia Layer
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Copyright (C) 1997-2009 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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*/
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/**
* \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.
*/
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#ifndef _SDL_rwops_h
#define _SDL_rwops_h
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#include "SDL_stdinc.h"
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#include "SDL_error.h"
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#include "begin_code.h"
/* Set up for C function definitions, even when using C++ */
#ifdef __cplusplus
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/* *INDENT-OFF* */
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extern "C" {
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/* *INDENT-ON* */
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#endif
/* This is the read/write operation structure -- very basic */
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typedef struct SDL_RWops
{
/* Seek to 'offset' relative to whence, one of stdio's whence values:
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RW_SEEK_SET, RW_SEEK_CUR, RW_SEEK_END
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Returns the final offset in the data source.
*/
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long (SDLCALL * seek) (struct SDL_RWops * context, long 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'.
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Returns the number of objects read, or 0 at error or end of file.
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size_t(SDLCALL * read) (struct SDL_RWops * context, void *ptr,
size_t size, size_t maxnum);
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/* Write exactly 'num' objects each of size 'objsize' from the area
pointed at by 'ptr' to data source.
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Returns the number of objects written, or 0 at error or end of file.
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size_t(SDLCALL * write) (struct SDL_RWops * context, const void *ptr,
size_t size, size_t num);
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/* Close and free an allocated SDL_RWops structure.
Returns 0 if successful or -1 on write error when flushing data.
*/
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int (SDLCALL * close) (struct SDL_RWops * context);
Uint32 type;
union
{
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#ifdef __WIN32__
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SDL_bool append;
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struct
{
void *data;
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size_t size;
size_t left;
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#ifdef HAVE_STDIO_H
struct
{
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SDL_bool autoclose;
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FILE *fp;
} stdio;
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struct
{
Uint8 *base;
Uint8 *here;
Uint8 *stop;
} mem;
struct
{
void *data1;
} unknown;
} hidden;
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} 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,
SDL_bool autoclose);
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extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromMem(void *mem, int size);
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)
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/* Read an item of the specified endianness and return in native format */
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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);
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/* Write an item of native format to the specified endianness */
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extern DECLSPEC size_t SDLCALL SDL_WriteLE16(SDL_RWops * dst, Uint16 value);
extern DECLSPEC size_t SDLCALL SDL_WriteBE16(SDL_RWops * dst, Uint16 value);
extern DECLSPEC size_t SDLCALL SDL_WriteLE32(SDL_RWops * dst, Uint32 value);
extern DECLSPEC size_t SDLCALL SDL_WriteBE32(SDL_RWops * dst, Uint32 value);
extern DECLSPEC size_t SDLCALL SDL_WriteLE64(SDL_RWops * dst, Uint64 value);
extern DECLSPEC size_t SDLCALL SDL_WriteBE64(SDL_RWops * dst, Uint64 value);
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/* Ends C function definitions when using C++ */
#ifdef __cplusplus
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/* *INDENT-OFF* */
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}
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/* *INDENT-ON* */
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#endif
#include "close_code.h"
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#endif /* _SDL_rwops_h */
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/* vi: set ts=4 sw=4 expandtab: */