1 /* 2 SDL - Simple DirectMedia Layer 3 Copyright (C) 1997-2006 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 (at) libsdl.org 21 */ 22 23 /* This file provides a general interface for SDL to read and write 24 data sources. It can easily be extended to files, memory, etc. 25 */ 26 27 #ifndef _SDL_rwops_h 28 #define _SDL_rwops_h 29 30 #include "SDL_stdinc.h" 31 #include "SDL_error.h" 32 33 #include "begin_code.h" 34 /* Set up for C function definitions, even when using C++ */ 35 #ifdef __cplusplus 36 extern "C" { 37 #endif 38 39 /* This is the read/write operation structure -- very basic */ 40 41 typedef struct SDL_RWops { 42 /* Seek to 'offset' relative to whence, one of stdio's whence values: 43 SEEK_SET, SEEK_CUR, SEEK_END 44 Returns the final offset in the data source. 45 */ 46 int (SDLCALL *seek)(struct SDL_RWops *context, int offset, int whence); 47 48 /* Read up to 'num' objects each of size 'objsize' from the data 49 source to the area pointed at by 'ptr'. 50 Returns the number of objects read, or -1 if the read failed. 51 */ 52 int (SDLCALL *read)(struct SDL_RWops *context, void *ptr, int size, int maxnum); 53 54 /* Write exactly 'num' objects each of size 'objsize' from the area 55 pointed at by 'ptr' to data source. 56 Returns 'num', or -1 if the write failed. 57 */ 58 int (SDLCALL *write)(struct SDL_RWops *context, const void *ptr, int size, int num); 59 60 /* Close and free an allocated SDL_FSops structure */ 61 int (SDLCALL *close)(struct SDL_RWops *context); 62 63 Uint32 type; 64 union { 65 #if defined(__WIN32__) && !defined(__SYMBIAN32__) 66 struct { 67 int append; 68 void *h; 69 struct { 70 void *data; 71 int size; 72 int left; 73 } buffer; 74 } win32io; 75 #endif 76 #ifdef HAVE_STDIO_H 77 struct { 78 int autoclose; 79 FILE *fp; 80 } stdio; 81 #endif 82 struct { 83 Uint8 *base; 84 Uint8 *here; 85 Uint8 *stop; 86 } mem; 87 struct { 88 void *data1; 89 } unknown; 90 } hidden; 91 92 } SDL_RWops; 93 94 95 /* Functions to create SDL_RWops structures from various data sources */ 96 97 extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromFile(const char *file, const char *mode); 98 99 #ifdef HAVE_STDIO_H 100 extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromFP(FILE *fp, int autoclose); 101 #endif 102 103 extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromMem(void *mem, int size); 104 extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromConstMem(const void *mem, int size); 105 106 extern DECLSPEC SDL_RWops * SDLCALL SDL_AllocRW(void); 107 extern DECLSPEC void SDLCALL SDL_FreeRW(SDL_RWops *area); 108 109 #define RW_SEEK_SET 0 /* Seek from the beginning of data */ 110 #define RW_SEEK_CUR 1 /* Seek relative to current read point */ 111 #define RW_SEEK_END 2 /* Seek relative to the end of data */ 112 113 /* Macros to easily read and write from an SDL_RWops structure */ 114 #define SDL_RWseek(ctx, offset, whence) (ctx)->seek(ctx, offset, whence) 115 #define SDL_RWtell(ctx) (ctx)->seek(ctx, 0, RW_SEEK_CUR) 116 #define SDL_RWread(ctx, ptr, size, n) (ctx)->read(ctx, ptr, size, n) 117 #define SDL_RWwrite(ctx, ptr, size, n) (ctx)->write(ctx, ptr, size, n) 118 #define SDL_RWclose(ctx) (ctx)->close(ctx) 119 120 121 /* Read an item of the specified endianness and return in native format */ 122 extern DECLSPEC Uint16 SDLCALL SDL_ReadLE16(SDL_RWops *src); 123 extern DECLSPEC Uint16 SDLCALL SDL_ReadBE16(SDL_RWops *src); 124 extern DECLSPEC Uint32 SDLCALL SDL_ReadLE32(SDL_RWops *src); 125 extern DECLSPEC Uint32 SDLCALL SDL_ReadBE32(SDL_RWops *src); 126 extern DECLSPEC Uint64 SDLCALL SDL_ReadLE64(SDL_RWops *src); 127 extern DECLSPEC Uint64 SDLCALL SDL_ReadBE64(SDL_RWops *src); 128 129 /* Write an item of native format to the specified endianness */ 130 extern DECLSPEC int SDLCALL SDL_WriteLE16(SDL_RWops *dst, Uint16 value); 131 extern DECLSPEC int SDLCALL SDL_WriteBE16(SDL_RWops *dst, Uint16 value); 132 extern DECLSPEC int SDLCALL SDL_WriteLE32(SDL_RWops *dst, Uint32 value); 133 extern DECLSPEC int SDLCALL SDL_WriteBE32(SDL_RWops *dst, Uint32 value); 134 extern DECLSPEC int SDLCALL SDL_WriteLE64(SDL_RWops *dst, Uint64 value); 135 extern DECLSPEC int SDLCALL SDL_WriteBE64(SDL_RWops *dst, Uint64 value); 136 137 138 /* Ends C function definitions when using C++ */ 139 #ifdef __cplusplus 140 } 141 #endif 142 #include "close_code.h" 143 144 #endif /* _SDL_rwops_h */ 145
