1 /* 2 Simple DirectMedia Layer 3 Copyright (C) 1997-2018 Sam Lantinga <slouken@libsdl.org> 4 5 This software is provided 'as-is', without any express or implied 6 warranty. In no event will the authors be held liable for any damages 7 arising from the use of this software. 8 9 Permission is granted to anyone to use this software for any purpose, 10 including commercial applications, and to alter it and redistribute it 11 freely, subject to the following restrictions: 12 13 1. The origin of this software must not be misrepresented; you must not 14 claim that you wrote the original software. If you use this software 15 in a product, an acknowledgment in the product documentation would be 16 appreciated but is not required. 17 2. Altered source versions must be plainly marked as such, and must not be 18 misrepresented as being the original software. 19 3. This notice may not be removed or altered from any source distribution. 20 */ 21 22 /** 23 * \file SDL_rwops.h 24 * 25 * This file provides a general interface for SDL to read and write 26 * data streams. It can easily be extended to files, memory, etc. 27 */ 28 29 #ifndef SDL_rwops_h_ 30 #define SDL_rwops_h_ 31 32 #include "SDL_stdinc.h" 33 #include "SDL_error.h" 34 35 #include "begin_code.h" 36 /* Set up for C function definitions, even when using C++ */ 37 #ifdef __cplusplus 38 extern "C" { 39 #endif 40 41 /* RWops Types */ 42 #define SDL_RWOPS_UNKNOWN 0U /**< Unknown stream type */ 43 #define SDL_RWOPS_WINFILE 1U /**< Win32 file */ 44 #define SDL_RWOPS_STDFILE 2U /**< Stdio file */ 45 #define SDL_RWOPS_JNIFILE 3U /**< Android asset */ 46 #define SDL_RWOPS_MEMORY 4U /**< Memory stream */ 47 #define SDL_RWOPS_MEMORY_RO 5U /**< Read-Only memory stream */ 48 49 /** 50 * This is the read/write operation structure -- very basic. 51 */ 52 typedef struct SDL_RWops 53 { 54 /** 55 * Return the size of the file in this rwops, or -1 if unknown 56 */ 57 Sint64 (SDLCALL * size) (struct SDL_RWops * context); 58 59 /** 60 * Seek to \c offset relative to \c whence, one of stdio's whence values: 61 * RW_SEEK_SET, RW_SEEK_CUR, RW_SEEK_END 62 * 63 * \return the final offset in the data stream, or -1 on error. 64 */ 65 Sint64 (SDLCALL * seek) (struct SDL_RWops * context, Sint64 offset, 66 int whence); 67 68 /** 69 * Read up to \c maxnum objects each of size \c size from the data 70 * stream to the area pointed at by \c ptr. 71 * 72 * \return the number of objects read, or 0 at error or end of file. 73 */ 74 size_t (SDLCALL * read) (struct SDL_RWops * context, void *ptr, 75 size_t size, size_t maxnum); 76 77 /** 78 * Write exactly \c num objects each of size \c size from the area 79 * pointed at by \c ptr to data stream. 80 * 81 * \return the number of objects written, or 0 at error or end of file. 82 */ 83 size_t (SDLCALL * write) (struct SDL_RWops * context, const void *ptr, 84 size_t size, size_t num); 85 86 /** 87 * Close and free an allocated SDL_RWops structure. 88 * 89 * \return 0 if successful or -1 on write error when flushing data. 90 */ 91 int (SDLCALL * close) (struct SDL_RWops * context); 92 93 Uint32 type; 94 union 95 { 96 #if defined(__ANDROID__) 97 struct 98 { 99 void *fileNameRef; 100 void *inputStreamRef; 101 void *readableByteChannelRef; 102 void *readMethod; 103 void *assetFileDescriptorRef; 104 long position; 105 long size; 106 long offset; 107 int fd; 108 } androidio; 109 #elif defined(__WIN32__) 110 struct 111 { 112 SDL_bool append; 113 void *h; 114 struct 115 { 116 void *data; 117 size_t size; 118 size_t left; 119 } buffer; 120 } windowsio; 121 #endif 122 123 #ifdef HAVE_STDIO_H 124 struct 125 { 126 SDL_bool autoclose; 127 FILE *fp; 128 } stdio; 129 #endif 130 struct 131 { 132 Uint8 *base; 133 Uint8 *here; 134 Uint8 *stop; 135 } mem; 136 struct 137 { 138 void *data1; 139 void *data2; 140 } unknown; 141 } hidden; 142 143 } SDL_RWops; 144 145 146 /** 147 * \name RWFrom functions 148 * 149 * Functions to create SDL_RWops structures from various data streams. 150 */ 151 /* @{ */ 152 153 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromFile(const char *file, 154 const char *mode); 155 156 #ifdef HAVE_STDIO_H 157 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromFP(FILE * fp, 158 SDL_bool autoclose); 159 #else 160 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromFP(void * fp, 161 SDL_bool autoclose); 162 #endif 163 164 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromMem(void *mem, int size); 165 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromConstMem(const void *mem, 166 int size); 167 168 /* @} *//* RWFrom functions */ 169 170 171 extern DECLSPEC SDL_RWops *SDLCALL SDL_AllocRW(void); 172 extern DECLSPEC void SDLCALL SDL_FreeRW(SDL_RWops * area); 173 174 #define RW_SEEK_SET 0 /**< Seek from the beginning of data */ 175 #define RW_SEEK_CUR 1 /**< Seek relative to current read point */ 176 #define RW_SEEK_END 2 /**< Seek relative to the end of data */ 177 178 /** 179 * \name Read/write macros 180 * 181 * Macros to easily read and write from an SDL_RWops structure. 182 */ 183 /* @{ */ 184 #define SDL_RWsize(ctx) (ctx)->size(ctx) 185 #define SDL_RWseek(ctx, offset, whence) (ctx)->seek(ctx, offset, whence) 186 #define SDL_RWtell(ctx) (ctx)->seek(ctx, 0, RW_SEEK_CUR) 187 #define SDL_RWread(ctx, ptr, size, n) (ctx)->read(ctx, ptr, size, n) 188 #define SDL_RWwrite(ctx, ptr, size, n) (ctx)->write(ctx, ptr, size, n) 189 #define SDL_RWclose(ctx) (ctx)->close(ctx) 190 /* @} *//* Read/write macros */ 191 192 193 /** 194 * Load all the data from an SDL data stream. 195 * 196 * The data is allocated with a zero byte at the end (null terminated) 197 * 198 * If \c datasize is not NULL, it is filled with the size of the data read. 199 * 200 * If \c freesrc is non-zero, the stream will be closed after being read. 201 * 202 * The data should be freed with SDL_free(). 203 * 204 * \return the data, or NULL if there was an error. 205 */ 206 extern DECLSPEC void *SDLCALL SDL_LoadFile_RW(SDL_RWops * src, size_t *datasize, 207 int freesrc); 208 209 /** 210 * Load an entire file. 211 * 212 * Convenience macro. 213 */ 214 #define SDL_LoadFile(file, datasize) SDL_LoadFile_RW(SDL_RWFromFile(file, "rb"), datasize, 1) 215 216 /** 217 * \name Read endian functions 218 * 219 * Read an item of the specified endianness and return in native format. 220 */ 221 /* @{ */ 222 extern DECLSPEC Uint8 SDLCALL SDL_ReadU8(SDL_RWops * src); 223 extern DECLSPEC Uint16 SDLCALL SDL_ReadLE16(SDL_RWops * src); 224 extern DECLSPEC Uint16 SDLCALL SDL_ReadBE16(SDL_RWops * src); 225 extern DECLSPEC Uint32 SDLCALL SDL_ReadLE32(SDL_RWops * src); 226 extern DECLSPEC Uint32 SDLCALL SDL_ReadBE32(SDL_RWops * src); 227 extern DECLSPEC Uint64 SDLCALL SDL_ReadLE64(SDL_RWops * src); 228 extern DECLSPEC Uint64 SDLCALL SDL_ReadBE64(SDL_RWops * src); 229 /* @} *//* Read endian functions */ 230 231 /** 232 * \name Write endian functions 233 * 234 * Write an item of native format to the specified endianness. 235 */ 236 /* @{ */ 237 extern DECLSPEC size_t SDLCALL SDL_WriteU8(SDL_RWops * dst, Uint8 value); 238 extern DECLSPEC size_t SDLCALL SDL_WriteLE16(SDL_RWops * dst, Uint16 value); 239 extern DECLSPEC size_t SDLCALL SDL_WriteBE16(SDL_RWops * dst, Uint16 value); 240 extern DECLSPEC size_t SDLCALL SDL_WriteLE32(SDL_RWops * dst, Uint32 value); 241 extern DECLSPEC size_t SDLCALL SDL_WriteBE32(SDL_RWops * dst, Uint32 value); 242 extern DECLSPEC size_t SDLCALL SDL_WriteLE64(SDL_RWops * dst, Uint64 value); 243 extern DECLSPEC size_t SDLCALL SDL_WriteBE64(SDL_RWops * dst, Uint64 value); 244 /* @} *//* Write endian functions */ 245 246 /* Ends C function definitions when using C++ */ 247 #ifdef __cplusplus 248 } 249 #endif 250 #include "close_code.h" 251 252 #endif /* SDL_rwops_h_ */ 253 254 /* vi: set ts=4 sw=4 expandtab: */ 255