include/SDL_rwops.h
author Sam Lantinga <slouken@libsdl.org>
Wed, 01 Feb 2006 06:32:25 +0000
changeset 1312 c9b51268668f
parent 930 02759105b989
child 1330 450721ad5436
permissions -rw-r--r--
Updated copyright information and removed rcs id lines (problematic in branch merges)
I batch edited these files, so please let me know if I've accidentally removed anybody's
credit here.
     1 /*
     2     SDL - Simple DirectMedia Layer
     3     Copyright (C) 1997-2006 Sam Lantinga
     4 
     5     This library is free software; you can redistribute it and/or
     6     modify it under the terms of the GNU Lesser General Public
     7     License as published by the Free Software Foundation; either
     8     version 2.1 of the License, or (at your option) any later version.
     9 
    10     This library is distributed in the hope that it will be useful,
    11     but WITHOUT ANY WARRANTY; without even the implied warranty of
    12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    13     Lesser General Public License for more details.
    14 
    15     You should have received a copy of the GNU Lesser General Public
    16     License along with this library; if not, write to the Free Software
    17     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
    18 
    19     Sam Lantinga
    20     slouken@libsdl.org
    21 */
    22 
    23 /* This file provides a general interface for SDL to read and write
    24    data sources.  It can easily be extended to files, memory, etc.
    25 */
    26 
    27 #ifndef _SDL_RWops_h
    28 #define _SDL_RWops_h
    29 
    30 #include <stdio.h>
    31 
    32 #include "SDL_types.h"
    33 
    34 #include "begin_code.h"
    35 /* Set up for C function definitions, even when using C++ */
    36 #ifdef __cplusplus
    37 extern "C" {
    38 #endif
    39 
    40 /* This is the read/write operation structure -- very basic */
    41 
    42 typedef struct SDL_RWops {
    43 	/* Seek to 'offset' relative to whence, one of stdio's whence values:
    44 		SEEK_SET, SEEK_CUR, SEEK_END
    45 	   Returns the final offset in the data source.
    46 	 */
    47 	int (SDLCALL *seek)(struct SDL_RWops *context, int offset, int whence);
    48 
    49 	/* Read up to 'num' objects each of size 'objsize' from the data
    50 	   source to the area pointed at by 'ptr'.
    51 	   Returns the number of objects read, or -1 if the read failed.
    52 	 */
    53 	int (SDLCALL *read)(struct SDL_RWops *context, void *ptr, int size, int maxnum);
    54 
    55 	/* Write exactly 'num' objects each of size 'objsize' from the area
    56 	   pointed at by 'ptr' to data source.
    57 	   Returns 'num', or -1 if the write failed.
    58 	 */
    59 	int (SDLCALL *write)(struct SDL_RWops *context, const void *ptr, int size, int num);
    60 
    61 	/* Close and free an allocated SDL_FSops structure */
    62 	int (SDLCALL *close)(struct SDL_RWops *context);
    63 
    64 	Uint32 type;
    65 	union {
    66 	    struct {
    67 		int autoclose;
    68 	 	FILE *fp;
    69 	    } stdio;
    70 	    struct {
    71 		Uint8 *base;
    72 	 	Uint8 *here;
    73 		Uint8 *stop;
    74 	    } mem;
    75 	    struct {
    76 		void *data1;
    77 	    } unknown;
    78 	} hidden;
    79 
    80 } SDL_RWops;
    81 
    82 
    83 /* Functions to create SDL_RWops structures from various data sources */
    84 
    85 extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromFile(const char *file, const char *mode);
    86 
    87 extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromFP(FILE *fp, int autoclose);
    88 
    89 extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromMem(void *mem, int size);
    90 extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromConstMem(const void *mem, int size);
    91 
    92 extern DECLSPEC SDL_RWops * SDLCALL SDL_AllocRW(void);
    93 extern DECLSPEC void SDLCALL SDL_FreeRW(SDL_RWops *area);
    94 
    95 /* Macros to easily read and write from an SDL_RWops structure */
    96 #define SDL_RWseek(ctx, offset, whence)	(ctx)->seek(ctx, offset, whence)
    97 #define SDL_RWtell(ctx)			(ctx)->seek(ctx, 0, SEEK_CUR)
    98 #define SDL_RWread(ctx, ptr, size, n)	(ctx)->read(ctx, ptr, size, n)
    99 #define SDL_RWwrite(ctx, ptr, size, n)	(ctx)->write(ctx, ptr, size, n)
   100 #define SDL_RWclose(ctx)		(ctx)->close(ctx)
   101 
   102 
   103 /* Ends C function definitions when using C++ */
   104 #ifdef __cplusplus
   105 }
   106 #endif
   107 #include "close_code.h"
   108 
   109 #endif /* _SDL_RWops_h */