comparison include/SDL_rwops.h @ 0:74212992fb08

Initial revision
author Sam Lantinga <slouken@lokigames.com>
date Thu, 26 Apr 2001 16:45:43 +0000
parents
children b8688cfdc232
comparison
equal deleted inserted replaced
-1:000000000000 0:74212992fb08
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 "@(#) $Id$";
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 */