1 /* 2 SDL - Simple DirectMedia Layer 3 Copyright (C) 1997-2004 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 (at) libsdl.org 21 */ 22 23 #ifdef SAVE_RCSID 24 static char rcsid = 25 "@(#) $Id: SDL_rwops.h,v 1.8 2004/08/20 18:57:01 slouken 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 (SDLCALL *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 (SDLCALL *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 (SDLCALL *write)(struct SDL_RWops *context, const void *ptr, int size, int num); 65 66 /* Close and free an allocated SDL_FSops structure */ 67 int (SDLCALL *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 * SDLCALL SDL_RWFromFile(const char *file, const char *mode); 91 92 extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromFP(FILE *fp, int autoclose); 93 94 extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromMem(void *mem, int size); 95 extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromConstMem(const void *mem, int size); 96 97 extern DECLSPEC SDL_RWops * SDLCALL SDL_AllocRW(void); 98 extern DECLSPEC void SDLCALL SDL_FreeRW(SDL_RWops *area); 99 100 /* Macros to easily read and write from an SDL_RWops structure */ 101 #define SDL_RWseek(ctx, offset, whence) (ctx)->seek(ctx, offset, whence) 102 #define SDL_RWtell(ctx) (ctx)->seek(ctx, 0, SEEK_CUR) 103 #define SDL_RWread(ctx, ptr, size, n) (ctx)->read(ctx, ptr, size, n) 104 #define SDL_RWwrite(ctx, ptr, size, n) (ctx)->write(ctx, ptr, size, n) 105 #define SDL_RWclose(ctx) (ctx)->close(ctx) 106 107 108 /* Ends C function definitions when using C++ */ 109 #ifdef __cplusplus 110 } 111 #endif 112 #include "close_code.h" 113 114 #endif /* _SDL_RWops_h */ 115
