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 */ |