text: /*
      SDL - Simple DirectMedia Layer
      Copyright (C) 1997-2004 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@libsdl.org
  */
  
  #ifdef SAVE_RCSID
  static char rcsid =
   "@(#) $Id: SDL_rwops.h,v 1.1 2006/01/06 02:37:08 harkon Exp $";
  #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 * SDLCALL SDL_RWFromFile(const char *file, const char *mode);
  
  extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromFP(FILE *fp, int autoclose);
  
  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);
  
  /* 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 */
  