/*

     SDL - Simple DirectMedia Layer

     Copyright (C) 1997-2006 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

 /* *INDENT-OFF* */

 extern "C" {

 /* *INDENT-ON* */

 #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 '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 (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

     {

 #ifdef __WIN32__

         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;

 /* 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);

 #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 */

 /* 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)

 /* 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);

 /* 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

 /* *INDENT-OFF* */

 }

 /* *INDENT-ON* */

 #endif

 #include "close_code.h"

 #endif /* _SDL_rwops_h */

 /* vi: set ts=4 sw=4 expandtab: */