api/include/SDL_rwops.h

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997, 1998, 1999, 2000, 2001  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@devolution.com
*/

#ifdef SAVE_RCSID
static char rcsid =
 "@(#) $Id: SDL_rwops.h,v 1.4.2.4 2001/02/17 01:45:30 hercules 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 * SDL_RWFromFile(const char *file, const char *mode);

extern DECLSPEC SDL_RWops * SDL_RWFromFP(FILE *fp, int autoclose);

extern DECLSPEC SDL_RWops * SDL_RWFromMem(void *mem, int size);

extern DECLSPEC SDL_RWops * SDL_AllocRW(void);
extern DECLSPEC void 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 */
1	/*
2	SDL - Simple DirectMedia Layer
3	Copyright (C) 1997, 1998, 1999, 2000, 2001 Sam Lantinga
4
5	This library is free software; you can redistribute it and/or
6	modify it under the terms of the GNU Library General Public
7	License as published by the Free Software Foundation; either
8	version 2 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	Library General Public License for more details.
14
15	You should have received a copy of the GNU Library General Public
16	License along with this library; if not, write to the Free
17	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18
19	Sam Lantinga
20	slouken@devolution.com
21	*/
22
23	#ifdef SAVE_RCSID
24	static char rcsid =
25	"@(#) $Id: SDL_rwops.h,v 1.4.2.4 2001/02/17 01:45:30 hercules Exp $";
26	#endif
27
28	/* This file provides a general interface for SDL to read and write
29	data sources. It can easily be extended to files, memory, etc.
30	*/
31
32	#ifndef _SDL_RWops_h
33	#define _SDL_RWops_h
34
35	#include <stdio.h>
36
37	#include "SDL_types.h"
38
39	#include "begin_code.h"
40	/* Set up for C function definitions, even when using C++ */
41	#ifdef __cplusplus
42	extern "C" {
43	#endif
44
45	/* This is the read/write operation structure -- very basic */
46
47	typedef struct SDL_RWops {
48	/* Seek to 'offset' relative to whence, one of stdio's whence values:
49	SEEK_SET, SEEK_CUR, SEEK_END
50	Returns the final offset in the data source.
51	*/
52	int (seek)(struct SDL_RWops context, int offset, int whence);
53
54	/* Read up to 'num' objects each of size 'objsize' from the data
55	source to the area pointed at by 'ptr'.
56	Returns the number of objects read, or -1 if the read failed.
57	*/
58	int (read)(struct SDL_RWops context, void *ptr, int size, int maxnum);
59
60	/* Write exactly 'num' objects each of size 'objsize' from the area
61	pointed at by 'ptr' to data source.
62	Returns 'num', or -1 if the write failed.
63	*/
64	int (write)(struct SDL_RWops context, const void *ptr, int size, int num);
65
66	/* Close and free an allocated SDL_FSops structure */
67	int (close)(struct SDL_RWops context);
68
69	Uint32 type;
70	union {
71	struct {
72	int autoclose;
73	FILE *fp;
74	} stdio;
75	struct {
76	Uint8 *base;
77	Uint8 *here;
78	Uint8 *stop;
79	} mem;
80	struct {
81	void *data1;
82	} unknown;
83	} hidden;
84
85	} SDL_RWops;
86
87
88	/* Functions to create SDL_RWops structures from various data sources */
89
90	extern DECLSPEC SDL_RWops * SDL_RWFromFile(const char file, const char mode);
91
92	extern DECLSPEC SDL_RWops * SDL_RWFromFP(FILE *fp, int autoclose);
93
94	extern DECLSPEC SDL_RWops * SDL_RWFromMem(void *mem, int size);
95
96	extern DECLSPEC SDL_RWops * SDL_AllocRW(void);
97	extern DECLSPEC void SDL_FreeRW(SDL_RWops *area);
98
99	/* Macros to easily read and write from an SDL_RWops structure */
100	#define SDL_RWseek(ctx, offset, whence) (ctx)->seek(ctx, offset, whence)
101	#define SDL_RWtell(ctx) (ctx)->seek(ctx, 0, SEEK_CUR)
102	#define SDL_RWread(ctx, ptr, size, n) (ctx)->read(ctx, ptr, size, n)
103	#define SDL_RWwrite(ctx, ptr, size, n) (ctx)->write(ctx, ptr, size, n)
104	#define SDL_RWclose(ctx) (ctx)->close(ctx)
105
106
107	/* Ends C function definitions when using C++ */
108	#ifdef __cplusplus
109	}
110	#endif
111	#include "close_code.h"
112
113	#endif /* _SDL_RWops_h */