2 SDL - Simple DirectMedia Layer
3 Copyright (C) 1997-2006 Sam Lantinga
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.
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.
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
26 * This file provides a general interface for SDL to read and write
27 * data sources. It can easily be extended to files, memory, etc.
33 #include "SDL_stdinc.h"
34 #include "SDL_error.h"
36 #include "begin_code.h"
37 /* Set up for C function definitions, even when using C++ */
44 /* This is the read/write operation structure -- very basic */
46 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.
52 int (SDLCALL * seek) (struct SDL_RWops * context, int offset, int whence);
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.
58 int (SDLCALL * read) (struct SDL_RWops * context, void *ptr, int size,
61 /* Write exactly 'num' objects each of size 'objsize' from the area
62 pointed at by 'ptr' to data source.
63 Returns 'num', or -1 if the write failed.
65 int (SDLCALL * write) (struct SDL_RWops * context, const void *ptr,
68 /* Close and free an allocated SDL_FSops structure */
69 int (SDLCALL * close) (struct SDL_RWops * context);
109 /* Functions to create SDL_RWops structures from various data sources */
111 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromFile(const char *file,
115 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromFP(FILE * fp, int autoclose);
118 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromMem(void *mem, int size);
119 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromConstMem(const void *mem,
122 extern DECLSPEC SDL_RWops *SDLCALL SDL_AllocRW(void);
123 extern DECLSPEC void SDLCALL SDL_FreeRW(SDL_RWops * area);
125 #define RW_SEEK_SET 0 /* Seek from the beginning of data */
126 #define RW_SEEK_CUR 1 /* Seek relative to current read point */
127 #define RW_SEEK_END 2 /* Seek relative to the end of data */
129 /* Macros to easily read and write from an SDL_RWops structure */
130 #define SDL_RWseek(ctx, offset, whence) (ctx)->seek(ctx, offset, whence)
131 #define SDL_RWtell(ctx) (ctx)->seek(ctx, 0, RW_SEEK_CUR)
132 #define SDL_RWread(ctx, ptr, size, n) (ctx)->read(ctx, ptr, size, n)
133 #define SDL_RWwrite(ctx, ptr, size, n) (ctx)->write(ctx, ptr, size, n)
134 #define SDL_RWclose(ctx) (ctx)->close(ctx)
137 /* Read an item of the specified endianness and return in native format */
138 extern DECLSPEC Uint16 SDLCALL SDL_ReadLE16(SDL_RWops * src);
139 extern DECLSPEC Uint16 SDLCALL SDL_ReadBE16(SDL_RWops * src);
140 extern DECLSPEC Uint32 SDLCALL SDL_ReadLE32(SDL_RWops * src);
141 extern DECLSPEC Uint32 SDLCALL SDL_ReadBE32(SDL_RWops * src);
142 extern DECLSPEC Uint64 SDLCALL SDL_ReadLE64(SDL_RWops * src);
143 extern DECLSPEC Uint64 SDLCALL SDL_ReadBE64(SDL_RWops * src);
145 /* Write an item of native format to the specified endianness */
146 extern DECLSPEC int SDLCALL SDL_WriteLE16(SDL_RWops * dst, Uint16 value);
147 extern DECLSPEC int SDLCALL SDL_WriteBE16(SDL_RWops * dst, Uint16 value);
148 extern DECLSPEC int SDLCALL SDL_WriteLE32(SDL_RWops * dst, Uint32 value);
149 extern DECLSPEC int SDLCALL SDL_WriteBE32(SDL_RWops * dst, Uint32 value);
150 extern DECLSPEC int SDLCALL SDL_WriteLE64(SDL_RWops * dst, Uint64 value);
151 extern DECLSPEC int SDLCALL SDL_WriteBE64(SDL_RWops * dst, Uint64 value);
154 /* Ends C function definitions when using C++ */
160 #include "close_code.h"
162 #endif /* _SDL_rwops_h */
164 /* vi: set ts=4 sw=4 expandtab: */