• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /*
2     SDL - Simple DirectMedia Layer
3     Copyright (C) 1997-2012 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 /** @file SDL_rwops.h
24  *  This file provides a general interface for SDL to read and write
25  *  data sources.  It can easily be extended to files, memory, etc.
26  */
27 
28 #ifndef _SDL_rwops_h
29 #define _SDL_rwops_h
30 
31 #include "SDL_stdinc.h"
32 #include "SDL_error.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 'maxnum' objects each of size 'size' 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 #if defined(__WIN32__) && !defined(__SYMBIAN32__)
67 	    struct {
68 		int   append;
69 		void *h;
70 		struct {
71 		    void *data;
72 		    int size;
73 		    int left;
74 		} buffer;
75 	    } win32io;
76 #endif
77 #ifdef HAVE_STDIO_H
78 	    struct {
79 		int autoclose;
80 	 	FILE *fp;
81 	    } stdio;
82 #endif
83 	    struct {
84 		Uint8 *base;
85 	 	Uint8 *here;
86 		Uint8 *stop;
87 	    } mem;
88 	    struct {
89 		void *data1;
90 	    } unknown;
91 	} hidden;
92 
93 } SDL_RWops;
94 
95 
96 /** @name Functions to create SDL_RWops structures from various data sources */
97 /*@{*/
98 
99 extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromFile(const char *file, const char *mode);
100 
101 #ifdef HAVE_STDIO_H
102 extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromFP(FILE *fp, int autoclose);
103 #endif
104 
105 extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromMem(void *mem, int size);
106 extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromConstMem(const void *mem, int size);
107 
108 extern DECLSPEC SDL_RWops * SDLCALL SDL_AllocRW(void);
109 extern DECLSPEC void SDLCALL SDL_FreeRW(SDL_RWops *area);
110 
111 /*@}*/
112 
113 /** @name Seek Reference Points */
114 /*@{*/
115 #define RW_SEEK_SET	0	/**< Seek from the beginning of data */
116 #define RW_SEEK_CUR	1	/**< Seek relative to current read point */
117 #define RW_SEEK_END	2	/**< Seek relative to the end of data */
118 /*@}*/
119 
120 /** @name Macros to easily read and write from an SDL_RWops structure */
121 /*@{*/
122 #define SDL_RWseek(ctx, offset, whence)	(ctx)->seek(ctx, offset, whence)
123 #define SDL_RWtell(ctx)			(ctx)->seek(ctx, 0, RW_SEEK_CUR)
124 #define SDL_RWread(ctx, ptr, size, n)	(ctx)->read(ctx, ptr, size, n)
125 #define SDL_RWwrite(ctx, ptr, size, n)	(ctx)->write(ctx, ptr, size, n)
126 #define SDL_RWclose(ctx)		(ctx)->close(ctx)
127 /*@}*/
128 
129 /** @name Read an item of the specified endianness and return in native format */
130 /*@{*/
131 extern DECLSPEC Uint16 SDLCALL SDL_ReadLE16(SDL_RWops *src);
132 extern DECLSPEC Uint16 SDLCALL SDL_ReadBE16(SDL_RWops *src);
133 extern DECLSPEC Uint32 SDLCALL SDL_ReadLE32(SDL_RWops *src);
134 extern DECLSPEC Uint32 SDLCALL SDL_ReadBE32(SDL_RWops *src);
135 extern DECLSPEC Uint64 SDLCALL SDL_ReadLE64(SDL_RWops *src);
136 extern DECLSPEC Uint64 SDLCALL SDL_ReadBE64(SDL_RWops *src);
137 /*@}*/
138 
139 /** @name Write an item of native format to the specified endianness */
140 /*@{*/
141 extern DECLSPEC int SDLCALL SDL_WriteLE16(SDL_RWops *dst, Uint16 value);
142 extern DECLSPEC int SDLCALL SDL_WriteBE16(SDL_RWops *dst, Uint16 value);
143 extern DECLSPEC int SDLCALL SDL_WriteLE32(SDL_RWops *dst, Uint32 value);
144 extern DECLSPEC int SDLCALL SDL_WriteBE32(SDL_RWops *dst, Uint32 value);
145 extern DECLSPEC int SDLCALL SDL_WriteLE64(SDL_RWops *dst, Uint64 value);
146 extern DECLSPEC int SDLCALL SDL_WriteBE64(SDL_RWops *dst, Uint64 value);
147 /*@}*/
148 
149 /* Ends C function definitions when using C++ */
150 #ifdef __cplusplus
151 }
152 #endif
153 #include "close_code.h"
154 
155 #endif /* _SDL_rwops_h */
156