1 /* 2 Simple DirectMedia Layer 3 Copyright (C) 1997-2025 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 /* WIKI CATEGORY: RWOPS */ 23 24 /** 25 * # CategoryRWOPS 26 * 27 * This file provides a general interface for SDL to read and write data 28 * streams. It can easily be extended to files, memory, etc. 29 */ 30 31 #ifndef SDL_rwops_h_ 32 #define SDL_rwops_h_ 33 34 #include "SDL_stdinc.h" 35 #include "SDL_error.h" 36 37 #include "begin_code.h" 38 /* Set up for C function definitions, even when using C++ */ 39 #ifdef __cplusplus 40 extern "C" { 41 #endif 42 43 /* RWops Types */ 44 #define SDL_RWOPS_UNKNOWN 0U /**< Unknown stream type */ 45 #define SDL_RWOPS_WINFILE 1U /**< Win32 file */ 46 #define SDL_RWOPS_STDFILE 2U /**< Stdio file */ 47 #define SDL_RWOPS_JNIFILE 3U /**< Android asset */ 48 #define SDL_RWOPS_MEMORY 4U /**< Memory stream */ 49 #define SDL_RWOPS_MEMORY_RO 5U /**< Read-Only memory stream */ 50 51 /** 52 * This is the read/write operation structure -- very basic. 53 */ 54 typedef struct SDL_RWops 55 { 56 /** 57 * Return the size of the file in this rwops, or -1 if unknown 58 */ 59 Sint64 (SDLCALL * size) (struct SDL_RWops * context); 60 61 /** 62 * Seek to `offset` relative to `whence`, one of stdio's whence values: 63 * RW_SEEK_SET, RW_SEEK_CUR, RW_SEEK_END 64 * 65 * \return the final offset in the data stream, or -1 on error. 66 */ 67 Sint64 (SDLCALL * seek) (struct SDL_RWops * context, Sint64 offset, 68 int whence); 69 70 /** 71 * Read up to `maxnum` objects each of size `size` from the data 72 * stream to the area pointed at by `ptr`. 73 * 74 * \return the number of objects read, or 0 at error or end of file. 75 */ 76 size_t (SDLCALL * read) (struct SDL_RWops * context, void *ptr, 77 size_t size, size_t maxnum); 78 79 /** 80 * Write exactly `num` objects each of size `size` from the area 81 * pointed at by `ptr` to data stream. 82 * 83 * \return the number of objects written, or 0 at error or end of file. 84 */ 85 size_t (SDLCALL * write) (struct SDL_RWops * context, const void *ptr, 86 size_t size, size_t num); 87 88 /** 89 * Close and free an allocated SDL_RWops structure. 90 * 91 * \return 0 if successful or -1 on write error when flushing data. 92 */ 93 int (SDLCALL * close) (struct SDL_RWops * context); 94 95 Uint32 type; 96 union 97 { 98 #if defined(__ANDROID__) 99 struct 100 { 101 void *asset; 102 } androidio; 103 #elif defined(__WIN32__) || defined(__GDK__) 104 struct 105 { 106 SDL_bool append; 107 void *h; 108 struct 109 { 110 void *data; 111 size_t size; 112 size_t left; 113 } buffer; 114 } windowsio; 115 #endif 116 117 #ifdef HAVE_STDIO_H 118 struct 119 { 120 SDL_bool autoclose; 121 FILE *fp; 122 } stdio; 123 #endif 124 struct 125 { 126 Uint8 *base; 127 Uint8 *here; 128 Uint8 *stop; 129 } mem; 130 struct 131 { 132 void *data1; 133 void *data2; 134 } unknown; 135 } hidden; 136 137 } SDL_RWops; 138 139 140 /** 141 * \name RWFrom functions 142 * 143 * Functions to create SDL_RWops structures from various data streams. 144 */ 145 /* @{ */ 146 147 /** 148 * Use this function to create a new SDL_RWops structure for reading from 149 * and/or writing to a named file. 150 * 151 * The `mode` string is treated roughly the same as in a call to the C 152 * library's fopen(), even if SDL doesn't happen to use fopen() behind the 153 * scenes. 154 * 155 * Available `mode` strings: 156 * 157 * - "r": Open a file for reading. The file must exist. 158 * - "w": Create an empty file for writing. If a file with the same name 159 * already exists its content is erased and the file is treated as a new 160 * empty file. 161 * - "a": Append to a file. Writing operations append data at the end of the 162 * file. The file is created if it does not exist. 163 * - "r+": Open a file for update both reading and writing. The file must 164 * exist. 165 * - "w+": Create an empty file for both reading and writing. If a file with 166 * the same name already exists its content is erased and the file is 167 * treated as a new empty file. 168 * - "a+": Open a file for reading and appending. All writing operations are 169 * performed at the end of the file, protecting the previous content to be 170 * overwritten. You can reposition (fseek, rewind) the internal pointer to 171 * anywhere in the file for reading, but writing operations will move it 172 * back to the end of file. The file is created if it does not exist. 173 * 174 * **NOTE**: In order to open a file as a binary file, a "b" character has to 175 * be included in the `mode` string. This additional "b" character can either 176 * be appended at the end of the string (thus making the following compound 177 * modes: "rb", "wb", "ab", "r+b", "w+b", "a+b") or be inserted between the 178 * letter and the "+" sign for the mixed modes ("rb+", "wb+", "ab+"). 179 * Additional characters may follow the sequence, although they should have no 180 * effect. For example, "t" is sometimes appended to make explicit the file is 181 * a text file. 182 * 183 * This function supports Unicode filenames, but they must be encoded in UTF-8 184 * format, regardless of the underlying operating system. 185 * 186 * As a fallback, SDL_RWFromFile() will transparently open a matching filename 187 * in an Android app's `assets`. 188 * 189 * Closing the SDL_RWops will close the file handle SDL is holding internally. 190 * 191 * \param file a UTF-8 string representing the filename to open. 192 * \param mode an ASCII string representing the mode to be used for opening 193 * the file. 194 * \returns a pointer to the SDL_RWops structure that is created, or NULL on 195 * failure; call SDL_GetError() for more information. 196 * 197 * \since This function is available since SDL 2.0.0. 198 * 199 * \sa SDL_RWclose 200 * \sa SDL_RWFromConstMem 201 * \sa SDL_RWFromFP 202 * \sa SDL_RWFromMem 203 * \sa SDL_RWread 204 * \sa SDL_RWseek 205 * \sa SDL_RWtell 206 * \sa SDL_RWwrite 207 */ 208 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromFile(const char *file, 209 const char *mode); 210 211 #ifdef HAVE_STDIO_H 212 213 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromFP(FILE * fp, SDL_bool autoclose); 214 215 #else 216 217 /** 218 * Use this function to create an SDL_RWops structure from a standard I/O file 219 * pointer (stdio.h's `FILE*`). 220 * 221 * This function is not available on Windows, since files opened in an 222 * application on that platform cannot be used by a dynamically linked 223 * library. 224 * 225 * On some platforms, the first parameter is a `void*`, on others, it's a 226 * `FILE*`, depending on what system headers are available to SDL. It is 227 * always intended to be the `FILE*` type from the C runtime's stdio.h. 228 * 229 * \param fp the `FILE*` that feeds the SDL_RWops stream. 230 * \param autoclose SDL_TRUE to close the `FILE*` when closing the SDL_RWops, 231 * SDL_FALSE to leave the `FILE*` open when the RWops is 232 * closed. 233 * \returns a pointer to the SDL_RWops structure that is created, or NULL on 234 * failure; call SDL_GetError() for more information. 235 * 236 * \since This function is available since SDL 2.0.0. 237 * 238 * \sa SDL_RWclose 239 * \sa SDL_RWFromConstMem 240 * \sa SDL_RWFromFile 241 * \sa SDL_RWFromMem 242 * \sa SDL_RWread 243 * \sa SDL_RWseek 244 * \sa SDL_RWtell 245 * \sa SDL_RWwrite 246 */ 247 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromFP(void * fp, 248 SDL_bool autoclose); 249 #endif 250 251 /** 252 * Use this function to prepare a read-write memory buffer for use with 253 * SDL_RWops. 254 * 255 * This function sets up an SDL_RWops struct based on a memory area of a 256 * certain size, for both read and write access. 257 * 258 * This memory buffer is not copied by the RWops; the pointer you provide must 259 * remain valid until you close the stream. Closing the stream will not free 260 * the original buffer. 261 * 262 * If you need to make sure the RWops never writes to the memory buffer, you 263 * should use SDL_RWFromConstMem() with a read-only buffer of memory instead. 264 * 265 * \param mem a pointer to a buffer to feed an SDL_RWops stream. 266 * \param size the buffer size, in bytes. 267 * \returns a pointer to a new SDL_RWops structure, or NULL if it fails; call 268 * SDL_GetError() for more information. 269 * 270 * \since This function is available since SDL 2.0.0. 271 * 272 * \sa SDL_RWclose 273 * \sa SDL_RWFromConstMem 274 * \sa SDL_RWFromFile 275 * \sa SDL_RWFromFP 276 * \sa SDL_RWFromMem 277 * \sa SDL_RWread 278 * \sa SDL_RWseek 279 * \sa SDL_RWtell 280 * \sa SDL_RWwrite 281 */ 282 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromMem(void *mem, int size); 283 284 /** 285 * Use this function to prepare a read-only memory buffer for use with RWops. 286 * 287 * This function sets up an SDL_RWops struct based on a memory area of a 288 * certain size. It assumes the memory area is not writable. 289 * 290 * Attempting to write to this RWops stream will report an error without 291 * writing to the memory buffer. 292 * 293 * This memory buffer is not copied by the RWops; the pointer you provide must 294 * remain valid until you close the stream. Closing the stream will not free 295 * the original buffer. 296 * 297 * If you need to write to a memory buffer, you should use SDL_RWFromMem() 298 * with a writable buffer of memory instead. 299 * 300 * \param mem a pointer to a read-only buffer to feed an SDL_RWops stream. 301 * \param size the buffer size, in bytes. 302 * \returns a pointer to a new SDL_RWops structure, or NULL if it fails; call 303 * SDL_GetError() for more information. 304 * 305 * \since This function is available since SDL 2.0.0. 306 * 307 * \sa SDL_RWclose 308 * \sa SDL_RWFromConstMem 309 * \sa SDL_RWFromFile 310 * \sa SDL_RWFromFP 311 * \sa SDL_RWFromMem 312 * \sa SDL_RWread 313 * \sa SDL_RWseek 314 * \sa SDL_RWtell 315 */ 316 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromConstMem(const void *mem, 317 int size); 318 319 /* @} *//* RWFrom functions */ 320 321 322 /** 323 * Use this function to allocate an empty, unpopulated SDL_RWops structure. 324 * 325 * Applications do not need to use this function unless they are providing 326 * their own SDL_RWops implementation. If you just need a SDL_RWops to 327 * read/write a common data source, you should use the built-in 328 * implementations in SDL, like SDL_RWFromFile() or SDL_RWFromMem(), etc. 329 * 330 * You must free the returned pointer with SDL_FreeRW(). Depending on your 331 * operating system and compiler, there may be a difference between the 332 * malloc() and free() your program uses and the versions SDL calls 333 * internally. Trying to mix the two can cause crashing such as segmentation 334 * faults. Since all SDL_RWops must free themselves when their **close** 335 * method is called, all SDL_RWops must be allocated through this function, so 336 * they can all be freed correctly with SDL_FreeRW(). 337 * 338 * \returns a pointer to the allocated memory on success, or NULL on failure; 339 * call SDL_GetError() for more information. 340 * 341 * \since This function is available since SDL 2.0.0. 342 * 343 * \sa SDL_FreeRW 344 */ 345 extern DECLSPEC SDL_RWops *SDLCALL SDL_AllocRW(void); 346 347 /** 348 * Use this function to free an SDL_RWops structure allocated by 349 * SDL_AllocRW(). 350 * 351 * Applications do not need to use this function unless they are providing 352 * their own SDL_RWops implementation. If you just need a SDL_RWops to 353 * read/write a common data source, you should use the built-in 354 * implementations in SDL, like SDL_RWFromFile() or SDL_RWFromMem(), etc, and 355 * call the **close** method on those SDL_RWops pointers when you are done 356 * with them. 357 * 358 * Only use SDL_FreeRW() on pointers returned by SDL_AllocRW(). The pointer is 359 * invalid as soon as this function returns. Any extra memory allocated during 360 * creation of the SDL_RWops is not freed by SDL_FreeRW(); the programmer must 361 * be responsible for managing that memory in their **close** method. 362 * 363 * \param area the SDL_RWops structure to be freed. 364 * 365 * \since This function is available since SDL 2.0.0. 366 * 367 * \sa SDL_AllocRW 368 */ 369 extern DECLSPEC void SDLCALL SDL_FreeRW(SDL_RWops * area); 370 371 /* Possible `whence` values for SDL_RWops seeking... */ 372 #define RW_SEEK_SET 0 /**< Seek from the beginning of data */ 373 #define RW_SEEK_CUR 1 /**< Seek relative to current read point */ 374 #define RW_SEEK_END 2 /**< Seek relative to the end of data */ 375 376 /** 377 * Use this function to get the size of the data stream in an SDL_RWops. 378 * 379 * Prior to SDL 2.0.10, this function was a macro. 380 * 381 * \param context the SDL_RWops to get the size of the data stream from. 382 * \returns the size of the data stream in the SDL_RWops on success, -1 if 383 * unknown or a negative error code on failure; call SDL_GetError() 384 * for more information. 385 * 386 * \since This function is available since SDL 2.0.10. 387 */ 388 extern DECLSPEC Sint64 SDLCALL SDL_RWsize(SDL_RWops *context); 389 390 /** 391 * Seek within an SDL_RWops data stream. 392 * 393 * This function seeks to byte `offset`, relative to `whence`. 394 * 395 * `whence` may be any of the following values: 396 * 397 * - `RW_SEEK_SET`: seek from the beginning of data 398 * - `RW_SEEK_CUR`: seek relative to current read point 399 * - `RW_SEEK_END`: seek relative to the end of data 400 * 401 * If this stream can not seek, it will return -1. 402 * 403 * SDL_RWseek() is actually a wrapper function that calls the SDL_RWops's 404 * `seek` method appropriately, to simplify application development. 405 * 406 * Prior to SDL 2.0.10, this function was a macro. 407 * 408 * \param context a pointer to an SDL_RWops structure. 409 * \param offset an offset in bytes, relative to **whence** location; can be 410 * negative. 411 * \param whence any of `RW_SEEK_SET`, `RW_SEEK_CUR`, `RW_SEEK_END`. 412 * \returns the final offset in the data stream after the seek or -1 on error. 413 * 414 * \since This function is available since SDL 2.0.10. 415 * 416 * \sa SDL_RWclose 417 * \sa SDL_RWFromConstMem 418 * \sa SDL_RWFromFile 419 * \sa SDL_RWFromFP 420 * \sa SDL_RWFromMem 421 * \sa SDL_RWread 422 * \sa SDL_RWtell 423 * \sa SDL_RWwrite 424 */ 425 extern DECLSPEC Sint64 SDLCALL SDL_RWseek(SDL_RWops *context, 426 Sint64 offset, int whence); 427 428 /** 429 * Determine the current read/write offset in an SDL_RWops data stream. 430 * 431 * SDL_RWtell is actually a wrapper function that calls the SDL_RWops's `seek` 432 * method, with an offset of 0 bytes from `RW_SEEK_CUR`, to simplify 433 * application development. 434 * 435 * Prior to SDL 2.0.10, this function was a macro. 436 * 437 * \param context a SDL_RWops data stream object from which to get the current 438 * offset. 439 * \returns the current offset in the stream, or -1 if the information can not 440 * be determined. 441 * 442 * \since This function is available since SDL 2.0.10. 443 * 444 * \sa SDL_RWclose 445 * \sa SDL_RWFromConstMem 446 * \sa SDL_RWFromFile 447 * \sa SDL_RWFromFP 448 * \sa SDL_RWFromMem 449 * \sa SDL_RWread 450 * \sa SDL_RWseek 451 * \sa SDL_RWwrite 452 */ 453 extern DECLSPEC Sint64 SDLCALL SDL_RWtell(SDL_RWops *context); 454 455 /** 456 * Read from a data source. 457 * 458 * This function reads up to `maxnum` objects each of size `size` from the 459 * data source to the area pointed at by `ptr`. This function may read less 460 * objects than requested. It will return zero when there has been an error or 461 * the data stream is completely read. 462 * 463 * SDL_RWread() is actually a function wrapper that calls the SDL_RWops's 464 * `read` method appropriately, to simplify application development. 465 * 466 * Prior to SDL 2.0.10, this function was a macro. 467 * 468 * \param context a pointer to an SDL_RWops structure. 469 * \param ptr a pointer to a buffer to read data into. 470 * \param size the size of each object to read, in bytes. 471 * \param maxnum the maximum number of objects to be read. 472 * \returns the number of objects read, or 0 at error or end of file; call 473 * SDL_GetError() for more information. 474 * 475 * \since This function is available since SDL 2.0.10. 476 * 477 * \sa SDL_RWclose 478 * \sa SDL_RWFromConstMem 479 * \sa SDL_RWFromFile 480 * \sa SDL_RWFromFP 481 * \sa SDL_RWFromMem 482 * \sa SDL_RWseek 483 * \sa SDL_RWwrite 484 */ 485 extern DECLSPEC size_t SDLCALL SDL_RWread(SDL_RWops *context, 486 void *ptr, size_t size, 487 size_t maxnum); 488 489 /** 490 * Write to an SDL_RWops data stream. 491 * 492 * This function writes exactly `num` objects each of size `size` from the 493 * area pointed at by `ptr` to the stream. If this fails for any reason, it'll 494 * return less than `num` to demonstrate how far the write progressed. On 495 * success, it returns `num`. 496 * 497 * SDL_RWwrite is actually a function wrapper that calls the SDL_RWops's 498 * `write` method appropriately, to simplify application development. 499 * 500 * Prior to SDL 2.0.10, this function was a macro. 501 * 502 * \param context a pointer to an SDL_RWops structure. 503 * \param ptr a pointer to a buffer containing data to write. 504 * \param size the size of an object to write, in bytes. 505 * \param num the number of objects to write. 506 * \returns the number of objects written, which will be less than **num** on 507 * error; call SDL_GetError() for more information. 508 * 509 * \since This function is available since SDL 2.0.10. 510 * 511 * \sa SDL_RWclose 512 * \sa SDL_RWFromConstMem 513 * \sa SDL_RWFromFile 514 * \sa SDL_RWFromFP 515 * \sa SDL_RWFromMem 516 * \sa SDL_RWread 517 * \sa SDL_RWseek 518 */ 519 extern DECLSPEC size_t SDLCALL SDL_RWwrite(SDL_RWops *context, 520 const void *ptr, size_t size, 521 size_t num); 522 523 /** 524 * Close and free an allocated SDL_RWops structure. 525 * 526 * SDL_RWclose() closes and cleans up the SDL_RWops stream. It releases any 527 * resources used by the stream and frees the SDL_RWops itself with 528 * SDL_FreeRW(). This returns 0 on success, or -1 if the stream failed to 529 * flush to its output (e.g. to disk). 530 * 531 * Note that if this fails to flush the stream to disk, this function reports 532 * an error, but the SDL_RWops is still invalid once this function returns. 533 * 534 * Prior to SDL 2.0.10, this function was a macro. 535 * 536 * \param context SDL_RWops structure to close. 537 * \returns 0 on success or a negative error code on failure; call 538 * SDL_GetError() for more information. 539 * 540 * \since This function is available since SDL 2.0.10. 541 * 542 * \sa SDL_RWFromConstMem 543 * \sa SDL_RWFromFile 544 * \sa SDL_RWFromFP 545 * \sa SDL_RWFromMem 546 * \sa SDL_RWread 547 * \sa SDL_RWseek 548 * \sa SDL_RWwrite 549 */ 550 extern DECLSPEC int SDLCALL SDL_RWclose(SDL_RWops *context); 551 552 /** 553 * Load all the data from an SDL data stream. 554 * 555 * The data is allocated with a zero byte at the end (null terminated) for 556 * convenience. This extra byte is not included in the value reported via 557 * `datasize`. 558 * 559 * The data should be freed with SDL_free(). 560 * 561 * \param src the SDL_RWops to read all available data from. 562 * \param datasize if not NULL, will store the number of bytes read. 563 * \param freesrc if non-zero, calls SDL_RWclose() on `src` before returning. 564 * \returns the data, or NULL if there was an error. 565 * 566 * \since This function is available since SDL 2.0.6. 567 */ 568 extern DECLSPEC void *SDLCALL SDL_LoadFile_RW(SDL_RWops *src, 569 size_t *datasize, 570 int freesrc); 571 572 /** 573 * Load all the data from a file path. 574 * 575 * The data is allocated with a zero byte at the end (null terminated) for 576 * convenience. This extra byte is not included in the value reported via 577 * `datasize`. 578 * 579 * The data should be freed with SDL_free(). 580 * 581 * Prior to SDL 2.0.10, this function was a macro wrapping around 582 * SDL_LoadFile_RW. 583 * 584 * \param file the path to read all available data from. 585 * \param datasize if not NULL, will store the number of bytes read. 586 * \returns the data, or NULL if there was an error. 587 * 588 * \since This function is available since SDL 2.0.10. 589 */ 590 extern DECLSPEC void *SDLCALL SDL_LoadFile(const char *file, size_t *datasize); 591 592 /** 593 * \name Read endian functions 594 * 595 * Read an item of the specified endianness and return in native format. 596 */ 597 /* @{ */ 598 599 /** 600 * Use this function to read a byte from an SDL_RWops. 601 * 602 * \param src the SDL_RWops to read from. 603 * \returns the read byte on success or 0 on failure; call SDL_GetError() for 604 * more information. 605 * 606 * \since This function is available since SDL 2.0.0. 607 * 608 * \sa SDL_WriteU8 609 */ 610 extern DECLSPEC Uint8 SDLCALL SDL_ReadU8(SDL_RWops * src); 611 612 /** 613 * Use this function to read 16 bits of little-endian data from an SDL_RWops 614 * and return in native format. 615 * 616 * SDL byteswaps the data only if necessary, so the data returned will be in 617 * the native byte order. 618 * 619 * \param src the stream from which to read data. 620 * \returns 16 bits of data in the native byte order of the platform. 621 * 622 * \since This function is available since SDL 2.0.0. 623 * 624 * \sa SDL_ReadBE16 625 */ 626 extern DECLSPEC Uint16 SDLCALL SDL_ReadLE16(SDL_RWops * src); 627 628 /** 629 * Use this function to read 16 bits of big-endian data from an SDL_RWops and 630 * return in native format. 631 * 632 * SDL byteswaps the data only if necessary, so the data returned will be in 633 * the native byte order. 634 * 635 * \param src the stream from which to read data. 636 * \returns 16 bits of data in the native byte order of the platform. 637 * 638 * \since This function is available since SDL 2.0.0. 639 * 640 * \sa SDL_ReadLE16 641 */ 642 extern DECLSPEC Uint16 SDLCALL SDL_ReadBE16(SDL_RWops * src); 643 644 /** 645 * Use this function to read 32 bits of little-endian data from an SDL_RWops 646 * and return in native format. 647 * 648 * SDL byteswaps the data only if necessary, so the data returned will be in 649 * the native byte order. 650 * 651 * \param src the stream from which to read data. 652 * \returns 32 bits of data in the native byte order of the platform. 653 * 654 * \since This function is available since SDL 2.0.0. 655 * 656 * \sa SDL_ReadBE32 657 */ 658 extern DECLSPEC Uint32 SDLCALL SDL_ReadLE32(SDL_RWops * src); 659 660 /** 661 * Use this function to read 32 bits of big-endian data from an SDL_RWops and 662 * return in native format. 663 * 664 * SDL byteswaps the data only if necessary, so the data returned will be in 665 * the native byte order. 666 * 667 * \param src the stream from which to read data. 668 * \returns 32 bits of data in the native byte order of the platform. 669 * 670 * \since This function is available since SDL 2.0.0. 671 * 672 * \sa SDL_ReadLE32 673 */ 674 extern DECLSPEC Uint32 SDLCALL SDL_ReadBE32(SDL_RWops * src); 675 676 /** 677 * Use this function to read 64 bits of little-endian data from an SDL_RWops 678 * and return in native format. 679 * 680 * SDL byteswaps the data only if necessary, so the data returned will be in 681 * the native byte order. 682 * 683 * \param src the stream from which to read data. 684 * \returns 64 bits of data in the native byte order of the platform. 685 * 686 * \since This function is available since SDL 2.0.0. 687 * 688 * \sa SDL_ReadBE64 689 */ 690 extern DECLSPEC Uint64 SDLCALL SDL_ReadLE64(SDL_RWops * src); 691 692 /** 693 * Use this function to read 64 bits of big-endian data from an SDL_RWops and 694 * return in native format. 695 * 696 * SDL byteswaps the data only if necessary, so the data returned will be in 697 * the native byte order. 698 * 699 * \param src the stream from which to read data. 700 * \returns 64 bits of data in the native byte order of the platform. 701 * 702 * \since This function is available since SDL 2.0.0. 703 * 704 * \sa SDL_ReadLE64 705 */ 706 extern DECLSPEC Uint64 SDLCALL SDL_ReadBE64(SDL_RWops * src); 707 /* @} *//* Read endian functions */ 708 709 /** 710 * \name Write endian functions 711 * 712 * Write an item of native format to the specified endianness. 713 */ 714 /* @{ */ 715 716 /** 717 * Use this function to write a byte to an SDL_RWops. 718 * 719 * \param dst the SDL_RWops to write to. 720 * \param value the byte value to write. 721 * \returns 1 on success or 0 on failure; call SDL_GetError() for more 722 * information. 723 * 724 * \since This function is available since SDL 2.0.0. 725 * 726 * \sa SDL_ReadU8 727 */ 728 extern DECLSPEC size_t SDLCALL SDL_WriteU8(SDL_RWops * dst, Uint8 value); 729 730 /** 731 * Use this function to write 16 bits in native format to a SDL_RWops as 732 * little-endian data. 733 * 734 * SDL byteswaps the data only if necessary, so the application always 735 * specifies native format, and the data written will be in little-endian 736 * format. 737 * 738 * \param dst the stream to which data will be written. 739 * \param value the data to be written, in native format. 740 * \returns 1 on successful write, 0 on error. 741 * 742 * \since This function is available since SDL 2.0.0. 743 * 744 * \sa SDL_WriteBE16 745 */ 746 extern DECLSPEC size_t SDLCALL SDL_WriteLE16(SDL_RWops * dst, Uint16 value); 747 748 /** 749 * Use this function to write 16 bits in native format to a SDL_RWops as 750 * big-endian data. 751 * 752 * SDL byteswaps the data only if necessary, so the application always 753 * specifies native format, and the data written will be in big-endian format. 754 * 755 * \param dst the stream to which data will be written. 756 * \param value the data to be written, in native format. 757 * \returns 1 on successful write, 0 on error. 758 * 759 * \since This function is available since SDL 2.0.0. 760 * 761 * \sa SDL_WriteLE16 762 */ 763 extern DECLSPEC size_t SDLCALL SDL_WriteBE16(SDL_RWops * dst, Uint16 value); 764 765 /** 766 * Use this function to write 32 bits in native format to a SDL_RWops as 767 * little-endian data. 768 * 769 * SDL byteswaps the data only if necessary, so the application always 770 * specifies native format, and the data written will be in little-endian 771 * format. 772 * 773 * \param dst the stream to which data will be written. 774 * \param value the data to be written, in native format. 775 * \returns 1 on successful write, 0 on error. 776 * 777 * \since This function is available since SDL 2.0.0. 778 * 779 * \sa SDL_WriteBE32 780 */ 781 extern DECLSPEC size_t SDLCALL SDL_WriteLE32(SDL_RWops * dst, Uint32 value); 782 783 /** 784 * Use this function to write 32 bits in native format to a SDL_RWops as 785 * big-endian data. 786 * 787 * SDL byteswaps the data only if necessary, so the application always 788 * specifies native format, and the data written will be in big-endian format. 789 * 790 * \param dst the stream to which data will be written. 791 * \param value the data to be written, in native format. 792 * \returns 1 on successful write, 0 on error. 793 * 794 * \since This function is available since SDL 2.0.0. 795 * 796 * \sa SDL_WriteLE32 797 */ 798 extern DECLSPEC size_t SDLCALL SDL_WriteBE32(SDL_RWops * dst, Uint32 value); 799 800 /** 801 * Use this function to write 64 bits in native format to a SDL_RWops as 802 * little-endian data. 803 * 804 * SDL byteswaps the data only if necessary, so the application always 805 * specifies native format, and the data written will be in little-endian 806 * format. 807 * 808 * \param dst the stream to which data will be written. 809 * \param value the data to be written, in native format. 810 * \returns 1 on successful write, 0 on error. 811 * 812 * \since This function is available since SDL 2.0.0. 813 * 814 * \sa SDL_WriteBE64 815 */ 816 extern DECLSPEC size_t SDLCALL SDL_WriteLE64(SDL_RWops * dst, Uint64 value); 817 818 /** 819 * Use this function to write 64 bits in native format to a SDL_RWops as 820 * big-endian data. 821 * 822 * SDL byteswaps the data only if necessary, so the application always 823 * specifies native format, and the data written will be in big-endian format. 824 * 825 * \param dst the stream to which data will be written. 826 * \param value the data to be written, in native format. 827 * \returns 1 on successful write, 0 on error. 828 * 829 * \since This function is available since SDL 2.0.0. 830 * 831 * \sa SDL_WriteLE64 832 */ 833 extern DECLSPEC size_t SDLCALL SDL_WriteBE64(SDL_RWops * dst, Uint64 value); 834 /* @} *//* Write endian functions */ 835 836 /* Ends C function definitions when using C++ */ 837 #ifdef __cplusplus 838 } 839 #endif 840 #include "close_code.h" 841 842 #endif /* SDL_rwops_h_ */ 843 844 /* vi: set ts=4 sw=4 expandtab: */