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stb_image.h (260289B)
1 /* stb_image - v2.19 - public domain image loader - http://nothings.org/stb 2 no warranty implied; use at your own risk 3 4 Do this: 5 #define STB_IMAGE_IMPLEMENTATION 6 before you include this file in *one* C or C++ file to create the implementation. 7 8 // i.e. it should look like this: 9 #include ... 10 #include ... 11 #include ... 12 #define STB_IMAGE_IMPLEMENTATION 13 #include "stb_image.h" 14 15 You can #define STBI_ASSERT(x) before the #include to avoid using assert.h. 16 And #define STBI_MALLOC, STBI_REALLOC, and STBI_FREE to avoid using malloc,realloc,free 17 18 19 QUICK NOTES: 20 Primarily of interest to game developers and other people who can 21 avoid problematic images and only need the trivial interface 22 23 JPEG baseline & progressive (12 bpc/arithmetic not supported, same as stock IJG lib) 24 PNG 1/2/4/8/16-bit-per-channel 25 26 TGA (not sure what subset, if a subset) 27 BMP non-1bpp, non-RLE 28 PSD (composited view only, no extra channels, 8/16 bit-per-channel) 29 30 GIF (*comp always reports as 4-channel) 31 HDR (radiance rgbE format) 32 PIC (Softimage PIC) 33 PNM (PPM and PGM binary only) 34 35 Animated GIF still needs a proper API, but here's one way to do it: 36 http://gist.github.com/urraka/685d9a6340b26b830d49 37 38 - decode from memory or through FILE (define STBI_NO_STDIO to remove code) 39 - decode from arbitrary I/O callbacks 40 - SIMD acceleration on x86/x64 (SSE2) and ARM (NEON) 41 42 Full documentation under "DOCUMENTATION" below. 43 44 45 LICENSE 46 47 See end of file for license information. 48 49 RECENT REVISION HISTORY: 50 51 2.19 (2018-02-11) fix warning 52 2.18 (2018-01-30) fix warnings 53 2.17 (2018-01-29) bugfix, 1-bit BMP, 16-bitness query, fix warnings 54 2.16 (2017-07-23) all functions have 16-bit variants; optimizations; bugfixes 55 2.15 (2017-03-18) fix png-1,2,4; all Imagenet JPGs; no runtime SSE detection on GCC 56 2.14 (2017-03-03) remove deprecated STBI_JPEG_OLD; fixes for Imagenet JPGs 57 2.13 (2016-12-04) experimental 16-bit API, only for PNG so far; fixes 58 2.12 (2016-04-02) fix typo in 2.11 PSD fix that caused crashes 59 2.11 (2016-04-02) 16-bit PNGS; enable SSE2 in non-gcc x64 60 RGB-format JPEG; remove white matting in PSD; 61 allocate large structures on the stack; 62 correct channel count for PNG & BMP 63 2.10 (2016-01-22) avoid warning introduced in 2.09 64 2.09 (2016-01-16) 16-bit TGA; comments in PNM files; STBI_REALLOC_SIZED 65 66 See end of file for full revision history. 67 68 69 ============================ Contributors ========================= 70 71 Image formats Extensions, features 72 Sean Barrett (jpeg, png, bmp) Jetro Lauha (stbi_info) 73 Nicolas Schulz (hdr, psd) Martin "SpartanJ" Golini (stbi_info) 74 Jonathan Dummer (tga) James "moose2000" Brown (iPhone PNG) 75 Jean-Marc Lienher (gif) Ben "Disch" Wenger (io callbacks) 76 Tom Seddon (pic) Omar Cornut (1/2/4-bit PNG) 77 Thatcher Ulrich (psd) Nicolas Guillemot (vertical flip) 78 Ken Miller (pgm, ppm) Richard Mitton (16-bit PSD) 79 github:urraka (animated gif) Junggon Kim (PNM comments) 80 Christopher Forseth (animated gif) Daniel Gibson (16-bit TGA) 81 socks-the-fox (16-bit PNG) 82 Jeremy Sawicki (handle all ImageNet JPGs) 83 Optimizations & bugfixes Mikhail Morozov (1-bit BMP) 84 Fabian "ryg" Giesen Anael Seghezzi (is-16-bit query) 85 Arseny Kapoulkine 86 John-Mark Allen 87 88 Bug & warning fixes 89 Marc LeBlanc David Woo Guillaume George Martins Mozeiko 90 Christpher Lloyd Jerry Jansson Joseph Thomson Phil Jordan 91 Dave Moore Roy Eltham Hayaki Saito Nathan Reed 92 Won Chun Luke Graham Johan Duparc Nick Verigakis 93 the Horde3D community Thomas Ruf Ronny Chevalier github:rlyeh 94 Janez Zemva John Bartholomew Michal Cichon github:romigrou 95 Jonathan Blow Ken Hamada Tero Hanninen github:svdijk 96 Laurent Gomila Cort Stratton Sergio Gonzalez github:snagar 97 Aruelien Pocheville Thibault Reuille Cass Everitt github:Zelex 98 Ryamond Barbiero Paul Du Bois Engin Manap github:grim210 99 Aldo Culquicondor Philipp Wiesemann Dale Weiler github:sammyhw 100 Oriol Ferrer Mesia Josh Tobin Matthew Gregan github:phprus 101 Julian Raschke Gregory Mullen Baldur Karlsson github:poppolopoppo 102 Christian Floisand Kevin Schmidt github:darealshinji 103 Blazej Dariusz Roszkowski github:Michaelangel007 104 */ 105 106 #ifndef STBI_INCLUDE_STB_IMAGE_H 107 #define STBI_INCLUDE_STB_IMAGE_H 108 109 // DOCUMENTATION 110 // 111 // Limitations: 112 // - no 12-bit-per-channel JPEG 113 // - no JPEGs with arithmetic coding 114 // - GIF always returns *comp=4 115 // 116 // Basic usage (see HDR discussion below for HDR usage): 117 // int x,y,n; 118 // unsigned char *data = stbi_load(filename, &x, &y, &n, 0); 119 // // ... process data if not NULL ... 120 // // ... x = width, y = height, n = # 8-bit components per pixel ... 121 // // ... replace '0' with '1'..'4' to force that many components per pixel 122 // // ... but 'n' will always be the number that it would have been if you said 0 123 // stbi_image_free(data) 124 // 125 // Standard parameters: 126 // int *x -- outputs image width in pixels 127 // int *y -- outputs image height in pixels 128 // int *channels_in_file -- outputs # of image components in image file 129 // int desired_channels -- if non-zero, # of image components requested in result 130 // 131 // The return value from an image loader is an 'unsigned char *' which points 132 // to the pixel data, or NULL on an allocation failure or if the image is 133 // corrupt or invalid. The pixel data consists of *y scanlines of *x pixels, 134 // with each pixel consisting of N interleaved 8-bit components; the first 135 // pixel pointed to is top-left-most in the image. There is no padding between 136 // image scanlines or between pixels, regardless of format. The number of 137 // components N is 'desired_channels' if desired_channels is non-zero, or 138 // *channels_in_file otherwise. If desired_channels is non-zero, 139 // *channels_in_file has the number of components that _would_ have been 140 // output otherwise. E.g. if you set desired_channels to 4, you will always 141 // get RGBA output, but you can check *channels_in_file to see if it's trivially 142 // opaque because e.g. there were only 3 channels in the source image. 143 // 144 // An output image with N components has the following components interleaved 145 // in this order in each pixel: 146 // 147 // N=#comp components 148 // 1 grey 149 // 2 grey, alpha 150 // 3 red, green, blue 151 // 4 red, green, blue, alpha 152 // 153 // If image loading fails for any reason, the return value will be NULL, 154 // and *x, *y, *channels_in_file will be unchanged. The function 155 // stbi_failure_reason() can be queried for an extremely brief, end-user 156 // unfriendly explanation of why the load failed. Define STBI_NO_FAILURE_STRINGS 157 // to avoid compiling these strings at all, and STBI_FAILURE_USERMSG to get slightly 158 // more user-friendly ones. 159 // 160 // Paletted PNG, BMP, GIF, and PIC images are automatically depalettized. 161 // 162 // =========================================================================== 163 // 164 // Philosophy 165 // 166 // stb libraries are designed with the following priorities: 167 // 168 // 1. easy to use 169 // 2. easy to maintain 170 // 3. good performance 171 // 172 // Sometimes I let "good performance" creep up in priority over "easy to maintain", 173 // and for best performance I may provide less-easy-to-use APIs that give higher 174 // performance, in addition to the easy to use ones. Nevertheless, it's important 175 // to keep in mind that from the standpoint of you, a client of this library, 176 // all you care about is #1 and #3, and stb libraries DO NOT emphasize #3 above all. 177 // 178 // Some secondary priorities arise directly from the first two, some of which 179 // make more explicit reasons why performance can't be emphasized. 180 // 181 // - Portable ("ease of use") 182 // - Small source code footprint ("easy to maintain") 183 // - No dependencies ("ease of use") 184 // 185 // =========================================================================== 186 // 187 // I/O callbacks 188 // 189 // I/O callbacks allow you to read from arbitrary sources, like packaged 190 // files or some other source. Data read from callbacks are processed 191 // through a small internal buffer (currently 128 bytes) to try to reduce 192 // overhead. 193 // 194 // The three functions you must define are "read" (reads some bytes of data), 195 // "skip" (skips some bytes of data), "eof" (reports if the stream is at the end). 196 // 197 // =========================================================================== 198 // 199 // SIMD support 200 // 201 // The JPEG decoder will try to automatically use SIMD kernels on x86 when 202 // supported by the compiler. For ARM Neon support, you must explicitly 203 // request it. 204 // 205 // (The old do-it-yourself SIMD API is no longer supported in the current 206 // code.) 207 // 208 // On x86, SSE2 will automatically be used when available based on a run-time 209 // test; if not, the generic C versions are used as a fall-back. On ARM targets, 210 // the typical path is to have separate builds for NEON and non-NEON devices 211 // (at least this is true for iOS and Android). Therefore, the NEON support is 212 // toggled by a build flag: define STBI_NEON to get NEON loops. 213 // 214 // If for some reason you do not want to use any of SIMD code, or if 215 // you have issues compiling it, you can disable it entirely by 216 // defining STBI_NO_SIMD. 217 // 218 // =========================================================================== 219 // 220 // HDR image support (disable by defining STBI_NO_HDR) 221 // 222 // stb_image now supports loading HDR images in general, and currently 223 // the Radiance .HDR file format, although the support is provided 224 // generically. You can still load any file through the existing interface; 225 // if you attempt to load an HDR file, it will be automatically remapped to 226 // LDR, assuming gamma 2.2 and an arbitrary scale factor defaulting to 1; 227 // both of these constants can be reconfigured through this interface: 228 // 229 // stbi_hdr_to_ldr_gamma(2.2f); 230 // stbi_hdr_to_ldr_scale(1.0f); 231 // 232 // (note, do not use _inverse_ constants; stbi_image will invert them 233 // appropriately). 234 // 235 // Additionally, there is a new, parallel interface for loading files as 236 // (linear) floats to preserve the full dynamic range: 237 // 238 // float *data = stbi_loadf(filename, &x, &y, &n, 0); 239 // 240 // If you load LDR images through this interface, those images will 241 // be promoted to floating point values, run through the inverse of 242 // constants corresponding to the above: 243 // 244 // stbi_ldr_to_hdr_scale(1.0f); 245 // stbi_ldr_to_hdr_gamma(2.2f); 246 // 247 // Finally, given a filename (or an open file or memory block--see header 248 // file for details) containing image data, you can query for the "most 249 // appropriate" interface to use (that is, whether the image is HDR or 250 // not), using: 251 // 252 // stbi_is_hdr(char *filename); 253 // 254 // =========================================================================== 255 // 256 // iPhone PNG support: 257 // 258 // By default we convert iphone-formatted PNGs back to RGB, even though 259 // they are internally encoded differently. You can disable this conversion 260 // by by calling stbi_convert_iphone_png_to_rgb(0), in which case 261 // you will always just get the native iphone "format" through (which 262 // is BGR stored in RGB). 263 // 264 // Call stbi_set_unpremultiply_on_load(1) as well to force a divide per 265 // pixel to remove any premultiplied alpha *only* if the image file explicitly 266 // says there's premultiplied data (currently only happens in iPhone images, 267 // and only if iPhone convert-to-rgb processing is on). 268 // 269 // =========================================================================== 270 // 271 // ADDITIONAL CONFIGURATION 272 // 273 // - You can suppress implementation of any of the decoders to reduce 274 // your code footprint by #defining one or more of the following 275 // symbols before creating the implementation. 276 // 277 // STBI_NO_JPEG 278 // STBI_NO_PNG 279 // STBI_NO_BMP 280 // STBI_NO_PSD 281 // STBI_NO_TGA 282 // STBI_NO_GIF 283 // STBI_NO_HDR 284 // STBI_NO_PIC 285 // STBI_NO_PNM (.ppm and .pgm) 286 // 287 // - You can request *only* certain decoders and suppress all other ones 288 // (this will be more forward-compatible, as addition of new decoders 289 // doesn't require you to disable them explicitly): 290 // 291 // STBI_ONLY_JPEG 292 // STBI_ONLY_PNG 293 // STBI_ONLY_BMP 294 // STBI_ONLY_PSD 295 // STBI_ONLY_TGA 296 // STBI_ONLY_GIF 297 // STBI_ONLY_HDR 298 // STBI_ONLY_PIC 299 // STBI_ONLY_PNM (.ppm and .pgm) 300 // 301 // - If you use STBI_NO_PNG (or _ONLY_ without PNG), and you still 302 // want the zlib decoder to be available, #define STBI_SUPPORT_ZLIB 303 // 304 305 306 #ifndef STBI_NO_STDIO 307 #include <stdio.h> 308 #endif // STBI_NO_STDIO 309 310 #define STBI_VERSION 1 311 312 enum 313 { 314 STBI_default = 0, // only used for desired_channels 315 316 STBI_grey = 1, 317 STBI_grey_alpha = 2, 318 STBI_rgb = 3, 319 STBI_rgb_alpha = 4 320 }; 321 322 typedef unsigned char stbi_uc; 323 typedef unsigned short stbi_us; 324 325 #ifdef __cplusplus 326 extern "C" { 327 #endif 328 329 #ifdef STB_IMAGE_STATIC 330 #define STBIDEF static 331 #else 332 #define STBIDEF extern 333 #endif 334 335 ////////////////////////////////////////////////////////////////////////////// 336 // 337 // PRIMARY API - works on images of any type 338 // 339 340 // 341 // load image by filename, open file, or memory buffer 342 // 343 344 typedef struct 345 { 346 int (*read) (void *user,char *data,int size); // fill 'data' with 'size' bytes. return number of bytes actually read 347 void (*skip) (void *user,int n); // skip the next 'n' bytes, or 'unget' the last -n bytes if negative 348 int (*eof) (void *user); // returns nonzero if we are at end of file/data 349 } stbi_io_callbacks; 350 351 //////////////////////////////////// 352 // 353 // 8-bits-per-channel interface 354 // 355 356 STBIDEF stbi_uc *stbi_load_from_memory (stbi_uc const *buffer, int len , int *x, int *y, int *channels_in_file, int desired_channels); 357 STBIDEF stbi_uc *stbi_load_from_callbacks(stbi_io_callbacks const *clbk , void *user, int *x, int *y, int *channels_in_file, int desired_channels); 358 #ifndef STBI_NO_GIF 359 STBIDEF stbi_uc *stbi_load_gif_from_memory(stbi_uc const *buffer, int len, int **delays, int *x, int *y, int *z, int *comp, int req_comp); 360 #endif 361 362 363 #ifndef STBI_NO_STDIO 364 STBIDEF stbi_uc *stbi_load (char const *filename, int *x, int *y, int *channels_in_file, int desired_channels); 365 STBIDEF stbi_uc *stbi_load_from_file (FILE *f, int *x, int *y, int *channels_in_file, int desired_channels); 366 // for stbi_load_from_file, file pointer is left pointing immediately after image 367 #endif 368 369 //////////////////////////////////// 370 // 371 // 16-bits-per-channel interface 372 // 373 374 STBIDEF stbi_us *stbi_load_16_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *channels_in_file, int desired_channels); 375 STBIDEF stbi_us *stbi_load_16_from_callbacks(stbi_io_callbacks const *clbk, void *user, int *x, int *y, int *channels_in_file, int desired_channels); 376 377 #ifndef STBI_NO_STDIO 378 STBIDEF stbi_us *stbi_load_16 (char const *filename, int *x, int *y, int *channels_in_file, int desired_channels); 379 STBIDEF stbi_us *stbi_load_from_file_16(FILE *f, int *x, int *y, int *channels_in_file, int desired_channels); 380 #endif 381 382 //////////////////////////////////// 383 // 384 // float-per-channel interface 385 // 386 #ifndef STBI_NO_LINEAR 387 STBIDEF float *stbi_loadf_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *channels_in_file, int desired_channels); 388 STBIDEF float *stbi_loadf_from_callbacks (stbi_io_callbacks const *clbk, void *user, int *x, int *y, int *channels_in_file, int desired_channels); 389 390 #ifndef STBI_NO_STDIO 391 STBIDEF float *stbi_loadf (char const *filename, int *x, int *y, int *channels_in_file, int desired_channels); 392 STBIDEF float *stbi_loadf_from_file (FILE *f, int *x, int *y, int *channels_in_file, int desired_channels); 393 #endif 394 #endif 395 396 #ifndef STBI_NO_HDR 397 STBIDEF void stbi_hdr_to_ldr_gamma(float gamma); 398 STBIDEF void stbi_hdr_to_ldr_scale(float scale); 399 #endif // STBI_NO_HDR 400 401 #ifndef STBI_NO_LINEAR 402 STBIDEF void stbi_ldr_to_hdr_gamma(float gamma); 403 STBIDEF void stbi_ldr_to_hdr_scale(float scale); 404 #endif // STBI_NO_LINEAR 405 406 // stbi_is_hdr is always defined, but always returns false if STBI_NO_HDR 407 STBIDEF int stbi_is_hdr_from_callbacks(stbi_io_callbacks const *clbk, void *user); 408 STBIDEF int stbi_is_hdr_from_memory(stbi_uc const *buffer, int len); 409 #ifndef STBI_NO_STDIO 410 STBIDEF int stbi_is_hdr (char const *filename); 411 STBIDEF int stbi_is_hdr_from_file(FILE *f); 412 #endif // STBI_NO_STDIO 413 414 415 // get a VERY brief reason for failure 416 // NOT THREADSAFE 417 STBIDEF const char *stbi_failure_reason (void); 418 419 // free the loaded image -- this is just free() 420 STBIDEF void stbi_image_free (void *retval_from_stbi_load); 421 422 // get image dimensions & components without fully decoding 423 STBIDEF int stbi_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp); 424 STBIDEF int stbi_info_from_callbacks(stbi_io_callbacks const *clbk, void *user, int *x, int *y, int *comp); 425 STBIDEF int stbi_is_16_bit_from_memory(stbi_uc const *buffer, int len); 426 STBIDEF int stbi_is_16_bit_from_callbacks(stbi_io_callbacks const *clbk, void *user); 427 428 #ifndef STBI_NO_STDIO 429 STBIDEF int stbi_info (char const *filename, int *x, int *y, int *comp); 430 STBIDEF int stbi_info_from_file (FILE *f, int *x, int *y, int *comp); 431 STBIDEF int stbi_is_16_bit (char const *filename); 432 STBIDEF int stbi_is_16_bit_from_file(FILE *f); 433 #endif 434 435 436 437 // for image formats that explicitly notate that they have premultiplied alpha, 438 // we just return the colors as stored in the file. set this flag to force 439 // unpremultiplication. results are undefined if the unpremultiply overflow. 440 STBIDEF void stbi_set_unpremultiply_on_load(int flag_true_if_should_unpremultiply); 441 442 // indicate whether we should process iphone images back to canonical format, 443 // or just pass them through "as-is" 444 STBIDEF void stbi_convert_iphone_png_to_rgb(int flag_true_if_should_convert); 445 446 // flip the image vertically, so the first pixel in the output array is the bottom left 447 STBIDEF void stbi_set_flip_vertically_on_load(int flag_true_if_should_flip); 448 449 // ZLIB client - used by PNG, available for other purposes 450 451 STBIDEF char *stbi_zlib_decode_malloc_guesssize(const char *buffer, int len, int initial_size, int *outlen); 452 STBIDEF char *stbi_zlib_decode_malloc_guesssize_headerflag(const char *buffer, int len, int initial_size, int *outlen, int parse_header); 453 STBIDEF char *stbi_zlib_decode_malloc(const char *buffer, int len, int *outlen); 454 STBIDEF int stbi_zlib_decode_buffer(char *obuffer, int olen, const char *ibuffer, int ilen); 455 456 STBIDEF char *stbi_zlib_decode_noheader_malloc(const char *buffer, int len, int *outlen); 457 STBIDEF int stbi_zlib_decode_noheader_buffer(char *obuffer, int olen, const char *ibuffer, int ilen); 458 459 460 #ifdef __cplusplus 461 } 462 #endif 463 464 // 465 // 466 //// end header file ///////////////////////////////////////////////////// 467 #endif // STBI_INCLUDE_STB_IMAGE_H 468 469 #ifdef STB_IMAGE_IMPLEMENTATION 470 471 #if defined(STBI_ONLY_JPEG) || defined(STBI_ONLY_PNG) || defined(STBI_ONLY_BMP) \ 472 || defined(STBI_ONLY_TGA) || defined(STBI_ONLY_GIF) || defined(STBI_ONLY_PSD) \ 473 || defined(STBI_ONLY_HDR) || defined(STBI_ONLY_PIC) || defined(STBI_ONLY_PNM) \ 474 || defined(STBI_ONLY_ZLIB) 475 #ifndef STBI_ONLY_JPEG 476 #define STBI_NO_JPEG 477 #endif 478 #ifndef STBI_ONLY_PNG 479 #define STBI_NO_PNG 480 #endif 481 #ifndef STBI_ONLY_BMP 482 #define STBI_NO_BMP 483 #endif 484 #ifndef STBI_ONLY_PSD 485 #define STBI_NO_PSD 486 #endif 487 #ifndef STBI_ONLY_TGA 488 #define STBI_NO_TGA 489 #endif 490 #ifndef STBI_ONLY_GIF 491 #define STBI_NO_GIF 492 #endif 493 #ifndef STBI_ONLY_HDR 494 #define STBI_NO_HDR 495 #endif 496 #ifndef STBI_ONLY_PIC 497 #define STBI_NO_PIC 498 #endif 499 #ifndef STBI_ONLY_PNM 500 #define STBI_NO_PNM 501 #endif 502 #endif 503 504 #if defined(STBI_NO_PNG) && !defined(STBI_SUPPORT_ZLIB) && !defined(STBI_NO_ZLIB) 505 #define STBI_NO_ZLIB 506 #endif 507 508 509 #include <stdarg.h> 510 #include <stddef.h> // ptrdiff_t on osx 511 #include <stdlib.h> 512 #include <string.h> 513 #include <limits.h> 514 515 #if !defined(STBI_NO_LINEAR) || !defined(STBI_NO_HDR) 516 #include <math.h> // ldexp, pow 517 #endif 518 519 #ifndef STBI_NO_STDIO 520 #include <stdio.h> 521 #endif 522 523 #ifndef STBI_ASSERT 524 #include <assert.h> 525 #define STBI_ASSERT(x) assert(x) 526 #endif 527 528 529 #ifndef _MSC_VER 530 #ifdef __cplusplus 531 #define stbi_inline inline 532 #else 533 #define stbi_inline 534 #endif 535 #else 536 #define stbi_inline __forceinline 537 #endif 538 539 540 #ifdef _MSC_VER 541 typedef unsigned short stbi__uint16; 542 typedef signed short stbi__int16; 543 typedef unsigned int stbi__uint32; 544 typedef signed int stbi__int32; 545 #else 546 #include <stdint.h> 547 typedef uint16_t stbi__uint16; 548 typedef int16_t stbi__int16; 549 typedef uint32_t stbi__uint32; 550 typedef int32_t stbi__int32; 551 #endif 552 553 // should produce compiler error if size is wrong 554 typedef unsigned char validate_uint32[sizeof(stbi__uint32)==4 ? 1 : -1]; 555 556 #ifdef _MSC_VER 557 #define STBI_NOTUSED(v) (void)(v) 558 #else 559 #define STBI_NOTUSED(v) (void)sizeof(v) 560 #endif 561 562 #ifdef _MSC_VER 563 #define STBI_HAS_LROTL 564 #endif 565 566 #ifdef STBI_HAS_LROTL 567 #define stbi_lrot(x,y) _lrotl(x,y) 568 #else 569 #define stbi_lrot(x,y) (((x) << (y)) | ((x) >> (32 - (y)))) 570 #endif 571 572 #if defined(STBI_MALLOC) && defined(STBI_FREE) && (defined(STBI_REALLOC) || defined(STBI_REALLOC_SIZED)) 573 // ok 574 #elif !defined(STBI_MALLOC) && !defined(STBI_FREE) && !defined(STBI_REALLOC) && !defined(STBI_REALLOC_SIZED) 575 // ok 576 #else 577 #error "Must define all or none of STBI_MALLOC, STBI_FREE, and STBI_REALLOC (or STBI_REALLOC_SIZED)." 578 #endif 579 580 #ifndef STBI_MALLOC 581 #define STBI_MALLOC(sz) malloc(sz) 582 #define STBI_REALLOC(p,newsz) realloc(p,newsz) 583 #define STBI_FREE(p) free(p) 584 #endif 585 586 #ifndef STBI_REALLOC_SIZED 587 #define STBI_REALLOC_SIZED(p,oldsz,newsz) STBI_REALLOC(p,newsz) 588 #endif 589 590 // x86/x64 detection 591 #if defined(__x86_64__) || defined(_M_X64) 592 #define STBI__X64_TARGET 593 #elif defined(__i386) || defined(_M_IX86) 594 #define STBI__X86_TARGET 595 #endif 596 597 #if defined(__GNUC__) && defined(STBI__X86_TARGET) && !defined(__SSE2__) && !defined(STBI_NO_SIMD) 598 // gcc doesn't support sse2 intrinsics unless you compile with -msse2, 599 // which in turn means it gets to use SSE2 everywhere. This is unfortunate, 600 // but previous attempts to provide the SSE2 functions with runtime 601 // detection caused numerous issues. The way architecture extensions are 602 // exposed in GCC/Clang is, sadly, not really suited for one-file libs. 603 // New behavior: if compiled with -msse2, we use SSE2 without any 604 // detection; if not, we don't use it at all. 605 #define STBI_NO_SIMD 606 #endif 607 608 #if defined(__MINGW32__) && defined(STBI__X86_TARGET) && !defined(STBI_MINGW_ENABLE_SSE2) && !defined(STBI_NO_SIMD) 609 // Note that __MINGW32__ doesn't actually mean 32-bit, so we have to avoid STBI__X64_TARGET 610 // 611 // 32-bit MinGW wants ESP to be 16-byte aligned, but this is not in the 612 // Windows ABI and VC++ as well as Windows DLLs don't maintain that invariant. 613 // As a result, enabling SSE2 on 32-bit MinGW is dangerous when not 614 // simultaneously enabling "-mstackrealign". 615 // 616 // See https://github.com/nothings/stb/issues/81 for more information. 617 // 618 // So default to no SSE2 on 32-bit MinGW. If you've read this far and added 619 // -mstackrealign to your build settings, feel free to #define STBI_MINGW_ENABLE_SSE2. 620 #define STBI_NO_SIMD 621 #endif 622 623 #if !defined(STBI_NO_SIMD) && (defined(STBI__X86_TARGET) || defined(STBI__X64_TARGET)) 624 #define STBI_SSE2 625 #include <emmintrin.h> 626 627 #ifdef _MSC_VER 628 629 #if _MSC_VER >= 1400 // not VC6 630 #include <intrin.h> // __cpuid 631 static int stbi__cpuid3(void) 632 { 633 int info[4]; 634 __cpuid(info,1); 635 return info[3]; 636 } 637 #else 638 static int stbi__cpuid3(void) 639 { 640 int res; 641 __asm { 642 mov eax,1 643 cpuid 644 mov res,edx 645 } 646 return res; 647 } 648 #endif 649 650 #define STBI_SIMD_ALIGN(type, name) __declspec(align(16)) type name 651 652 static int stbi__sse2_available(void) 653 { 654 int info3 = stbi__cpuid3(); 655 return ((info3 >> 26) & 1) != 0; 656 } 657 #else // assume GCC-style if not VC++ 658 #define STBI_SIMD_ALIGN(type, name) type name __attribute__((aligned(16))) 659 660 static int stbi__sse2_available(void) 661 { 662 // If we're even attempting to compile this on GCC/Clang, that means 663 // -msse2 is on, which means the compiler is allowed to use SSE2 664 // instructions at will, and so are we. 665 return 1; 666 } 667 #endif 668 #endif 669 670 // ARM NEON 671 #if defined(STBI_NO_SIMD) && defined(STBI_NEON) 672 #undef STBI_NEON 673 #endif 674 675 #ifdef STBI_NEON 676 #include <arm_neon.h> 677 // assume GCC or Clang on ARM targets 678 #define STBI_SIMD_ALIGN(type, name) type name __attribute__((aligned(16))) 679 #endif 680 681 #ifndef STBI_SIMD_ALIGN 682 #define STBI_SIMD_ALIGN(type, name) type name 683 #endif 684 685 /////////////////////////////////////////////// 686 // 687 // stbi__context struct and start_xxx functions 688 689 // stbi__context structure is our basic context used by all images, so it 690 // contains all the IO context, plus some basic image information 691 typedef struct 692 { 693 stbi__uint32 img_x, img_y; 694 int img_n, img_out_n; 695 696 stbi_io_callbacks io; 697 void *io_user_data; 698 699 int read_from_callbacks; 700 int buflen; 701 stbi_uc buffer_start[128]; 702 703 stbi_uc *img_buffer, *img_buffer_end; 704 stbi_uc *img_buffer_original, *img_buffer_original_end; 705 } stbi__context; 706 707 708 static void stbi__refill_buffer(stbi__context *s); 709 710 // initialize a memory-decode context 711 static void stbi__start_mem(stbi__context *s, stbi_uc const *buffer, int len) 712 { 713 s->io.read = NULL; 714 s->read_from_callbacks = 0; 715 s->img_buffer = s->img_buffer_original = (stbi_uc *) buffer; 716 s->img_buffer_end = s->img_buffer_original_end = (stbi_uc *) buffer+len; 717 } 718 719 // initialize a callback-based context 720 static void stbi__start_callbacks(stbi__context *s, stbi_io_callbacks *c, void *user) 721 { 722 s->io = *c; 723 s->io_user_data = user; 724 s->buflen = sizeof(s->buffer_start); 725 s->read_from_callbacks = 1; 726 s->img_buffer_original = s->buffer_start; 727 stbi__refill_buffer(s); 728 s->img_buffer_original_end = s->img_buffer_end; 729 } 730 731 #ifndef STBI_NO_STDIO 732 733 static int stbi__stdio_read(void *user, char *data, int size) 734 { 735 return (int) fread(data,1,size,(FILE*) user); 736 } 737 738 static void stbi__stdio_skip(void *user, int n) 739 { 740 fseek((FILE*) user, n, SEEK_CUR); 741 } 742 743 static int stbi__stdio_eof(void *user) 744 { 745 return feof((FILE*) user); 746 } 747 748 static stbi_io_callbacks stbi__stdio_callbacks = 749 { 750 stbi__stdio_read, 751 stbi__stdio_skip, 752 stbi__stdio_eof, 753 }; 754 755 static void stbi__start_file(stbi__context *s, FILE *f) 756 { 757 stbi__start_callbacks(s, &stbi__stdio_callbacks, (void *) f); 758 } 759 760 //static void stop_file(stbi__context *s) { } 761 762 #endif // !STBI_NO_STDIO 763 764 static void stbi__rewind(stbi__context *s) 765 { 766 // conceptually rewind SHOULD rewind to the beginning of the stream, 767 // but we just rewind to the beginning of the initial buffer, because 768 // we only use it after doing 'test', which only ever looks at at most 92 bytes 769 s->img_buffer = s->img_buffer_original; 770 s->img_buffer_end = s->img_buffer_original_end; 771 } 772 773 enum 774 { 775 STBI_ORDER_RGB, 776 STBI_ORDER_BGR 777 }; 778 779 typedef struct 780 { 781 int bits_per_channel; 782 int num_channels; 783 int channel_order; 784 } stbi__result_info; 785 786 #ifndef STBI_NO_JPEG 787 static int stbi__jpeg_test(stbi__context *s); 788 static void *stbi__jpeg_load(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri); 789 static int stbi__jpeg_info(stbi__context *s, int *x, int *y, int *comp); 790 #endif 791 792 #ifndef STBI_NO_PNG 793 static int stbi__png_test(stbi__context *s); 794 static void *stbi__png_load(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri); 795 static int stbi__png_info(stbi__context *s, int *x, int *y, int *comp); 796 static int stbi__png_is16(stbi__context *s); 797 #endif 798 799 #ifndef STBI_NO_BMP 800 static int stbi__bmp_test(stbi__context *s); 801 static void *stbi__bmp_load(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri); 802 static int stbi__bmp_info(stbi__context *s, int *x, int *y, int *comp); 803 #endif 804 805 #ifndef STBI_NO_TGA 806 static int stbi__tga_test(stbi__context *s); 807 static void *stbi__tga_load(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri); 808 static int stbi__tga_info(stbi__context *s, int *x, int *y, int *comp); 809 #endif 810 811 #ifndef STBI_NO_PSD 812 static int stbi__psd_test(stbi__context *s); 813 static void *stbi__psd_load(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri, int bpc); 814 static int stbi__psd_info(stbi__context *s, int *x, int *y, int *comp); 815 static int stbi__psd_is16(stbi__context *s); 816 #endif 817 818 #ifndef STBI_NO_HDR 819 static int stbi__hdr_test(stbi__context *s); 820 static float *stbi__hdr_load(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri); 821 static int stbi__hdr_info(stbi__context *s, int *x, int *y, int *comp); 822 #endif 823 824 #ifndef STBI_NO_PIC 825 static int stbi__pic_test(stbi__context *s); 826 static void *stbi__pic_load(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri); 827 static int stbi__pic_info(stbi__context *s, int *x, int *y, int *comp); 828 #endif 829 830 #ifndef STBI_NO_GIF 831 static int stbi__gif_test(stbi__context *s); 832 static void *stbi__gif_load(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri); 833 static void *stbi__load_gif_main(stbi__context *s, int **delays, int *x, int *y, int *z, int *comp, int req_comp); 834 static int stbi__gif_info(stbi__context *s, int *x, int *y, int *comp); 835 #endif 836 837 #ifndef STBI_NO_PNM 838 static int stbi__pnm_test(stbi__context *s); 839 static void *stbi__pnm_load(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri); 840 static int stbi__pnm_info(stbi__context *s, int *x, int *y, int *comp); 841 #endif 842 843 // this is not threadsafe 844 static const char *stbi__g_failure_reason; 845 846 STBIDEF const char *stbi_failure_reason(void) 847 { 848 return stbi__g_failure_reason; 849 } 850 851 static int stbi__err(const char *str) 852 { 853 stbi__g_failure_reason = str; 854 return 0; 855 } 856 857 static void *stbi__malloc(size_t size) 858 { 859 return STBI_MALLOC(size); 860 } 861 862 // stb_image uses ints pervasively, including for offset calculations. 863 // therefore the largest decoded image size we can support with the 864 // current code, even on 64-bit targets, is INT_MAX. this is not a 865 // significant limitation for the intended use case. 866 // 867 // we do, however, need to make sure our size calculations don't 868 // overflow. hence a few helper functions for size calculations that 869 // multiply integers together, making sure that they're non-negative 870 // and no overflow occurs. 871 872 // return 1 if the sum is valid, 0 on overflow. 873 // negative terms are considered invalid. 874 static int stbi__addsizes_valid(int a, int b) 875 { 876 if (b < 0) return 0; 877 // now 0 <= b <= INT_MAX, hence also 878 // 0 <= INT_MAX - b <= INTMAX. 879 // And "a + b <= INT_MAX" (which might overflow) is the 880 // same as a <= INT_MAX - b (no overflow) 881 return a <= INT_MAX - b; 882 } 883 884 // returns 1 if the product is valid, 0 on overflow. 885 // negative factors are considered invalid. 886 static int stbi__mul2sizes_valid(int a, int b) 887 { 888 if (a < 0 || b < 0) return 0; 889 if (b == 0) return 1; // mul-by-0 is always safe 890 // portable way to check for no overflows in a*b 891 return a <= INT_MAX/b; 892 } 893 894 // returns 1 if "a*b + add" has no negative terms/factors and doesn't overflow 895 static int stbi__mad2sizes_valid(int a, int b, int add) 896 { 897 return stbi__mul2sizes_valid(a, b) && stbi__addsizes_valid(a*b, add); 898 } 899 900 // returns 1 if "a*b*c + add" has no negative terms/factors and doesn't overflow 901 static int stbi__mad3sizes_valid(int a, int b, int c, int add) 902 { 903 return stbi__mul2sizes_valid(a, b) && stbi__mul2sizes_valid(a*b, c) && 904 stbi__addsizes_valid(a*b*c, add); 905 } 906 907 // returns 1 if "a*b*c*d + add" has no negative terms/factors and doesn't overflow 908 #if !defined(STBI_NO_LINEAR) || !defined(STBI_NO_HDR) 909 static int stbi__mad4sizes_valid(int a, int b, int c, int d, int add) 910 { 911 return stbi__mul2sizes_valid(a, b) && stbi__mul2sizes_valid(a*b, c) && 912 stbi__mul2sizes_valid(a*b*c, d) && stbi__addsizes_valid(a*b*c*d, add); 913 } 914 #endif 915 916 // mallocs with size overflow checking 917 static void *stbi__malloc_mad2(int a, int b, int add) 918 { 919 if (!stbi__mad2sizes_valid(a, b, add)) return NULL; 920 return stbi__malloc(a*b + add); 921 } 922 923 static void *stbi__malloc_mad3(int a, int b, int c, int add) 924 { 925 if (!stbi__mad3sizes_valid(a, b, c, add)) return NULL; 926 return stbi__malloc(a*b*c + add); 927 } 928 929 #if !defined(STBI_NO_LINEAR) || !defined(STBI_NO_HDR) 930 static void *stbi__malloc_mad4(int a, int b, int c, int d, int add) 931 { 932 if (!stbi__mad4sizes_valid(a, b, c, d, add)) return NULL; 933 return stbi__malloc(a*b*c*d + add); 934 } 935 #endif 936 937 // stbi__err - error 938 // stbi__errpf - error returning pointer to float 939 // stbi__errpuc - error returning pointer to unsigned char 940 941 #ifdef STBI_NO_FAILURE_STRINGS 942 #define stbi__err(x,y) 0 943 #elif defined(STBI_FAILURE_USERMSG) 944 #define stbi__err(x,y) stbi__err(y) 945 #else 946 #define stbi__err(x,y) stbi__err(x) 947 #endif 948 949 #define stbi__errpf(x,y) ((float *)(size_t) (stbi__err(x,y)?NULL:NULL)) 950 #define stbi__errpuc(x,y) ((unsigned char *)(size_t) (stbi__err(x,y)?NULL:NULL)) 951 952 STBIDEF void stbi_image_free(void *retval_from_stbi_load) 953 { 954 STBI_FREE(retval_from_stbi_load); 955 } 956 957 #ifndef STBI_NO_LINEAR 958 static float *stbi__ldr_to_hdr(stbi_uc *data, int x, int y, int comp); 959 #endif 960 961 #ifndef STBI_NO_HDR 962 static stbi_uc *stbi__hdr_to_ldr(float *data, int x, int y, int comp); 963 #endif 964 965 static int stbi__vertically_flip_on_load = 0; 966 967 STBIDEF void stbi_set_flip_vertically_on_load(int flag_true_if_should_flip) 968 { 969 stbi__vertically_flip_on_load = flag_true_if_should_flip; 970 } 971 972 static void *stbi__load_main(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri, int bpc) 973 { 974 memset(ri, 0, sizeof(*ri)); // make sure it's initialized if we add new fields 975 ri->bits_per_channel = 8; // default is 8 so most paths don't have to be changed 976 ri->channel_order = STBI_ORDER_RGB; // all current input & output are this, but this is here so we can add BGR order 977 ri->num_channels = 0; 978 979 #ifndef STBI_NO_JPEG 980 if (stbi__jpeg_test(s)) return stbi__jpeg_load(s,x,y,comp,req_comp, ri); 981 #endif 982 #ifndef STBI_NO_PNG 983 if (stbi__png_test(s)) return stbi__png_load(s,x,y,comp,req_comp, ri); 984 #endif 985 #ifndef STBI_NO_BMP 986 if (stbi__bmp_test(s)) return stbi__bmp_load(s,x,y,comp,req_comp, ri); 987 #endif 988 #ifndef STBI_NO_GIF 989 if (stbi__gif_test(s)) return stbi__gif_load(s,x,y,comp,req_comp, ri); 990 #endif 991 #ifndef STBI_NO_PSD 992 if (stbi__psd_test(s)) return stbi__psd_load(s,x,y,comp,req_comp, ri, bpc); 993 #endif 994 #ifndef STBI_NO_PIC 995 if (stbi__pic_test(s)) return stbi__pic_load(s,x,y,comp,req_comp, ri); 996 #endif 997 #ifndef STBI_NO_PNM 998 if (stbi__pnm_test(s)) return stbi__pnm_load(s,x,y,comp,req_comp, ri); 999 #endif 1000 1001 #ifndef STBI_NO_HDR 1002 if (stbi__hdr_test(s)) { 1003 float *hdr = stbi__hdr_load(s, x,y,comp,req_comp, ri); 1004 return stbi__hdr_to_ldr(hdr, *x, *y, req_comp ? req_comp : *comp); 1005 } 1006 #endif 1007 1008 #ifndef STBI_NO_TGA 1009 // test tga last because it's a crappy test! 1010 if (stbi__tga_test(s)) 1011 return stbi__tga_load(s,x,y,comp,req_comp, ri); 1012 #endif 1013 1014 return stbi__errpuc("unknown image type", "Image not of any known type, or corrupt"); 1015 } 1016 1017 static stbi_uc *stbi__convert_16_to_8(stbi__uint16 *orig, int w, int h, int channels) 1018 { 1019 int i; 1020 int img_len = w * h * channels; 1021 stbi_uc *reduced; 1022 1023 reduced = (stbi_uc *) stbi__malloc(img_len); 1024 if (reduced == NULL) return stbi__errpuc("outofmem", "Out of memory"); 1025 1026 for (i = 0; i < img_len; ++i) 1027 reduced[i] = (stbi_uc)((orig[i] >> 8) & 0xFF); // top half of each byte is sufficient approx of 16->8 bit scaling 1028 1029 STBI_FREE(orig); 1030 return reduced; 1031 } 1032 1033 static stbi__uint16 *stbi__convert_8_to_16(stbi_uc *orig, int w, int h, int channels) 1034 { 1035 int i; 1036 int img_len = w * h * channels; 1037 stbi__uint16 *enlarged; 1038 1039 enlarged = (stbi__uint16 *) stbi__malloc(img_len*2); 1040 if (enlarged == NULL) return (stbi__uint16 *) stbi__errpuc("outofmem", "Out of memory"); 1041 1042 for (i = 0; i < img_len; ++i) 1043 enlarged[i] = (stbi__uint16)((orig[i] << 8) + orig[i]); // replicate to high and low byte, maps 0->0, 255->0xffff 1044 1045 STBI_FREE(orig); 1046 return enlarged; 1047 } 1048 1049 static void stbi__vertical_flip(void *image, int w, int h, int bytes_per_pixel) 1050 { 1051 int row; 1052 size_t bytes_per_row = (size_t)w * bytes_per_pixel; 1053 stbi_uc temp[2048]; 1054 stbi_uc *bytes = (stbi_uc *)image; 1055 1056 for (row = 0; row < (h>>1); row++) { 1057 stbi_uc *row0 = bytes + row*bytes_per_row; 1058 stbi_uc *row1 = bytes + (h - row - 1)*bytes_per_row; 1059 // swap row0 with row1 1060 size_t bytes_left = bytes_per_row; 1061 while (bytes_left) { 1062 size_t bytes_copy = (bytes_left < sizeof(temp)) ? bytes_left : sizeof(temp); 1063 memcpy(temp, row0, bytes_copy); 1064 memcpy(row0, row1, bytes_copy); 1065 memcpy(row1, temp, bytes_copy); 1066 row0 += bytes_copy; 1067 row1 += bytes_copy; 1068 bytes_left -= bytes_copy; 1069 } 1070 } 1071 } 1072 1073 static void stbi__vertical_flip_slices(void *image, int w, int h, int z, int bytes_per_pixel) 1074 { 1075 int slice; 1076 int slice_size = w * h * bytes_per_pixel; 1077 1078 stbi_uc *bytes = (stbi_uc *)image; 1079 for (slice = 0; slice < z; ++slice) { 1080 stbi__vertical_flip(bytes, w, h, bytes_per_pixel); 1081 bytes += slice_size; 1082 } 1083 } 1084 1085 static unsigned char *stbi__load_and_postprocess_8bit(stbi__context *s, int *x, int *y, int *comp, int req_comp) 1086 { 1087 stbi__result_info ri; 1088 void *result = stbi__load_main(s, x, y, comp, req_comp, &ri, 8); 1089 1090 if (result == NULL) 1091 return NULL; 1092 1093 if (ri.bits_per_channel != 8) { 1094 STBI_ASSERT(ri.bits_per_channel == 16); 1095 result = stbi__convert_16_to_8((stbi__uint16 *) result, *x, *y, req_comp == 0 ? *comp : req_comp); 1096 ri.bits_per_channel = 8; 1097 } 1098 1099 // @TODO: move stbi__convert_format to here 1100 1101 if (stbi__vertically_flip_on_load) { 1102 int channels = req_comp ? req_comp : *comp; 1103 stbi__vertical_flip(result, *x, *y, channels * sizeof(stbi_uc)); 1104 } 1105 1106 return (unsigned char *) result; 1107 } 1108 1109 static stbi__uint16 *stbi__load_and_postprocess_16bit(stbi__context *s, int *x, int *y, int *comp, int req_comp) 1110 { 1111 stbi__result_info ri; 1112 void *result = stbi__load_main(s, x, y, comp, req_comp, &ri, 16); 1113 1114 if (result == NULL) 1115 return NULL; 1116 1117 if (ri.bits_per_channel != 16) { 1118 STBI_ASSERT(ri.bits_per_channel == 8); 1119 result = stbi__convert_8_to_16((stbi_uc *) result, *x, *y, req_comp == 0 ? *comp : req_comp); 1120 ri.bits_per_channel = 16; 1121 } 1122 1123 // @TODO: move stbi__convert_format16 to here 1124 // @TODO: special case RGB-to-Y (and RGBA-to-YA) for 8-bit-to-16-bit case to keep more precision 1125 1126 if (stbi__vertically_flip_on_load) { 1127 int channels = req_comp ? req_comp : *comp; 1128 stbi__vertical_flip(result, *x, *y, channels * sizeof(stbi__uint16)); 1129 } 1130 1131 return (stbi__uint16 *) result; 1132 } 1133 1134 #if !defined(STBI_NO_HDR) || !defined(STBI_NO_LINEAR) 1135 static void stbi__float_postprocess(float *result, int *x, int *y, int *comp, int req_comp) 1136 { 1137 if (stbi__vertically_flip_on_load && result != NULL) { 1138 int channels = req_comp ? req_comp : *comp; 1139 stbi__vertical_flip(result, *x, *y, channels * sizeof(float)); 1140 } 1141 } 1142 #endif 1143 1144 #ifndef STBI_NO_STDIO 1145 1146 static FILE *stbi__fopen(char const *filename, char const *mode) 1147 { 1148 FILE *f; 1149 #if defined(_MSC_VER) && _MSC_VER >= 1400 1150 if (0 != fopen_s(&f, filename, mode)) 1151 f=0; 1152 #else 1153 f = fopen(filename, mode); 1154 #endif 1155 return f; 1156 } 1157 1158 1159 STBIDEF stbi_uc *stbi_load(char const *filename, int *x, int *y, int *comp, int req_comp) 1160 { 1161 FILE *f = stbi__fopen(filename, "rb"); 1162 unsigned char *result; 1163 if (!f) return stbi__errpuc("can't fopen", "Unable to open file"); 1164 result = stbi_load_from_file(f,x,y,comp,req_comp); 1165 fclose(f); 1166 return result; 1167 } 1168 1169 STBIDEF stbi_uc *stbi_load_from_file(FILE *f, int *x, int *y, int *comp, int req_comp) 1170 { 1171 unsigned char *result; 1172 stbi__context s; 1173 stbi__start_file(&s,f); 1174 result = stbi__load_and_postprocess_8bit(&s,x,y,comp,req_comp); 1175 if (result) { 1176 // need to 'unget' all the characters in the IO buffer 1177 fseek(f, - (int) (s.img_buffer_end - s.img_buffer), SEEK_CUR); 1178 } 1179 return result; 1180 } 1181 1182 STBIDEF stbi__uint16 *stbi_load_from_file_16(FILE *f, int *x, int *y, int *comp, int req_comp) 1183 { 1184 stbi__uint16 *result; 1185 stbi__context s; 1186 stbi__start_file(&s,f); 1187 result = stbi__load_and_postprocess_16bit(&s,x,y,comp,req_comp); 1188 if (result) { 1189 // need to 'unget' all the characters in the IO buffer 1190 fseek(f, - (int) (s.img_buffer_end - s.img_buffer), SEEK_CUR); 1191 } 1192 return result; 1193 } 1194 1195 STBIDEF stbi_us *stbi_load_16(char const *filename, int *x, int *y, int *comp, int req_comp) 1196 { 1197 FILE *f = stbi__fopen(filename, "rb"); 1198 stbi__uint16 *result; 1199 if (!f) return (stbi_us *) stbi__errpuc("can't fopen", "Unable to open file"); 1200 result = stbi_load_from_file_16(f,x,y,comp,req_comp); 1201 fclose(f); 1202 return result; 1203 } 1204 1205 1206 #endif //!STBI_NO_STDIO 1207 1208 STBIDEF stbi_us *stbi_load_16_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *channels_in_file, int desired_channels) 1209 { 1210 stbi__context s; 1211 stbi__start_mem(&s,buffer,len); 1212 return stbi__load_and_postprocess_16bit(&s,x,y,channels_in_file,desired_channels); 1213 } 1214 1215 STBIDEF stbi_us *stbi_load_16_from_callbacks(stbi_io_callbacks const *clbk, void *user, int *x, int *y, int *channels_in_file, int desired_channels) 1216 { 1217 stbi__context s; 1218 stbi__start_callbacks(&s, (stbi_io_callbacks *)clbk, user); 1219 return stbi__load_and_postprocess_16bit(&s,x,y,channels_in_file,desired_channels); 1220 } 1221 1222 STBIDEF stbi_uc *stbi_load_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) 1223 { 1224 stbi__context s; 1225 stbi__start_mem(&s,buffer,len); 1226 return stbi__load_and_postprocess_8bit(&s,x,y,comp,req_comp); 1227 } 1228 1229 STBIDEF stbi_uc *stbi_load_from_callbacks(stbi_io_callbacks const *clbk, void *user, int *x, int *y, int *comp, int req_comp) 1230 { 1231 stbi__context s; 1232 stbi__start_callbacks(&s, (stbi_io_callbacks *) clbk, user); 1233 return stbi__load_and_postprocess_8bit(&s,x,y,comp,req_comp); 1234 } 1235 1236 #ifndef STBI_NO_GIF 1237 STBIDEF stbi_uc *stbi_load_gif_from_memory(stbi_uc const *buffer, int len, int **delays, int *x, int *y, int *z, int *comp, int req_comp) 1238 { 1239 unsigned char *result; 1240 stbi__context s; 1241 stbi__start_mem(&s,buffer,len); 1242 1243 result = (unsigned char*) stbi__load_gif_main(&s, delays, x, y, z, comp, req_comp); 1244 if (stbi__vertically_flip_on_load) { 1245 stbi__vertical_flip_slices( result, *x, *y, *z, *comp ); 1246 } 1247 1248 return result; 1249 } 1250 #endif 1251 1252 #ifndef STBI_NO_LINEAR 1253 static float *stbi__loadf_main(stbi__context *s, int *x, int *y, int *comp, int req_comp) 1254 { 1255 unsigned char *data; 1256 #ifndef STBI_NO_HDR 1257 if (stbi__hdr_test(s)) { 1258 stbi__result_info ri; 1259 float *hdr_data = stbi__hdr_load(s,x,y,comp,req_comp, &ri); 1260 if (hdr_data) 1261 stbi__float_postprocess(hdr_data,x,y,comp,req_comp); 1262 return hdr_data; 1263 } 1264 #endif 1265 data = stbi__load_and_postprocess_8bit(s, x, y, comp, req_comp); 1266 if (data) 1267 return stbi__ldr_to_hdr(data, *x, *y, req_comp ? req_comp : *comp); 1268 return stbi__errpf("unknown image type", "Image not of any known type, or corrupt"); 1269 } 1270 1271 STBIDEF float *stbi_loadf_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) 1272 { 1273 stbi__context s; 1274 stbi__start_mem(&s,buffer,len); 1275 return stbi__loadf_main(&s,x,y,comp,req_comp); 1276 } 1277 1278 STBIDEF float *stbi_loadf_from_callbacks(stbi_io_callbacks const *clbk, void *user, int *x, int *y, int *comp, int req_comp) 1279 { 1280 stbi__context s; 1281 stbi__start_callbacks(&s, (stbi_io_callbacks *) clbk, user); 1282 return stbi__loadf_main(&s,x,y,comp,req_comp); 1283 } 1284 1285 #ifndef STBI_NO_STDIO 1286 STBIDEF float *stbi_loadf(char const *filename, int *x, int *y, int *comp, int req_comp) 1287 { 1288 float *result; 1289 FILE *f = stbi__fopen(filename, "rb"); 1290 if (!f) return stbi__errpf("can't fopen", "Unable to open file"); 1291 result = stbi_loadf_from_file(f,x,y,comp,req_comp); 1292 fclose(f); 1293 return result; 1294 } 1295 1296 STBIDEF float *stbi_loadf_from_file(FILE *f, int *x, int *y, int *comp, int req_comp) 1297 { 1298 stbi__context s; 1299 stbi__start_file(&s,f); 1300 return stbi__loadf_main(&s,x,y,comp,req_comp); 1301 } 1302 #endif // !STBI_NO_STDIO 1303 1304 #endif // !STBI_NO_LINEAR 1305 1306 // these is-hdr-or-not is defined independent of whether STBI_NO_LINEAR is 1307 // defined, for API simplicity; if STBI_NO_LINEAR is defined, it always 1308 // reports false! 1309 1310 STBIDEF int stbi_is_hdr_from_memory(stbi_uc const *buffer, int len) 1311 { 1312 #ifndef STBI_NO_HDR 1313 stbi__context s; 1314 stbi__start_mem(&s,buffer,len); 1315 return stbi__hdr_test(&s); 1316 #else 1317 STBI_NOTUSED(buffer); 1318 STBI_NOTUSED(len); 1319 return 0; 1320 #endif 1321 } 1322 1323 #ifndef STBI_NO_STDIO 1324 STBIDEF int stbi_is_hdr (char const *filename) 1325 { 1326 FILE *f = stbi__fopen(filename, "rb"); 1327 int result=0; 1328 if (f) { 1329 result = stbi_is_hdr_from_file(f); 1330 fclose(f); 1331 } 1332 return result; 1333 } 1334 1335 STBIDEF int stbi_is_hdr_from_file(FILE *f) 1336 { 1337 #ifndef STBI_NO_HDR 1338 long pos = ftell(f); 1339 int res; 1340 stbi__context s; 1341 stbi__start_file(&s,f); 1342 res = stbi__hdr_test(&s); 1343 fseek(f, pos, SEEK_SET); 1344 return res; 1345 #else 1346 STBI_NOTUSED(f); 1347 return 0; 1348 #endif 1349 } 1350 #endif // !STBI_NO_STDIO 1351 1352 STBIDEF int stbi_is_hdr_from_callbacks(stbi_io_callbacks const *clbk, void *user) 1353 { 1354 #ifndef STBI_NO_HDR 1355 stbi__context s; 1356 stbi__start_callbacks(&s, (stbi_io_callbacks *) clbk, user); 1357 return stbi__hdr_test(&s); 1358 #else 1359 STBI_NOTUSED(clbk); 1360 STBI_NOTUSED(user); 1361 return 0; 1362 #endif 1363 } 1364 1365 #ifndef STBI_NO_LINEAR 1366 static float stbi__l2h_gamma=2.2f, stbi__l2h_scale=1.0f; 1367 1368 STBIDEF void stbi_ldr_to_hdr_gamma(float gamma) { stbi__l2h_gamma = gamma; } 1369 STBIDEF void stbi_ldr_to_hdr_scale(float scale) { stbi__l2h_scale = scale; } 1370 #endif 1371 1372 static float stbi__h2l_gamma_i=1.0f/2.2f, stbi__h2l_scale_i=1.0f; 1373 1374 STBIDEF void stbi_hdr_to_ldr_gamma(float gamma) { stbi__h2l_gamma_i = 1/gamma; } 1375 STBIDEF void stbi_hdr_to_ldr_scale(float scale) { stbi__h2l_scale_i = 1/scale; } 1376 1377 1378 ////////////////////////////////////////////////////////////////////////////// 1379 // 1380 // Common code used by all image loaders 1381 // 1382 1383 enum 1384 { 1385 STBI__SCAN_load=0, 1386 STBI__SCAN_type, 1387 STBI__SCAN_header 1388 }; 1389 1390 static void stbi__refill_buffer(stbi__context *s) 1391 { 1392 int n = (s->io.read)(s->io_user_data,(char*)s->buffer_start,s->buflen); 1393 if (n == 0) { 1394 // at end of file, treat same as if from memory, but need to handle case 1395 // where s->img_buffer isn't pointing to safe memory, e.g. 0-byte file 1396 s->read_from_callbacks = 0; 1397 s->img_buffer = s->buffer_start; 1398 s->img_buffer_end = s->buffer_start+1; 1399 *s->img_buffer = 0; 1400 } else { 1401 s->img_buffer = s->buffer_start; 1402 s->img_buffer_end = s->buffer_start + n; 1403 } 1404 } 1405 1406 stbi_inline static stbi_uc stbi__get8(stbi__context *s) 1407 { 1408 if (s->img_buffer < s->img_buffer_end) 1409 return *s->img_buffer++; 1410 if (s->read_from_callbacks) { 1411 stbi__refill_buffer(s); 1412 return *s->img_buffer++; 1413 } 1414 return 0; 1415 } 1416 1417 stbi_inline static int stbi__at_eof(stbi__context *s) 1418 { 1419 if (s->io.read) { 1420 if (!(s->io.eof)(s->io_user_data)) return 0; 1421 // if feof() is true, check if buffer = end 1422 // special case: we've only got the special 0 character at the end 1423 if (s->read_from_callbacks == 0) return 1; 1424 } 1425 1426 return s->img_buffer >= s->img_buffer_end; 1427 } 1428 1429 static void stbi__skip(stbi__context *s, int n) 1430 { 1431 if (n < 0) { 1432 s->img_buffer = s->img_buffer_end; 1433 return; 1434 } 1435 if (s->io.read) { 1436 int blen = (int) (s->img_buffer_end - s->img_buffer); 1437 if (blen < n) { 1438 s->img_buffer = s->img_buffer_end; 1439 (s->io.skip)(s->io_user_data, n - blen); 1440 return; 1441 } 1442 } 1443 s->img_buffer += n; 1444 } 1445 1446 static int stbi__getn(stbi__context *s, stbi_uc *buffer, int n) 1447 { 1448 if (s->io.read) { 1449 int blen = (int) (s->img_buffer_end - s->img_buffer); 1450 if (blen < n) { 1451 int res, count; 1452 1453 memcpy(buffer, s->img_buffer, blen); 1454 1455 count = (s->io.read)(s->io_user_data, (char*) buffer + blen, n - blen); 1456 res = (count == (n-blen)); 1457 s->img_buffer = s->img_buffer_end; 1458 return res; 1459 } 1460 } 1461 1462 if (s->img_buffer+n <= s->img_buffer_end) { 1463 memcpy(buffer, s->img_buffer, n); 1464 s->img_buffer += n; 1465 return 1; 1466 } else 1467 return 0; 1468 } 1469 1470 static int stbi__get16be(stbi__context *s) 1471 { 1472 int z = stbi__get8(s); 1473 return (z << 8) + stbi__get8(s); 1474 } 1475 1476 static stbi__uint32 stbi__get32be(stbi__context *s) 1477 { 1478 stbi__uint32 z = stbi__get16be(s); 1479 return (z << 16) + stbi__get16be(s); 1480 } 1481 1482 #if defined(STBI_NO_BMP) && defined(STBI_NO_TGA) && defined(STBI_NO_GIF) 1483 // nothing 1484 #else 1485 static int stbi__get16le(stbi__context *s) 1486 { 1487 int z = stbi__get8(s); 1488 return z + (stbi__get8(s) << 8); 1489 } 1490 #endif 1491 1492 #ifndef STBI_NO_BMP 1493 static stbi__uint32 stbi__get32le(stbi__context *s) 1494 { 1495 stbi__uint32 z = stbi__get16le(s); 1496 return z + (stbi__get16le(s) << 16); 1497 } 1498 #endif 1499 1500 #define STBI__BYTECAST(x) ((stbi_uc) ((x) & 255)) // truncate int to byte without warnings 1501 1502 1503 ////////////////////////////////////////////////////////////////////////////// 1504 // 1505 // generic converter from built-in img_n to req_comp 1506 // individual types do this automatically as much as possible (e.g. jpeg 1507 // does all cases internally since it needs to colorspace convert anyway, 1508 // and it never has alpha, so very few cases ). png can automatically 1509 // interleave an alpha=255 channel, but falls back to this for other cases 1510 // 1511 // assume data buffer is malloced, so malloc a new one and free that one 1512 // only failure mode is malloc failing 1513 1514 static stbi_uc stbi__compute_y(int r, int g, int b) 1515 { 1516 return (stbi_uc) (((r*77) + (g*150) + (29*b)) >> 8); 1517 } 1518 1519 static unsigned char *stbi__convert_format(unsigned char *data, int img_n, int req_comp, unsigned int x, unsigned int y) 1520 { 1521 int i,j; 1522 unsigned char *good; 1523 1524 if (req_comp == img_n) return data; 1525 STBI_ASSERT(req_comp >= 1 && req_comp <= 4); 1526 1527 good = (unsigned char *) stbi__malloc_mad3(req_comp, x, y, 0); 1528 if (good == NULL) { 1529 STBI_FREE(data); 1530 return stbi__errpuc("outofmem", "Out of memory"); 1531 } 1532 1533 for (j=0; j < (int) y; ++j) { 1534 unsigned char *src = data + j * x * img_n ; 1535 unsigned char *dest = good + j * x * req_comp; 1536 1537 #define STBI__COMBO(a,b) ((a)*8+(b)) 1538 #define STBI__CASE(a,b) case STBI__COMBO(a,b): for(i=x-1; i >= 0; --i, src += a, dest += b) 1539 // convert source image with img_n components to one with req_comp components; 1540 // avoid switch per pixel, so use switch per scanline and massive macros 1541 switch (STBI__COMBO(img_n, req_comp)) { 1542 STBI__CASE(1,2) { dest[0]=src[0], dest[1]=255; } break; 1543 STBI__CASE(1,3) { dest[0]=dest[1]=dest[2]=src[0]; } break; 1544 STBI__CASE(1,4) { dest[0]=dest[1]=dest[2]=src[0], dest[3]=255; } break; 1545 STBI__CASE(2,1) { dest[0]=src[0]; } break; 1546 STBI__CASE(2,3) { dest[0]=dest[1]=dest[2]=src[0]; } break; 1547 STBI__CASE(2,4) { dest[0]=dest[1]=dest[2]=src[0], dest[3]=src[1]; } break; 1548 STBI__CASE(3,4) { dest[0]=src[0],dest[1]=src[1],dest[2]=src[2],dest[3]=255; } break; 1549 STBI__CASE(3,1) { dest[0]=stbi__compute_y(src[0],src[1],src[2]); } break; 1550 STBI__CASE(3,2) { dest[0]=stbi__compute_y(src[0],src[1],src[2]), dest[1] = 255; } break; 1551 STBI__CASE(4,1) { dest[0]=stbi__compute_y(src[0],src[1],src[2]); } break; 1552 STBI__CASE(4,2) { dest[0]=stbi__compute_y(src[0],src[1],src[2]), dest[1] = src[3]; } break; 1553 STBI__CASE(4,3) { dest[0]=src[0],dest[1]=src[1],dest[2]=src[2]; } break; 1554 default: STBI_ASSERT(0); 1555 } 1556 #undef STBI__CASE 1557 } 1558 1559 STBI_FREE(data); 1560 return good; 1561 } 1562 1563 static stbi__uint16 stbi__compute_y_16(int r, int g, int b) 1564 { 1565 return (stbi__uint16) (((r*77) + (g*150) + (29*b)) >> 8); 1566 } 1567 1568 static stbi__uint16 *stbi__convert_format16(stbi__uint16 *data, int img_n, int req_comp, unsigned int x, unsigned int y) 1569 { 1570 int i,j; 1571 stbi__uint16 *good; 1572 1573 if (req_comp == img_n) return data; 1574 STBI_ASSERT(req_comp >= 1 && req_comp <= 4); 1575 1576 good = (stbi__uint16 *) stbi__malloc(req_comp * x * y * 2); 1577 if (good == NULL) { 1578 STBI_FREE(data); 1579 return (stbi__uint16 *) stbi__errpuc("outofmem", "Out of memory"); 1580 } 1581 1582 for (j=0; j < (int) y; ++j) { 1583 stbi__uint16 *src = data + j * x * img_n ; 1584 stbi__uint16 *dest = good + j * x * req_comp; 1585 1586 #define STBI__COMBO(a,b) ((a)*8+(b)) 1587 #define STBI__CASE(a,b) case STBI__COMBO(a,b): for(i=x-1; i >= 0; --i, src += a, dest += b) 1588 // convert source image with img_n components to one with req_comp components; 1589 // avoid switch per pixel, so use switch per scanline and massive macros 1590 switch (STBI__COMBO(img_n, req_comp)) { 1591 STBI__CASE(1,2) { dest[0]=src[0], dest[1]=0xffff; } break; 1592 STBI__CASE(1,3) { dest[0]=dest[1]=dest[2]=src[0]; } break; 1593 STBI__CASE(1,4) { dest[0]=dest[1]=dest[2]=src[0], dest[3]=0xffff; } break; 1594 STBI__CASE(2,1) { dest[0]=src[0]; } break; 1595 STBI__CASE(2,3) { dest[0]=dest[1]=dest[2]=src[0]; } break; 1596 STBI__CASE(2,4) { dest[0]=dest[1]=dest[2]=src[0], dest[3]=src[1]; } break; 1597 STBI__CASE(3,4) { dest[0]=src[0],dest[1]=src[1],dest[2]=src[2],dest[3]=0xffff; } break; 1598 STBI__CASE(3,1) { dest[0]=stbi__compute_y_16(src[0],src[1],src[2]); } break; 1599 STBI__CASE(3,2) { dest[0]=stbi__compute_y_16(src[0],src[1],src[2]), dest[1] = 0xffff; } break; 1600 STBI__CASE(4,1) { dest[0]=stbi__compute_y_16(src[0],src[1],src[2]); } break; 1601 STBI__CASE(4,2) { dest[0]=stbi__compute_y_16(src[0],src[1],src[2]), dest[1] = src[3]; } break; 1602 STBI__CASE(4,3) { dest[0]=src[0],dest[1]=src[1],dest[2]=src[2]; } break; 1603 default: STBI_ASSERT(0); 1604 } 1605 #undef STBI__CASE 1606 } 1607 1608 STBI_FREE(data); 1609 return good; 1610 } 1611 1612 #ifndef STBI_NO_LINEAR 1613 static float *stbi__ldr_to_hdr(stbi_uc *data, int x, int y, int comp) 1614 { 1615 int i,k,n; 1616 float *output; 1617 if (!data) return NULL; 1618 output = (float *) stbi__malloc_mad4(x, y, comp, sizeof(float), 0); 1619 if (output == NULL) { STBI_FREE(data); return stbi__errpf("outofmem", "Out of memory"); } 1620 // compute number of non-alpha components 1621 if (comp & 1) n = comp; else n = comp-1; 1622 for (i=0; i < x*y; ++i) { 1623 for (k=0; k < n; ++k) { 1624 output[i*comp + k] = (float) (pow(data[i*comp+k]/255.0f, stbi__l2h_gamma) * stbi__l2h_scale); 1625 } 1626 if (k < comp) output[i*comp + k] = data[i*comp+k]/255.0f; 1627 } 1628 STBI_FREE(data); 1629 return output; 1630 } 1631 #endif 1632 1633 #ifndef STBI_NO_HDR 1634 #define stbi__float2int(x) ((int) (x)) 1635 static stbi_uc *stbi__hdr_to_ldr(float *data, int x, int y, int comp) 1636 { 1637 int i,k,n; 1638 stbi_uc *output; 1639 if (!data) return NULL; 1640 output = (stbi_uc *) stbi__malloc_mad3(x, y, comp, 0); 1641 if (output == NULL) { STBI_FREE(data); return stbi__errpuc("outofmem", "Out of memory"); } 1642 // compute number of non-alpha components 1643 if (comp & 1) n = comp; else n = comp-1; 1644 for (i=0; i < x*y; ++i) { 1645 for (k=0; k < n; ++k) { 1646 float z = (float) pow(data[i*comp+k]*stbi__h2l_scale_i, stbi__h2l_gamma_i) * 255 + 0.5f; 1647 if (z < 0) z = 0; 1648 if (z > 255) z = 255; 1649 output[i*comp + k] = (stbi_uc) stbi__float2int(z); 1650 } 1651 if (k < comp) { 1652 float z = data[i*comp+k] * 255 + 0.5f; 1653 if (z < 0) z = 0; 1654 if (z > 255) z = 255; 1655 output[i*comp + k] = (stbi_uc) stbi__float2int(z); 1656 } 1657 } 1658 STBI_FREE(data); 1659 return output; 1660 } 1661 #endif 1662 1663 ////////////////////////////////////////////////////////////////////////////// 1664 // 1665 // "baseline" JPEG/JFIF decoder 1666 // 1667 // simple implementation 1668 // - doesn't support delayed output of y-dimension 1669 // - simple interface (only one output format: 8-bit interleaved RGB) 1670 // - doesn't try to recover corrupt jpegs 1671 // - doesn't allow partial loading, loading multiple at once 1672 // - still fast on x86 (copying globals into locals doesn't help x86) 1673 // - allocates lots of intermediate memory (full size of all components) 1674 // - non-interleaved case requires this anyway 1675 // - allows good upsampling (see next) 1676 // high-quality 1677 // - upsampled channels are bilinearly interpolated, even across blocks 1678 // - quality integer IDCT derived from IJG's 'slow' 1679 // performance 1680 // - fast huffman; reasonable integer IDCT 1681 // - some SIMD kernels for common paths on targets with SSE2/NEON 1682 // - uses a lot of intermediate memory, could cache poorly 1683 1684 #ifndef STBI_NO_JPEG 1685 1686 // huffman decoding acceleration 1687 #define FAST_BITS 9 // larger handles more cases; smaller stomps less cache 1688 1689 typedef struct 1690 { 1691 stbi_uc fast[1 << FAST_BITS]; 1692 // weirdly, repacking this into AoS is a 10% speed loss, instead of a win 1693 stbi__uint16 code[256]; 1694 stbi_uc values[256]; 1695 stbi_uc size[257]; 1696 unsigned int maxcode[18]; 1697 int delta[17]; // old 'firstsymbol' - old 'firstcode' 1698 } stbi__huffman; 1699 1700 typedef struct 1701 { 1702 stbi__context *s; 1703 stbi__huffman huff_dc[4]; 1704 stbi__huffman huff_ac[4]; 1705 stbi__uint16 dequant[4][64]; 1706 stbi__int16 fast_ac[4][1 << FAST_BITS]; 1707 1708 // sizes for components, interleaved MCUs 1709 int img_h_max, img_v_max; 1710 int img_mcu_x, img_mcu_y; 1711 int img_mcu_w, img_mcu_h; 1712 1713 // definition of jpeg image component 1714 struct 1715 { 1716 int id; 1717 int h,v; 1718 int tq; 1719 int hd,ha; 1720 int dc_pred; 1721 1722 int x,y,w2,h2; 1723 stbi_uc *data; 1724 void *raw_data, *raw_coeff; 1725 stbi_uc *linebuf; 1726 short *coeff; // progressive only 1727 int coeff_w, coeff_h; // number of 8x8 coefficient blocks 1728 } img_comp[4]; 1729 1730 stbi__uint32 code_buffer; // jpeg entropy-coded buffer 1731 int code_bits; // number of valid bits 1732 unsigned char marker; // marker seen while filling entropy buffer 1733 int nomore; // flag if we saw a marker so must stop 1734 1735 int progressive; 1736 int spec_start; 1737 int spec_end; 1738 int succ_high; 1739 int succ_low; 1740 int eob_run; 1741 int jfif; 1742 int app14_color_transform; // Adobe APP14 tag 1743 int rgb; 1744 1745 int scan_n, order[4]; 1746 int restart_interval, todo; 1747 1748 // kernels 1749 void (*idct_block_kernel)(stbi_uc *out, int out_stride, short data[64]); 1750 void (*YCbCr_to_RGB_kernel)(stbi_uc *out, const stbi_uc *y, const stbi_uc *pcb, const stbi_uc *pcr, int count, int step); 1751 stbi_uc *(*resample_row_hv_2_kernel)(stbi_uc *out, stbi_uc *in_near, stbi_uc *in_far, int w, int hs); 1752 } stbi__jpeg; 1753 1754 static int stbi__build_huffman(stbi__huffman *h, int *count) 1755 { 1756 int i,j,k=0; 1757 unsigned int code; 1758 // build size list for each symbol (from JPEG spec) 1759 for (i=0; i < 16; ++i) 1760 for (j=0; j < count[i]; ++j) 1761 h->size[k++] = (stbi_uc) (i+1); 1762 h->size[k] = 0; 1763 1764 // compute actual symbols (from jpeg spec) 1765 code = 0; 1766 k = 0; 1767 for(j=1; j <= 16; ++j) { 1768 // compute delta to add to code to compute symbol id 1769 h->delta[j] = k - code; 1770 if (h->size[k] == j) { 1771 while (h->size[k] == j) 1772 h->code[k++] = (stbi__uint16) (code++); 1773 if (code-1 >= (1u << j)) return stbi__err("bad code lengths","Corrupt JPEG"); 1774 } 1775 // compute largest code + 1 for this size, preshifted as needed later 1776 h->maxcode[j] = code << (16-j); 1777 code <<= 1; 1778 } 1779 h->maxcode[j] = 0xffffffff; 1780 1781 // build non-spec acceleration table; 255 is flag for not-accelerated 1782 memset(h->fast, 255, 1 << FAST_BITS); 1783 for (i=0; i < k; ++i) { 1784 int s = h->size[i]; 1785 if (s <= FAST_BITS) { 1786 int c = h->code[i] << (FAST_BITS-s); 1787 int m = 1 << (FAST_BITS-s); 1788 for (j=0; j < m; ++j) { 1789 h->fast[c+j] = (stbi_uc) i; 1790 } 1791 } 1792 } 1793 return 1; 1794 } 1795 1796 // build a table that decodes both magnitude and value of small ACs in 1797 // one go. 1798 static void stbi__build_fast_ac(stbi__int16 *fast_ac, stbi__huffman *h) 1799 { 1800 int i; 1801 for (i=0; i < (1 << FAST_BITS); ++i) { 1802 stbi_uc fast = h->fast[i]; 1803 fast_ac[i] = 0; 1804 if (fast < 255) { 1805 int rs = h->values[fast]; 1806 int run = (rs >> 4) & 15; 1807 int magbits = rs & 15; 1808 int len = h->size[fast]; 1809 1810 if (magbits && len + magbits <= FAST_BITS) { 1811 // magnitude code followed by receive_extend code 1812 int k = ((i << len) & ((1 << FAST_BITS) - 1)) >> (FAST_BITS - magbits); 1813 int m = 1 << (magbits - 1); 1814 if (k < m) k += (~0U << magbits) + 1; 1815 // if the result is small enough, we can fit it in fast_ac table 1816 if (k >= -128 && k <= 127) 1817 fast_ac[i] = (stbi__int16) ((k * 256) + (run * 16) + (len + magbits)); 1818 } 1819 } 1820 } 1821 } 1822 1823 static void stbi__grow_buffer_unsafe(stbi__jpeg *j) 1824 { 1825 do { 1826 unsigned int b = j->nomore ? 0 : stbi__get8(j->s); 1827 if (b == 0xff) { 1828 int c = stbi__get8(j->s); 1829 while (c == 0xff) c = stbi__get8(j->s); // consume fill bytes 1830 if (c != 0) { 1831 j->marker = (unsigned char) c; 1832 j->nomore = 1; 1833 return; 1834 } 1835 } 1836 j->code_buffer |= b << (24 - j->code_bits); 1837 j->code_bits += 8; 1838 } while (j->code_bits <= 24); 1839 } 1840 1841 // (1 << n) - 1 1842 static const stbi__uint32 stbi__bmask[17]={0,1,3,7,15,31,63,127,255,511,1023,2047,4095,8191,16383,32767,65535}; 1843 1844 // decode a jpeg huffman value from the bitstream 1845 stbi_inline static int stbi__jpeg_huff_decode(stbi__jpeg *j, stbi__huffman *h) 1846 { 1847 unsigned int temp; 1848 int c,k; 1849 1850 if (j->code_bits < 16) stbi__grow_buffer_unsafe(j); 1851 1852 // look at the top FAST_BITS and determine what symbol ID it is, 1853 // if the code is <= FAST_BITS 1854 c = (j->code_buffer >> (32 - FAST_BITS)) & ((1 << FAST_BITS)-1); 1855 k = h->fast[c]; 1856 if (k < 255) { 1857 int s = h->size[k]; 1858 if (s > j->code_bits) 1859 return -1; 1860 j->code_buffer <<= s; 1861 j->code_bits -= s; 1862 return h->values[k]; 1863 } 1864 1865 // naive test is to shift the code_buffer down so k bits are 1866 // valid, then test against maxcode. To speed this up, we've 1867 // preshifted maxcode left so that it has (16-k) 0s at the 1868 // end; in other words, regardless of the number of bits, it 1869 // wants to be compared against something shifted to have 16; 1870 // that way we don't need to shift inside the loop. 1871 temp = j->code_buffer >> 16; 1872 for (k=FAST_BITS+1 ; ; ++k) 1873 if (temp < h->maxcode[k]) 1874 break; 1875 if (k == 17) { 1876 // error! code not found 1877 j->code_bits -= 16; 1878 return -1; 1879 } 1880 1881 if (k > j->code_bits) 1882 return -1; 1883 1884 // convert the huffman code to the symbol id 1885 c = ((j->code_buffer >> (32 - k)) & stbi__bmask[k]) + h->delta[k]; 1886 STBI_ASSERT((((j->code_buffer) >> (32 - h->size[c])) & stbi__bmask[h->size[c]]) == h->code[c]); 1887 1888 // convert the id to a symbol 1889 j->code_bits -= k; 1890 j->code_buffer <<= k; 1891 return h->values[c]; 1892 } 1893 1894 // bias[n] = (-1<<n) + 1 1895 static const int stbi__jbias[16] = {0,-1,-3,-7,-15,-31,-63,-127,-255,-511,-1023,-2047,-4095,-8191,-16383,-32767}; 1896 1897 // combined JPEG 'receive' and JPEG 'extend', since baseline 1898 // always extends everything it receives. 1899 stbi_inline static int stbi__extend_receive(stbi__jpeg *j, int n) 1900 { 1901 unsigned int k; 1902 int sgn; 1903 if (j->code_bits < n) stbi__grow_buffer_unsafe(j); 1904 1905 sgn = (stbi__int32)j->code_buffer >> 31; // sign bit is always in MSB 1906 k = stbi_lrot(j->code_buffer, n); 1907 STBI_ASSERT(n >= 0 && n < (int) (sizeof(stbi__bmask)/sizeof(*stbi__bmask))); 1908 j->code_buffer = k & ~stbi__bmask[n]; 1909 k &= stbi__bmask[n]; 1910 j->code_bits -= n; 1911 return k + (stbi__jbias[n] & ~sgn); 1912 } 1913 1914 // get some unsigned bits 1915 stbi_inline static int stbi__jpeg_get_bits(stbi__jpeg *j, int n) 1916 { 1917 unsigned int k; 1918 if (j->code_bits < n) stbi__grow_buffer_unsafe(j); 1919 k = stbi_lrot(j->code_buffer, n); 1920 j->code_buffer = k & ~stbi__bmask[n]; 1921 k &= stbi__bmask[n]; 1922 j->code_bits -= n; 1923 return k; 1924 } 1925 1926 stbi_inline static int stbi__jpeg_get_bit(stbi__jpeg *j) 1927 { 1928 unsigned int k; 1929 if (j->code_bits < 1) stbi__grow_buffer_unsafe(j); 1930 k = j->code_buffer; 1931 j->code_buffer <<= 1; 1932 --j->code_bits; 1933 return k & 0x80000000; 1934 } 1935 1936 // given a value that's at position X in the zigzag stream, 1937 // where does it appear in the 8x8 matrix coded as row-major? 1938 static const stbi_uc stbi__jpeg_dezigzag[64+15] = 1939 { 1940 0, 1, 8, 16, 9, 2, 3, 10, 1941 17, 24, 32, 25, 18, 11, 4, 5, 1942 12, 19, 26, 33, 40, 48, 41, 34, 1943 27, 20, 13, 6, 7, 14, 21, 28, 1944 35, 42, 49, 56, 57, 50, 43, 36, 1945 29, 22, 15, 23, 30, 37, 44, 51, 1946 58, 59, 52, 45, 38, 31, 39, 46, 1947 53, 60, 61, 54, 47, 55, 62, 63, 1948 // let corrupt input sample past end 1949 63, 63, 63, 63, 63, 63, 63, 63, 1950 63, 63, 63, 63, 63, 63, 63 1951 }; 1952 1953 // decode one 64-entry block-- 1954 static int stbi__jpeg_decode_block(stbi__jpeg *j, short data[64], stbi__huffman *hdc, stbi__huffman *hac, stbi__int16 *fac, int b, stbi__uint16 *dequant) 1955 { 1956 int diff,dc,k; 1957 int t; 1958 1959 if (j->code_bits < 16) stbi__grow_buffer_unsafe(j); 1960 t = stbi__jpeg_huff_decode(j, hdc); 1961 if (t < 0) return stbi__err("bad huffman code","Corrupt JPEG"); 1962 1963 // 0 all the ac values now so we can do it 32-bits at a time 1964 memset(data,0,64*sizeof(data[0])); 1965 1966 diff = t ? stbi__extend_receive(j, t) : 0; 1967 dc = j->img_comp[b].dc_pred + diff; 1968 j->img_comp[b].dc_pred = dc; 1969 data[0] = (short) (dc * dequant[0]); 1970 1971 // decode AC components, see JPEG spec 1972 k = 1; 1973 do { 1974 unsigned int zig; 1975 int c,r,s; 1976 if (j->code_bits < 16) stbi__grow_buffer_unsafe(j); 1977 c = (j->code_buffer >> (32 - FAST_BITS)) & ((1 << FAST_BITS)-1); 1978 r = fac[c]; 1979 if (r) { // fast-AC path 1980 k += (r >> 4) & 15; // run 1981 s = r & 15; // combined length 1982 j->code_buffer <<= s; 1983 j->code_bits -= s; 1984 // decode into unzigzag'd location 1985 zig = stbi__jpeg_dezigzag[k++]; 1986 data[zig] = (short) ((r >> 8) * dequant[zig]); 1987 } else { 1988 int rs = stbi__jpeg_huff_decode(j, hac); 1989 if (rs < 0) return stbi__err("bad huffman code","Corrupt JPEG"); 1990 s = rs & 15; 1991 r = rs >> 4; 1992 if (s == 0) { 1993 if (rs != 0xf0) break; // end block 1994 k += 16; 1995 } else { 1996 k += r; 1997 // decode into unzigzag'd location 1998 zig = stbi__jpeg_dezigzag[k++]; 1999 data[zig] = (short) (stbi__extend_receive(j,s) * dequant[zig]); 2000 } 2001 } 2002 } while (k < 64); 2003 return 1; 2004 } 2005 2006 static int stbi__jpeg_decode_block_prog_dc(stbi__jpeg *j, short data[64], stbi__huffman *hdc, int b) 2007 { 2008 int diff,dc; 2009 int t; 2010 if (j->spec_end != 0) return stbi__err("can't merge dc and ac", "Corrupt JPEG"); 2011 2012 if (j->code_bits < 16) stbi__grow_buffer_unsafe(j); 2013 2014 if (j->succ_high == 0) { 2015 // first scan for DC coefficient, must be first 2016 memset(data,0,64*sizeof(data[0])); // 0 all the ac values now 2017 t = stbi__jpeg_huff_decode(j, hdc); 2018 diff = t ? stbi__extend_receive(j, t) : 0; 2019 2020 dc = j->img_comp[b].dc_pred + diff; 2021 j->img_comp[b].dc_pred = dc; 2022 data[0] = (short) (dc << j->succ_low); 2023 } else { 2024 // refinement scan for DC coefficient 2025 if (stbi__jpeg_get_bit(j)) 2026 data[0] += (short) (1 << j->succ_low); 2027 } 2028 return 1; 2029 } 2030 2031 // @OPTIMIZE: store non-zigzagged during the decode passes, 2032 // and only de-zigzag when dequantizing 2033 static int stbi__jpeg_decode_block_prog_ac(stbi__jpeg *j, short data[64], stbi__huffman *hac, stbi__int16 *fac) 2034 { 2035 int k; 2036 if (j->spec_start == 0) return stbi__err("can't merge dc and ac", "Corrupt JPEG"); 2037 2038 if (j->succ_high == 0) { 2039 int shift = j->succ_low; 2040 2041 if (j->eob_run) { 2042 --j->eob_run; 2043 return 1; 2044 } 2045 2046 k = j->spec_start; 2047 do { 2048 unsigned int zig; 2049 int c,r,s; 2050 if (j->code_bits < 16) stbi__grow_buffer_unsafe(j); 2051 c = (j->code_buffer >> (32 - FAST_BITS)) & ((1 << FAST_BITS)-1); 2052 r = fac[c]; 2053 if (r) { // fast-AC path 2054 k += (r >> 4) & 15; // run 2055 s = r & 15; // combined length 2056 j->code_buffer <<= s; 2057 j->code_bits -= s; 2058 zig = stbi__jpeg_dezigzag[k++]; 2059 data[zig] = (short) ((r >> 8) << shift); 2060 } else { 2061 int rs = stbi__jpeg_huff_decode(j, hac); 2062 if (rs < 0) return stbi__err("bad huffman code","Corrupt JPEG"); 2063 s = rs & 15; 2064 r = rs >> 4; 2065 if (s == 0) { 2066 if (r < 15) { 2067 j->eob_run = (1 << r); 2068 if (r) 2069 j->eob_run += stbi__jpeg_get_bits(j, r); 2070 --j->eob_run; 2071 break; 2072 } 2073 k += 16; 2074 } else { 2075 k += r; 2076 zig = stbi__jpeg_dezigzag[k++]; 2077 data[zig] = (short) (stbi__extend_receive(j,s) << shift); 2078 } 2079 } 2080 } while (k <= j->spec_end); 2081 } else { 2082 // refinement scan for these AC coefficients 2083 2084 short bit = (short) (1 << j->succ_low); 2085 2086 if (j->eob_run) { 2087 --j->eob_run; 2088 for (k = j->spec_start; k <= j->spec_end; ++k) { 2089 short *p = &data[stbi__jpeg_dezigzag[k]]; 2090 if (*p != 0) 2091 if (stbi__jpeg_get_bit(j)) 2092 if ((*p & bit)==0) { 2093 if (*p > 0) 2094 *p += bit; 2095 else 2096 *p -= bit; 2097 } 2098 } 2099 } else { 2100 k = j->spec_start; 2101 do { 2102 int r,s; 2103 int rs = stbi__jpeg_huff_decode(j, hac); // @OPTIMIZE see if we can use the fast path here, advance-by-r is so slow, eh 2104 if (rs < 0) return stbi__err("bad huffman code","Corrupt JPEG"); 2105 s = rs & 15; 2106 r = rs >> 4; 2107 if (s == 0) { 2108 if (r < 15) { 2109 j->eob_run = (1 << r) - 1; 2110 if (r) 2111 j->eob_run += stbi__jpeg_get_bits(j, r); 2112 r = 64; // force end of block 2113 } else { 2114 // r=15 s=0 should write 16 0s, so we just do 2115 // a run of 15 0s and then write s (which is 0), 2116 // so we don't have to do anything special here 2117 } 2118 } else { 2119 if (s != 1) return stbi__err("bad huffman code", "Corrupt JPEG"); 2120 // sign bit 2121 if (stbi__jpeg_get_bit(j)) 2122 s = bit; 2123 else 2124 s = -bit; 2125 } 2126 2127 // advance by r 2128 while (k <= j->spec_end) { 2129 short *p = &data[stbi__jpeg_dezigzag[k++]]; 2130 if (*p != 0) { 2131 if (stbi__jpeg_get_bit(j)) 2132 if ((*p & bit)==0) { 2133 if (*p > 0) 2134 *p += bit; 2135 else 2136 *p -= bit; 2137 } 2138 } else { 2139 if (r == 0) { 2140 *p = (short) s; 2141 break; 2142 } 2143 --r; 2144 } 2145 } 2146 } while (k <= j->spec_end); 2147 } 2148 } 2149 return 1; 2150 } 2151 2152 // take a -128..127 value and stbi__clamp it and convert to 0..255 2153 stbi_inline static stbi_uc stbi__clamp(int x) 2154 { 2155 // trick to use a single test to catch both cases 2156 if ((unsigned int) x > 255) { 2157 if (x < 0) return 0; 2158 if (x > 255) return 255; 2159 } 2160 return (stbi_uc) x; 2161 } 2162 2163 #define stbi__f2f(x) ((int) (((x) * 4096 + 0.5))) 2164 #define stbi__fsh(x) ((x) * 4096) 2165 2166 // derived from jidctint -- DCT_ISLOW 2167 #define STBI__IDCT_1D(s0,s1,s2,s3,s4,s5,s6,s7) \ 2168 int t0,t1,t2,t3,p1,p2,p3,p4,p5,x0,x1,x2,x3; \ 2169 p2 = s2; \ 2170 p3 = s6; \ 2171 p1 = (p2+p3) * stbi__f2f(0.5411961f); \ 2172 t2 = p1 + p3*stbi__f2f(-1.847759065f); \ 2173 t3 = p1 + p2*stbi__f2f( 0.765366865f); \ 2174 p2 = s0; \ 2175 p3 = s4; \ 2176 t0 = stbi__fsh(p2+p3); \ 2177 t1 = stbi__fsh(p2-p3); \ 2178 x0 = t0+t3; \ 2179 x3 = t0-t3; \ 2180 x1 = t1+t2; \ 2181 x2 = t1-t2; \ 2182 t0 = s7; \ 2183 t1 = s5; \ 2184 t2 = s3; \ 2185 t3 = s1; \ 2186 p3 = t0+t2; \ 2187 p4 = t1+t3; \ 2188 p1 = t0+t3; \ 2189 p2 = t1+t2; \ 2190 p5 = (p3+p4)*stbi__f2f( 1.175875602f); \ 2191 t0 = t0*stbi__f2f( 0.298631336f); \ 2192 t1 = t1*stbi__f2f( 2.053119869f); \ 2193 t2 = t2*stbi__f2f( 3.072711026f); \ 2194 t3 = t3*stbi__f2f( 1.501321110f); \ 2195 p1 = p5 + p1*stbi__f2f(-0.899976223f); \ 2196 p2 = p5 + p2*stbi__f2f(-2.562915447f); \ 2197 p3 = p3*stbi__f2f(-1.961570560f); \ 2198 p4 = p4*stbi__f2f(-0.390180644f); \ 2199 t3 += p1+p4; \ 2200 t2 += p2+p3; \ 2201 t1 += p2+p4; \ 2202 t0 += p1+p3; 2203 2204 static void stbi__idct_block(stbi_uc *out, int out_stride, short data[64]) 2205 { 2206 int i,val[64],*v=val; 2207 stbi_uc *o; 2208 short *d = data; 2209 2210 // columns 2211 for (i=0; i < 8; ++i,++d, ++v) { 2212 // if all zeroes, shortcut -- this avoids dequantizing 0s and IDCTing 2213 if (d[ 8]==0 && d[16]==0 && d[24]==0 && d[32]==0 2214 && d[40]==0 && d[48]==0 && d[56]==0) { 2215 // no shortcut 0 seconds 2216 // (1|2|3|4|5|6|7)==0 0 seconds 2217 // all separate -0.047 seconds 2218 // 1 && 2|3 && 4|5 && 6|7: -0.047 seconds 2219 int dcterm = d[0]*4; 2220 v[0] = v[8] = v[16] = v[24] = v[32] = v[40] = v[48] = v[56] = dcterm; 2221 } else { 2222 STBI__IDCT_1D(d[ 0],d[ 8],d[16],d[24],d[32],d[40],d[48],d[56]) 2223 // constants scaled things up by 1<<12; let's bring them back 2224 // down, but keep 2 extra bits of precision 2225 x0 += 512; x1 += 512; x2 += 512; x3 += 512; 2226 v[ 0] = (x0+t3) >> 10; 2227 v[56] = (x0-t3) >> 10; 2228 v[ 8] = (x1+t2) >> 10; 2229 v[48] = (x1-t2) >> 10; 2230 v[16] = (x2+t1) >> 10; 2231 v[40] = (x2-t1) >> 10; 2232 v[24] = (x3+t0) >> 10; 2233 v[32] = (x3-t0) >> 10; 2234 } 2235 } 2236 2237 for (i=0, v=val, o=out; i < 8; ++i,v+=8,o+=out_stride) { 2238 // no fast case since the first 1D IDCT spread components out 2239 STBI__IDCT_1D(v[0],v[1],v[2],v[3],v[4],v[5],v[6],v[7]) 2240 // constants scaled things up by 1<<12, plus we had 1<<2 from first 2241 // loop, plus horizontal and vertical each scale by sqrt(8) so together 2242 // we've got an extra 1<<3, so 1<<17 total we need to remove. 2243 // so we want to round that, which means adding 0.5 * 1<<17, 2244 // aka 65536. Also, we'll end up with -128 to 127 that we want 2245 // to encode as 0..255 by adding 128, so we'll add that before the shift 2246 x0 += 65536 + (128<<17); 2247 x1 += 65536 + (128<<17); 2248 x2 += 65536 + (128<<17); 2249 x3 += 65536 + (128<<17); 2250 // tried computing the shifts into temps, or'ing the temps to see 2251 // if any were out of range, but that was slower 2252 o[0] = stbi__clamp((x0+t3) >> 17); 2253 o[7] = stbi__clamp((x0-t3) >> 17); 2254 o[1] = stbi__clamp((x1+t2) >> 17); 2255 o[6] = stbi__clamp((x1-t2) >> 17); 2256 o[2] = stbi__clamp((x2+t1) >> 17); 2257 o[5] = stbi__clamp((x2-t1) >> 17); 2258 o[3] = stbi__clamp((x3+t0) >> 17); 2259 o[4] = stbi__clamp((x3-t0) >> 17); 2260 } 2261 } 2262 2263 #ifdef STBI_SSE2 2264 // sse2 integer IDCT. not the fastest possible implementation but it 2265 // produces bit-identical results to the generic C version so it's 2266 // fully "transparent". 2267 static void stbi__idct_simd(stbi_uc *out, int out_stride, short data[64]) 2268 { 2269 // This is constructed to match our regular (generic) integer IDCT exactly. 2270 __m128i row0, row1, row2, row3, row4, row5, row6, row7; 2271 __m128i tmp; 2272 2273 // dot product constant: even elems=x, odd elems=y 2274 #define dct_const(x,y) _mm_setr_epi16((x),(y),(x),(y),(x),(y),(x),(y)) 2275 2276 // out(0) = c0[even]*x + c0[odd]*y (c0, x, y 16-bit, out 32-bit) 2277 // out(1) = c1[even]*x + c1[odd]*y 2278 #define dct_rot(out0,out1, x,y,c0,c1) \ 2279 __m128i c0##lo = _mm_unpacklo_epi16((x),(y)); \ 2280 __m128i c0##hi = _mm_unpackhi_epi16((x),(y)); \ 2281 __m128i out0##_l = _mm_madd_epi16(c0##lo, c0); \ 2282 __m128i out0##_h = _mm_madd_epi16(c0##hi, c0); \ 2283 __m128i out1##_l = _mm_madd_epi16(c0##lo, c1); \ 2284 __m128i out1##_h = _mm_madd_epi16(c0##hi, c1) 2285 2286 // out = in << 12 (in 16-bit, out 32-bit) 2287 #define dct_widen(out, in) \ 2288 __m128i out##_l = _mm_srai_epi32(_mm_unpacklo_epi16(_mm_setzero_si128(), (in)), 4); \ 2289 __m128i out##_h = _mm_srai_epi32(_mm_unpackhi_epi16(_mm_setzero_si128(), (in)), 4) 2290 2291 // wide add 2292 #define dct_wadd(out, a, b) \ 2293 __m128i out##_l = _mm_add_epi32(a##_l, b##_l); \ 2294 __m128i out##_h = _mm_add_epi32(a##_h, b##_h) 2295 2296 // wide sub 2297 #define dct_wsub(out, a, b) \ 2298 __m128i out##_l = _mm_sub_epi32(a##_l, b##_l); \ 2299 __m128i out##_h = _mm_sub_epi32(a##_h, b##_h) 2300 2301 // butterfly a/b, add bias, then shift by "s" and pack 2302 #define dct_bfly32o(out0, out1, a,b,bias,s) \ 2303 { \ 2304 __m128i abiased_l = _mm_add_epi32(a##_l, bias); \ 2305 __m128i abiased_h = _mm_add_epi32(a##_h, bias); \ 2306 dct_wadd(sum, abiased, b); \ 2307 dct_wsub(dif, abiased, b); \ 2308 out0 = _mm_packs_epi32(_mm_srai_epi32(sum_l, s), _mm_srai_epi32(sum_h, s)); \ 2309 out1 = _mm_packs_epi32(_mm_srai_epi32(dif_l, s), _mm_srai_epi32(dif_h, s)); \ 2310 } 2311 2312 // 8-bit interleave step (for transposes) 2313 #define dct_interleave8(a, b) \ 2314 tmp = a; \ 2315 a = _mm_unpacklo_epi8(a, b); \ 2316 b = _mm_unpackhi_epi8(tmp, b) 2317 2318 // 16-bit interleave step (for transposes) 2319 #define dct_interleave16(a, b) \ 2320 tmp = a; \ 2321 a = _mm_unpacklo_epi16(a, b); \ 2322 b = _mm_unpackhi_epi16(tmp, b) 2323 2324 #define dct_pass(bias,shift) \ 2325 { \ 2326 /* even part */ \ 2327 dct_rot(t2e,t3e, row2,row6, rot0_0,rot0_1); \ 2328 __m128i sum04 = _mm_add_epi16(row0, row4); \ 2329 __m128i dif04 = _mm_sub_epi16(row0, row4); \ 2330 dct_widen(t0e, sum04); \ 2331 dct_widen(t1e, dif04); \ 2332 dct_wadd(x0, t0e, t3e); \ 2333 dct_wsub(x3, t0e, t3e); \ 2334 dct_wadd(x1, t1e, t2e); \ 2335 dct_wsub(x2, t1e, t2e); \ 2336 /* odd part */ \ 2337 dct_rot(y0o,y2o, row7,row3, rot2_0,rot2_1); \ 2338 dct_rot(y1o,y3o, row5,row1, rot3_0,rot3_1); \ 2339 __m128i sum17 = _mm_add_epi16(row1, row7); \ 2340 __m128i sum35 = _mm_add_epi16(row3, row5); \ 2341 dct_rot(y4o,y5o, sum17,sum35, rot1_0,rot1_1); \ 2342 dct_wadd(x4, y0o, y4o); \ 2343 dct_wadd(x5, y1o, y5o); \ 2344 dct_wadd(x6, y2o, y5o); \ 2345 dct_wadd(x7, y3o, y4o); \ 2346 dct_bfly32o(row0,row7, x0,x7,bias,shift); \ 2347 dct_bfly32o(row1,row6, x1,x6,bias,shift); \ 2348 dct_bfly32o(row2,row5, x2,x5,bias,shift); \ 2349 dct_bfly32o(row3,row4, x3,x4,bias,shift); \ 2350 } 2351 2352 __m128i rot0_0 = dct_const(stbi__f2f(0.5411961f), stbi__f2f(0.5411961f) + stbi__f2f(-1.847759065f)); 2353 __m128i rot0_1 = dct_const(stbi__f2f(0.5411961f) + stbi__f2f( 0.765366865f), stbi__f2f(0.5411961f)); 2354 __m128i rot1_0 = dct_const(stbi__f2f(1.175875602f) + stbi__f2f(-0.899976223f), stbi__f2f(1.175875602f)); 2355 __m128i rot1_1 = dct_const(stbi__f2f(1.175875602f), stbi__f2f(1.175875602f) + stbi__f2f(-2.562915447f)); 2356 __m128i rot2_0 = dct_const(stbi__f2f(-1.961570560f) + stbi__f2f( 0.298631336f), stbi__f2f(-1.961570560f)); 2357 __m128i rot2_1 = dct_const(stbi__f2f(-1.961570560f), stbi__f2f(-1.961570560f) + stbi__f2f( 3.072711026f)); 2358 __m128i rot3_0 = dct_const(stbi__f2f(-0.390180644f) + stbi__f2f( 2.053119869f), stbi__f2f(-0.390180644f)); 2359 __m128i rot3_1 = dct_const(stbi__f2f(-0.390180644f), stbi__f2f(-0.390180644f) + stbi__f2f( 1.501321110f)); 2360 2361 // rounding biases in column/row passes, see stbi__idct_block for explanation. 2362 __m128i bias_0 = _mm_set1_epi32(512); 2363 __m128i bias_1 = _mm_set1_epi32(65536 + (128<<17)); 2364 2365 // load 2366 row0 = _mm_load_si128((const __m128i *) (data + 0*8)); 2367 row1 = _mm_load_si128((const __m128i *) (data + 1*8)); 2368 row2 = _mm_load_si128((const __m128i *) (data + 2*8)); 2369 row3 = _mm_load_si128((const __m128i *) (data + 3*8)); 2370 row4 = _mm_load_si128((const __m128i *) (data + 4*8)); 2371 row5 = _mm_load_si128((const __m128i *) (data + 5*8)); 2372 row6 = _mm_load_si128((const __m128i *) (data + 6*8)); 2373 row7 = _mm_load_si128((const __m128i *) (data + 7*8)); 2374 2375 // column pass 2376 dct_pass(bias_0, 10); 2377 2378 { 2379 // 16bit 8x8 transpose pass 1 2380 dct_interleave16(row0, row4); 2381 dct_interleave16(row1, row5); 2382 dct_interleave16(row2, row6); 2383 dct_interleave16(row3, row7); 2384 2385 // transpose pass 2 2386 dct_interleave16(row0, row2); 2387 dct_interleave16(row1, row3); 2388 dct_interleave16(row4, row6); 2389 dct_interleave16(row5, row7); 2390 2391 // transpose pass 3 2392 dct_interleave16(row0, row1); 2393 dct_interleave16(row2, row3); 2394 dct_interleave16(row4, row5); 2395 dct_interleave16(row6, row7); 2396 } 2397 2398 // row pass 2399 dct_pass(bias_1, 17); 2400 2401 { 2402 // pack 2403 __m128i p0 = _mm_packus_epi16(row0, row1); // a0a1a2a3...a7b0b1b2b3...b7 2404 __m128i p1 = _mm_packus_epi16(row2, row3); 2405 __m128i p2 = _mm_packus_epi16(row4, row5); 2406 __m128i p3 = _mm_packus_epi16(row6, row7); 2407 2408 // 8bit 8x8 transpose pass 1 2409 dct_interleave8(p0, p2); // a0e0a1e1... 2410 dct_interleave8(p1, p3); // c0g0c1g1... 2411 2412 // transpose pass 2 2413 dct_interleave8(p0, p1); // a0c0e0g0... 2414 dct_interleave8(p2, p3); // b0d0f0h0... 2415 2416 // transpose pass 3 2417 dct_interleave8(p0, p2); // a0b0c0d0... 2418 dct_interleave8(p1, p3); // a4b4c4d4... 2419 2420 // store 2421 _mm_storel_epi64((__m128i *) out, p0); out += out_stride; 2422 _mm_storel_epi64((__m128i *) out, _mm_shuffle_epi32(p0, 0x4e)); out += out_stride; 2423 _mm_storel_epi64((__m128i *) out, p2); out += out_stride; 2424 _mm_storel_epi64((__m128i *) out, _mm_shuffle_epi32(p2, 0x4e)); out += out_stride; 2425 _mm_storel_epi64((__m128i *) out, p1); out += out_stride; 2426 _mm_storel_epi64((__m128i *) out, _mm_shuffle_epi32(p1, 0x4e)); out += out_stride; 2427 _mm_storel_epi64((__m128i *) out, p3); out += out_stride; 2428 _mm_storel_epi64((__m128i *) out, _mm_shuffle_epi32(p3, 0x4e)); 2429 } 2430 2431 #undef dct_const 2432 #undef dct_rot 2433 #undef dct_widen 2434 #undef dct_wadd 2435 #undef dct_wsub 2436 #undef dct_bfly32o 2437 #undef dct_interleave8 2438 #undef dct_interleave16 2439 #undef dct_pass 2440 } 2441 2442 #endif // STBI_SSE2 2443 2444 #ifdef STBI_NEON 2445 2446 // NEON integer IDCT. should produce bit-identical 2447 // results to the generic C version. 2448 static void stbi__idct_simd(stbi_uc *out, int out_stride, short data[64]) 2449 { 2450 int16x8_t row0, row1, row2, row3, row4, row5, row6, row7; 2451 2452 int16x4_t rot0_0 = vdup_n_s16(stbi__f2f(0.5411961f)); 2453 int16x4_t rot0_1 = vdup_n_s16(stbi__f2f(-1.847759065f)); 2454 int16x4_t rot0_2 = vdup_n_s16(stbi__f2f( 0.765366865f)); 2455 int16x4_t rot1_0 = vdup_n_s16(stbi__f2f( 1.175875602f)); 2456 int16x4_t rot1_1 = vdup_n_s16(stbi__f2f(-0.899976223f)); 2457 int16x4_t rot1_2 = vdup_n_s16(stbi__f2f(-2.562915447f)); 2458 int16x4_t rot2_0 = vdup_n_s16(stbi__f2f(-1.961570560f)); 2459 int16x4_t rot2_1 = vdup_n_s16(stbi__f2f(-0.390180644f)); 2460 int16x4_t rot3_0 = vdup_n_s16(stbi__f2f( 0.298631336f)); 2461 int16x4_t rot3_1 = vdup_n_s16(stbi__f2f( 2.053119869f)); 2462 int16x4_t rot3_2 = vdup_n_s16(stbi__f2f( 3.072711026f)); 2463 int16x4_t rot3_3 = vdup_n_s16(stbi__f2f( 1.501321110f)); 2464 2465 #define dct_long_mul(out, inq, coeff) \ 2466 int32x4_t out##_l = vmull_s16(vget_low_s16(inq), coeff); \ 2467 int32x4_t out##_h = vmull_s16(vget_high_s16(inq), coeff) 2468 2469 #define dct_long_mac(out, acc, inq, coeff) \ 2470 int32x4_t out##_l = vmlal_s16(acc##_l, vget_low_s16(inq), coeff); \ 2471 int32x4_t out##_h = vmlal_s16(acc##_h, vget_high_s16(inq), coeff) 2472 2473 #define dct_widen(out, inq) \ 2474 int32x4_t out##_l = vshll_n_s16(vget_low_s16(inq), 12); \ 2475 int32x4_t out##_h = vshll_n_s16(vget_high_s16(inq), 12) 2476 2477 // wide add 2478 #define dct_wadd(out, a, b) \ 2479 int32x4_t out##_l = vaddq_s32(a##_l, b##_l); \ 2480 int32x4_t out##_h = vaddq_s32(a##_h, b##_h) 2481 2482 // wide sub 2483 #define dct_wsub(out, a, b) \ 2484 int32x4_t out##_l = vsubq_s32(a##_l, b##_l); \ 2485 int32x4_t out##_h = vsubq_s32(a##_h, b##_h) 2486 2487 // butterfly a/b, then shift using "shiftop" by "s" and pack 2488 #define dct_bfly32o(out0,out1, a,b,shiftop,s) \ 2489 { \ 2490 dct_wadd(sum, a, b); \ 2491 dct_wsub(dif, a, b); \ 2492 out0 = vcombine_s16(shiftop(sum_l, s), shiftop(sum_h, s)); \ 2493 out1 = vcombine_s16(shiftop(dif_l, s), shiftop(dif_h, s)); \ 2494 } 2495 2496 #define dct_pass(shiftop, shift) \ 2497 { \ 2498 /* even part */ \ 2499 int16x8_t sum26 = vaddq_s16(row2, row6); \ 2500 dct_long_mul(p1e, sum26, rot0_0); \ 2501 dct_long_mac(t2e, p1e, row6, rot0_1); \ 2502 dct_long_mac(t3e, p1e, row2, rot0_2); \ 2503 int16x8_t sum04 = vaddq_s16(row0, row4); \ 2504 int16x8_t dif04 = vsubq_s16(row0, row4); \ 2505 dct_widen(t0e, sum04); \ 2506 dct_widen(t1e, dif04); \ 2507 dct_wadd(x0, t0e, t3e); \ 2508 dct_wsub(x3, t0e, t3e); \ 2509 dct_wadd(x1, t1e, t2e); \ 2510 dct_wsub(x2, t1e, t2e); \ 2511 /* odd part */ \ 2512 int16x8_t sum15 = vaddq_s16(row1, row5); \ 2513 int16x8_t sum17 = vaddq_s16(row1, row7); \ 2514 int16x8_t sum35 = vaddq_s16(row3, row5); \ 2515 int16x8_t sum37 = vaddq_s16(row3, row7); \ 2516 int16x8_t sumodd = vaddq_s16(sum17, sum35); \ 2517 dct_long_mul(p5o, sumodd, rot1_0); \ 2518 dct_long_mac(p1o, p5o, sum17, rot1_1); \ 2519 dct_long_mac(p2o, p5o, sum35, rot1_2); \ 2520 dct_long_mul(p3o, sum37, rot2_0); \ 2521 dct_long_mul(p4o, sum15, rot2_1); \ 2522 dct_wadd(sump13o, p1o, p3o); \ 2523 dct_wadd(sump24o, p2o, p4o); \ 2524 dct_wadd(sump23o, p2o, p3o); \ 2525 dct_wadd(sump14o, p1o, p4o); \ 2526 dct_long_mac(x4, sump13o, row7, rot3_0); \ 2527 dct_long_mac(x5, sump24o, row5, rot3_1); \ 2528 dct_long_mac(x6, sump23o, row3, rot3_2); \ 2529 dct_long_mac(x7, sump14o, row1, rot3_3); \ 2530 dct_bfly32o(row0,row7, x0,x7,shiftop,shift); \ 2531 dct_bfly32o(row1,row6, x1,x6,shiftop,shift); \ 2532 dct_bfly32o(row2,row5, x2,x5,shiftop,shift); \ 2533 dct_bfly32o(row3,row4, x3,x4,shiftop,shift); \ 2534 } 2535 2536 // load 2537 row0 = vld1q_s16(data + 0*8); 2538 row1 = vld1q_s16(data + 1*8); 2539 row2 = vld1q_s16(data + 2*8); 2540 row3 = vld1q_s16(data + 3*8); 2541 row4 = vld1q_s16(data + 4*8); 2542 row5 = vld1q_s16(data + 5*8); 2543 row6 = vld1q_s16(data + 6*8); 2544 row7 = vld1q_s16(data + 7*8); 2545 2546 // add DC bias 2547 row0 = vaddq_s16(row0, vsetq_lane_s16(1024, vdupq_n_s16(0), 0)); 2548 2549 // column pass 2550 dct_pass(vrshrn_n_s32, 10); 2551 2552 // 16bit 8x8 transpose 2553 { 2554 // these three map to a single VTRN.16, VTRN.32, and VSWP, respectively. 2555 // whether compilers actually get this is another story, sadly. 2556 #define dct_trn16(x, y) { int16x8x2_t t = vtrnq_s16(x, y); x = t.val[0]; y = t.val[1]; } 2557 #define dct_trn32(x, y) { int32x4x2_t t = vtrnq_s32(vreinterpretq_s32_s16(x), vreinterpretq_s32_s16(y)); x = vreinterpretq_s16_s32(t.val[0]); y = vreinterpretq_s16_s32(t.val[1]); } 2558 #define dct_trn64(x, y) { int16x8_t x0 = x; int16x8_t y0 = y; x = vcombine_s16(vget_low_s16(x0), vget_low_s16(y0)); y = vcombine_s16(vget_high_s16(x0), vget_high_s16(y0)); } 2559 2560 // pass 1 2561 dct_trn16(row0, row1); // a0b0a2b2a4b4a6b6 2562 dct_trn16(row2, row3); 2563 dct_trn16(row4, row5); 2564 dct_trn16(row6, row7); 2565 2566 // pass 2 2567 dct_trn32(row0, row2); // a0b0c0d0a4b4c4d4 2568 dct_trn32(row1, row3); 2569 dct_trn32(row4, row6); 2570 dct_trn32(row5, row7); 2571 2572 // pass 3 2573 dct_trn64(row0, row4); // a0b0c0d0e0f0g0h0 2574 dct_trn64(row1, row5); 2575 dct_trn64(row2, row6); 2576 dct_trn64(row3, row7); 2577 2578 #undef dct_trn16 2579 #undef dct_trn32 2580 #undef dct_trn64 2581 } 2582 2583 // row pass 2584 // vrshrn_n_s32 only supports shifts up to 16, we need 2585 // 17. so do a non-rounding shift of 16 first then follow 2586 // up with a rounding shift by 1. 2587 dct_pass(vshrn_n_s32, 16); 2588 2589 { 2590 // pack and round 2591 uint8x8_t p0 = vqrshrun_n_s16(row0, 1); 2592 uint8x8_t p1 = vqrshrun_n_s16(row1, 1); 2593 uint8x8_t p2 = vqrshrun_n_s16(row2, 1); 2594 uint8x8_t p3 = vqrshrun_n_s16(row3, 1); 2595 uint8x8_t p4 = vqrshrun_n_s16(row4, 1); 2596 uint8x8_t p5 = vqrshrun_n_s16(row5, 1); 2597 uint8x8_t p6 = vqrshrun_n_s16(row6, 1); 2598 uint8x8_t p7 = vqrshrun_n_s16(row7, 1); 2599 2600 // again, these can translate into one instruction, but often don't. 2601 #define dct_trn8_8(x, y) { uint8x8x2_t t = vtrn_u8(x, y); x = t.val[0]; y = t.val[1]; } 2602 #define dct_trn8_16(x, y) { uint16x4x2_t t = vtrn_u16(vreinterpret_u16_u8(x), vreinterpret_u16_u8(y)); x = vreinterpret_u8_u16(t.val[0]); y = vreinterpret_u8_u16(t.val[1]); } 2603 #define dct_trn8_32(x, y) { uint32x2x2_t t = vtrn_u32(vreinterpret_u32_u8(x), vreinterpret_u32_u8(y)); x = vreinterpret_u8_u32(t.val[0]); y = vreinterpret_u8_u32(t.val[1]); } 2604 2605 // sadly can't use interleaved stores here since we only write 2606 // 8 bytes to each scan line! 2607 2608 // 8x8 8-bit transpose pass 1 2609 dct_trn8_8(p0, p1); 2610 dct_trn8_8(p2, p3); 2611 dct_trn8_8(p4, p5); 2612 dct_trn8_8(p6, p7); 2613 2614 // pass 2 2615 dct_trn8_16(p0, p2); 2616 dct_trn8_16(p1, p3); 2617 dct_trn8_16(p4, p6); 2618 dct_trn8_16(p5, p7); 2619 2620 // pass 3 2621 dct_trn8_32(p0, p4); 2622 dct_trn8_32(p1, p5); 2623 dct_trn8_32(p2, p6); 2624 dct_trn8_32(p3, p7); 2625 2626 // store 2627 vst1_u8(out, p0); out += out_stride; 2628 vst1_u8(out, p1); out += out_stride; 2629 vst1_u8(out, p2); out += out_stride; 2630 vst1_u8(out, p3); out += out_stride; 2631 vst1_u8(out, p4); out += out_stride; 2632 vst1_u8(out, p5); out += out_stride; 2633 vst1_u8(out, p6); out += out_stride; 2634 vst1_u8(out, p7); 2635 2636 #undef dct_trn8_8 2637 #undef dct_trn8_16 2638 #undef dct_trn8_32 2639 } 2640 2641 #undef dct_long_mul 2642 #undef dct_long_mac 2643 #undef dct_widen 2644 #undef dct_wadd 2645 #undef dct_wsub 2646 #undef dct_bfly32o 2647 #undef dct_pass 2648 } 2649 2650 #endif // STBI_NEON 2651 2652 #define STBI__MARKER_none 0xff 2653 // if there's a pending marker from the entropy stream, return that 2654 // otherwise, fetch from the stream and get a marker. if there's no 2655 // marker, return 0xff, which is never a valid marker value 2656 static stbi_uc stbi__get_marker(stbi__jpeg *j) 2657 { 2658 stbi_uc x; 2659 if (j->marker != STBI__MARKER_none) { x = j->marker; j->marker = STBI__MARKER_none; return x; } 2660 x = stbi__get8(j->s); 2661 if (x != 0xff) return STBI__MARKER_none; 2662 while (x == 0xff) 2663 x = stbi__get8(j->s); // consume repeated 0xff fill bytes 2664 return x; 2665 } 2666 2667 // in each scan, we'll have scan_n components, and the order 2668 // of the components is specified by order[] 2669 #define STBI__RESTART(x) ((x) >= 0xd0 && (x) <= 0xd7) 2670 2671 // after a restart interval, stbi__jpeg_reset the entropy decoder and 2672 // the dc prediction 2673 static void stbi__jpeg_reset(stbi__jpeg *j) 2674 { 2675 j->code_bits = 0; 2676 j->code_buffer = 0; 2677 j->nomore = 0; 2678 j->img_comp[0].dc_pred = j->img_comp[1].dc_pred = j->img_comp[2].dc_pred = j->img_comp[3].dc_pred = 0; 2679 j->marker = STBI__MARKER_none; 2680 j->todo = j->restart_interval ? j->restart_interval : 0x7fffffff; 2681 j->eob_run = 0; 2682 // no more than 1<<31 MCUs if no restart_interal? that's plenty safe, 2683 // since we don't even allow 1<<30 pixels 2684 } 2685 2686 static int stbi__parse_entropy_coded_data(stbi__jpeg *z) 2687 { 2688 stbi__jpeg_reset(z); 2689 if (!z->progressive) { 2690 if (z->scan_n == 1) { 2691 int i,j; 2692 STBI_SIMD_ALIGN(short, data[64]); 2693 int n = z->order[0]; 2694 // non-interleaved data, we just need to process one block at a time, 2695 // in trivial scanline order 2696 // number of blocks to do just depends on how many actual "pixels" this 2697 // component has, independent of interleaved MCU blocking and such 2698 int w = (z->img_comp[n].x+7) >> 3; 2699 int h = (z->img_comp[n].y+7) >> 3; 2700 for (j=0; j < h; ++j) { 2701 for (i=0; i < w; ++i) { 2702 int ha = z->img_comp[n].ha; 2703 if (!stbi__jpeg_decode_block(z, data, z->huff_dc+z->img_comp[n].hd, z->huff_ac+ha, z->fast_ac[ha], n, z->dequant[z->img_comp[n].tq])) return 0; 2704 z->idct_block_kernel(z->img_comp[n].data+z->img_comp[n].w2*j*8+i*8, z->img_comp[n].w2, data); 2705 // every data block is an MCU, so countdown the restart interval 2706 if (--z->todo <= 0) { 2707 if (z->code_bits < 24) stbi__grow_buffer_unsafe(z); 2708 // if it's NOT a restart, then just bail, so we get corrupt data 2709 // rather than no data 2710 if (!STBI__RESTART(z->marker)) return 1; 2711 stbi__jpeg_reset(z); 2712 } 2713 } 2714 } 2715 return 1; 2716 } else { // interleaved 2717 int i,j,k,x,y; 2718 STBI_SIMD_ALIGN(short, data[64]); 2719 for (j=0; j < z->img_mcu_y; ++j) { 2720 for (i=0; i < z->img_mcu_x; ++i) { 2721 // scan an interleaved mcu... process scan_n components in order 2722 for (k=0; k < z->scan_n; ++k) { 2723 int n = z->order[k]; 2724 // scan out an mcu's worth of this component; that's just determined 2725 // by the basic H and V specified for the component 2726 for (y=0; y < z->img_comp[n].v; ++y) { 2727 for (x=0; x < z->img_comp[n].h; ++x) { 2728 int x2 = (i*z->img_comp[n].h + x)*8; 2729 int y2 = (j*z->img_comp[n].v + y)*8; 2730 int ha = z->img_comp[n].ha; 2731 if (!stbi__jpeg_decode_block(z, data, z->huff_dc+z->img_comp[n].hd, z->huff_ac+ha, z->fast_ac[ha], n, z->dequant[z->img_comp[n].tq])) return 0; 2732 z->idct_block_kernel(z->img_comp[n].data+z->img_comp[n].w2*y2+x2, z->img_comp[n].w2, data); 2733 } 2734 } 2735 } 2736 // after all interleaved components, that's an interleaved MCU, 2737 // so now count down the restart interval 2738 if (--z->todo <= 0) { 2739 if (z->code_bits < 24) stbi__grow_buffer_unsafe(z); 2740 if (!STBI__RESTART(z->marker)) return 1; 2741 stbi__jpeg_reset(z); 2742 } 2743 } 2744 } 2745 return 1; 2746 } 2747 } else { 2748 if (z->scan_n == 1) { 2749 int i,j; 2750 int n = z->order[0]; 2751 // non-interleaved data, we just need to process one block at a time, 2752 // in trivial scanline order 2753 // number of blocks to do just depends on how many actual "pixels" this 2754 // component has, independent of interleaved MCU blocking and such 2755 int w = (z->img_comp[n].x+7) >> 3; 2756 int h = (z->img_comp[n].y+7) >> 3; 2757 for (j=0; j < h; ++j) { 2758 for (i=0; i < w; ++i) { 2759 short *data = z->img_comp[n].coeff + 64 * (i + j * z->img_comp[n].coeff_w); 2760 if (z->spec_start == 0) { 2761 if (!stbi__jpeg_decode_block_prog_dc(z, data, &z->huff_dc[z->img_comp[n].hd], n)) 2762 return 0; 2763 } else { 2764 int ha = z->img_comp[n].ha; 2765 if (!stbi__jpeg_decode_block_prog_ac(z, data, &z->huff_ac[ha], z->fast_ac[ha])) 2766 return 0; 2767 } 2768 // every data block is an MCU, so countdown the restart interval 2769 if (--z->todo <= 0) { 2770 if (z->code_bits < 24) stbi__grow_buffer_unsafe(z); 2771 if (!STBI__RESTART(z->marker)) return 1; 2772 stbi__jpeg_reset(z); 2773 } 2774 } 2775 } 2776 return 1; 2777 } else { // interleaved 2778 int i,j,k,x,y; 2779 for (j=0; j < z->img_mcu_y; ++j) { 2780 for (i=0; i < z->img_mcu_x; ++i) { 2781 // scan an interleaved mcu... process scan_n components in order 2782 for (k=0; k < z->scan_n; ++k) { 2783 int n = z->order[k]; 2784 // scan out an mcu's worth of this component; that's just determined 2785 // by the basic H and V specified for the component 2786 for (y=0; y < z->img_comp[n].v; ++y) { 2787 for (x=0; x < z->img_comp[n].h; ++x) { 2788 int x2 = (i*z->img_comp[n].h + x); 2789 int y2 = (j*z->img_comp[n].v + y); 2790 short *data = z->img_comp[n].coeff + 64 * (x2 + y2 * z->img_comp[n].coeff_w); 2791 if (!stbi__jpeg_decode_block_prog_dc(z, data, &z->huff_dc[z->img_comp[n].hd], n)) 2792 return 0; 2793 } 2794 } 2795 } 2796 // after all interleaved components, that's an interleaved MCU, 2797 // so now count down the restart interval 2798 if (--z->todo <= 0) { 2799 if (z->code_bits < 24) stbi__grow_buffer_unsafe(z); 2800 if (!STBI__RESTART(z->marker)) return 1; 2801 stbi__jpeg_reset(z); 2802 } 2803 } 2804 } 2805 return 1; 2806 } 2807 } 2808 } 2809 2810 static void stbi__jpeg_dequantize(short *data, stbi__uint16 *dequant) 2811 { 2812 int i; 2813 for (i=0; i < 64; ++i) 2814 data[i] *= dequant[i]; 2815 } 2816 2817 static void stbi__jpeg_finish(stbi__jpeg *z) 2818 { 2819 if (z->progressive) { 2820 // dequantize and idct the data 2821 int i,j,n; 2822 for (n=0; n < z->s->img_n; ++n) { 2823 int w = (z->img_comp[n].x+7) >> 3; 2824 int h = (z->img_comp[n].y+7) >> 3; 2825 for (j=0; j < h; ++j) { 2826 for (i=0; i < w; ++i) { 2827 short *data = z->img_comp[n].coeff + 64 * (i + j * z->img_comp[n].coeff_w); 2828 stbi__jpeg_dequantize(data, z->dequant[z->img_comp[n].tq]); 2829 z->idct_block_kernel(z->img_comp[n].data+z->img_comp[n].w2*j*8+i*8, z->img_comp[n].w2, data); 2830 } 2831 } 2832 } 2833 } 2834 } 2835 2836 static int stbi__process_marker(stbi__jpeg *z, int m) 2837 { 2838 int L; 2839 switch (m) { 2840 case STBI__MARKER_none: // no marker found 2841 return stbi__err("expected marker","Corrupt JPEG"); 2842 2843 case 0xDD: // DRI - specify restart interval 2844 if (stbi__get16be(z->s) != 4) return stbi__err("bad DRI len","Corrupt JPEG"); 2845 z->restart_interval = stbi__get16be(z->s); 2846 return 1; 2847 2848 case 0xDB: // DQT - define quantization table 2849 L = stbi__get16be(z->s)-2; 2850 while (L > 0) { 2851 int q = stbi__get8(z->s); 2852 int p = q >> 4, sixteen = (p != 0); 2853 int t = q & 15,i; 2854 if (p != 0 && p != 1) return stbi__err("bad DQT type","Corrupt JPEG"); 2855 if (t > 3) return stbi__err("bad DQT table","Corrupt JPEG"); 2856 2857 for (i=0; i < 64; ++i) 2858 z->dequant[t][stbi__jpeg_dezigzag[i]] = (stbi__uint16)(sixteen ? stbi__get16be(z->s) : stbi__get8(z->s)); 2859 L -= (sixteen ? 129 : 65); 2860 } 2861 return L==0; 2862 2863 case 0xC4: // DHT - define huffman table 2864 L = stbi__get16be(z->s)-2; 2865 while (L > 0) { 2866 stbi_uc *v; 2867 int sizes[16],i,n=0; 2868 int q = stbi__get8(z->s); 2869 int tc = q >> 4; 2870 int th = q & 15; 2871 if (tc > 1 || th > 3) return stbi__err("bad DHT header","Corrupt JPEG"); 2872 for (i=0; i < 16; ++i) { 2873 sizes[i] = stbi__get8(z->s); 2874 n += sizes[i]; 2875 } 2876 L -= 17; 2877 if (tc == 0) { 2878 if (!stbi__build_huffman(z->huff_dc+th, sizes)) return 0; 2879 v = z->huff_dc[th].values; 2880 } else { 2881 if (!stbi__build_huffman(z->huff_ac+th, sizes)) return 0; 2882 v = z->huff_ac[th].values; 2883 } 2884 for (i=0; i < n; ++i) 2885 v[i] = stbi__get8(z->s); 2886 if (tc != 0) 2887 stbi__build_fast_ac(z->fast_ac[th], z->huff_ac + th); 2888 L -= n; 2889 } 2890 return L==0; 2891 } 2892 2893 // check for comment block or APP blocks 2894 if ((m >= 0xE0 && m <= 0xEF) || m == 0xFE) { 2895 L = stbi__get16be(z->s); 2896 if (L < 2) { 2897 if (m == 0xFE) 2898 return stbi__err("bad COM len","Corrupt JPEG"); 2899 else 2900 return stbi__err("bad APP len","Corrupt JPEG"); 2901 } 2902 L -= 2; 2903 2904 if (m == 0xE0 && L >= 5) { // JFIF APP0 segment 2905 static const unsigned char tag[5] = {'J','F','I','F','\0'}; 2906 int ok = 1; 2907 int i; 2908 for (i=0; i < 5; ++i) 2909 if (stbi__get8(z->s) != tag[i]) 2910 ok = 0; 2911 L -= 5; 2912 if (ok) 2913 z->jfif = 1; 2914 } else if (m == 0xEE && L >= 12) { // Adobe APP14 segment 2915 static const unsigned char tag[6] = {'A','d','o','b','e','\0'}; 2916 int ok = 1; 2917 int i; 2918 for (i=0; i < 6; ++i) 2919 if (stbi__get8(z->s) != tag[i]) 2920 ok = 0; 2921 L -= 6; 2922 if (ok) { 2923 stbi__get8(z->s); // version 2924 stbi__get16be(z->s); // flags0 2925 stbi__get16be(z->s); // flags1 2926 z->app14_color_transform = stbi__get8(z->s); // color transform 2927 L -= 6; 2928 } 2929 } 2930 2931 stbi__skip(z->s, L); 2932 return 1; 2933 } 2934 2935 return stbi__err("unknown marker","Corrupt JPEG"); 2936 } 2937 2938 // after we see SOS 2939 static int stbi__process_scan_header(stbi__jpeg *z) 2940 { 2941 int i; 2942 int Ls = stbi__get16be(z->s); 2943 z->scan_n = stbi__get8(z->s); 2944 if (z->scan_n < 1 || z->scan_n > 4 || z->scan_n > (int) z->s->img_n) return stbi__err("bad SOS component count","Corrupt JPEG"); 2945 if (Ls != 6+2*z->scan_n) return stbi__err("bad SOS len","Corrupt JPEG"); 2946 for (i=0; i < z->scan_n; ++i) { 2947 int id = stbi__get8(z->s), which; 2948 int q = stbi__get8(z->s); 2949 for (which = 0; which < z->s->img_n; ++which) 2950 if (z->img_comp[which].id == id) 2951 break; 2952 if (which == z->s->img_n) return 0; // no match 2953 z->img_comp[which].hd = q >> 4; if (z->img_comp[which].hd > 3) return stbi__err("bad DC huff","Corrupt JPEG"); 2954 z->img_comp[which].ha = q & 15; if (z->img_comp[which].ha > 3) return stbi__err("bad AC huff","Corrupt JPEG"); 2955 z->order[i] = which; 2956 } 2957 2958 { 2959 int aa; 2960 z->spec_start = stbi__get8(z->s); 2961 z->spec_end = stbi__get8(z->s); // should be 63, but might be 0 2962 aa = stbi__get8(z->s); 2963 z->succ_high = (aa >> 4); 2964 z->succ_low = (aa & 15); 2965 if (z->progressive) { 2966 if (z->spec_start > 63 || z->spec_end > 63 || z->spec_start > z->spec_end || z->succ_high > 13 || z->succ_low > 13) 2967 return stbi__err("bad SOS", "Corrupt JPEG"); 2968 } else { 2969 if (z->spec_start != 0) return stbi__err("bad SOS","Corrupt JPEG"); 2970 if (z->succ_high != 0 || z->succ_low != 0) return stbi__err("bad SOS","Corrupt JPEG"); 2971 z->spec_end = 63; 2972 } 2973 } 2974 2975 return 1; 2976 } 2977 2978 static int stbi__free_jpeg_components(stbi__jpeg *z, int ncomp, int why) 2979 { 2980 int i; 2981 for (i=0; i < ncomp; ++i) { 2982 if (z->img_comp[i].raw_data) { 2983 STBI_FREE(z->img_comp[i].raw_data); 2984 z->img_comp[i].raw_data = NULL; 2985 z->img_comp[i].data = NULL; 2986 } 2987 if (z->img_comp[i].raw_coeff) { 2988 STBI_FREE(z->img_comp[i].raw_coeff); 2989 z->img_comp[i].raw_coeff = 0; 2990 z->img_comp[i].coeff = 0; 2991 } 2992 if (z->img_comp[i].linebuf) { 2993 STBI_FREE(z->img_comp[i].linebuf); 2994 z->img_comp[i].linebuf = NULL; 2995 } 2996 } 2997 return why; 2998 } 2999 3000 static int stbi__process_frame_header(stbi__jpeg *z, int scan) 3001 { 3002 stbi__context *s = z->s; 3003 int Lf,p,i,q, h_max=1,v_max=1,c; 3004 Lf = stbi__get16be(s); if (Lf < 11) return stbi__err("bad SOF len","Corrupt JPEG"); // JPEG 3005 p = stbi__get8(s); if (p != 8) return stbi__err("only 8-bit","JPEG format not supported: 8-bit only"); // JPEG baseline 3006 s->img_y = stbi__get16be(s); if (s->img_y == 0) return stbi__err("no header height", "JPEG format not supported: delayed height"); // Legal, but we don't handle it--but neither does IJG 3007 s->img_x = stbi__get16be(s); if (s->img_x == 0) return stbi__err("0 width","Corrupt JPEG"); // JPEG requires 3008 c = stbi__get8(s); 3009 if (c != 3 && c != 1 && c != 4) return stbi__err("bad component count","Corrupt JPEG"); 3010 s->img_n = c; 3011 for (i=0; i < c; ++i) { 3012 z->img_comp[i].data = NULL; 3013 z->img_comp[i].linebuf = NULL; 3014 } 3015 3016 if (Lf != 8+3*s->img_n) return stbi__err("bad SOF len","Corrupt JPEG"); 3017 3018 z->rgb = 0; 3019 for (i=0; i < s->img_n; ++i) { 3020 static const unsigned char rgb[3] = { 'R', 'G', 'B' }; 3021 z->img_comp[i].id = stbi__get8(s); 3022 if (s->img_n == 3 && z->img_comp[i].id == rgb[i]) 3023 ++z->rgb; 3024 q = stbi__get8(s); 3025 z->img_comp[i].h = (q >> 4); if (!z->img_comp[i].h || z->img_comp[i].h > 4) return stbi__err("bad H","Corrupt JPEG"); 3026 z->img_comp[i].v = q & 15; if (!z->img_comp[i].v || z->img_comp[i].v > 4) return stbi__err("bad V","Corrupt JPEG"); 3027 z->img_comp[i].tq = stbi__get8(s); if (z->img_comp[i].tq > 3) return stbi__err("bad TQ","Corrupt JPEG"); 3028 } 3029 3030 if (scan != STBI__SCAN_load) return 1; 3031 3032 if (!stbi__mad3sizes_valid(s->img_x, s->img_y, s->img_n, 0)) return stbi__err("too large", "Image too large to decode"); 3033 3034 for (i=0; i < s->img_n; ++i) { 3035 if (z->img_comp[i].h > h_max) h_max = z->img_comp[i].h; 3036 if (z->img_comp[i].v > v_max) v_max = z->img_comp[i].v; 3037 } 3038 3039 // compute interleaved mcu info 3040 z->img_h_max = h_max; 3041 z->img_v_max = v_max; 3042 z->img_mcu_w = h_max * 8; 3043 z->img_mcu_h = v_max * 8; 3044 // these sizes can't be more than 17 bits 3045 z->img_mcu_x = (s->img_x + z->img_mcu_w-1) / z->img_mcu_w; 3046 z->img_mcu_y = (s->img_y + z->img_mcu_h-1) / z->img_mcu_h; 3047 3048 for (i=0; i < s->img_n; ++i) { 3049 // number of effective pixels (e.g. for non-interleaved MCU) 3050 z->img_comp[i].x = (s->img_x * z->img_comp[i].h + h_max-1) / h_max; 3051 z->img_comp[i].y = (s->img_y * z->img_comp[i].v + v_max-1) / v_max; 3052 // to simplify generation, we'll allocate enough memory to decode 3053 // the bogus oversized data from using interleaved MCUs and their 3054 // big blocks (e.g. a 16x16 iMCU on an image of width 33); we won't 3055 // discard the extra data until colorspace conversion 3056 // 3057 // img_mcu_x, img_mcu_y: <=17 bits; comp[i].h and .v are <=4 (checked earlier) 3058 // so these muls can't overflow with 32-bit ints (which we require) 3059 z->img_comp[i].w2 = z->img_mcu_x * z->img_comp[i].h * 8; 3060 z->img_comp[i].h2 = z->img_mcu_y * z->img_comp[i].v * 8; 3061 z->img_comp[i].coeff = 0; 3062 z->img_comp[i].raw_coeff = 0; 3063 z->img_comp[i].linebuf = NULL; 3064 z->img_comp[i].raw_data = stbi__malloc_mad2(z->img_comp[i].w2, z->img_comp[i].h2, 15); 3065 if (z->img_comp[i].raw_data == NULL) 3066 return stbi__free_jpeg_components(z, i+1, stbi__err("outofmem", "Out of memory")); 3067 // align blocks for idct using mmx/sse 3068 z->img_comp[i].data = (stbi_uc*) (((size_t) z->img_comp[i].raw_data + 15) & ~15); 3069 if (z->progressive) { 3070 // w2, h2 are multiples of 8 (see above) 3071 z->img_comp[i].coeff_w = z->img_comp[i].w2 / 8; 3072 z->img_comp[i].coeff_h = z->img_comp[i].h2 / 8; 3073 z->img_comp[i].raw_coeff = stbi__malloc_mad3(z->img_comp[i].w2, z->img_comp[i].h2, sizeof(short), 15); 3074 if (z->img_comp[i].raw_coeff == NULL) 3075 return stbi__free_jpeg_components(z, i+1, stbi__err("outofmem", "Out of memory")); 3076 z->img_comp[i].coeff = (short*) (((size_t) z->img_comp[i].raw_coeff + 15) & ~15); 3077 } 3078 } 3079 3080 return 1; 3081 } 3082 3083 // use comparisons since in some cases we handle more than one case (e.g. SOF) 3084 #define stbi__DNL(x) ((x) == 0xdc) 3085 #define stbi__SOI(x) ((x) == 0xd8) 3086 #define stbi__EOI(x) ((x) == 0xd9) 3087 #define stbi__SOF(x) ((x) == 0xc0 || (x) == 0xc1 || (x) == 0xc2) 3088 #define stbi__SOS(x) ((x) == 0xda) 3089 3090 #define stbi__SOF_progressive(x) ((x) == 0xc2) 3091 3092 static int stbi__decode_jpeg_header(stbi__jpeg *z, int scan) 3093 { 3094 int m; 3095 z->jfif = 0; 3096 z->app14_color_transform = -1; // valid values are 0,1,2 3097 z->marker = STBI__MARKER_none; // initialize cached marker to empty 3098 m = stbi__get_marker(z); 3099 if (!stbi__SOI(m)) return stbi__err("no SOI","Corrupt JPEG"); 3100 if (scan == STBI__SCAN_type) return 1; 3101 m = stbi__get_marker(z); 3102 while (!stbi__SOF(m)) { 3103 if (!stbi__process_marker(z,m)) return 0; 3104 m = stbi__get_marker(z); 3105 while (m == STBI__MARKER_none) { 3106 // some files have extra padding after their blocks, so ok, we'll scan 3107 if (stbi__at_eof(z->s)) return stbi__err("no SOF", "Corrupt JPEG"); 3108 m = stbi__get_marker(z); 3109 } 3110 } 3111 z->progressive = stbi__SOF_progressive(m); 3112 if (!stbi__process_frame_header(z, scan)) return 0; 3113 return 1; 3114 } 3115 3116 // decode image to YCbCr format 3117 static int stbi__decode_jpeg_image(stbi__jpeg *j) 3118 { 3119 int m; 3120 for (m = 0; m < 4; m++) { 3121 j->img_comp[m].raw_data = NULL; 3122 j->img_comp[m].raw_coeff = NULL; 3123 } 3124 j->restart_interval = 0; 3125 if (!stbi__decode_jpeg_header(j, STBI__SCAN_load)) return 0; 3126 m = stbi__get_marker(j); 3127 while (!stbi__EOI(m)) { 3128 if (stbi__SOS(m)) { 3129 if (!stbi__process_scan_header(j)) return 0; 3130 if (!stbi__parse_entropy_coded_data(j)) return 0; 3131 if (j->marker == STBI__MARKER_none ) { 3132 // handle 0s at the end of image data from IP Kamera 9060 3133 while (!stbi__at_eof(j->s)) { 3134 int x = stbi__get8(j->s); 3135 if (x == 255) { 3136 j->marker = stbi__get8(j->s); 3137 break; 3138 } 3139 } 3140 // if we reach eof without hitting a marker, stbi__get_marker() below will fail and we'll eventually return 0 3141 } 3142 } else if (stbi__DNL(m)) { 3143 int Ld = stbi__get16be(j->s); 3144 stbi__uint32 NL = stbi__get16be(j->s); 3145 if (Ld != 4) return stbi__err("bad DNL len", "Corrupt JPEG"); 3146 if (NL != j->s->img_y) return stbi__err("bad DNL height", "Corrupt JPEG"); 3147 } else { 3148 if (!stbi__process_marker(j, m)) return 0; 3149 } 3150 m = stbi__get_marker(j); 3151 } 3152 if (j->progressive) 3153 stbi__jpeg_finish(j); 3154 return 1; 3155 } 3156 3157 // static jfif-centered resampling (across block boundaries) 3158 3159 typedef stbi_uc *(*resample_row_func)(stbi_uc *out, stbi_uc *in0, stbi_uc *in1, 3160 int w, int hs); 3161 3162 #define stbi__div4(x) ((stbi_uc) ((x) >> 2)) 3163 3164 static stbi_uc *resample_row_1(stbi_uc *out, stbi_uc *in_near, stbi_uc *in_far, int w, int hs) 3165 { 3166 STBI_NOTUSED(out); 3167 STBI_NOTUSED(in_far); 3168 STBI_NOTUSED(w); 3169 STBI_NOTUSED(hs); 3170 return in_near; 3171 } 3172 3173 static stbi_uc* stbi__resample_row_v_2(stbi_uc *out, stbi_uc *in_near, stbi_uc *in_far, int w, int hs) 3174 { 3175 // need to generate two samples vertically for every one in input 3176 int i; 3177 STBI_NOTUSED(hs); 3178 for (i=0; i < w; ++i) 3179 out[i] = stbi__div4(3*in_near[i] + in_far[i] + 2); 3180 return out; 3181 } 3182 3183 static stbi_uc* stbi__resample_row_h_2(stbi_uc *out, stbi_uc *in_near, stbi_uc *in_far, int w, int hs) 3184 { 3185 // need to generate two samples horizontally for every one in input 3186 int i; 3187 stbi_uc *input = in_near; 3188 3189 if (w == 1) { 3190 // if only one sample, can't do any interpolation 3191 out[0] = out[1] = input[0]; 3192 return out; 3193 } 3194 3195 out[0] = input[0]; 3196 out[1] = stbi__div4(input[0]*3 + input[1] + 2); 3197 for (i=1; i < w-1; ++i) { 3198 int n = 3*input[i]+2; 3199 out[i*2+0] = stbi__div4(n+input[i-1]); 3200 out[i*2+1] = stbi__div4(n+input[i+1]); 3201 } 3202 out[i*2+0] = stbi__div4(input[w-2]*3 + input[w-1] + 2); 3203 out[i*2+1] = input[w-1]; 3204 3205 STBI_NOTUSED(in_far); 3206 STBI_NOTUSED(hs); 3207 3208 return out; 3209 } 3210 3211 #define stbi__div16(x) ((stbi_uc) ((x) >> 4)) 3212 3213 static stbi_uc *stbi__resample_row_hv_2(stbi_uc *out, stbi_uc *in_near, stbi_uc *in_far, int w, int hs) 3214 { 3215 // need to generate 2x2 samples for every one in input 3216 int i,t0,t1; 3217 if (w == 1) { 3218 out[0] = out[1] = stbi__div4(3*in_near[0] + in_far[0] + 2); 3219 return out; 3220 } 3221 3222 t1 = 3*in_near[0] + in_far[0]; 3223 out[0] = stbi__div4(t1+2); 3224 for (i=1; i < w; ++i) { 3225 t0 = t1; 3226 t1 = 3*in_near[i]+in_far[i]; 3227 out[i*2-1] = stbi__div16(3*t0 + t1 + 8); 3228 out[i*2 ] = stbi__div16(3*t1 + t0 + 8); 3229 } 3230 out[w*2-1] = stbi__div4(t1+2); 3231 3232 STBI_NOTUSED(hs); 3233 3234 return out; 3235 } 3236 3237 #if defined(STBI_SSE2) || defined(STBI_NEON) 3238 static stbi_uc *stbi__resample_row_hv_2_simd(stbi_uc *out, stbi_uc *in_near, stbi_uc *in_far, int w, int hs) 3239 { 3240 // need to generate 2x2 samples for every one in input 3241 int i=0,t0,t1; 3242 3243 if (w == 1) { 3244 out[0] = out[1] = stbi__div4(3*in_near[0] + in_far[0] + 2); 3245 return out; 3246 } 3247 3248 t1 = 3*in_near[0] + in_far[0]; 3249 // process groups of 8 pixels for as long as we can. 3250 // note we can't handle the last pixel in a row in this loop 3251 // because we need to handle the filter boundary conditions. 3252 for (; i < ((w-1) & ~7); i += 8) { 3253 #if defined(STBI_SSE2) 3254 // load and perform the vertical filtering pass 3255 // this uses 3*x + y = 4*x + (y - x) 3256 __m128i zero = _mm_setzero_si128(); 3257 __m128i farb = _mm_loadl_epi64((__m128i *) (in_far + i)); 3258 __m128i nearb = _mm_loadl_epi64((__m128i *) (in_near + i)); 3259 __m128i farw = _mm_unpacklo_epi8(farb, zero); 3260 __m128i nearw = _mm_unpacklo_epi8(nearb, zero); 3261 __m128i diff = _mm_sub_epi16(farw, nearw); 3262 __m128i nears = _mm_slli_epi16(nearw, 2); 3263 __m128i curr = _mm_add_epi16(nears, diff); // current row 3264 3265 // horizontal filter works the same based on shifted vers of current 3266 // row. "prev" is current row shifted right by 1 pixel; we need to 3267 // insert the previous pixel value (from t1). 3268 // "next" is current row shifted left by 1 pixel, with first pixel 3269 // of next block of 8 pixels added in. 3270 __m128i prv0 = _mm_slli_si128(curr, 2); 3271 __m128i nxt0 = _mm_srli_si128(curr, 2); 3272 __m128i prev = _mm_insert_epi16(prv0, t1, 0); 3273 __m128i next = _mm_insert_epi16(nxt0, 3*in_near[i+8] + in_far[i+8], 7); 3274 3275 // horizontal filter, polyphase implementation since it's convenient: 3276 // even pixels = 3*cur + prev = cur*4 + (prev - cur) 3277 // odd pixels = 3*cur + next = cur*4 + (next - cur) 3278 // note the shared term. 3279 __m128i bias = _mm_set1_epi16(8); 3280 __m128i curs = _mm_slli_epi16(curr, 2); 3281 __m128i prvd = _mm_sub_epi16(prev, curr); 3282 __m128i nxtd = _mm_sub_epi16(next, curr); 3283 __m128i curb = _mm_add_epi16(curs, bias); 3284 __m128i even = _mm_add_epi16(prvd, curb); 3285 __m128i odd = _mm_add_epi16(nxtd, curb); 3286 3287 // interleave even and odd pixels, then undo scaling. 3288 __m128i int0 = _mm_unpacklo_epi16(even, odd); 3289 __m128i int1 = _mm_unpackhi_epi16(even, odd); 3290 __m128i de0 = _mm_srli_epi16(int0, 4); 3291 __m128i de1 = _mm_srli_epi16(int1, 4); 3292 3293 // pack and write output 3294 __m128i outv = _mm_packus_epi16(de0, de1); 3295 _mm_storeu_si128((__m128i *) (out + i*2), outv); 3296 #elif defined(STBI_NEON) 3297 // load and perform the vertical filtering pass 3298 // this uses 3*x + y = 4*x + (y - x) 3299 uint8x8_t farb = vld1_u8(in_far + i); 3300 uint8x8_t nearb = vld1_u8(in_near + i); 3301 int16x8_t diff = vreinterpretq_s16_u16(vsubl_u8(farb, nearb)); 3302 int16x8_t nears = vreinterpretq_s16_u16(vshll_n_u8(nearb, 2)); 3303 int16x8_t curr = vaddq_s16(nears, diff); // current row 3304 3305 // horizontal filter works the same based on shifted vers of current 3306 // row. "prev" is current row shifted right by 1 pixel; we need to 3307 // insert the previous pixel value (from t1). 3308 // "next" is current row shifted left by 1 pixel, with first pixel 3309 // of next block of 8 pixels added in. 3310 int16x8_t prv0 = vextq_s16(curr, curr, 7); 3311 int16x8_t nxt0 = vextq_s16(curr, curr, 1); 3312 int16x8_t prev = vsetq_lane_s16(t1, prv0, 0); 3313 int16x8_t next = vsetq_lane_s16(3*in_near[i+8] + in_far[i+8], nxt0, 7); 3314 3315 // horizontal filter, polyphase implementation since it's convenient: 3316 // even pixels = 3*cur + prev = cur*4 + (prev - cur) 3317 // odd pixels = 3*cur + next = cur*4 + (next - cur) 3318 // note the shared term. 3319 int16x8_t curs = vshlq_n_s16(curr, 2); 3320 int16x8_t prvd = vsubq_s16(prev, curr); 3321 int16x8_t nxtd = vsubq_s16(next, curr); 3322 int16x8_t even = vaddq_s16(curs, prvd); 3323 int16x8_t odd = vaddq_s16(curs, nxtd); 3324 3325 // undo scaling and round, then store with even/odd phases interleaved 3326 uint8x8x2_t o; 3327 o.val[0] = vqrshrun_n_s16(even, 4); 3328 o.val[1] = vqrshrun_n_s16(odd, 4); 3329 vst2_u8(out + i*2, o); 3330 #endif 3331 3332 // "previous" value for next iter 3333 t1 = 3*in_near[i+7] + in_far[i+7]; 3334 } 3335 3336 t0 = t1; 3337 t1 = 3*in_near[i] + in_far[i]; 3338 out[i*2] = stbi__div16(3*t1 + t0 + 8); 3339 3340 for (++i; i < w; ++i) { 3341 t0 = t1; 3342 t1 = 3*in_near[i]+in_far[i]; 3343 out[i*2-1] = stbi__div16(3*t0 + t1 + 8); 3344 out[i*2 ] = stbi__div16(3*t1 + t0 + 8); 3345 } 3346 out[w*2-1] = stbi__div4(t1+2); 3347 3348 STBI_NOTUSED(hs); 3349 3350 return out; 3351 } 3352 #endif 3353 3354 static stbi_uc *stbi__resample_row_generic(stbi_uc *out, stbi_uc *in_near, stbi_uc *in_far, int w, int hs) 3355 { 3356 // resample with nearest-neighbor 3357 int i,j; 3358 STBI_NOTUSED(in_far); 3359 for (i=0; i < w; ++i) 3360 for (j=0; j < hs; ++j) 3361 out[i*hs+j] = in_near[i]; 3362 return out; 3363 } 3364 3365 // this is a reduced-precision calculation of YCbCr-to-RGB introduced 3366 // to make sure the code produces the same results in both SIMD and scalar 3367 #define stbi__float2fixed(x) (((int) ((x) * 4096.0f + 0.5f)) << 8) 3368 static void stbi__YCbCr_to_RGB_row(stbi_uc *out, const stbi_uc *y, const stbi_uc *pcb, const stbi_uc *pcr, int count, int step) 3369 { 3370 int i; 3371 for (i=0; i < count; ++i) { 3372 int y_fixed = (y[i] << 20) + (1<<19); // rounding 3373 int r,g,b; 3374 int cr = pcr[i] - 128; 3375 int cb = pcb[i] - 128; 3376 r = y_fixed + cr* stbi__float2fixed(1.40200f); 3377 g = y_fixed + (cr*-stbi__float2fixed(0.71414f)) + ((cb*-stbi__float2fixed(0.34414f)) & 0xffff0000); 3378 b = y_fixed + cb* stbi__float2fixed(1.77200f); 3379 r >>= 20; 3380 g >>= 20; 3381 b >>= 20; 3382 if ((unsigned) r > 255) { if (r < 0) r = 0; else r = 255; } 3383 if ((unsigned) g > 255) { if (g < 0) g = 0; else g = 255; } 3384 if ((unsigned) b > 255) { if (b < 0) b = 0; else b = 255; } 3385 out[0] = (stbi_uc)r; 3386 out[1] = (stbi_uc)g; 3387 out[2] = (stbi_uc)b; 3388 out[3] = 255; 3389 out += step; 3390 } 3391 } 3392 3393 #if defined(STBI_SSE2) || defined(STBI_NEON) 3394 static void stbi__YCbCr_to_RGB_simd(stbi_uc *out, stbi_uc const *y, stbi_uc const *pcb, stbi_uc const *pcr, int count, int step) 3395 { 3396 int i = 0; 3397 3398 #ifdef STBI_SSE2 3399 // step == 3 is pretty ugly on the final interleave, and i'm not convinced 3400 // it's useful in practice (you wouldn't use it for textures, for example). 3401 // so just accelerate step == 4 case. 3402 if (step == 4) { 3403 // this is a fairly straightforward implementation and not super-optimized. 3404 __m128i signflip = _mm_set1_epi8(-0x80); 3405 __m128i cr_const0 = _mm_set1_epi16( (short) ( 1.40200f*4096.0f+0.5f)); 3406 __m128i cr_const1 = _mm_set1_epi16( - (short) ( 0.71414f*4096.0f+0.5f)); 3407 __m128i cb_const0 = _mm_set1_epi16( - (short) ( 0.34414f*4096.0f+0.5f)); 3408 __m128i cb_const1 = _mm_set1_epi16( (short) ( 1.77200f*4096.0f+0.5f)); 3409 __m128i y_bias = _mm_set1_epi8((char) (unsigned char) 128); 3410 __m128i xw = _mm_set1_epi16(255); // alpha channel 3411 3412 for (; i+7 < count; i += 8) { 3413 // load 3414 __m128i y_bytes = _mm_loadl_epi64((__m128i *) (y+i)); 3415 __m128i cr_bytes = _mm_loadl_epi64((__m128i *) (pcr+i)); 3416 __m128i cb_bytes = _mm_loadl_epi64((__m128i *) (pcb+i)); 3417 __m128i cr_biased = _mm_xor_si128(cr_bytes, signflip); // -128 3418 __m128i cb_biased = _mm_xor_si128(cb_bytes, signflip); // -128 3419 3420 // unpack to short (and left-shift cr, cb by 8) 3421 __m128i yw = _mm_unpacklo_epi8(y_bias, y_bytes); 3422 __m128i crw = _mm_unpacklo_epi8(_mm_setzero_si128(), cr_biased); 3423 __m128i cbw = _mm_unpacklo_epi8(_mm_setzero_si128(), cb_biased); 3424 3425 // color transform 3426 __m128i yws = _mm_srli_epi16(yw, 4); 3427 __m128i cr0 = _mm_mulhi_epi16(cr_const0, crw); 3428 __m128i cb0 = _mm_mulhi_epi16(cb_const0, cbw); 3429 __m128i cb1 = _mm_mulhi_epi16(cbw, cb_const1); 3430 __m128i cr1 = _mm_mulhi_epi16(crw, cr_const1); 3431 __m128i rws = _mm_add_epi16(cr0, yws); 3432 __m128i gwt = _mm_add_epi16(cb0, yws); 3433 __m128i bws = _mm_add_epi16(yws, cb1); 3434 __m128i gws = _mm_add_epi16(gwt, cr1); 3435 3436 // descale 3437 __m128i rw = _mm_srai_epi16(rws, 4); 3438 __m128i bw = _mm_srai_epi16(bws, 4); 3439 __m128i gw = _mm_srai_epi16(gws, 4); 3440 3441 // back to byte, set up for transpose 3442 __m128i brb = _mm_packus_epi16(rw, bw); 3443 __m128i gxb = _mm_packus_epi16(gw, xw); 3444 3445 // transpose to interleave channels 3446 __m128i t0 = _mm_unpacklo_epi8(brb, gxb); 3447 __m128i t1 = _mm_unpackhi_epi8(brb, gxb); 3448 __m128i o0 = _mm_unpacklo_epi16(t0, t1); 3449 __m128i o1 = _mm_unpackhi_epi16(t0, t1); 3450 3451 // store 3452 _mm_storeu_si128((__m128i *) (out + 0), o0); 3453 _mm_storeu_si128((__m128i *) (out + 16), o1); 3454 out += 32; 3455 } 3456 } 3457 #endif 3458 3459 #ifdef STBI_NEON 3460 // in this version, step=3 support would be easy to add. but is there demand? 3461 if (step == 4) { 3462 // this is a fairly straightforward implementation and not super-optimized. 3463 uint8x8_t signflip = vdup_n_u8(0x80); 3464 int16x8_t cr_const0 = vdupq_n_s16( (short) ( 1.40200f*4096.0f+0.5f)); 3465 int16x8_t cr_const1 = vdupq_n_s16( - (short) ( 0.71414f*4096.0f+0.5f)); 3466 int16x8_t cb_const0 = vdupq_n_s16( - (short) ( 0.34414f*4096.0f+0.5f)); 3467 int16x8_t cb_const1 = vdupq_n_s16( (short) ( 1.77200f*4096.0f+0.5f)); 3468 3469 for (; i+7 < count; i += 8) { 3470 // load 3471 uint8x8_t y_bytes = vld1_u8(y + i); 3472 uint8x8_t cr_bytes = vld1_u8(pcr + i); 3473 uint8x8_t cb_bytes = vld1_u8(pcb + i); 3474 int8x8_t cr_biased = vreinterpret_s8_u8(vsub_u8(cr_bytes, signflip)); 3475 int8x8_t cb_biased = vreinterpret_s8_u8(vsub_u8(cb_bytes, signflip)); 3476 3477 // expand to s16 3478 int16x8_t yws = vreinterpretq_s16_u16(vshll_n_u8(y_bytes, 4)); 3479 int16x8_t crw = vshll_n_s8(cr_biased, 7); 3480 int16x8_t cbw = vshll_n_s8(cb_biased, 7); 3481 3482 // color transform 3483 int16x8_t cr0 = vqdmulhq_s16(crw, cr_const0); 3484 int16x8_t cb0 = vqdmulhq_s16(cbw, cb_const0); 3485 int16x8_t cr1 = vqdmulhq_s16(crw, cr_const1); 3486 int16x8_t cb1 = vqdmulhq_s16(cbw, cb_const1); 3487 int16x8_t rws = vaddq_s16(yws, cr0); 3488 int16x8_t gws = vaddq_s16(vaddq_s16(yws, cb0), cr1); 3489 int16x8_t bws = vaddq_s16(yws, cb1); 3490 3491 // undo scaling, round, convert to byte 3492 uint8x8x4_t o; 3493 o.val[0] = vqrshrun_n_s16(rws, 4); 3494 o.val[1] = vqrshrun_n_s16(gws, 4); 3495 o.val[2] = vqrshrun_n_s16(bws, 4); 3496 o.val[3] = vdup_n_u8(255); 3497 3498 // store, interleaving r/g/b/a 3499 vst4_u8(out, o); 3500 out += 8*4; 3501 } 3502 } 3503 #endif 3504 3505 for (; i < count; ++i) { 3506 int y_fixed = (y[i] << 20) + (1<<19); // rounding 3507 int r,g,b; 3508 int cr = pcr[i] - 128; 3509 int cb = pcb[i] - 128; 3510 r = y_fixed + cr* stbi__float2fixed(1.40200f); 3511 g = y_fixed + cr*-stbi__float2fixed(0.71414f) + ((cb*-stbi__float2fixed(0.34414f)) & 0xffff0000); 3512 b = y_fixed + cb* stbi__float2fixed(1.77200f); 3513 r >>= 20; 3514 g >>= 20; 3515 b >>= 20; 3516 if ((unsigned) r > 255) { if (r < 0) r = 0; else r = 255; } 3517 if ((unsigned) g > 255) { if (g < 0) g = 0; else g = 255; } 3518 if ((unsigned) b > 255) { if (b < 0) b = 0; else b = 255; } 3519 out[0] = (stbi_uc)r; 3520 out[1] = (stbi_uc)g; 3521 out[2] = (stbi_uc)b; 3522 out[3] = 255; 3523 out += step; 3524 } 3525 } 3526 #endif 3527 3528 // set up the kernels 3529 static void stbi__setup_jpeg(stbi__jpeg *j) 3530 { 3531 j->idct_block_kernel = stbi__idct_block; 3532 j->YCbCr_to_RGB_kernel = stbi__YCbCr_to_RGB_row; 3533 j->resample_row_hv_2_kernel = stbi__resample_row_hv_2; 3534 3535 #ifdef STBI_SSE2 3536 if (stbi__sse2_available()) { 3537 j->idct_block_kernel = stbi__idct_simd; 3538 j->YCbCr_to_RGB_kernel = stbi__YCbCr_to_RGB_simd; 3539 j->resample_row_hv_2_kernel = stbi__resample_row_hv_2_simd; 3540 } 3541 #endif 3542 3543 #ifdef STBI_NEON 3544 j->idct_block_kernel = stbi__idct_simd; 3545 j->YCbCr_to_RGB_kernel = stbi__YCbCr_to_RGB_simd; 3546 j->resample_row_hv_2_kernel = stbi__resample_row_hv_2_simd; 3547 #endif 3548 } 3549 3550 // clean up the temporary component buffers 3551 static void stbi__cleanup_jpeg(stbi__jpeg *j) 3552 { 3553 stbi__free_jpeg_components(j, j->s->img_n, 0); 3554 } 3555 3556 typedef struct 3557 { 3558 resample_row_func resample; 3559 stbi_uc *line0,*line1; 3560 int hs,vs; // expansion factor in each axis 3561 int w_lores; // horizontal pixels pre-expansion 3562 int ystep; // how far through vertical expansion we are 3563 int ypos; // which pre-expansion row we're on 3564 } stbi__resample; 3565 3566 // fast 0..255 * 0..255 => 0..255 rounded multiplication 3567 static stbi_uc stbi__blinn_8x8(stbi_uc x, stbi_uc y) 3568 { 3569 unsigned int t = x*y + 128; 3570 return (stbi_uc) ((t + (t >>8)) >> 8); 3571 } 3572 3573 static stbi_uc *load_jpeg_image(stbi__jpeg *z, int *out_x, int *out_y, int *comp, int req_comp) 3574 { 3575 int n, decode_n, is_rgb; 3576 z->s->img_n = 0; // make stbi__cleanup_jpeg safe 3577 3578 // validate req_comp 3579 if (req_comp < 0 || req_comp > 4) return stbi__errpuc("bad req_comp", "Internal error"); 3580 3581 // load a jpeg image from whichever source, but leave in YCbCr format 3582 if (!stbi__decode_jpeg_image(z)) { stbi__cleanup_jpeg(z); return NULL; } 3583 3584 // determine actual number of components to generate 3585 n = req_comp ? req_comp : z->s->img_n >= 3 ? 3 : 1; 3586 3587 is_rgb = z->s->img_n == 3 && (z->rgb == 3 || (z->app14_color_transform == 0 && !z->jfif)); 3588 3589 if (z->s->img_n == 3 && n < 3 && !is_rgb) 3590 decode_n = 1; 3591 else 3592 decode_n = z->s->img_n; 3593 3594 // resample and color-convert 3595 { 3596 int k; 3597 unsigned int i,j; 3598 stbi_uc *output; 3599 stbi_uc *coutput[4]; 3600 3601 stbi__resample res_comp[4]; 3602 3603 for (k=0; k < decode_n; ++k) { 3604 stbi__resample *r = &res_comp[k]; 3605 3606 // allocate line buffer big enough for upsampling off the edges 3607 // with upsample factor of 4 3608 z->img_comp[k].linebuf = (stbi_uc *) stbi__malloc(z->s->img_x + 3); 3609 if (!z->img_comp[k].linebuf) { stbi__cleanup_jpeg(z); return stbi__errpuc("outofmem", "Out of memory"); } 3610 3611 r->hs = z->img_h_max / z->img_comp[k].h; 3612 r->vs = z->img_v_max / z->img_comp[k].v; 3613 r->ystep = r->vs >> 1; 3614 r->w_lores = (z->s->img_x + r->hs-1) / r->hs; 3615 r->ypos = 0; 3616 r->line0 = r->line1 = z->img_comp[k].data; 3617 3618 if (r->hs == 1 && r->vs == 1) r->resample = resample_row_1; 3619 else if (r->hs == 1 && r->vs == 2) r->resample = stbi__resample_row_v_2; 3620 else if (r->hs == 2 && r->vs == 1) r->resample = stbi__resample_row_h_2; 3621 else if (r->hs == 2 && r->vs == 2) r->resample = z->resample_row_hv_2_kernel; 3622 else r->resample = stbi__resample_row_generic; 3623 } 3624 3625 // can't error after this so, this is safe 3626 output = (stbi_uc *) stbi__malloc_mad3(n, z->s->img_x, z->s->img_y, 1); 3627 if (!output) { stbi__cleanup_jpeg(z); return stbi__errpuc("outofmem", "Out of memory"); } 3628 3629 // now go ahead and resample 3630 for (j=0; j < z->s->img_y; ++j) { 3631 stbi_uc *out = output + n * z->s->img_x * j; 3632 for (k=0; k < decode_n; ++k) { 3633 stbi__resample *r = &res_comp[k]; 3634 int y_bot = r->ystep >= (r->vs >> 1); 3635 coutput[k] = r->resample(z->img_comp[k].linebuf, 3636 y_bot ? r->line1 : r->line0, 3637 y_bot ? r->line0 : r->line1, 3638 r->w_lores, r->hs); 3639 if (++r->ystep >= r->vs) { 3640 r->ystep = 0; 3641 r->line0 = r->line1; 3642 if (++r->ypos < z->img_comp[k].y) 3643 r->line1 += z->img_comp[k].w2; 3644 } 3645 } 3646 if (n >= 3) { 3647 stbi_uc *y = coutput[0]; 3648 if (z->s->img_n == 3) { 3649 if (is_rgb) { 3650 for (i=0; i < z->s->img_x; ++i) { 3651 out[0] = y[i]; 3652 out[1] = coutput[1][i]; 3653 out[2] = coutput[2][i]; 3654 out[3] = 255; 3655 out += n; 3656 } 3657 } else { 3658 z->YCbCr_to_RGB_kernel(out, y, coutput[1], coutput[2], z->s->img_x, n); 3659 } 3660 } else if (z->s->img_n == 4) { 3661 if (z->app14_color_transform == 0) { // CMYK 3662 for (i=0; i < z->s->img_x; ++i) { 3663 stbi_uc m = coutput[3][i]; 3664 out[0] = stbi__blinn_8x8(coutput[0][i], m); 3665 out[1] = stbi__blinn_8x8(coutput[1][i], m); 3666 out[2] = stbi__blinn_8x8(coutput[2][i], m); 3667 out[3] = 255; 3668 out += n; 3669 } 3670 } else if (z->app14_color_transform == 2) { // YCCK 3671 z->YCbCr_to_RGB_kernel(out, y, coutput[1], coutput[2], z->s->img_x, n); 3672 for (i=0; i < z->s->img_x; ++i) { 3673 stbi_uc m = coutput[3][i]; 3674 out[0] = stbi__blinn_8x8(255 - out[0], m); 3675 out[1] = stbi__blinn_8x8(255 - out[1], m); 3676 out[2] = stbi__blinn_8x8(255 - out[2], m); 3677 out += n; 3678 } 3679 } else { // YCbCr + alpha? Ignore the fourth channel for now 3680 z->YCbCr_to_RGB_kernel(out, y, coutput[1], coutput[2], z->s->img_x, n); 3681 } 3682 } else 3683 for (i=0; i < z->s->img_x; ++i) { 3684 out[0] = out[1] = out[2] = y[i]; 3685 out[3] = 255; // not used if n==3 3686 out += n; 3687 } 3688 } else { 3689 if (is_rgb) { 3690 if (n == 1) 3691 for (i=0; i < z->s->img_x; ++i) 3692 *out++ = stbi__compute_y(coutput[0][i], coutput[1][i], coutput[2][i]); 3693 else { 3694 for (i=0; i < z->s->img_x; ++i, out += 2) { 3695 out[0] = stbi__compute_y(coutput[0][i], coutput[1][i], coutput[2][i]); 3696 out[1] = 255; 3697 } 3698 } 3699 } else if (z->s->img_n == 4 && z->app14_color_transform == 0) { 3700 for (i=0; i < z->s->img_x; ++i) { 3701 stbi_uc m = coutput[3][i]; 3702 stbi_uc r = stbi__blinn_8x8(coutput[0][i], m); 3703 stbi_uc g = stbi__blinn_8x8(coutput[1][i], m); 3704 stbi_uc b = stbi__blinn_8x8(coutput[2][i], m); 3705 out[0] = stbi__compute_y(r, g, b); 3706 out[1] = 255; 3707 out += n; 3708 } 3709 } else if (z->s->img_n == 4 && z->app14_color_transform == 2) { 3710 for (i=0; i < z->s->img_x; ++i) { 3711 out[0] = stbi__blinn_8x8(255 - coutput[0][i], coutput[3][i]); 3712 out[1] = 255; 3713 out += n; 3714 } 3715 } else { 3716 stbi_uc *y = coutput[0]; 3717 if (n == 1) 3718 for (i=0; i < z->s->img_x; ++i) out[i] = y[i]; 3719 else 3720 for (i=0; i < z->s->img_x; ++i) *out++ = y[i], *out++ = 255; 3721 } 3722 } 3723 } 3724 stbi__cleanup_jpeg(z); 3725 *out_x = z->s->img_x; 3726 *out_y = z->s->img_y; 3727 if (comp) *comp = z->s->img_n >= 3 ? 3 : 1; // report original components, not output 3728 return output; 3729 } 3730 } 3731 3732 static void *stbi__jpeg_load(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri) 3733 { 3734 unsigned char* result; 3735 stbi__jpeg* j = (stbi__jpeg*) stbi__malloc(sizeof(stbi__jpeg)); 3736 STBI_NOTUSED(ri); 3737 j->s = s; 3738 stbi__setup_jpeg(j); 3739 result = load_jpeg_image(j, x,y,comp,req_comp); 3740 STBI_FREE(j); 3741 return result; 3742 } 3743 3744 static int stbi__jpeg_test(stbi__context *s) 3745 { 3746 int r; 3747 stbi__jpeg* j = (stbi__jpeg*)stbi__malloc(sizeof(stbi__jpeg)); 3748 j->s = s; 3749 stbi__setup_jpeg(j); 3750 r = stbi__decode_jpeg_header(j, STBI__SCAN_type); 3751 stbi__rewind(s); 3752 STBI_FREE(j); 3753 return r; 3754 } 3755 3756 static int stbi__jpeg_info_raw(stbi__jpeg *j, int *x, int *y, int *comp) 3757 { 3758 if (!stbi__decode_jpeg_header(j, STBI__SCAN_header)) { 3759 stbi__rewind( j->s ); 3760 return 0; 3761 } 3762 if (x) *x = j->s->img_x; 3763 if (y) *y = j->s->img_y; 3764 if (comp) *comp = j->s->img_n >= 3 ? 3 : 1; 3765 return 1; 3766 } 3767 3768 static int stbi__jpeg_info(stbi__context *s, int *x, int *y, int *comp) 3769 { 3770 int result; 3771 stbi__jpeg* j = (stbi__jpeg*) (stbi__malloc(sizeof(stbi__jpeg))); 3772 j->s = s; 3773 result = stbi__jpeg_info_raw(j, x, y, comp); 3774 STBI_FREE(j); 3775 return result; 3776 } 3777 #endif 3778 3779 // public domain zlib decode v0.2 Sean Barrett 2006-11-18 3780 // simple implementation 3781 // - all input must be provided in an upfront buffer 3782 // - all output is written to a single output buffer (can malloc/realloc) 3783 // performance 3784 // - fast huffman 3785 3786 #ifndef STBI_NO_ZLIB 3787 3788 // fast-way is faster to check than jpeg huffman, but slow way is slower 3789 #define STBI__ZFAST_BITS 9 // accelerate all cases in default tables 3790 #define STBI__ZFAST_MASK ((1 << STBI__ZFAST_BITS) - 1) 3791 3792 // zlib-style huffman encoding 3793 // (jpegs packs from left, zlib from right, so can't share code) 3794 typedef struct 3795 { 3796 stbi__uint16 fast[1 << STBI__ZFAST_BITS]; 3797 stbi__uint16 firstcode[16]; 3798 int maxcode[17]; 3799 stbi__uint16 firstsymbol[16]; 3800 stbi_uc size[288]; 3801 stbi__uint16 value[288]; 3802 } stbi__zhuffman; 3803 3804 stbi_inline static int stbi__bitreverse16(int n) 3805 { 3806 n = ((n & 0xAAAA) >> 1) | ((n & 0x5555) << 1); 3807 n = ((n & 0xCCCC) >> 2) | ((n & 0x3333) << 2); 3808 n = ((n & 0xF0F0) >> 4) | ((n & 0x0F0F) << 4); 3809 n = ((n & 0xFF00) >> 8) | ((n & 0x00FF) << 8); 3810 return n; 3811 } 3812 3813 stbi_inline static int stbi__bit_reverse(int v, int bits) 3814 { 3815 STBI_ASSERT(bits <= 16); 3816 // to bit reverse n bits, reverse 16 and shift 3817 // e.g. 11 bits, bit reverse and shift away 5 3818 return stbi__bitreverse16(v) >> (16-bits); 3819 } 3820 3821 static int stbi__zbuild_huffman(stbi__zhuffman *z, const stbi_uc *sizelist, int num) 3822 { 3823 int i,k=0; 3824 int code, next_code[16], sizes[17]; 3825 3826 // DEFLATE spec for generating codes 3827 memset(sizes, 0, sizeof(sizes)); 3828 memset(z->fast, 0, sizeof(z->fast)); 3829 for (i=0; i < num; ++i) 3830 ++sizes[sizelist[i]]; 3831 sizes[0] = 0; 3832 for (i=1; i < 16; ++i) 3833 if (sizes[i] > (1 << i)) 3834 return stbi__err("bad sizes", "Corrupt PNG"); 3835 code = 0; 3836 for (i=1; i < 16; ++i) { 3837 next_code[i] = code; 3838 z->firstcode[i] = (stbi__uint16) code; 3839 z->firstsymbol[i] = (stbi__uint16) k; 3840 code = (code + sizes[i]); 3841 if (sizes[i]) 3842 if (code-1 >= (1 << i)) return stbi__err("bad codelengths","Corrupt PNG"); 3843 z->maxcode[i] = code << (16-i); // preshift for inner loop 3844 code <<= 1; 3845 k += sizes[i]; 3846 } 3847 z->maxcode[16] = 0x10000; // sentinel 3848 for (i=0; i < num; ++i) { 3849 int s = sizelist[i]; 3850 if (s) { 3851 int c = next_code[s] - z->firstcode[s] + z->firstsymbol[s]; 3852 stbi__uint16 fastv = (stbi__uint16) ((s << 9) | i); 3853 z->size [c] = (stbi_uc ) s; 3854 z->value[c] = (stbi__uint16) i; 3855 if (s <= STBI__ZFAST_BITS) { 3856 int j = stbi__bit_reverse(next_code[s],s); 3857 while (j < (1 << STBI__ZFAST_BITS)) { 3858 z->fast[j] = fastv; 3859 j += (1 << s); 3860 } 3861 } 3862 ++next_code[s]; 3863 } 3864 } 3865 return 1; 3866 } 3867 3868 // zlib-from-memory implementation for PNG reading 3869 // because PNG allows splitting the zlib stream arbitrarily, 3870 // and it's annoying structurally to have PNG call ZLIB call PNG, 3871 // we require PNG read all the IDATs and combine them into a single 3872 // memory buffer 3873 3874 typedef struct 3875 { 3876 stbi_uc *zbuffer, *zbuffer_end; 3877 int num_bits; 3878 stbi__uint32 code_buffer; 3879 3880 char *zout; 3881 char *zout_start; 3882 char *zout_end; 3883 int z_expandable; 3884 3885 stbi__zhuffman z_length, z_distance; 3886 } stbi__zbuf; 3887 3888 stbi_inline static stbi_uc stbi__zget8(stbi__zbuf *z) 3889 { 3890 if (z->zbuffer >= z->zbuffer_end) return 0; 3891 return *z->zbuffer++; 3892 } 3893 3894 static void stbi__fill_bits(stbi__zbuf *z) 3895 { 3896 do { 3897 STBI_ASSERT(z->code_buffer < (1U << z->num_bits)); 3898 z->code_buffer |= (unsigned int) stbi__zget8(z) << z->num_bits; 3899 z->num_bits += 8; 3900 } while (z->num_bits <= 24); 3901 } 3902 3903 stbi_inline static unsigned int stbi__zreceive(stbi__zbuf *z, int n) 3904 { 3905 unsigned int k; 3906 if (z->num_bits < n) stbi__fill_bits(z); 3907 k = z->code_buffer & ((1 << n) - 1); 3908 z->code_buffer >>= n; 3909 z->num_bits -= n; 3910 return k; 3911 } 3912 3913 static int stbi__zhuffman_decode_slowpath(stbi__zbuf *a, stbi__zhuffman *z) 3914 { 3915 int b,s,k; 3916 // not resolved by fast table, so compute it the slow way 3917 // use jpeg approach, which requires MSbits at top 3918 k = stbi__bit_reverse(a->code_buffer, 16); 3919 for (s=STBI__ZFAST_BITS+1; ; ++s) 3920 if (k < z->maxcode[s]) 3921 break; 3922 if (s == 16) return -1; // invalid code! 3923 // code size is s, so: 3924 b = (k >> (16-s)) - z->firstcode[s] + z->firstsymbol[s]; 3925 STBI_ASSERT(z->size[b] == s); 3926 a->code_buffer >>= s; 3927 a->num_bits -= s; 3928 return z->value[b]; 3929 } 3930 3931 stbi_inline static int stbi__zhuffman_decode(stbi__zbuf *a, stbi__zhuffman *z) 3932 { 3933 int b,s; 3934 if (a->num_bits < 16) stbi__fill_bits(a); 3935 b = z->fast[a->code_buffer & STBI__ZFAST_MASK]; 3936 if (b) { 3937 s = b >> 9; 3938 a->code_buffer >>= s; 3939 a->num_bits -= s; 3940 return b & 511; 3941 } 3942 return stbi__zhuffman_decode_slowpath(a, z); 3943 } 3944 3945 static int stbi__zexpand(stbi__zbuf *z, char *zout, int n) // need to make room for n bytes 3946 { 3947 char *q; 3948 int cur, limit, old_limit; 3949 z->zout = zout; 3950 if (!z->z_expandable) return stbi__err("output buffer limit","Corrupt PNG"); 3951 cur = (int) (z->zout - z->zout_start); 3952 limit = old_limit = (int) (z->zout_end - z->zout_start); 3953 while (cur + n > limit) 3954 limit *= 2; 3955 q = (char *) STBI_REALLOC_SIZED(z->zout_start, old_limit, limit); 3956 STBI_NOTUSED(old_limit); 3957 if (q == NULL) return stbi__err("outofmem", "Out of memory"); 3958 z->zout_start = q; 3959 z->zout = q + cur; 3960 z->zout_end = q + limit; 3961 return 1; 3962 } 3963 3964 static const int stbi__zlength_base[31] = { 3965 3,4,5,6,7,8,9,10,11,13, 3966 15,17,19,23,27,31,35,43,51,59, 3967 67,83,99,115,131,163,195,227,258,0,0 }; 3968 3969 static const int stbi__zlength_extra[31]= 3970 { 0,0,0,0,0,0,0,0,1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5,0,0,0 }; 3971 3972 static const int stbi__zdist_base[32] = { 1,2,3,4,5,7,9,13,17,25,33,49,65,97,129,193, 3973 257,385,513,769,1025,1537,2049,3073,4097,6145,8193,12289,16385,24577,0,0}; 3974 3975 static const int stbi__zdist_extra[32] = 3976 { 0,0,0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13}; 3977 3978 static int stbi__parse_huffman_block(stbi__zbuf *a) 3979 { 3980 char *zout = a->zout; 3981 for(;;) { 3982 int z = stbi__zhuffman_decode(a, &a->z_length); 3983 if (z < 256) { 3984 if (z < 0) return stbi__err("bad huffman code","Corrupt PNG"); // error in huffman codes 3985 if (zout >= a->zout_end) { 3986 if (!stbi__zexpand(a, zout, 1)) return 0; 3987 zout = a->zout; 3988 } 3989 *zout++ = (char) z; 3990 } else { 3991 stbi_uc *p; 3992 int len,dist; 3993 if (z == 256) { 3994 a->zout = zout; 3995 return 1; 3996 } 3997 z -= 257; 3998 len = stbi__zlength_base[z]; 3999 if (stbi__zlength_extra[z]) len += stbi__zreceive(a, stbi__zlength_extra[z]); 4000 z = stbi__zhuffman_decode(a, &a->z_distance); 4001 if (z < 0) return stbi__err("bad huffman code","Corrupt PNG"); 4002 dist = stbi__zdist_base[z]; 4003 if (stbi__zdist_extra[z]) dist += stbi__zreceive(a, stbi__zdist_extra[z]); 4004 if (zout - a->zout_start < dist) return stbi__err("bad dist","Corrupt PNG"); 4005 if (zout + len > a->zout_end) { 4006 if (!stbi__zexpand(a, zout, len)) return 0; 4007 zout = a->zout; 4008 } 4009 p = (stbi_uc *) (zout - dist); 4010 if (dist == 1) { // run of one byte; common in images. 4011 stbi_uc v = *p; 4012 if (len) { do *zout++ = v; while (--len); } 4013 } else { 4014 if (len) { do *zout++ = *p++; while (--len); } 4015 } 4016 } 4017 } 4018 } 4019 4020 static int stbi__compute_huffman_codes(stbi__zbuf *a) 4021 { 4022 static const stbi_uc length_dezigzag[19] = { 16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15 }; 4023 stbi__zhuffman z_codelength; 4024 stbi_uc lencodes[286+32+137];//padding for maximum single op 4025 stbi_uc codelength_sizes[19]; 4026 int i,n; 4027 4028 int hlit = stbi__zreceive(a,5) + 257; 4029 int hdist = stbi__zreceive(a,5) + 1; 4030 int hclen = stbi__zreceive(a,4) + 4; 4031 int ntot = hlit + hdist; 4032 4033 memset(codelength_sizes, 0, sizeof(codelength_sizes)); 4034 for (i=0; i < hclen; ++i) { 4035 int s = stbi__zreceive(a,3); 4036 codelength_sizes[length_dezigzag[i]] = (stbi_uc) s; 4037 } 4038 if (!stbi__zbuild_huffman(&z_codelength, codelength_sizes, 19)) return 0; 4039 4040 n = 0; 4041 while (n < ntot) { 4042 int c = stbi__zhuffman_decode(a, &z_codelength); 4043 if (c < 0 || c >= 19) return stbi__err("bad codelengths", "Corrupt PNG"); 4044 if (c < 16) 4045 lencodes[n++] = (stbi_uc) c; 4046 else { 4047 stbi_uc fill = 0; 4048 if (c == 16) { 4049 c = stbi__zreceive(a,2)+3; 4050 if (n == 0) return stbi__err("bad codelengths", "Corrupt PNG"); 4051 fill = lencodes[n-1]; 4052 } else if (c == 17) 4053 c = stbi__zreceive(a,3)+3; 4054 else { 4055 STBI_ASSERT(c == 18); 4056 c = stbi__zreceive(a,7)+11; 4057 } 4058 if (ntot - n < c) return stbi__err("bad codelengths", "Corrupt PNG"); 4059 memset(lencodes+n, fill, c); 4060 n += c; 4061 } 4062 } 4063 if (n != ntot) return stbi__err("bad codelengths","Corrupt PNG"); 4064 if (!stbi__zbuild_huffman(&a->z_length, lencodes, hlit)) return 0; 4065 if (!stbi__zbuild_huffman(&a->z_distance, lencodes+hlit, hdist)) return 0; 4066 return 1; 4067 } 4068 4069 static int stbi__parse_uncompressed_block(stbi__zbuf *a) 4070 { 4071 stbi_uc header[4]; 4072 int len,nlen,k; 4073 if (a->num_bits & 7) 4074 stbi__zreceive(a, a->num_bits & 7); // discard 4075 // drain the bit-packed data into header 4076 k = 0; 4077 while (a->num_bits > 0) { 4078 header[k++] = (stbi_uc) (a->code_buffer & 255); // suppress MSVC run-time check 4079 a->code_buffer >>= 8; 4080 a->num_bits -= 8; 4081 } 4082 STBI_ASSERT(a->num_bits == 0); 4083 // now fill header the normal way 4084 while (k < 4) 4085 header[k++] = stbi__zget8(a); 4086 len = header[1] * 256 + header[0]; 4087 nlen = header[3] * 256 + header[2]; 4088 if (nlen != (len ^ 0xffff)) return stbi__err("zlib corrupt","Corrupt PNG"); 4089 if (a->zbuffer + len > a->zbuffer_end) return stbi__err("read past buffer","Corrupt PNG"); 4090 if (a->zout + len > a->zout_end) 4091 if (!stbi__zexpand(a, a->zout, len)) return 0; 4092 memcpy(a->zout, a->zbuffer, len); 4093 a->zbuffer += len; 4094 a->zout += len; 4095 return 1; 4096 } 4097 4098 static int stbi__parse_zlib_header(stbi__zbuf *a) 4099 { 4100 int cmf = stbi__zget8(a); 4101 int cm = cmf & 15; 4102 /* int cinfo = cmf >> 4; */ 4103 int flg = stbi__zget8(a); 4104 if ((cmf*256+flg) % 31 != 0) return stbi__err("bad zlib header","Corrupt PNG"); // zlib spec 4105 if (flg & 32) return stbi__err("no preset dict","Corrupt PNG"); // preset dictionary not allowed in png 4106 if (cm != 8) return stbi__err("bad compression","Corrupt PNG"); // DEFLATE required for png 4107 // window = 1 << (8 + cinfo)... but who cares, we fully buffer output 4108 return 1; 4109 } 4110 4111 static const stbi_uc stbi__zdefault_length[288] = 4112 { 4113 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, 4114 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, 4115 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, 4116 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, 4117 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, 4118 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, 4119 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, 4120 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, 4121 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, 7,7,7,7,7,7,7,7,8,8,8,8,8,8,8,8 4122 }; 4123 static const stbi_uc stbi__zdefault_distance[32] = 4124 { 4125 5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5 4126 }; 4127 /* 4128 Init algorithm: 4129 { 4130 int i; // use <= to match clearly with spec 4131 for (i=0; i <= 143; ++i) stbi__zdefault_length[i] = 8; 4132 for ( ; i <= 255; ++i) stbi__zdefault_length[i] = 9; 4133 for ( ; i <= 279; ++i) stbi__zdefault_length[i] = 7; 4134 for ( ; i <= 287; ++i) stbi__zdefault_length[i] = 8; 4135 4136 for (i=0; i <= 31; ++i) stbi__zdefault_distance[i] = 5; 4137 } 4138 */ 4139 4140 static int stbi__parse_zlib(stbi__zbuf *a, int parse_header) 4141 { 4142 int final, type; 4143 if (parse_header) 4144 if (!stbi__parse_zlib_header(a)) return 0; 4145 a->num_bits = 0; 4146 a->code_buffer = 0; 4147 do { 4148 final = stbi__zreceive(a,1); 4149 type = stbi__zreceive(a,2); 4150 if (type == 0) { 4151 if (!stbi__parse_uncompressed_block(a)) return 0; 4152 } else if (type == 3) { 4153 return 0; 4154 } else { 4155 if (type == 1) { 4156 // use fixed code lengths 4157 if (!stbi__zbuild_huffman(&a->z_length , stbi__zdefault_length , 288)) return 0; 4158 if (!stbi__zbuild_huffman(&a->z_distance, stbi__zdefault_distance, 32)) return 0; 4159 } else { 4160 if (!stbi__compute_huffman_codes(a)) return 0; 4161 } 4162 if (!stbi__parse_huffman_block(a)) return 0; 4163 } 4164 } while (!final); 4165 return 1; 4166 } 4167 4168 static int stbi__do_zlib(stbi__zbuf *a, char *obuf, int olen, int exp, int parse_header) 4169 { 4170 a->zout_start = obuf; 4171 a->zout = obuf; 4172 a->zout_end = obuf + olen; 4173 a->z_expandable = exp; 4174 4175 return stbi__parse_zlib(a, parse_header); 4176 } 4177 4178 STBIDEF char *stbi_zlib_decode_malloc_guesssize(const char *buffer, int len, int initial_size, int *outlen) 4179 { 4180 stbi__zbuf a; 4181 char *p = (char *) stbi__malloc(initial_size); 4182 if (p == NULL) return NULL; 4183 a.zbuffer = (stbi_uc *) buffer; 4184 a.zbuffer_end = (stbi_uc *) buffer + len; 4185 if (stbi__do_zlib(&a, p, initial_size, 1, 1)) { 4186 if (outlen) *outlen = (int) (a.zout - a.zout_start); 4187 return a.zout_start; 4188 } else { 4189 STBI_FREE(a.zout_start); 4190 return NULL; 4191 } 4192 } 4193 4194 STBIDEF char *stbi_zlib_decode_malloc(char const *buffer, int len, int *outlen) 4195 { 4196 return stbi_zlib_decode_malloc_guesssize(buffer, len, 16384, outlen); 4197 } 4198 4199 STBIDEF char *stbi_zlib_decode_malloc_guesssize_headerflag(const char *buffer, int len, int initial_size, int *outlen, int parse_header) 4200 { 4201 stbi__zbuf a; 4202 char *p = (char *) stbi__malloc(initial_size); 4203 if (p == NULL) return NULL; 4204 a.zbuffer = (stbi_uc *) buffer; 4205 a.zbuffer_end = (stbi_uc *) buffer + len; 4206 if (stbi__do_zlib(&a, p, initial_size, 1, parse_header)) { 4207 if (outlen) *outlen = (int) (a.zout - a.zout_start); 4208 return a.zout_start; 4209 } else { 4210 STBI_FREE(a.zout_start); 4211 return NULL; 4212 } 4213 } 4214 4215 STBIDEF int stbi_zlib_decode_buffer(char *obuffer, int olen, char const *ibuffer, int ilen) 4216 { 4217 stbi__zbuf a; 4218 a.zbuffer = (stbi_uc *) ibuffer; 4219 a.zbuffer_end = (stbi_uc *) ibuffer + ilen; 4220 if (stbi__do_zlib(&a, obuffer, olen, 0, 1)) 4221 return (int) (a.zout - a.zout_start); 4222 else 4223 return -1; 4224 } 4225 4226 STBIDEF char *stbi_zlib_decode_noheader_malloc(char const *buffer, int len, int *outlen) 4227 { 4228 stbi__zbuf a; 4229 char *p = (char *) stbi__malloc(16384); 4230 if (p == NULL) return NULL; 4231 a.zbuffer = (stbi_uc *) buffer; 4232 a.zbuffer_end = (stbi_uc *) buffer+len; 4233 if (stbi__do_zlib(&a, p, 16384, 1, 0)) { 4234 if (outlen) *outlen = (int) (a.zout - a.zout_start); 4235 return a.zout_start; 4236 } else { 4237 STBI_FREE(a.zout_start); 4238 return NULL; 4239 } 4240 } 4241 4242 STBIDEF int stbi_zlib_decode_noheader_buffer(char *obuffer, int olen, const char *ibuffer, int ilen) 4243 { 4244 stbi__zbuf a; 4245 a.zbuffer = (stbi_uc *) ibuffer; 4246 a.zbuffer_end = (stbi_uc *) ibuffer + ilen; 4247 if (stbi__do_zlib(&a, obuffer, olen, 0, 0)) 4248 return (int) (a.zout - a.zout_start); 4249 else 4250 return -1; 4251 } 4252 #endif 4253 4254 // public domain "baseline" PNG decoder v0.10 Sean Barrett 2006-11-18 4255 // simple implementation 4256 // - only 8-bit samples 4257 // - no CRC checking 4258 // - allocates lots of intermediate memory 4259 // - avoids problem of streaming data between subsystems 4260 // - avoids explicit window management 4261 // performance 4262 // - uses stb_zlib, a PD zlib implementation with fast huffman decoding 4263 4264 #ifndef STBI_NO_PNG 4265 typedef struct 4266 { 4267 stbi__uint32 length; 4268 stbi__uint32 type; 4269 } stbi__pngchunk; 4270 4271 static stbi__pngchunk stbi__get_chunk_header(stbi__context *s) 4272 { 4273 stbi__pngchunk c; 4274 c.length = stbi__get32be(s); 4275 c.type = stbi__get32be(s); 4276 return c; 4277 } 4278 4279 static int stbi__check_png_header(stbi__context *s) 4280 { 4281 static const stbi_uc png_sig[8] = { 137,80,78,71,13,10,26,10 }; 4282 int i; 4283 for (i=0; i < 8; ++i) 4284 if (stbi__get8(s) != png_sig[i]) return stbi__err("bad png sig","Not a PNG"); 4285 return 1; 4286 } 4287 4288 typedef struct 4289 { 4290 stbi__context *s; 4291 stbi_uc *idata, *expanded, *out; 4292 int depth; 4293 } stbi__png; 4294 4295 4296 enum { 4297 STBI__F_none=0, 4298 STBI__F_sub=1, 4299 STBI__F_up=2, 4300 STBI__F_avg=3, 4301 STBI__F_paeth=4, 4302 // synthetic filters used for first scanline to avoid needing a dummy row of 0s 4303 STBI__F_avg_first, 4304 STBI__F_paeth_first 4305 }; 4306 4307 static stbi_uc first_row_filter[5] = 4308 { 4309 STBI__F_none, 4310 STBI__F_sub, 4311 STBI__F_none, 4312 STBI__F_avg_first, 4313 STBI__F_paeth_first 4314 }; 4315 4316 static int stbi__paeth(int a, int b, int c) 4317 { 4318 int p = a + b - c; 4319 int pa = abs(p-a); 4320 int pb = abs(p-b); 4321 int pc = abs(p-c); 4322 if (pa <= pb && pa <= pc) return a; 4323 if (pb <= pc) return b; 4324 return c; 4325 } 4326 4327 static const stbi_uc stbi__depth_scale_table[9] = { 0, 0xff, 0x55, 0, 0x11, 0,0,0, 0x01 }; 4328 4329 // create the png data from post-deflated data 4330 static int stbi__create_png_image_raw(stbi__png *a, stbi_uc *raw, stbi__uint32 raw_len, int out_n, stbi__uint32 x, stbi__uint32 y, int depth, int color) 4331 { 4332 int bytes = (depth == 16? 2 : 1); 4333 stbi__context *s = a->s; 4334 stbi__uint32 i,j,stride = x*out_n*bytes; 4335 stbi__uint32 img_len, img_width_bytes; 4336 int k; 4337 int img_n = s->img_n; // copy it into a local for later 4338 4339 int output_bytes = out_n*bytes; 4340 int filter_bytes = img_n*bytes; 4341 int width = x; 4342 4343 STBI_ASSERT(out_n == s->img_n || out_n == s->img_n+1); 4344 a->out = (stbi_uc *) stbi__malloc_mad3(x, y, output_bytes, 0); // extra bytes to write off the end into 4345 if (!a->out) return stbi__err("outofmem", "Out of memory"); 4346 4347 if (!stbi__mad3sizes_valid(img_n, x, depth, 7)) return stbi__err("too large", "Corrupt PNG"); 4348 img_width_bytes = (((img_n * x * depth) + 7) >> 3); 4349 img_len = (img_width_bytes + 1) * y; 4350 4351 // we used to check for exact match between raw_len and img_len on non-interlaced PNGs, 4352 // but issue #276 reported a PNG in the wild that had extra data at the end (all zeros), 4353 // so just check for raw_len < img_len always. 4354 if (raw_len < img_len) return stbi__err("not enough pixels","Corrupt PNG"); 4355 4356 for (j=0; j < y; ++j) { 4357 stbi_uc *cur = a->out + stride*j; 4358 stbi_uc *prior; 4359 int filter = *raw++; 4360 4361 if (filter > 4) 4362 return stbi__err("invalid filter","Corrupt PNG"); 4363 4364 if (depth < 8) { 4365 STBI_ASSERT(img_width_bytes <= x); 4366 cur += x*out_n - img_width_bytes; // store output to the rightmost img_len bytes, so we can decode in place 4367 filter_bytes = 1; 4368 width = img_width_bytes; 4369 } 4370 prior = cur - stride; // bugfix: need to compute this after 'cur +=' computation above 4371 4372 // if first row, use special filter that doesn't sample previous row 4373 if (j == 0) filter = first_row_filter[filter]; 4374 4375 // handle first byte explicitly 4376 for (k=0; k < filter_bytes; ++k) { 4377 switch (filter) { 4378 case STBI__F_none : cur[k] = raw[k]; break; 4379 case STBI__F_sub : cur[k] = raw[k]; break; 4380 case STBI__F_up : cur[k] = STBI__BYTECAST(raw[k] + prior[k]); break; 4381 case STBI__F_avg : cur[k] = STBI__BYTECAST(raw[k] + (prior[k]>>1)); break; 4382 case STBI__F_paeth : cur[k] = STBI__BYTECAST(raw[k] + stbi__paeth(0,prior[k],0)); break; 4383 case STBI__F_avg_first : cur[k] = raw[k]; break; 4384 case STBI__F_paeth_first: cur[k] = raw[k]; break; 4385 } 4386 } 4387 4388 if (depth == 8) { 4389 if (img_n != out_n) 4390 cur[img_n] = 255; // first pixel 4391 raw += img_n; 4392 cur += out_n; 4393 prior += out_n; 4394 } else if (depth == 16) { 4395 if (img_n != out_n) { 4396 cur[filter_bytes] = 255; // first pixel top byte 4397 cur[filter_bytes+1] = 255; // first pixel bottom byte 4398 } 4399 raw += filter_bytes; 4400 cur += output_bytes; 4401 prior += output_bytes; 4402 } else { 4403 raw += 1; 4404 cur += 1; 4405 prior += 1; 4406 } 4407 4408 // this is a little gross, so that we don't switch per-pixel or per-component 4409 if (depth < 8 || img_n == out_n) { 4410 int nk = (width - 1)*filter_bytes; 4411 #define STBI__CASE(f) \ 4412 case f: \ 4413 for (k=0; k < nk; ++k) 4414 switch (filter) { 4415 // "none" filter turns into a memcpy here; make that explicit. 4416 case STBI__F_none: memcpy(cur, raw, nk); break; 4417 STBI__CASE(STBI__F_sub) { cur[k] = STBI__BYTECAST(raw[k] + cur[k-filter_bytes]); } break; 4418 STBI__CASE(STBI__F_up) { cur[k] = STBI__BYTECAST(raw[k] + prior[k]); } break; 4419 STBI__CASE(STBI__F_avg) { cur[k] = STBI__BYTECAST(raw[k] + ((prior[k] + cur[k-filter_bytes])>>1)); } break; 4420 STBI__CASE(STBI__F_paeth) { cur[k] = STBI__BYTECAST(raw[k] + stbi__paeth(cur[k-filter_bytes],prior[k],prior[k-filter_bytes])); } break; 4421 STBI__CASE(STBI__F_avg_first) { cur[k] = STBI__BYTECAST(raw[k] + (cur[k-filter_bytes] >> 1)); } break; 4422 STBI__CASE(STBI__F_paeth_first) { cur[k] = STBI__BYTECAST(raw[k] + stbi__paeth(cur[k-filter_bytes],0,0)); } break; 4423 } 4424 #undef STBI__CASE 4425 raw += nk; 4426 } else { 4427 STBI_ASSERT(img_n+1 == out_n); 4428 #define STBI__CASE(f) \ 4429 case f: \ 4430 for (i=x-1; i >= 1; --i, cur[filter_bytes]=255,raw+=filter_bytes,cur+=output_bytes,prior+=output_bytes) \ 4431 for (k=0; k < filter_bytes; ++k) 4432 switch (filter) { 4433 STBI__CASE(STBI__F_none) { cur[k] = raw[k]; } break; 4434 STBI__CASE(STBI__F_sub) { cur[k] = STBI__BYTECAST(raw[k] + cur[k- output_bytes]); } break; 4435 STBI__CASE(STBI__F_up) { cur[k] = STBI__BYTECAST(raw[k] + prior[k]); } break; 4436 STBI__CASE(STBI__F_avg) { cur[k] = STBI__BYTECAST(raw[k] + ((prior[k] + cur[k- output_bytes])>>1)); } break; 4437 STBI__CASE(STBI__F_paeth) { cur[k] = STBI__BYTECAST(raw[k] + stbi__paeth(cur[k- output_bytes],prior[k],prior[k- output_bytes])); } break; 4438 STBI__CASE(STBI__F_avg_first) { cur[k] = STBI__BYTECAST(raw[k] + (cur[k- output_bytes] >> 1)); } break; 4439 STBI__CASE(STBI__F_paeth_first) { cur[k] = STBI__BYTECAST(raw[k] + stbi__paeth(cur[k- output_bytes],0,0)); } break; 4440 } 4441 #undef STBI__CASE 4442 4443 // the loop above sets the high byte of the pixels' alpha, but for 4444 // 16 bit png files we also need the low byte set. we'll do that here. 4445 if (depth == 16) { 4446 cur = a->out + stride*j; // start at the beginning of the row again 4447 for (i=0; i < x; ++i,cur+=output_bytes) { 4448 cur[filter_bytes+1] = 255; 4449 } 4450 } 4451 } 4452 } 4453 4454 // we make a separate pass to expand bits to pixels; for performance, 4455 // this could run two scanlines behind the above code, so it won't 4456 // intefere with filtering but will still be in the cache. 4457 if (depth < 8) { 4458 for (j=0; j < y; ++j) { 4459 stbi_uc *cur = a->out + stride*j; 4460 stbi_uc *in = a->out + stride*j + x*out_n - img_width_bytes; 4461 // unpack 1/2/4-bit into a 8-bit buffer. allows us to keep the common 8-bit path optimal at minimal cost for 1/2/4-bit 4462 // png guarante byte alignment, if width is not multiple of 8/4/2 we'll decode dummy trailing data that will be skipped in the later loop 4463 stbi_uc scale = (color == 0) ? stbi__depth_scale_table[depth] : 1; // scale grayscale values to 0..255 range 4464 4465 // note that the final byte might overshoot and write more data than desired. 4466 // we can allocate enough data that this never writes out of memory, but it 4467 // could also overwrite the next scanline. can it overwrite non-empty data 4468 // on the next scanline? yes, consider 1-pixel-wide scanlines with 1-bit-per-pixel. 4469 // so we need to explicitly clamp the final ones 4470 4471 if (depth == 4) { 4472 for (k=x*img_n; k >= 2; k-=2, ++in) { 4473 *cur++ = scale * ((*in >> 4) ); 4474 *cur++ = scale * ((*in ) & 0x0f); 4475 } 4476 if (k > 0) *cur++ = scale * ((*in >> 4) ); 4477 } else if (depth == 2) { 4478 for (k=x*img_n; k >= 4; k-=4, ++in) { 4479 *cur++ = scale * ((*in >> 6) ); 4480 *cur++ = scale * ((*in >> 4) & 0x03); 4481 *cur++ = scale * ((*in >> 2) & 0x03); 4482 *cur++ = scale * ((*in ) & 0x03); 4483 } 4484 if (k > 0) *cur++ = scale * ((*in >> 6) ); 4485 if (k > 1) *cur++ = scale * ((*in >> 4) & 0x03); 4486 if (k > 2) *cur++ = scale * ((*in >> 2) & 0x03); 4487 } else if (depth == 1) { 4488 for (k=x*img_n; k >= 8; k-=8, ++in) { 4489 *cur++ = scale * ((*in >> 7) ); 4490 *cur++ = scale * ((*in >> 6) & 0x01); 4491 *cur++ = scale * ((*in >> 5) & 0x01); 4492 *cur++ = scale * ((*in >> 4) & 0x01); 4493 *cur++ = scale * ((*in >> 3) & 0x01); 4494 *cur++ = scale * ((*in >> 2) & 0x01); 4495 *cur++ = scale * ((*in >> 1) & 0x01); 4496 *cur++ = scale * ((*in ) & 0x01); 4497 } 4498 if (k > 0) *cur++ = scale * ((*in >> 7) ); 4499 if (k > 1) *cur++ = scale * ((*in >> 6) & 0x01); 4500 if (k > 2) *cur++ = scale * ((*in >> 5) & 0x01); 4501 if (k > 3) *cur++ = scale * ((*in >> 4) & 0x01); 4502 if (k > 4) *cur++ = scale * ((*in >> 3) & 0x01); 4503 if (k > 5) *cur++ = scale * ((*in >> 2) & 0x01); 4504 if (k > 6) *cur++ = scale * ((*in >> 1) & 0x01); 4505 } 4506 if (img_n != out_n) { 4507 int q; 4508 // insert alpha = 255 4509 cur = a->out + stride*j; 4510 if (img_n == 1) { 4511 for (q=x-1; q >= 0; --q) { 4512 cur[q*2+1] = 255; 4513 cur[q*2+0] = cur[q]; 4514 } 4515 } else { 4516 STBI_ASSERT(img_n == 3); 4517 for (q=x-1; q >= 0; --q) { 4518 cur[q*4+3] = 255; 4519 cur[q*4+2] = cur[q*3+2]; 4520 cur[q*4+1] = cur[q*3+1]; 4521 cur[q*4+0] = cur[q*3+0]; 4522 } 4523 } 4524 } 4525 } 4526 } else if (depth == 16) { 4527 // force the image data from big-endian to platform-native. 4528 // this is done in a separate pass due to the decoding relying 4529 // on the data being untouched, but could probably be done 4530 // per-line during decode if care is taken. 4531 stbi_uc *cur = a->out; 4532 stbi__uint16 *cur16 = (stbi__uint16*)cur; 4533 4534 for(i=0; i < x*y*out_n; ++i,cur16++,cur+=2) { 4535 *cur16 = (cur[0] << 8) | cur[1]; 4536 } 4537 } 4538 4539 return 1; 4540 } 4541 4542 static int stbi__create_png_image(stbi__png *a, stbi_uc *image_data, stbi__uint32 image_data_len, int out_n, int depth, int color, int interlaced) 4543 { 4544 int bytes = (depth == 16 ? 2 : 1); 4545 int out_bytes = out_n * bytes; 4546 stbi_uc *final; 4547 int p; 4548 if (!interlaced) 4549 return stbi__create_png_image_raw(a, image_data, image_data_len, out_n, a->s->img_x, a->s->img_y, depth, color); 4550 4551 // de-interlacing 4552 final = (stbi_uc *) stbi__malloc_mad3(a->s->img_x, a->s->img_y, out_bytes, 0); 4553 for (p=0; p < 7; ++p) { 4554 int xorig[] = { 0,4,0,2,0,1,0 }; 4555 int yorig[] = { 0,0,4,0,2,0,1 }; 4556 int xspc[] = { 8,8,4,4,2,2,1 }; 4557 int yspc[] = { 8,8,8,4,4,2,2 }; 4558 int i,j,x,y; 4559 // pass1_x[4] = 0, pass1_x[5] = 1, pass1_x[12] = 1 4560 x = (a->s->img_x - xorig[p] + xspc[p]-1) / xspc[p]; 4561 y = (a->s->img_y - yorig[p] + yspc[p]-1) / yspc[p]; 4562 if (x && y) { 4563 stbi__uint32 img_len = ((((a->s->img_n * x * depth) + 7) >> 3) + 1) * y; 4564 if (!stbi__create_png_image_raw(a, image_data, image_data_len, out_n, x, y, depth, color)) { 4565 STBI_FREE(final); 4566 return 0; 4567 } 4568 for (j=0; j < y; ++j) { 4569 for (i=0; i < x; ++i) { 4570 int out_y = j*yspc[p]+yorig[p]; 4571 int out_x = i*xspc[p]+xorig[p]; 4572 memcpy(final + out_y*a->s->img_x*out_bytes + out_x*out_bytes, 4573 a->out + (j*x+i)*out_bytes, out_bytes); 4574 } 4575 } 4576 STBI_FREE(a->out); 4577 image_data += img_len; 4578 image_data_len -= img_len; 4579 } 4580 } 4581 a->out = final; 4582 4583 return 1; 4584 } 4585 4586 static int stbi__compute_transparency(stbi__png *z, stbi_uc tc[3], int out_n) 4587 { 4588 stbi__context *s = z->s; 4589 stbi__uint32 i, pixel_count = s->img_x * s->img_y; 4590 stbi_uc *p = z->out; 4591 4592 // compute color-based transparency, assuming we've 4593 // already got 255 as the alpha value in the output 4594 STBI_ASSERT(out_n == 2 || out_n == 4); 4595 4596 if (out_n == 2) { 4597 for (i=0; i < pixel_count; ++i) { 4598 p[1] = (p[0] == tc[0] ? 0 : 255); 4599 p += 2; 4600 } 4601 } else { 4602 for (i=0; i < pixel_count; ++i) { 4603 if (p[0] == tc[0] && p[1] == tc[1] && p[2] == tc[2]) 4604 p[3] = 0; 4605 p += 4; 4606 } 4607 } 4608 return 1; 4609 } 4610 4611 static int stbi__compute_transparency16(stbi__png *z, stbi__uint16 tc[3], int out_n) 4612 { 4613 stbi__context *s = z->s; 4614 stbi__uint32 i, pixel_count = s->img_x * s->img_y; 4615 stbi__uint16 *p = (stbi__uint16*) z->out; 4616 4617 // compute color-based transparency, assuming we've 4618 // already got 65535 as the alpha value in the output 4619 STBI_ASSERT(out_n == 2 || out_n == 4); 4620 4621 if (out_n == 2) { 4622 for (i = 0; i < pixel_count; ++i) { 4623 p[1] = (p[0] == tc[0] ? 0 : 65535); 4624 p += 2; 4625 } 4626 } else { 4627 for (i = 0; i < pixel_count; ++i) { 4628 if (p[0] == tc[0] && p[1] == tc[1] && p[2] == tc[2]) 4629 p[3] = 0; 4630 p += 4; 4631 } 4632 } 4633 return 1; 4634 } 4635 4636 static int stbi__expand_png_palette(stbi__png *a, stbi_uc *palette, int len, int pal_img_n) 4637 { 4638 stbi__uint32 i, pixel_count = a->s->img_x * a->s->img_y; 4639 stbi_uc *p, *temp_out, *orig = a->out; 4640 4641 p = (stbi_uc *) stbi__malloc_mad2(pixel_count, pal_img_n, 0); 4642 if (p == NULL) return stbi__err("outofmem", "Out of memory"); 4643 4644 // between here and free(out) below, exitting would leak 4645 temp_out = p; 4646 4647 if (pal_img_n == 3) { 4648 for (i=0; i < pixel_count; ++i) { 4649 int n = orig[i]*4; 4650 p[0] = palette[n ]; 4651 p[1] = palette[n+1]; 4652 p[2] = palette[n+2]; 4653 p += 3; 4654 } 4655 } else { 4656 for (i=0; i < pixel_count; ++i) { 4657 int n = orig[i]*4; 4658 p[0] = palette[n ]; 4659 p[1] = palette[n+1]; 4660 p[2] = palette[n+2]; 4661 p[3] = palette[n+3]; 4662 p += 4; 4663 } 4664 } 4665 STBI_FREE(a->out); 4666 a->out = temp_out; 4667 4668 STBI_NOTUSED(len); 4669 4670 return 1; 4671 } 4672 4673 static int stbi__unpremultiply_on_load = 0; 4674 static int stbi__de_iphone_flag = 0; 4675 4676 STBIDEF void stbi_set_unpremultiply_on_load(int flag_true_if_should_unpremultiply) 4677 { 4678 stbi__unpremultiply_on_load = flag_true_if_should_unpremultiply; 4679 } 4680 4681 STBIDEF void stbi_convert_iphone_png_to_rgb(int flag_true_if_should_convert) 4682 { 4683 stbi__de_iphone_flag = flag_true_if_should_convert; 4684 } 4685 4686 static void stbi__de_iphone(stbi__png *z) 4687 { 4688 stbi__context *s = z->s; 4689 stbi__uint32 i, pixel_count = s->img_x * s->img_y; 4690 stbi_uc *p = z->out; 4691 4692 if (s->img_out_n == 3) { // convert bgr to rgb 4693 for (i=0; i < pixel_count; ++i) { 4694 stbi_uc t = p[0]; 4695 p[0] = p[2]; 4696 p[2] = t; 4697 p += 3; 4698 } 4699 } else { 4700 STBI_ASSERT(s->img_out_n == 4); 4701 if (stbi__unpremultiply_on_load) { 4702 // convert bgr to rgb and unpremultiply 4703 for (i=0; i < pixel_count; ++i) { 4704 stbi_uc a = p[3]; 4705 stbi_uc t = p[0]; 4706 if (a) { 4707 stbi_uc half = a / 2; 4708 p[0] = (p[2] * 255 + half) / a; 4709 p[1] = (p[1] * 255 + half) / a; 4710 p[2] = ( t * 255 + half) / a; 4711 } else { 4712 p[0] = p[2]; 4713 p[2] = t; 4714 } 4715 p += 4; 4716 } 4717 } else { 4718 // convert bgr to rgb 4719 for (i=0; i < pixel_count; ++i) { 4720 stbi_uc t = p[0]; 4721 p[0] = p[2]; 4722 p[2] = t; 4723 p += 4; 4724 } 4725 } 4726 } 4727 } 4728 4729 #define STBI__PNG_TYPE(a,b,c,d) (((unsigned) (a) << 24) + ((unsigned) (b) << 16) + ((unsigned) (c) << 8) + (unsigned) (d)) 4730 4731 static int stbi__parse_png_file(stbi__png *z, int scan, int req_comp) 4732 { 4733 stbi_uc palette[1024], pal_img_n=0; 4734 stbi_uc has_trans=0, tc[3]; 4735 stbi__uint16 tc16[3]; 4736 stbi__uint32 ioff=0, idata_limit=0, i, pal_len=0; 4737 int first=1,k,interlace=0, color=0, is_iphone=0; 4738 stbi__context *s = z->s; 4739 4740 z->expanded = NULL; 4741 z->idata = NULL; 4742 z->out = NULL; 4743 4744 if (!stbi__check_png_header(s)) return 0; 4745 4746 if (scan == STBI__SCAN_type) return 1; 4747 4748 for (;;) { 4749 stbi__pngchunk c = stbi__get_chunk_header(s); 4750 switch (c.type) { 4751 case STBI__PNG_TYPE('C','g','B','I'): 4752 is_iphone = 1; 4753 stbi__skip(s, c.length); 4754 break; 4755 case STBI__PNG_TYPE('I','H','D','R'): { 4756 int comp,filter; 4757 if (!first) return stbi__err("multiple IHDR","Corrupt PNG"); 4758 first = 0; 4759 if (c.length != 13) return stbi__err("bad IHDR len","Corrupt PNG"); 4760 s->img_x = stbi__get32be(s); if (s->img_x > (1 << 24)) return stbi__err("too large","Very large image (corrupt?)"); 4761 s->img_y = stbi__get32be(s); if (s->img_y > (1 << 24)) return stbi__err("too large","Very large image (corrupt?)"); 4762 z->depth = stbi__get8(s); if (z->depth != 1 && z->depth != 2 && z->depth != 4 && z->depth != 8 && z->depth != 16) return stbi__err("1/2/4/8/16-bit only","PNG not supported: 1/2/4/8/16-bit only"); 4763 color = stbi__get8(s); if (color > 6) return stbi__err("bad ctype","Corrupt PNG"); 4764 if (color == 3 && z->depth == 16) return stbi__err("bad ctype","Corrupt PNG"); 4765 if (color == 3) pal_img_n = 3; else if (color & 1) return stbi__err("bad ctype","Corrupt PNG"); 4766 comp = stbi__get8(s); if (comp) return stbi__err("bad comp method","Corrupt PNG"); 4767 filter= stbi__get8(s); if (filter) return stbi__err("bad filter method","Corrupt PNG"); 4768 interlace = stbi__get8(s); if (interlace>1) return stbi__err("bad interlace method","Corrupt PNG"); 4769 if (!s->img_x || !s->img_y) return stbi__err("0-pixel image","Corrupt PNG"); 4770 if (!pal_img_n) { 4771 s->img_n = (color & 2 ? 3 : 1) + (color & 4 ? 1 : 0); 4772 if ((1 << 30) / s->img_x / s->img_n < s->img_y) return stbi__err("too large", "Image too large to decode"); 4773 if (scan == STBI__SCAN_header) return 1; 4774 } else { 4775 // if paletted, then pal_n is our final components, and 4776 // img_n is # components to decompress/filter. 4777 s->img_n = 1; 4778 if ((1 << 30) / s->img_x / 4 < s->img_y) return stbi__err("too large","Corrupt PNG"); 4779 // if SCAN_header, have to scan to see if we have a tRNS 4780 } 4781 break; 4782 } 4783 4784 case STBI__PNG_TYPE('P','L','T','E'): { 4785 if (first) return stbi__err("first not IHDR", "Corrupt PNG"); 4786 if (c.length > 256*3) return stbi__err("invalid PLTE","Corrupt PNG"); 4787 pal_len = c.length / 3; 4788 if (pal_len * 3 != c.length) return stbi__err("invalid PLTE","Corrupt PNG"); 4789 for (i=0; i < pal_len; ++i) { 4790 palette[i*4+0] = stbi__get8(s); 4791 palette[i*4+1] = stbi__get8(s); 4792 palette[i*4+2] = stbi__get8(s); 4793 palette[i*4+3] = 255; 4794 } 4795 break; 4796 } 4797 4798 case STBI__PNG_TYPE('t','R','N','S'): { 4799 if (first) return stbi__err("first not IHDR", "Corrupt PNG"); 4800 if (z->idata) return stbi__err("tRNS after IDAT","Corrupt PNG"); 4801 if (pal_img_n) { 4802 if (scan == STBI__SCAN_header) { s->img_n = 4; return 1; } 4803 if (pal_len == 0) return stbi__err("tRNS before PLTE","Corrupt PNG"); 4804 if (c.length > pal_len) return stbi__err("bad tRNS len","Corrupt PNG"); 4805 pal_img_n = 4; 4806 for (i=0; i < c.length; ++i) 4807 palette[i*4+3] = stbi__get8(s); 4808 } else { 4809 if (!(s->img_n & 1)) return stbi__err("tRNS with alpha","Corrupt PNG"); 4810 if (c.length != (stbi__uint32) s->img_n*2) return stbi__err("bad tRNS len","Corrupt PNG"); 4811 has_trans = 1; 4812 if (z->depth == 16) { 4813 for (k = 0; k < s->img_n; ++k) tc16[k] = (stbi__uint16)stbi__get16be(s); // copy the values as-is 4814 } else { 4815 for (k = 0; k < s->img_n; ++k) tc[k] = (stbi_uc)(stbi__get16be(s) & 255) * stbi__depth_scale_table[z->depth]; // non 8-bit images will be larger 4816 } 4817 } 4818 break; 4819 } 4820 4821 case STBI__PNG_TYPE('I','D','A','T'): { 4822 if (first) return stbi__err("first not IHDR", "Corrupt PNG"); 4823 if (pal_img_n && !pal_len) return stbi__err("no PLTE","Corrupt PNG"); 4824 if (scan == STBI__SCAN_header) { s->img_n = pal_img_n; return 1; } 4825 if ((int)(ioff + c.length) < (int)ioff) return 0; 4826 if (ioff + c.length > idata_limit) { 4827 stbi__uint32 idata_limit_old = idata_limit; 4828 stbi_uc *p; 4829 if (idata_limit == 0) idata_limit = c.length > 4096 ? c.length : 4096; 4830 while (ioff + c.length > idata_limit) 4831 idata_limit *= 2; 4832 STBI_NOTUSED(idata_limit_old); 4833 p = (stbi_uc *) STBI_REALLOC_SIZED(z->idata, idata_limit_old, idata_limit); if (p == NULL) return stbi__err("outofmem", "Out of memory"); 4834 z->idata = p; 4835 } 4836 if (!stbi__getn(s, z->idata+ioff,c.length)) return stbi__err("outofdata","Corrupt PNG"); 4837 ioff += c.length; 4838 break; 4839 } 4840 4841 case STBI__PNG_TYPE('I','E','N','D'): { 4842 stbi__uint32 raw_len, bpl; 4843 if (first) return stbi__err("first not IHDR", "Corrupt PNG"); 4844 if (scan != STBI__SCAN_load) return 1; 4845 if (z->idata == NULL) return stbi__err("no IDAT","Corrupt PNG"); 4846 // initial guess for decoded data size to avoid unnecessary reallocs 4847 bpl = (s->img_x * z->depth + 7) / 8; // bytes per line, per component 4848 raw_len = bpl * s->img_y * s->img_n /* pixels */ + s->img_y /* filter mode per row */; 4849 z->expanded = (stbi_uc *) stbi_zlib_decode_malloc_guesssize_headerflag((char *) z->idata, ioff, raw_len, (int *) &raw_len, !is_iphone); 4850 if (z->expanded == NULL) return 0; // zlib should set error 4851 STBI_FREE(z->idata); z->idata = NULL; 4852 if ((req_comp == s->img_n+1 && req_comp != 3 && !pal_img_n) || has_trans) 4853 s->img_out_n = s->img_n+1; 4854 else 4855 s->img_out_n = s->img_n; 4856 if (!stbi__create_png_image(z, z->expanded, raw_len, s->img_out_n, z->depth, color, interlace)) return 0; 4857 if (has_trans) { 4858 if (z->depth == 16) { 4859 if (!stbi__compute_transparency16(z, tc16, s->img_out_n)) return 0; 4860 } else { 4861 if (!stbi__compute_transparency(z, tc, s->img_out_n)) return 0; 4862 } 4863 } 4864 if (is_iphone && stbi__de_iphone_flag && s->img_out_n > 2) 4865 stbi__de_iphone(z); 4866 if (pal_img_n) { 4867 // pal_img_n == 3 or 4 4868 s->img_n = pal_img_n; // record the actual colors we had 4869 s->img_out_n = pal_img_n; 4870 if (req_comp >= 3) s->img_out_n = req_comp; 4871 if (!stbi__expand_png_palette(z, palette, pal_len, s->img_out_n)) 4872 return 0; 4873 } else if (has_trans) { 4874 // non-paletted image with tRNS -> source image has (constant) alpha 4875 ++s->img_n; 4876 } 4877 STBI_FREE(z->expanded); z->expanded = NULL; 4878 return 1; 4879 } 4880 4881 default: 4882 // if critical, fail 4883 if (first) return stbi__err("first not IHDR", "Corrupt PNG"); 4884 if ((c.type & (1 << 29)) == 0) { 4885 #ifndef STBI_NO_FAILURE_STRINGS 4886 // not threadsafe 4887 static char invalid_chunk[] = "XXXX PNG chunk not known"; 4888 invalid_chunk[0] = STBI__BYTECAST(c.type >> 24); 4889 invalid_chunk[1] = STBI__BYTECAST(c.type >> 16); 4890 invalid_chunk[2] = STBI__BYTECAST(c.type >> 8); 4891 invalid_chunk[3] = STBI__BYTECAST(c.type >> 0); 4892 #endif 4893 return stbi__err(invalid_chunk, "PNG not supported: unknown PNG chunk type"); 4894 } 4895 stbi__skip(s, c.length); 4896 break; 4897 } 4898 // end of PNG chunk, read and skip CRC 4899 stbi__get32be(s); 4900 } 4901 } 4902 4903 static void *stbi__do_png(stbi__png *p, int *x, int *y, int *n, int req_comp, stbi__result_info *ri) 4904 { 4905 void *result=NULL; 4906 if (req_comp < 0 || req_comp > 4) return stbi__errpuc("bad req_comp", "Internal error"); 4907 if (stbi__parse_png_file(p, STBI__SCAN_load, req_comp)) { 4908 if (p->depth < 8) 4909 ri->bits_per_channel = 8; 4910 else 4911 ri->bits_per_channel = p->depth; 4912 result = p->out; 4913 p->out = NULL; 4914 if (req_comp && req_comp != p->s->img_out_n) { 4915 if (ri->bits_per_channel == 8) 4916 result = stbi__convert_format((unsigned char *) result, p->s->img_out_n, req_comp, p->s->img_x, p->s->img_y); 4917 else 4918 result = stbi__convert_format16((stbi__uint16 *) result, p->s->img_out_n, req_comp, p->s->img_x, p->s->img_y); 4919 p->s->img_out_n = req_comp; 4920 if (result == NULL) return result; 4921 } 4922 *x = p->s->img_x; 4923 *y = p->s->img_y; 4924 if (n) *n = p->s->img_n; 4925 } 4926 STBI_FREE(p->out); p->out = NULL; 4927 STBI_FREE(p->expanded); p->expanded = NULL; 4928 STBI_FREE(p->idata); p->idata = NULL; 4929 4930 return result; 4931 } 4932 4933 static void *stbi__png_load(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri) 4934 { 4935 stbi__png p; 4936 p.s = s; 4937 return stbi__do_png(&p, x,y,comp,req_comp, ri); 4938 } 4939 4940 static int stbi__png_test(stbi__context *s) 4941 { 4942 int r; 4943 r = stbi__check_png_header(s); 4944 stbi__rewind(s); 4945 return r; 4946 } 4947 4948 static int stbi__png_info_raw(stbi__png *p, int *x, int *y, int *comp) 4949 { 4950 if (!stbi__parse_png_file(p, STBI__SCAN_header, 0)) { 4951 stbi__rewind( p->s ); 4952 return 0; 4953 } 4954 if (x) *x = p->s->img_x; 4955 if (y) *y = p->s->img_y; 4956 if (comp) *comp = p->s->img_n; 4957 return 1; 4958 } 4959 4960 static int stbi__png_info(stbi__context *s, int *x, int *y, int *comp) 4961 { 4962 stbi__png p; 4963 p.s = s; 4964 return stbi__png_info_raw(&p, x, y, comp); 4965 } 4966 4967 static int stbi__png_is16(stbi__context *s) 4968 { 4969 stbi__png p; 4970 p.s = s; 4971 if (!stbi__png_info_raw(&p, NULL, NULL, NULL)) 4972 return 0; 4973 if (p.depth != 16) { 4974 stbi__rewind(p.s); 4975 return 0; 4976 } 4977 return 1; 4978 } 4979 #endif 4980 4981 // Microsoft/Windows BMP image 4982 4983 #ifndef STBI_NO_BMP 4984 static int stbi__bmp_test_raw(stbi__context *s) 4985 { 4986 int r; 4987 int sz; 4988 if (stbi__get8(s) != 'B') return 0; 4989 if (stbi__get8(s) != 'M') return 0; 4990 stbi__get32le(s); // discard filesize 4991 stbi__get16le(s); // discard reserved 4992 stbi__get16le(s); // discard reserved 4993 stbi__get32le(s); // discard data offset 4994 sz = stbi__get32le(s); 4995 r = (sz == 12 || sz == 40 || sz == 56 || sz == 108 || sz == 124); 4996 return r; 4997 } 4998 4999 static int stbi__bmp_test(stbi__context *s) 5000 { 5001 int r = stbi__bmp_test_raw(s); 5002 stbi__rewind(s); 5003 return r; 5004 } 5005 5006 5007 // returns 0..31 for the highest set bit 5008 static int stbi__high_bit(unsigned int z) 5009 { 5010 int n=0; 5011 if (z == 0) return -1; 5012 if (z >= 0x10000) n += 16, z >>= 16; 5013 if (z >= 0x00100) n += 8, z >>= 8; 5014 if (z >= 0x00010) n += 4, z >>= 4; 5015 if (z >= 0x00004) n += 2, z >>= 2; 5016 if (z >= 0x00002) n += 1, z >>= 1; 5017 return n; 5018 } 5019 5020 static int stbi__bitcount(unsigned int a) 5021 { 5022 a = (a & 0x55555555) + ((a >> 1) & 0x55555555); // max 2 5023 a = (a & 0x33333333) + ((a >> 2) & 0x33333333); // max 4 5024 a = (a + (a >> 4)) & 0x0f0f0f0f; // max 8 per 4, now 8 bits 5025 a = (a + (a >> 8)); // max 16 per 8 bits 5026 a = (a + (a >> 16)); // max 32 per 8 bits 5027 return a & 0xff; 5028 } 5029 5030 // extract an arbitrarily-aligned N-bit value (N=bits) 5031 // from v, and then make it 8-bits long and fractionally 5032 // extend it to full full range. 5033 static int stbi__shiftsigned(int v, int shift, int bits) 5034 { 5035 static unsigned int mul_table[9] = { 5036 0, 5037 0xff/*0b11111111*/, 0x55/*0b01010101*/, 0x49/*0b01001001*/, 0x11/*0b00010001*/, 5038 0x21/*0b00100001*/, 0x41/*0b01000001*/, 0x81/*0b10000001*/, 0x01/*0b00000001*/, 5039 }; 5040 static unsigned int shift_table[9] = { 5041 0, 0,0,1,0,2,4,6,0, 5042 }; 5043 if (shift < 0) 5044 v <<= -shift; 5045 else 5046 v >>= shift; 5047 STBI_ASSERT(v >= 0 && v < 256); 5048 v >>= (8-bits); 5049 STBI_ASSERT(bits >= 0 && bits <= 8); 5050 return (int) ((unsigned) v * mul_table[bits]) >> shift_table[bits]; 5051 } 5052 5053 typedef struct 5054 { 5055 int bpp, offset, hsz; 5056 unsigned int mr,mg,mb,ma, all_a; 5057 } stbi__bmp_data; 5058 5059 static void *stbi__bmp_parse_header(stbi__context *s, stbi__bmp_data *info) 5060 { 5061 int hsz; 5062 if (stbi__get8(s) != 'B' || stbi__get8(s) != 'M') return stbi__errpuc("not BMP", "Corrupt BMP"); 5063 stbi__get32le(s); // discard filesize 5064 stbi__get16le(s); // discard reserved 5065 stbi__get16le(s); // discard reserved 5066 info->offset = stbi__get32le(s); 5067 info->hsz = hsz = stbi__get32le(s); 5068 info->mr = info->mg = info->mb = info->ma = 0; 5069 5070 if (hsz != 12 && hsz != 40 && hsz != 56 && hsz != 108 && hsz != 124) return stbi__errpuc("unknown BMP", "BMP type not supported: unknown"); 5071 if (hsz == 12) { 5072 s->img_x = stbi__get16le(s); 5073 s->img_y = stbi__get16le(s); 5074 } else { 5075 s->img_x = stbi__get32le(s); 5076 s->img_y = stbi__get32le(s); 5077 } 5078 if (stbi__get16le(s) != 1) return stbi__errpuc("bad BMP", "bad BMP"); 5079 info->bpp = stbi__get16le(s); 5080 if (hsz != 12) { 5081 int compress = stbi__get32le(s); 5082 if (compress == 1 || compress == 2) return stbi__errpuc("BMP RLE", "BMP type not supported: RLE"); 5083 stbi__get32le(s); // discard sizeof 5084 stbi__get32le(s); // discard hres 5085 stbi__get32le(s); // discard vres 5086 stbi__get32le(s); // discard colorsused 5087 stbi__get32le(s); // discard max important 5088 if (hsz == 40 || hsz == 56) { 5089 if (hsz == 56) { 5090 stbi__get32le(s); 5091 stbi__get32le(s); 5092 stbi__get32le(s); 5093 stbi__get32le(s); 5094 } 5095 if (info->bpp == 16 || info->bpp == 32) { 5096 if (compress == 0) { 5097 if (info->bpp == 32) { 5098 info->mr = 0xffu << 16; 5099 info->mg = 0xffu << 8; 5100 info->mb = 0xffu << 0; 5101 info->ma = 0xffu << 24; 5102 info->all_a = 0; // if all_a is 0 at end, then we loaded alpha channel but it was all 0 5103 } else { 5104 info->mr = 31u << 10; 5105 info->mg = 31u << 5; 5106 info->mb = 31u << 0; 5107 } 5108 } else if (compress == 3) { 5109 info->mr = stbi__get32le(s); 5110 info->mg = stbi__get32le(s); 5111 info->mb = stbi__get32le(s); 5112 // not documented, but generated by photoshop and handled by mspaint 5113 if (info->mr == info->mg && info->mg == info->mb) { 5114 // ?!?!? 5115 return stbi__errpuc("bad BMP", "bad BMP"); 5116 } 5117 } else 5118 return stbi__errpuc("bad BMP", "bad BMP"); 5119 } 5120 } else { 5121 int i; 5122 if (hsz != 108 && hsz != 124) 5123 return stbi__errpuc("bad BMP", "bad BMP"); 5124 info->mr = stbi__get32le(s); 5125 info->mg = stbi__get32le(s); 5126 info->mb = stbi__get32le(s); 5127 info->ma = stbi__get32le(s); 5128 stbi__get32le(s); // discard color space 5129 for (i=0; i < 12; ++i) 5130 stbi__get32le(s); // discard color space parameters 5131 if (hsz == 124) { 5132 stbi__get32le(s); // discard rendering intent 5133 stbi__get32le(s); // discard offset of profile data 5134 stbi__get32le(s); // discard size of profile data 5135 stbi__get32le(s); // discard reserved 5136 } 5137 } 5138 } 5139 return (void *) 1; 5140 } 5141 5142 5143 static void *stbi__bmp_load(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri) 5144 { 5145 stbi_uc *out; 5146 unsigned int mr=0,mg=0,mb=0,ma=0, all_a; 5147 stbi_uc pal[256][4]; 5148 int psize=0,i,j,width; 5149 int flip_vertically, pad, target; 5150 stbi__bmp_data info; 5151 STBI_NOTUSED(ri); 5152 5153 info.all_a = 255; 5154 if (stbi__bmp_parse_header(s, &info) == NULL) 5155 return NULL; // error code already set 5156 5157 flip_vertically = ((int) s->img_y) > 0; 5158 s->img_y = abs((int) s->img_y); 5159 5160 mr = info.mr; 5161 mg = info.mg; 5162 mb = info.mb; 5163 ma = info.ma; 5164 all_a = info.all_a; 5165 5166 if (info.hsz == 12) { 5167 if (info.bpp < 24) 5168 psize = (info.offset - 14 - 24) / 3; 5169 } else { 5170 if (info.bpp < 16) 5171 psize = (info.offset - 14 - info.hsz) >> 2; 5172 } 5173 5174 s->img_n = ma ? 4 : 3; 5175 if (req_comp && req_comp >= 3) // we can directly decode 3 or 4 5176 target = req_comp; 5177 else 5178 target = s->img_n; // if they want monochrome, we'll post-convert 5179 5180 // sanity-check size 5181 if (!stbi__mad3sizes_valid(target, s->img_x, s->img_y, 0)) 5182 return stbi__errpuc("too large", "Corrupt BMP"); 5183 5184 out = (stbi_uc *) stbi__malloc_mad3(target, s->img_x, s->img_y, 0); 5185 if (!out) return stbi__errpuc("outofmem", "Out of memory"); 5186 if (info.bpp < 16) { 5187 int z=0; 5188 if (psize == 0 || psize > 256) { STBI_FREE(out); return stbi__errpuc("invalid", "Corrupt BMP"); } 5189 for (i=0; i < psize; ++i) { 5190 pal[i][2] = stbi__get8(s); 5191 pal[i][1] = stbi__get8(s); 5192 pal[i][0] = stbi__get8(s); 5193 if (info.hsz != 12) stbi__get8(s); 5194 pal[i][3] = 255; 5195 } 5196 stbi__skip(s, info.offset - 14 - info.hsz - psize * (info.hsz == 12 ? 3 : 4)); 5197 if (info.bpp == 1) width = (s->img_x + 7) >> 3; 5198 else if (info.bpp == 4) width = (s->img_x + 1) >> 1; 5199 else if (info.bpp == 8) width = s->img_x; 5200 else { STBI_FREE(out); return stbi__errpuc("bad bpp", "Corrupt BMP"); } 5201 pad = (-width)&3; 5202 if (info.bpp == 1) { 5203 for (j=0; j < (int) s->img_y; ++j) { 5204 int bit_offset = 7, v = stbi__get8(s); 5205 for (i=0; i < (int) s->img_x; ++i) { 5206 int color = (v>>bit_offset)&0x1; 5207 out[z++] = pal[color][0]; 5208 out[z++] = pal[color][1]; 5209 out[z++] = pal[color][2]; 5210 if((--bit_offset) < 0) { 5211 bit_offset = 7; 5212 v = stbi__get8(s); 5213 } 5214 } 5215 stbi__skip(s, pad); 5216 } 5217 } else { 5218 for (j=0; j < (int) s->img_y; ++j) { 5219 for (i=0; i < (int) s->img_x; i += 2) { 5220 int v=stbi__get8(s),v2=0; 5221 if (info.bpp == 4) { 5222 v2 = v & 15; 5223 v >>= 4; 5224 } 5225 out[z++] = pal[v][0]; 5226 out[z++] = pal[v][1]; 5227 out[z++] = pal[v][2]; 5228 if (target == 4) out[z++] = 255; 5229 if (i+1 == (int) s->img_x) break; 5230 v = (info.bpp == 8) ? stbi__get8(s) : v2; 5231 out[z++] = pal[v][0]; 5232 out[z++] = pal[v][1]; 5233 out[z++] = pal[v][2]; 5234 if (target == 4) out[z++] = 255; 5235 } 5236 stbi__skip(s, pad); 5237 } 5238 } 5239 } else { 5240 int rshift=0,gshift=0,bshift=0,ashift=0,rcount=0,gcount=0,bcount=0,acount=0; 5241 int z = 0; 5242 int easy=0; 5243 stbi__skip(s, info.offset - 14 - info.hsz); 5244 if (info.bpp == 24) width = 3 * s->img_x; 5245 else if (info.bpp == 16) width = 2*s->img_x; 5246 else /* bpp = 32 and pad = 0 */ width=0; 5247 pad = (-width) & 3; 5248 if (info.bpp == 24) { 5249 easy = 1; 5250 } else if (info.bpp == 32) { 5251 if (mb == 0xff && mg == 0xff00 && mr == 0x00ff0000 && ma == 0xff000000) 5252 easy = 2; 5253 } 5254 if (!easy) { 5255 if (!mr || !mg || !mb) { STBI_FREE(out); return stbi__errpuc("bad masks", "Corrupt BMP"); } 5256 // right shift amt to put high bit in position #7 5257 rshift = stbi__high_bit(mr)-7; rcount = stbi__bitcount(mr); 5258 gshift = stbi__high_bit(mg)-7; gcount = stbi__bitcount(mg); 5259 bshift = stbi__high_bit(mb)-7; bcount = stbi__bitcount(mb); 5260 ashift = stbi__high_bit(ma)-7; acount = stbi__bitcount(ma); 5261 } 5262 for (j=0; j < (int) s->img_y; ++j) { 5263 if (easy) { 5264 for (i=0; i < (int) s->img_x; ++i) { 5265 unsigned char a; 5266 out[z+2] = stbi__get8(s); 5267 out[z+1] = stbi__get8(s); 5268 out[z+0] = stbi__get8(s); 5269 z += 3; 5270 a = (easy == 2 ? stbi__get8(s) : 255); 5271 all_a |= a; 5272 if (target == 4) out[z++] = a; 5273 } 5274 } else { 5275 int bpp = info.bpp; 5276 for (i=0; i < (int) s->img_x; ++i) { 5277 stbi__uint32 v = (bpp == 16 ? (stbi__uint32) stbi__get16le(s) : stbi__get32le(s)); 5278 unsigned int a; 5279 out[z++] = STBI__BYTECAST(stbi__shiftsigned(v & mr, rshift, rcount)); 5280 out[z++] = STBI__BYTECAST(stbi__shiftsigned(v & mg, gshift, gcount)); 5281 out[z++] = STBI__BYTECAST(stbi__shiftsigned(v & mb, bshift, bcount)); 5282 a = (ma ? stbi__shiftsigned(v & ma, ashift, acount) : 255); 5283 all_a |= a; 5284 if (target == 4) out[z++] = STBI__BYTECAST(a); 5285 } 5286 } 5287 stbi__skip(s, pad); 5288 } 5289 } 5290 5291 // if alpha channel is all 0s, replace with all 255s 5292 if (target == 4 && all_a == 0) 5293 for (i=4*s->img_x*s->img_y-1; i >= 0; i -= 4) 5294 out[i] = 255; 5295 5296 if (flip_vertically) { 5297 stbi_uc t; 5298 for (j=0; j < (int) s->img_y>>1; ++j) { 5299 stbi_uc *p1 = out + j *s->img_x*target; 5300 stbi_uc *p2 = out + (s->img_y-1-j)*s->img_x*target; 5301 for (i=0; i < (int) s->img_x*target; ++i) { 5302 t = p1[i], p1[i] = p2[i], p2[i] = t; 5303 } 5304 } 5305 } 5306 5307 if (req_comp && req_comp != target) { 5308 out = stbi__convert_format(out, target, req_comp, s->img_x, s->img_y); 5309 if (out == NULL) return out; // stbi__convert_format frees input on failure 5310 } 5311 5312 *x = s->img_x; 5313 *y = s->img_y; 5314 if (comp) *comp = s->img_n; 5315 return out; 5316 } 5317 #endif 5318 5319 // Targa Truevision - TGA 5320 // by Jonathan Dummer 5321 #ifndef STBI_NO_TGA 5322 // returns STBI_rgb or whatever, 0 on error 5323 static int stbi__tga_get_comp(int bits_per_pixel, int is_grey, int* is_rgb16) 5324 { 5325 // only RGB or RGBA (incl. 16bit) or grey allowed 5326 if (is_rgb16) *is_rgb16 = 0; 5327 switch(bits_per_pixel) { 5328 case 8: return STBI_grey; 5329 case 16: if(is_grey) return STBI_grey_alpha; 5330 // fallthrough 5331 case 15: if(is_rgb16) *is_rgb16 = 1; 5332 return STBI_rgb; 5333 case 24: // fallthrough 5334 case 32: return bits_per_pixel/8; 5335 default: return 0; 5336 } 5337 } 5338 5339 static int stbi__tga_info(stbi__context *s, int *x, int *y, int *comp) 5340 { 5341 int tga_w, tga_h, tga_comp, tga_image_type, tga_bits_per_pixel, tga_colormap_bpp; 5342 int sz, tga_colormap_type; 5343 stbi__get8(s); // discard Offset 5344 tga_colormap_type = stbi__get8(s); // colormap type 5345 if( tga_colormap_type > 1 ) { 5346 stbi__rewind(s); 5347 return 0; // only RGB or indexed allowed 5348 } 5349 tga_image_type = stbi__get8(s); // image type 5350 if ( tga_colormap_type == 1 ) { // colormapped (paletted) image 5351 if (tga_image_type != 1 && tga_image_type != 9) { 5352 stbi__rewind(s); 5353 return 0; 5354 } 5355 stbi__skip(s,4); // skip index of first colormap entry and number of entries 5356 sz = stbi__get8(s); // check bits per palette color entry 5357 if ( (sz != 8) && (sz != 15) && (sz != 16) && (sz != 24) && (sz != 32) ) { 5358 stbi__rewind(s); 5359 return 0; 5360 } 5361 stbi__skip(s,4); // skip image x and y origin 5362 tga_colormap_bpp = sz; 5363 } else { // "normal" image w/o colormap - only RGB or grey allowed, +/- RLE 5364 if ( (tga_image_type != 2) && (tga_image_type != 3) && (tga_image_type != 10) && (tga_image_type != 11) ) { 5365 stbi__rewind(s); 5366 return 0; // only RGB or grey allowed, +/- RLE 5367 } 5368 stbi__skip(s,9); // skip colormap specification and image x/y origin 5369 tga_colormap_bpp = 0; 5370 } 5371 tga_w = stbi__get16le(s); 5372 if( tga_w < 1 ) { 5373 stbi__rewind(s); 5374 return 0; // test width 5375 } 5376 tga_h = stbi__get16le(s); 5377 if( tga_h < 1 ) { 5378 stbi__rewind(s); 5379 return 0; // test height 5380 } 5381 tga_bits_per_pixel = stbi__get8(s); // bits per pixel 5382 stbi__get8(s); // ignore alpha bits 5383 if (tga_colormap_bpp != 0) { 5384 if((tga_bits_per_pixel != 8) && (tga_bits_per_pixel != 16)) { 5385 // when using a colormap, tga_bits_per_pixel is the size of the indexes 5386 // I don't think anything but 8 or 16bit indexes makes sense 5387 stbi__rewind(s); 5388 return 0; 5389 } 5390 tga_comp = stbi__tga_get_comp(tga_colormap_bpp, 0, NULL); 5391 } else { 5392 tga_comp = stbi__tga_get_comp(tga_bits_per_pixel, (tga_image_type == 3) || (tga_image_type == 11), NULL); 5393 } 5394 if(!tga_comp) { 5395 stbi__rewind(s); 5396 return 0; 5397 } 5398 if (x) *x = tga_w; 5399 if (y) *y = tga_h; 5400 if (comp) *comp = tga_comp; 5401 return 1; // seems to have passed everything 5402 } 5403 5404 static int stbi__tga_test(stbi__context *s) 5405 { 5406 int res = 0; 5407 int sz, tga_color_type; 5408 stbi__get8(s); // discard Offset 5409 tga_color_type = stbi__get8(s); // color type 5410 if ( tga_color_type > 1 ) goto errorEnd; // only RGB or indexed allowed 5411 sz = stbi__get8(s); // image type 5412 if ( tga_color_type == 1 ) { // colormapped (paletted) image 5413 if (sz != 1 && sz != 9) goto errorEnd; // colortype 1 demands image type 1 or 9 5414 stbi__skip(s,4); // skip index of first colormap entry and number of entries 5415 sz = stbi__get8(s); // check bits per palette color entry 5416 if ( (sz != 8) && (sz != 15) && (sz != 16) && (sz != 24) && (sz != 32) ) goto errorEnd; 5417 stbi__skip(s,4); // skip image x and y origin 5418 } else { // "normal" image w/o colormap 5419 if ( (sz != 2) && (sz != 3) && (sz != 10) && (sz != 11) ) goto errorEnd; // only RGB or grey allowed, +/- RLE 5420 stbi__skip(s,9); // skip colormap specification and image x/y origin 5421 } 5422 if ( stbi__get16le(s) < 1 ) goto errorEnd; // test width 5423 if ( stbi__get16le(s) < 1 ) goto errorEnd; // test height 5424 sz = stbi__get8(s); // bits per pixel 5425 if ( (tga_color_type == 1) && (sz != 8) && (sz != 16) ) goto errorEnd; // for colormapped images, bpp is size of an index 5426 if ( (sz != 8) && (sz != 15) && (sz != 16) && (sz != 24) && (sz != 32) ) goto errorEnd; 5427 5428 res = 1; // if we got this far, everything's good and we can return 1 instead of 0 5429 5430 errorEnd: 5431 stbi__rewind(s); 5432 return res; 5433 } 5434 5435 // read 16bit value and convert to 24bit RGB 5436 static void stbi__tga_read_rgb16(stbi__context *s, stbi_uc* out) 5437 { 5438 stbi__uint16 px = (stbi__uint16)stbi__get16le(s); 5439 stbi__uint16 fiveBitMask = 31; 5440 // we have 3 channels with 5bits each 5441 int r = (px >> 10) & fiveBitMask; 5442 int g = (px >> 5) & fiveBitMask; 5443 int b = px & fiveBitMask; 5444 // Note that this saves the data in RGB(A) order, so it doesn't need to be swapped later 5445 out[0] = (stbi_uc)((r * 255)/31); 5446 out[1] = (stbi_uc)((g * 255)/31); 5447 out[2] = (stbi_uc)((b * 255)/31); 5448 5449 // some people claim that the most significant bit might be used for alpha 5450 // (possibly if an alpha-bit is set in the "image descriptor byte") 5451 // but that only made 16bit test images completely translucent.. 5452 // so let's treat all 15 and 16bit TGAs as RGB with no alpha. 5453 } 5454 5455 static void *stbi__tga_load(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri) 5456 { 5457 // read in the TGA header stuff 5458 int tga_offset = stbi__get8(s); 5459 int tga_indexed = stbi__get8(s); 5460 int tga_image_type = stbi__get8(s); 5461 int tga_is_RLE = 0; 5462 int tga_palette_start = stbi__get16le(s); 5463 int tga_palette_len = stbi__get16le(s); 5464 int tga_palette_bits = stbi__get8(s); 5465 int tga_x_origin = stbi__get16le(s); 5466 int tga_y_origin = stbi__get16le(s); 5467 int tga_width = stbi__get16le(s); 5468 int tga_height = stbi__get16le(s); 5469 int tga_bits_per_pixel = stbi__get8(s); 5470 int tga_comp, tga_rgb16=0; 5471 int tga_inverted = stbi__get8(s); 5472 // int tga_alpha_bits = tga_inverted & 15; // the 4 lowest bits - unused (useless?) 5473 // image data 5474 unsigned char *tga_data; 5475 unsigned char *tga_palette = NULL; 5476 int i, j; 5477 unsigned char raw_data[4] = {0}; 5478 int RLE_count = 0; 5479 int RLE_repeating = 0; 5480 int read_next_pixel = 1; 5481 STBI_NOTUSED(ri); 5482 5483 // do a tiny bit of precessing 5484 if ( tga_image_type >= 8 ) 5485 { 5486 tga_image_type -= 8; 5487 tga_is_RLE = 1; 5488 } 5489 tga_inverted = 1 - ((tga_inverted >> 5) & 1); 5490 5491 // If I'm paletted, then I'll use the number of bits from the palette 5492 if ( tga_indexed ) tga_comp = stbi__tga_get_comp(tga_palette_bits, 0, &tga_rgb16); 5493 else tga_comp = stbi__tga_get_comp(tga_bits_per_pixel, (tga_image_type == 3), &tga_rgb16); 5494 5495 if(!tga_comp) // shouldn't really happen, stbi__tga_test() should have ensured basic consistency 5496 return stbi__errpuc("bad format", "Can't find out TGA pixelformat"); 5497 5498 // tga info 5499 *x = tga_width; 5500 *y = tga_height; 5501 if (comp) *comp = tga_comp; 5502 5503 if (!stbi__mad3sizes_valid(tga_width, tga_height, tga_comp, 0)) 5504 return stbi__errpuc("too large", "Corrupt TGA"); 5505 5506 tga_data = (unsigned char*)stbi__malloc_mad3(tga_width, tga_height, tga_comp, 0); 5507 if (!tga_data) return stbi__errpuc("outofmem", "Out of memory"); 5508 5509 // skip to the data's starting position (offset usually = 0) 5510 stbi__skip(s, tga_offset ); 5511 5512 if ( !tga_indexed && !tga_is_RLE && !tga_rgb16 ) { 5513 for (i=0; i < tga_height; ++i) { 5514 int row = tga_inverted ? tga_height -i - 1 : i; 5515 stbi_uc *tga_row = tga_data + row*tga_width*tga_comp; 5516 stbi__getn(s, tga_row, tga_width * tga_comp); 5517 } 5518 } else { 5519 // do I need to load a palette? 5520 if ( tga_indexed) 5521 { 5522 // any data to skip? (offset usually = 0) 5523 stbi__skip(s, tga_palette_start ); 5524 // load the palette 5525 tga_palette = (unsigned char*)stbi__malloc_mad2(tga_palette_len, tga_comp, 0); 5526 if (!tga_palette) { 5527 STBI_FREE(tga_data); 5528 return stbi__errpuc("outofmem", "Out of memory"); 5529 } 5530 if (tga_rgb16) { 5531 stbi_uc *pal_entry = tga_palette; 5532 STBI_ASSERT(tga_comp == STBI_rgb); 5533 for (i=0; i < tga_palette_len; ++i) { 5534 stbi__tga_read_rgb16(s, pal_entry); 5535 pal_entry += tga_comp; 5536 } 5537 } else if (!stbi__getn(s, tga_palette, tga_palette_len * tga_comp)) { 5538 STBI_FREE(tga_data); 5539 STBI_FREE(tga_palette); 5540 return stbi__errpuc("bad palette", "Corrupt TGA"); 5541 } 5542 } 5543 // load the data 5544 for (i=0; i < tga_width * tga_height; ++i) 5545 { 5546 // if I'm in RLE mode, do I need to get a RLE stbi__pngchunk? 5547 if ( tga_is_RLE ) 5548 { 5549 if ( RLE_count == 0 ) 5550 { 5551 // yep, get the next byte as a RLE command 5552 int RLE_cmd = stbi__get8(s); 5553 RLE_count = 1 + (RLE_cmd & 127); 5554 RLE_repeating = RLE_cmd >> 7; 5555 read_next_pixel = 1; 5556 } else if ( !RLE_repeating ) 5557 { 5558 read_next_pixel = 1; 5559 } 5560 } else 5561 { 5562 read_next_pixel = 1; 5563 } 5564 // OK, if I need to read a pixel, do it now 5565 if ( read_next_pixel ) 5566 { 5567 // load however much data we did have 5568 if ( tga_indexed ) 5569 { 5570 // read in index, then perform the lookup 5571 int pal_idx = (tga_bits_per_pixel == 8) ? stbi__get8(s) : stbi__get16le(s); 5572 if ( pal_idx >= tga_palette_len ) { 5573 // invalid index 5574 pal_idx = 0; 5575 } 5576 pal_idx *= tga_comp; 5577 for (j = 0; j < tga_comp; ++j) { 5578 raw_data[j] = tga_palette[pal_idx+j]; 5579 } 5580 } else if(tga_rgb16) { 5581 STBI_ASSERT(tga_comp == STBI_rgb); 5582 stbi__tga_read_rgb16(s, raw_data); 5583 } else { 5584 // read in the data raw 5585 for (j = 0; j < tga_comp; ++j) { 5586 raw_data[j] = stbi__get8(s); 5587 } 5588 } 5589 // clear the reading flag for the next pixel 5590 read_next_pixel = 0; 5591 } // end of reading a pixel 5592 5593 // copy data 5594 for (j = 0; j < tga_comp; ++j) 5595 tga_data[i*tga_comp+j] = raw_data[j]; 5596 5597 // in case we're in RLE mode, keep counting down 5598 --RLE_count; 5599 } 5600 // do I need to invert the image? 5601 if ( tga_inverted ) 5602 { 5603 for (j = 0; j*2 < tga_height; ++j) 5604 { 5605 int index1 = j * tga_width * tga_comp; 5606 int index2 = (tga_height - 1 - j) * tga_width * tga_comp; 5607 for (i = tga_width * tga_comp; i > 0; --i) 5608 { 5609 unsigned char temp = tga_data[index1]; 5610 tga_data[index1] = tga_data[index2]; 5611 tga_data[index2] = temp; 5612 ++index1; 5613 ++index2; 5614 } 5615 } 5616 } 5617 // clear my palette, if I had one 5618 if ( tga_palette != NULL ) 5619 { 5620 STBI_FREE( tga_palette ); 5621 } 5622 } 5623 5624 // swap RGB - if the source data was RGB16, it already is in the right order 5625 if (tga_comp >= 3 && !tga_rgb16) 5626 { 5627 unsigned char* tga_pixel = tga_data; 5628 for (i=0; i < tga_width * tga_height; ++i) 5629 { 5630 unsigned char temp = tga_pixel[0]; 5631 tga_pixel[0] = tga_pixel[2]; 5632 tga_pixel[2] = temp; 5633 tga_pixel += tga_comp; 5634 } 5635 } 5636 5637 // convert to target component count 5638 if (req_comp && req_comp != tga_comp) 5639 tga_data = stbi__convert_format(tga_data, tga_comp, req_comp, tga_width, tga_height); 5640 5641 // the things I do to get rid of an error message, and yet keep 5642 // Microsoft's C compilers happy... [8^( 5643 tga_palette_start = tga_palette_len = tga_palette_bits = 5644 tga_x_origin = tga_y_origin = 0; 5645 // OK, done 5646 return tga_data; 5647 } 5648 #endif 5649 5650 // ************************************************************************************************* 5651 // Photoshop PSD loader -- PD by Thatcher Ulrich, integration by Nicolas Schulz, tweaked by STB 5652 5653 #ifndef STBI_NO_PSD 5654 static int stbi__psd_test(stbi__context *s) 5655 { 5656 int r = (stbi__get32be(s) == 0x38425053); 5657 stbi__rewind(s); 5658 return r; 5659 } 5660 5661 static int stbi__psd_decode_rle(stbi__context *s, stbi_uc *p, int pixelCount) 5662 { 5663 int count, nleft, len; 5664 5665 count = 0; 5666 while ((nleft = pixelCount - count) > 0) { 5667 len = stbi__get8(s); 5668 if (len == 128) { 5669 // No-op. 5670 } else if (len < 128) { 5671 // Copy next len+1 bytes literally. 5672 len++; 5673 if (len > nleft) return 0; // corrupt data 5674 count += len; 5675 while (len) { 5676 *p = stbi__get8(s); 5677 p += 4; 5678 len--; 5679 } 5680 } else if (len > 128) { 5681 stbi_uc val; 5682 // Next -len+1 bytes in the dest are replicated from next source byte. 5683 // (Interpret len as a negative 8-bit int.) 5684 len = 257 - len; 5685 if (len > nleft) return 0; // corrupt data 5686 val = stbi__get8(s); 5687 count += len; 5688 while (len) { 5689 *p = val; 5690 p += 4; 5691 len--; 5692 } 5693 } 5694 } 5695 5696 return 1; 5697 } 5698 5699 static void *stbi__psd_load(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri, int bpc) 5700 { 5701 int pixelCount; 5702 int channelCount, compression; 5703 int channel, i; 5704 int bitdepth; 5705 int w,h; 5706 stbi_uc *out; 5707 STBI_NOTUSED(ri); 5708 5709 // Check identifier 5710 if (stbi__get32be(s) != 0x38425053) // "8BPS" 5711 return stbi__errpuc("not PSD", "Corrupt PSD image"); 5712 5713 // Check file type version. 5714 if (stbi__get16be(s) != 1) 5715 return stbi__errpuc("wrong version", "Unsupported version of PSD image"); 5716 5717 // Skip 6 reserved bytes. 5718 stbi__skip(s, 6 ); 5719 5720 // Read the number of channels (R, G, B, A, etc). 5721 channelCount = stbi__get16be(s); 5722 if (channelCount < 0 || channelCount > 16) 5723 return stbi__errpuc("wrong channel count", "Unsupported number of channels in PSD image"); 5724 5725 // Read the rows and columns of the image. 5726 h = stbi__get32be(s); 5727 w = stbi__get32be(s); 5728 5729 // Make sure the depth is 8 bits. 5730 bitdepth = stbi__get16be(s); 5731 if (bitdepth != 8 && bitdepth != 16) 5732 return stbi__errpuc("unsupported bit depth", "PSD bit depth is not 8 or 16 bit"); 5733 5734 // Make sure the color mode is RGB. 5735 // Valid options are: 5736 // 0: Bitmap 5737 // 1: Grayscale 5738 // 2: Indexed color 5739 // 3: RGB color 5740 // 4: CMYK color 5741 // 7: Multichannel 5742 // 8: Duotone 5743 // 9: Lab color 5744 if (stbi__get16be(s) != 3) 5745 return stbi__errpuc("wrong color format", "PSD is not in RGB color format"); 5746 5747 // Skip the Mode Data. (It's the palette for indexed color; other info for other modes.) 5748 stbi__skip(s,stbi__get32be(s) ); 5749 5750 // Skip the image resources. (resolution, pen tool paths, etc) 5751 stbi__skip(s, stbi__get32be(s) ); 5752 5753 // Skip the reserved data. 5754 stbi__skip(s, stbi__get32be(s) ); 5755 5756 // Find out if the data is compressed. 5757 // Known values: 5758 // 0: no compression 5759 // 1: RLE compressed 5760 compression = stbi__get16be(s); 5761 if (compression > 1) 5762 return stbi__errpuc("bad compression", "PSD has an unknown compression format"); 5763 5764 // Check size 5765 if (!stbi__mad3sizes_valid(4, w, h, 0)) 5766 return stbi__errpuc("too large", "Corrupt PSD"); 5767 5768 // Create the destination image. 5769 5770 if (!compression && bitdepth == 16 && bpc == 16) { 5771 out = (stbi_uc *) stbi__malloc_mad3(8, w, h, 0); 5772 ri->bits_per_channel = 16; 5773 } else 5774 out = (stbi_uc *) stbi__malloc(4 * w*h); 5775 5776 if (!out) return stbi__errpuc("outofmem", "Out of memory"); 5777 pixelCount = w*h; 5778 5779 // Initialize the data to zero. 5780 //memset( out, 0, pixelCount * 4 ); 5781 5782 // Finally, the image data. 5783 if (compression) { 5784 // RLE as used by .PSD and .TIFF 5785 // Loop until you get the number of unpacked bytes you are expecting: 5786 // Read the next source byte into n. 5787 // If n is between 0 and 127 inclusive, copy the next n+1 bytes literally. 5788 // Else if n is between -127 and -1 inclusive, copy the next byte -n+1 times. 5789 // Else if n is 128, noop. 5790 // Endloop 5791 5792 // The RLE-compressed data is preceeded by a 2-byte data count for each row in the data, 5793 // which we're going to just skip. 5794 stbi__skip(s, h * channelCount * 2 ); 5795 5796 // Read the RLE data by channel. 5797 for (channel = 0; channel < 4; channel++) { 5798 stbi_uc *p; 5799 5800 p = out+channel; 5801 if (channel >= channelCount) { 5802 // Fill this channel with default data. 5803 for (i = 0; i < pixelCount; i++, p += 4) 5804 *p = (channel == 3 ? 255 : 0); 5805 } else { 5806 // Read the RLE data. 5807 if (!stbi__psd_decode_rle(s, p, pixelCount)) { 5808 STBI_FREE(out); 5809 return stbi__errpuc("corrupt", "bad RLE data"); 5810 } 5811 } 5812 } 5813 5814 } else { 5815 // We're at the raw image data. It's each channel in order (Red, Green, Blue, Alpha, ...) 5816 // where each channel consists of an 8-bit (or 16-bit) value for each pixel in the image. 5817 5818 // Read the data by channel. 5819 for (channel = 0; channel < 4; channel++) { 5820 if (channel >= channelCount) { 5821 // Fill this channel with default data. 5822 if (bitdepth == 16 && bpc == 16) { 5823 stbi__uint16 *q = ((stbi__uint16 *) out) + channel; 5824 stbi__uint16 val = channel == 3 ? 65535 : 0; 5825 for (i = 0; i < pixelCount; i++, q += 4) 5826 *q = val; 5827 } else { 5828 stbi_uc *p = out+channel; 5829 stbi_uc val = channel == 3 ? 255 : 0; 5830 for (i = 0; i < pixelCount; i++, p += 4) 5831 *p = val; 5832 } 5833 } else { 5834 if (ri->bits_per_channel == 16) { // output bpc 5835 stbi__uint16 *q = ((stbi__uint16 *) out) + channel; 5836 for (i = 0; i < pixelCount; i++, q += 4) 5837 *q = (stbi__uint16) stbi__get16be(s); 5838 } else { 5839 stbi_uc *p = out+channel; 5840 if (bitdepth == 16) { // input bpc 5841 for (i = 0; i < pixelCount; i++, p += 4) 5842 *p = (stbi_uc) (stbi__get16be(s) >> 8); 5843 } else { 5844 for (i = 0; i < pixelCount; i++, p += 4) 5845 *p = stbi__get8(s); 5846 } 5847 } 5848 } 5849 } 5850 } 5851 5852 // remove weird white matte from PSD 5853 if (channelCount >= 4) { 5854 if (ri->bits_per_channel == 16) { 5855 for (i=0; i < w*h; ++i) { 5856 stbi__uint16 *pixel = (stbi__uint16 *) out + 4*i; 5857 if (pixel[3] != 0 && pixel[3] != 65535) { 5858 float a = pixel[3] / 65535.0f; 5859 float ra = 1.0f / a; 5860 float inv_a = 65535.0f * (1 - ra); 5861 pixel[0] = (stbi__uint16) (pixel[0]*ra + inv_a); 5862 pixel[1] = (stbi__uint16) (pixel[1]*ra + inv_a); 5863 pixel[2] = (stbi__uint16) (pixel[2]*ra + inv_a); 5864 } 5865 } 5866 } else { 5867 for (i=0; i < w*h; ++i) { 5868 unsigned char *pixel = out + 4*i; 5869 if (pixel[3] != 0 && pixel[3] != 255) { 5870 float a = pixel[3] / 255.0f; 5871 float ra = 1.0f / a; 5872 float inv_a = 255.0f * (1 - ra); 5873 pixel[0] = (unsigned char) (pixel[0]*ra + inv_a); 5874 pixel[1] = (unsigned char) (pixel[1]*ra + inv_a); 5875 pixel[2] = (unsigned char) (pixel[2]*ra + inv_a); 5876 } 5877 } 5878 } 5879 } 5880 5881 // convert to desired output format 5882 if (req_comp && req_comp != 4) { 5883 if (ri->bits_per_channel == 16) 5884 out = (stbi_uc *) stbi__convert_format16((stbi__uint16 *) out, 4, req_comp, w, h); 5885 else 5886 out = stbi__convert_format(out, 4, req_comp, w, h); 5887 if (out == NULL) return out; // stbi__convert_format frees input on failure 5888 } 5889 5890 if (comp) *comp = 4; 5891 *y = h; 5892 *x = w; 5893 5894 return out; 5895 } 5896 #endif 5897 5898 // ************************************************************************************************* 5899 // Softimage PIC loader 5900 // by Tom Seddon 5901 // 5902 // See http://softimage.wiki.softimage.com/index.php/INFO:_PIC_file_format 5903 // See http://ozviz.wasp.uwa.edu.au/~pbourke/dataformats/softimagepic/ 5904 5905 #ifndef STBI_NO_PIC 5906 static int stbi__pic_is4(stbi__context *s,const char *str) 5907 { 5908 int i; 5909 for (i=0; i<4; ++i) 5910 if (stbi__get8(s) != (stbi_uc)str[i]) 5911 return 0; 5912 5913 return 1; 5914 } 5915 5916 static int stbi__pic_test_core(stbi__context *s) 5917 { 5918 int i; 5919 5920 if (!stbi__pic_is4(s,"\x53\x80\xF6\x34")) 5921 return 0; 5922 5923 for(i=0;i<84;++i) 5924 stbi__get8(s); 5925 5926 if (!stbi__pic_is4(s,"PICT")) 5927 return 0; 5928 5929 return 1; 5930 } 5931 5932 typedef struct 5933 { 5934 stbi_uc size,type,channel; 5935 } stbi__pic_packet; 5936 5937 static stbi_uc *stbi__readval(stbi__context *s, int channel, stbi_uc *dest) 5938 { 5939 int mask=0x80, i; 5940 5941 for (i=0; i<4; ++i, mask>>=1) { 5942 if (channel & mask) { 5943 if (stbi__at_eof(s)) return stbi__errpuc("bad file","PIC file too short"); 5944 dest[i]=stbi__get8(s); 5945 } 5946 } 5947 5948 return dest; 5949 } 5950 5951 static void stbi__copyval(int channel,stbi_uc *dest,const stbi_uc *src) 5952 { 5953 int mask=0x80,i; 5954 5955 for (i=0;i<4; ++i, mask>>=1) 5956 if (channel&mask) 5957 dest[i]=src[i]; 5958 } 5959 5960 static stbi_uc *stbi__pic_load_core(stbi__context *s,int width,int height,int *comp, stbi_uc *result) 5961 { 5962 int act_comp=0,num_packets=0,y,chained; 5963 stbi__pic_packet packets[10]; 5964 5965 // this will (should...) cater for even some bizarre stuff like having data 5966 // for the same channel in multiple packets. 5967 do { 5968 stbi__pic_packet *packet; 5969 5970 if (num_packets==sizeof(packets)/sizeof(packets[0])) 5971 return stbi__errpuc("bad format","too many packets"); 5972 5973 packet = &packets[num_packets++]; 5974 5975 chained = stbi__get8(s); 5976 packet->size = stbi__get8(s); 5977 packet->type = stbi__get8(s); 5978 packet->channel = stbi__get8(s); 5979 5980 act_comp |= packet->channel; 5981 5982 if (stbi__at_eof(s)) return stbi__errpuc("bad file","file too short (reading packets)"); 5983 if (packet->size != 8) return stbi__errpuc("bad format","packet isn't 8bpp"); 5984 } while (chained); 5985 5986 *comp = (act_comp & 0x10 ? 4 : 3); // has alpha channel? 5987 5988 for(y=0; y<height; ++y) { 5989 int packet_idx; 5990 5991 for(packet_idx=0; packet_idx < num_packets; ++packet_idx) { 5992 stbi__pic_packet *packet = &packets[packet_idx]; 5993 stbi_uc *dest = result+y*width*4; 5994 5995 switch (packet->type) { 5996 default: 5997 return stbi__errpuc("bad format","packet has bad compression type"); 5998 5999 case 0: {//uncompressed 6000 int x; 6001 6002 for(x=0;x<width;++x, dest+=4) 6003 if (!stbi__readval(s,packet->channel,dest)) 6004 return 0; 6005 break; 6006 } 6007 6008 case 1://Pure RLE 6009 { 6010 int left=width, i; 6011 6012 while (left>0) { 6013 stbi_uc count,value[4]; 6014 6015 count=stbi__get8(s); 6016 if (stbi__at_eof(s)) return stbi__errpuc("bad file","file too short (pure read count)"); 6017 6018 if (count > left) 6019 count = (stbi_uc) left; 6020 6021 if (!stbi__readval(s,packet->channel,value)) return 0; 6022 6023 for(i=0; i<count; ++i,dest+=4) 6024 stbi__copyval(packet->channel,dest,value); 6025 left -= count; 6026 } 6027 } 6028 break; 6029 6030 case 2: {//Mixed RLE 6031 int left=width; 6032 while (left>0) { 6033 int count = stbi__get8(s), i; 6034 if (stbi__at_eof(s)) return stbi__errpuc("bad file","file too short (mixed read count)"); 6035 6036 if (count >= 128) { // Repeated 6037 stbi_uc value[4]; 6038 6039 if (count==128) 6040 count = stbi__get16be(s); 6041 else 6042 count -= 127; 6043 if (count > left) 6044 return stbi__errpuc("bad file","scanline overrun"); 6045 6046 if (!stbi__readval(s,packet->channel,value)) 6047 return 0; 6048 6049 for(i=0;i<count;++i, dest += 4) 6050 stbi__copyval(packet->channel,dest,value); 6051 } else { // Raw 6052 ++count; 6053 if (count>left) return stbi__errpuc("bad file","scanline overrun"); 6054 6055 for(i=0;i<count;++i, dest+=4) 6056 if (!stbi__readval(s,packet->channel,dest)) 6057 return 0; 6058 } 6059 left-=count; 6060 } 6061 break; 6062 } 6063 } 6064 } 6065 } 6066 6067 return result; 6068 } 6069 6070 static void *stbi__pic_load(stbi__context *s,int *px,int *py,int *comp,int req_comp, stbi__result_info *ri) 6071 { 6072 stbi_uc *result; 6073 int i, x,y, internal_comp; 6074 STBI_NOTUSED(ri); 6075 6076 if (!comp) comp = &internal_comp; 6077 6078 for (i=0; i<92; ++i) 6079 stbi__get8(s); 6080 6081 x = stbi__get16be(s); 6082 y = stbi__get16be(s); 6083 if (stbi__at_eof(s)) return stbi__errpuc("bad file","file too short (pic header)"); 6084 if (!stbi__mad3sizes_valid(x, y, 4, 0)) return stbi__errpuc("too large", "PIC image too large to decode"); 6085 6086 stbi__get32be(s); //skip `ratio' 6087 stbi__get16be(s); //skip `fields' 6088 stbi__get16be(s); //skip `pad' 6089 6090 // intermediate buffer is RGBA 6091 result = (stbi_uc *) stbi__malloc_mad3(x, y, 4, 0); 6092 memset(result, 0xff, x*y*4); 6093 6094 if (!stbi__pic_load_core(s,x,y,comp, result)) { 6095 STBI_FREE(result); 6096 result=0; 6097 } 6098 *px = x; 6099 *py = y; 6100 if (req_comp == 0) req_comp = *comp; 6101 result=stbi__convert_format(result,4,req_comp,x,y); 6102 6103 return result; 6104 } 6105 6106 static int stbi__pic_test(stbi__context *s) 6107 { 6108 int r = stbi__pic_test_core(s); 6109 stbi__rewind(s); 6110 return r; 6111 } 6112 #endif 6113 6114 // ************************************************************************************************* 6115 // GIF loader -- public domain by Jean-Marc Lienher -- simplified/shrunk by stb 6116 6117 #ifndef STBI_NO_GIF 6118 typedef struct 6119 { 6120 stbi__int16 prefix; 6121 stbi_uc first; 6122 stbi_uc suffix; 6123 } stbi__gif_lzw; 6124 6125 typedef struct 6126 { 6127 int w,h; 6128 stbi_uc *out; // output buffer (always 4 components) 6129 stbi_uc *background; // The current "background" as far as a gif is concerned 6130 stbi_uc *history; 6131 int flags, bgindex, ratio, transparent, eflags; 6132 stbi_uc pal[256][4]; 6133 stbi_uc lpal[256][4]; 6134 stbi__gif_lzw codes[8192]; 6135 stbi_uc *color_table; 6136 int parse, step; 6137 int lflags; 6138 int start_x, start_y; 6139 int max_x, max_y; 6140 int cur_x, cur_y; 6141 int line_size; 6142 int delay; 6143 } stbi__gif; 6144 6145 static int stbi__gif_test_raw(stbi__context *s) 6146 { 6147 int sz; 6148 if (stbi__get8(s) != 'G' || stbi__get8(s) != 'I' || stbi__get8(s) != 'F' || stbi__get8(s) != '8') return 0; 6149 sz = stbi__get8(s); 6150 if (sz != '9' && sz != '7') return 0; 6151 if (stbi__get8(s) != 'a') return 0; 6152 return 1; 6153 } 6154 6155 static int stbi__gif_test(stbi__context *s) 6156 { 6157 int r = stbi__gif_test_raw(s); 6158 stbi__rewind(s); 6159 return r; 6160 } 6161 6162 static void stbi__gif_parse_colortable(stbi__context *s, stbi_uc pal[256][4], int num_entries, int transp) 6163 { 6164 int i; 6165 for (i=0; i < num_entries; ++i) { 6166 pal[i][2] = stbi__get8(s); 6167 pal[i][1] = stbi__get8(s); 6168 pal[i][0] = stbi__get8(s); 6169 pal[i][3] = transp == i ? 0 : 255; 6170 } 6171 } 6172 6173 static int stbi__gif_header(stbi__context *s, stbi__gif *g, int *comp, int is_info) 6174 { 6175 stbi_uc version; 6176 if (stbi__get8(s) != 'G' || stbi__get8(s) != 'I' || stbi__get8(s) != 'F' || stbi__get8(s) != '8') 6177 return stbi__err("not GIF", "Corrupt GIF"); 6178 6179 version = stbi__get8(s); 6180 if (version != '7' && version != '9') return stbi__err("not GIF", "Corrupt GIF"); 6181 if (stbi__get8(s) != 'a') return stbi__err("not GIF", "Corrupt GIF"); 6182 6183 stbi__g_failure_reason = ""; 6184 g->w = stbi__get16le(s); 6185 g->h = stbi__get16le(s); 6186 g->flags = stbi__get8(s); 6187 g->bgindex = stbi__get8(s); 6188 g->ratio = stbi__get8(s); 6189 g->transparent = -1; 6190 6191 if (comp != 0) *comp = 4; // can't actually tell whether it's 3 or 4 until we parse the comments 6192 6193 if (is_info) return 1; 6194 6195 if (g->flags & 0x80) 6196 stbi__gif_parse_colortable(s,g->pal, 2 << (g->flags & 7), -1); 6197 6198 return 1; 6199 } 6200 6201 static int stbi__gif_info_raw(stbi__context *s, int *x, int *y, int *comp) 6202 { 6203 stbi__gif* g = (stbi__gif*) stbi__malloc(sizeof(stbi__gif)); 6204 if (!stbi__gif_header(s, g, comp, 1)) { 6205 STBI_FREE(g); 6206 stbi__rewind( s ); 6207 return 0; 6208 } 6209 if (x) *x = g->w; 6210 if (y) *y = g->h; 6211 STBI_FREE(g); 6212 return 1; 6213 } 6214 6215 static void stbi__out_gif_code(stbi__gif *g, stbi__uint16 code) 6216 { 6217 stbi_uc *p, *c; 6218 int idx; 6219 6220 // recurse to decode the prefixes, since the linked-list is backwards, 6221 // and working backwards through an interleaved image would be nasty 6222 if (g->codes[code].prefix >= 0) 6223 stbi__out_gif_code(g, g->codes[code].prefix); 6224 6225 if (g->cur_y >= g->max_y) return; 6226 6227 idx = g->cur_x + g->cur_y; 6228 p = &g->out[idx]; 6229 g->history[idx / 4] = 1; 6230 6231 c = &g->color_table[g->codes[code].suffix * 4]; 6232 if (c[3] > 128) { // don't render transparent pixels; 6233 p[0] = c[2]; 6234 p[1] = c[1]; 6235 p[2] = c[0]; 6236 p[3] = c[3]; 6237 } 6238 g->cur_x += 4; 6239 6240 if (g->cur_x >= g->max_x) { 6241 g->cur_x = g->start_x; 6242 g->cur_y += g->step; 6243 6244 while (g->cur_y >= g->max_y && g->parse > 0) { 6245 g->step = (1 << g->parse) * g->line_size; 6246 g->cur_y = g->start_y + (g->step >> 1); 6247 --g->parse; 6248 } 6249 } 6250 } 6251 6252 static stbi_uc *stbi__process_gif_raster(stbi__context *s, stbi__gif *g) 6253 { 6254 stbi_uc lzw_cs; 6255 stbi__int32 len, init_code; 6256 stbi__uint32 first; 6257 stbi__int32 codesize, codemask, avail, oldcode, bits, valid_bits, clear; 6258 stbi__gif_lzw *p; 6259 6260 lzw_cs = stbi__get8(s); 6261 if (lzw_cs > 12) return NULL; 6262 clear = 1 << lzw_cs; 6263 first = 1; 6264 codesize = lzw_cs + 1; 6265 codemask = (1 << codesize) - 1; 6266 bits = 0; 6267 valid_bits = 0; 6268 for (init_code = 0; init_code < clear; init_code++) { 6269 g->codes[init_code].prefix = -1; 6270 g->codes[init_code].first = (stbi_uc) init_code; 6271 g->codes[init_code].suffix = (stbi_uc) init_code; 6272 } 6273 6274 // support no starting clear code 6275 avail = clear+2; 6276 oldcode = -1; 6277 6278 len = 0; 6279 for(;;) { 6280 if (valid_bits < codesize) { 6281 if (len == 0) { 6282 len = stbi__get8(s); // start new block 6283 if (len == 0) 6284 return g->out; 6285 } 6286 --len; 6287 bits |= (stbi__int32) stbi__get8(s) << valid_bits; 6288 valid_bits += 8; 6289 } else { 6290 stbi__int32 code = bits & codemask; 6291 bits >>= codesize; 6292 valid_bits -= codesize; 6293 // @OPTIMIZE: is there some way we can accelerate the non-clear path? 6294 if (code == clear) { // clear code 6295 codesize = lzw_cs + 1; 6296 codemask = (1 << codesize) - 1; 6297 avail = clear + 2; 6298 oldcode = -1; 6299 first = 0; 6300 } else if (code == clear + 1) { // end of stream code 6301 stbi__skip(s, len); 6302 while ((len = stbi__get8(s)) > 0) 6303 stbi__skip(s,len); 6304 return g->out; 6305 } else if (code <= avail) { 6306 if (first) { 6307 return stbi__errpuc("no clear code", "Corrupt GIF"); 6308 } 6309 6310 if (oldcode >= 0) { 6311 p = &g->codes[avail++]; 6312 if (avail > 8192) { 6313 return stbi__errpuc("too many codes", "Corrupt GIF"); 6314 } 6315 6316 p->prefix = (stbi__int16) oldcode; 6317 p->first = g->codes[oldcode].first; 6318 p->suffix = (code == avail) ? p->first : g->codes[code].first; 6319 } else if (code == avail) 6320 return stbi__errpuc("illegal code in raster", "Corrupt GIF"); 6321 6322 stbi__out_gif_code(g, (stbi__uint16) code); 6323 6324 if ((avail & codemask) == 0 && avail <= 0x0FFF) { 6325 codesize++; 6326 codemask = (1 << codesize) - 1; 6327 } 6328 6329 oldcode = code; 6330 } else { 6331 return stbi__errpuc("illegal code in raster", "Corrupt GIF"); 6332 } 6333 } 6334 } 6335 } 6336 6337 // this function is designed to support animated gifs, although stb_image doesn't support it 6338 // two back is the image from two frames ago, used for a very specific disposal format 6339 static stbi_uc *stbi__gif_load_next(stbi__context *s, stbi__gif *g, int *comp, int req_comp, stbi_uc *two_back) 6340 { 6341 int dispose; 6342 int first_frame; 6343 int pi; 6344 int pcount; 6345 6346 // on first frame, any non-written pixels get the background colour (non-transparent) 6347 first_frame = 0; 6348 if (g->out == 0) { 6349 if (!stbi__gif_header(s, g, comp,0)) return 0; // stbi__g_failure_reason set by stbi__gif_header 6350 g->out = (stbi_uc *) stbi__malloc(4 * g->w * g->h); 6351 g->background = (stbi_uc *) stbi__malloc(4 * g->w * g->h); 6352 g->history = (stbi_uc *) stbi__malloc(g->w * g->h); 6353 if (g->out == 0) return stbi__errpuc("outofmem", "Out of memory"); 6354 6355 // image is treated as "tranparent" at the start - ie, nothing overwrites the current background; 6356 // background colour is only used for pixels that are not rendered first frame, after that "background" 6357 // color refers to teh color that was there the previous frame. 6358 memset( g->out, 0x00, 4 * g->w * g->h ); 6359 memset( g->background, 0x00, 4 * g->w * g->h ); // state of the background (starts transparent) 6360 memset( g->history, 0x00, g->w * g->h ); // pixels that were affected previous frame 6361 first_frame = 1; 6362 } else { 6363 // second frame - how do we dispoase of the previous one? 6364 dispose = (g->eflags & 0x1C) >> 2; 6365 pcount = g->w * g->h; 6366 6367 if ((dispose == 3) && (two_back == 0)) { 6368 dispose = 2; // if I don't have an image to revert back to, default to the old background 6369 } 6370 6371 if (dispose == 3) { // use previous graphic 6372 for (pi = 0; pi < pcount; ++pi) { 6373 if (g->history[pi]) { 6374 memcpy( &g->out[pi * 4], &two_back[pi * 4], 4 ); 6375 } 6376 } 6377 } else if (dispose == 2) { 6378 // restore what was changed last frame to background before that frame; 6379 for (pi = 0; pi < pcount; ++pi) { 6380 if (g->history[pi]) { 6381 memcpy( &g->out[pi * 4], &g->background[pi * 4], 4 ); 6382 } 6383 } 6384 } else { 6385 // This is a non-disposal case eithe way, so just 6386 // leave the pixels as is, and they will become the new background 6387 // 1: do not dispose 6388 // 0: not specified. 6389 } 6390 6391 // background is what out is after the undoing of the previou frame; 6392 memcpy( g->background, g->out, 4 * g->w * g->h ); 6393 } 6394 6395 // clear my history; 6396 memset( g->history, 0x00, g->w * g->h ); // pixels that were affected previous frame 6397 6398 for (;;) { 6399 int tag = stbi__get8(s); 6400 switch (tag) { 6401 case 0x2C: /* Image Descriptor */ 6402 { 6403 stbi__int32 x, y, w, h; 6404 stbi_uc *o; 6405 6406 x = stbi__get16le(s); 6407 y = stbi__get16le(s); 6408 w = stbi__get16le(s); 6409 h = stbi__get16le(s); 6410 if (((x + w) > (g->w)) || ((y + h) > (g->h))) 6411 return stbi__errpuc("bad Image Descriptor", "Corrupt GIF"); 6412 6413 g->line_size = g->w * 4; 6414 g->start_x = x * 4; 6415 g->start_y = y * g->line_size; 6416 g->max_x = g->start_x + w * 4; 6417 g->max_y = g->start_y + h * g->line_size; 6418 g->cur_x = g->start_x; 6419 g->cur_y = g->start_y; 6420 6421 g->lflags = stbi__get8(s); 6422 6423 if (g->lflags & 0x40) { 6424 g->step = 8 * g->line_size; // first interlaced spacing 6425 g->parse = 3; 6426 } else { 6427 g->step = g->line_size; 6428 g->parse = 0; 6429 } 6430 6431 if (g->lflags & 0x80) { 6432 stbi__gif_parse_colortable(s,g->lpal, 2 << (g->lflags & 7), g->eflags & 0x01 ? g->transparent : -1); 6433 g->color_table = (stbi_uc *) g->lpal; 6434 } else if (g->flags & 0x80) { 6435 g->color_table = (stbi_uc *) g->pal; 6436 } else 6437 return stbi__errpuc("missing color table", "Corrupt GIF"); 6438 6439 o = stbi__process_gif_raster(s, g); 6440 if (o == NULL) return NULL; 6441 6442 // if this was the first frame, 6443 pcount = g->w * g->h; 6444 if (first_frame && (g->bgindex > 0)) { 6445 // if first frame, any pixel not drawn to gets the background color 6446 for (pi = 0; pi < pcount; ++pi) { 6447 if (g->history[pi] == 0) { 6448 g->pal[g->bgindex][3] = 255; // just in case it was made transparent, undo that; It will be reset next frame if need be; 6449 memcpy( &g->out[pi * 4], &g->pal[g->bgindex], 4 ); 6450 } 6451 } 6452 } 6453 6454 return o; 6455 } 6456 6457 case 0x21: // Comment Extension. 6458 { 6459 int len; 6460 int ext = stbi__get8(s); 6461 if (ext == 0xF9) { // Graphic Control Extension. 6462 len = stbi__get8(s); 6463 if (len == 4) { 6464 g->eflags = stbi__get8(s); 6465 g->delay = 10 * stbi__get16le(s); // delay - 1/100th of a second, saving as 1/1000ths. 6466 6467 // unset old transparent 6468 if (g->transparent >= 0) { 6469 g->pal[g->transparent][3] = 255; 6470 } 6471 if (g->eflags & 0x01) { 6472 g->transparent = stbi__get8(s); 6473 if (g->transparent >= 0) { 6474 g->pal[g->transparent][3] = 0; 6475 } 6476 } else { 6477 // don't need transparent 6478 stbi__skip(s, 1); 6479 g->transparent = -1; 6480 } 6481 } else { 6482 stbi__skip(s, len); 6483 break; 6484 } 6485 } 6486 while ((len = stbi__get8(s)) != 0) { 6487 stbi__skip(s, len); 6488 } 6489 break; 6490 } 6491 6492 case 0x3B: // gif stream termination code 6493 return (stbi_uc *) s; // using '1' causes warning on some compilers 6494 6495 default: 6496 return stbi__errpuc("unknown code", "Corrupt GIF"); 6497 } 6498 } 6499 } 6500 6501 static void *stbi__load_gif_main(stbi__context *s, int **delays, int *x, int *y, int *z, int *comp, int req_comp) 6502 { 6503 if (stbi__gif_test(s)) { 6504 int layers = 0; 6505 stbi_uc *u = 0; 6506 stbi_uc *out = 0; 6507 stbi_uc *two_back = 0; 6508 stbi__gif g; 6509 int stride; 6510 memset(&g, 0, sizeof(g)); 6511 if (delays) { 6512 *delays = 0; 6513 } 6514 6515 do { 6516 u = stbi__gif_load_next(s, &g, comp, req_comp, two_back); 6517 if (u == (stbi_uc *) s) u = 0; // end of animated gif marker 6518 6519 if (u) { 6520 *x = g.w; 6521 *y = g.h; 6522 ++layers; 6523 stride = g.w * g.h * 4; 6524 6525 if (out) { 6526 out = (stbi_uc*) STBI_REALLOC( out, layers * stride ); 6527 if (delays) { 6528 *delays = (int*) STBI_REALLOC( *delays, sizeof(int) * layers ); 6529 } 6530 } else { 6531 out = (stbi_uc*)stbi__malloc( layers * stride ); 6532 if (delays) { 6533 *delays = (int*) stbi__malloc( layers * sizeof(int) ); 6534 } 6535 } 6536 memcpy( out + ((layers - 1) * stride), u, stride ); 6537 if (layers >= 2) { 6538 two_back = out - 2 * stride; 6539 } 6540 6541 if (delays) { 6542 (*delays)[layers - 1U] = g.delay; 6543 } 6544 } 6545 } while (u != 0); 6546 6547 // free temp buffer; 6548 STBI_FREE(g.out); 6549 STBI_FREE(g.history); 6550 STBI_FREE(g.background); 6551 6552 // do the final conversion after loading everything; 6553 if (req_comp && req_comp != 4) 6554 out = stbi__convert_format(out, 4, req_comp, layers * g.w, g.h); 6555 6556 *z = layers; 6557 return out; 6558 } else { 6559 return stbi__errpuc("not GIF", "Image was not as a gif type."); 6560 } 6561 } 6562 6563 static void *stbi__gif_load(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri) 6564 { 6565 stbi_uc *u = 0; 6566 stbi__gif g; 6567 memset(&g, 0, sizeof(g)); 6568 6569 u = stbi__gif_load_next(s, &g, comp, req_comp, 0); 6570 if (u == (stbi_uc *) s) u = 0; // end of animated gif marker 6571 if (u) { 6572 *x = g.w; 6573 *y = g.h; 6574 6575 // moved conversion to after successful load so that the same 6576 // can be done for multiple frames. 6577 if (req_comp && req_comp != 4) 6578 u = stbi__convert_format(u, 4, req_comp, g.w, g.h); 6579 } 6580 6581 // free buffers needed for multiple frame loading; 6582 STBI_FREE(g.history); 6583 STBI_FREE(g.background); 6584 6585 return u; 6586 } 6587 6588 static int stbi__gif_info(stbi__context *s, int *x, int *y, int *comp) 6589 { 6590 return stbi__gif_info_raw(s,x,y,comp); 6591 } 6592 #endif 6593 6594 // ************************************************************************************************* 6595 // Radiance RGBE HDR loader 6596 // originally by Nicolas Schulz 6597 #ifndef STBI_NO_HDR 6598 static int stbi__hdr_test_core(stbi__context *s, const char *signature) 6599 { 6600 int i; 6601 for (i=0; signature[i]; ++i) 6602 if (stbi__get8(s) != signature[i]) 6603 return 0; 6604 stbi__rewind(s); 6605 return 1; 6606 } 6607 6608 static int stbi__hdr_test(stbi__context* s) 6609 { 6610 int r = stbi__hdr_test_core(s, "#?RADIANCE\n"); 6611 stbi__rewind(s); 6612 if(!r) { 6613 r = stbi__hdr_test_core(s, "#?RGBE\n"); 6614 stbi__rewind(s); 6615 } 6616 return r; 6617 } 6618 6619 #define STBI__HDR_BUFLEN 1024 6620 static char *stbi__hdr_gettoken(stbi__context *z, char *buffer) 6621 { 6622 int len=0; 6623 char c = '\0'; 6624 6625 c = (char) stbi__get8(z); 6626 6627 while (!stbi__at_eof(z) && c != '\n') { 6628 buffer[len++] = c; 6629 if (len == STBI__HDR_BUFLEN-1) { 6630 // flush to end of line 6631 while (!stbi__at_eof(z) && stbi__get8(z) != '\n') 6632 ; 6633 break; 6634 } 6635 c = (char) stbi__get8(z); 6636 } 6637 6638 buffer[len] = 0; 6639 return buffer; 6640 } 6641 6642 static void stbi__hdr_convert(float *output, stbi_uc *input, int req_comp) 6643 { 6644 if ( input[3] != 0 ) { 6645 float f1; 6646 // Exponent 6647 f1 = (float) ldexp(1.0f, input[3] - (int)(128 + 8)); 6648 if (req_comp <= 2) 6649 output[0] = (input[0] + input[1] + input[2]) * f1 / 3; 6650 else { 6651 output[0] = input[0] * f1; 6652 output[1] = input[1] * f1; 6653 output[2] = input[2] * f1; 6654 } 6655 if (req_comp == 2) output[1] = 1; 6656 if (req_comp == 4) output[3] = 1; 6657 } else { 6658 switch (req_comp) { 6659 case 4: output[3] = 1; /* fallthrough */ 6660 case 3: output[0] = output[1] = output[2] = 0; 6661 break; 6662 case 2: output[1] = 1; /* fallthrough */ 6663 case 1: output[0] = 0; 6664 break; 6665 } 6666 } 6667 } 6668 6669 static float *stbi__hdr_load(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri) 6670 { 6671 char buffer[STBI__HDR_BUFLEN]; 6672 char *token; 6673 int valid = 0; 6674 int width, height; 6675 stbi_uc *scanline; 6676 float *hdr_data; 6677 int len; 6678 unsigned char count, value; 6679 int i, j, k, c1,c2, z; 6680 const char *headerToken; 6681 STBI_NOTUSED(ri); 6682 6683 // Check identifier 6684 headerToken = stbi__hdr_gettoken(s,buffer); 6685 if (strcmp(headerToken, "#?RADIANCE") != 0 && strcmp(headerToken, "#?RGBE") != 0) 6686 return stbi__errpf("not HDR", "Corrupt HDR image"); 6687 6688 // Parse header 6689 for(;;) { 6690 token = stbi__hdr_gettoken(s,buffer); 6691 if (token[0] == 0) break; 6692 if (strcmp(token, "FORMAT=32-bit_rle_rgbe") == 0) valid = 1; 6693 } 6694 6695 if (!valid) return stbi__errpf("unsupported format", "Unsupported HDR format"); 6696 6697 // Parse width and height 6698 // can't use sscanf() if we're not using stdio! 6699 token = stbi__hdr_gettoken(s,buffer); 6700 if (strncmp(token, "-Y ", 3)) return stbi__errpf("unsupported data layout", "Unsupported HDR format"); 6701 token += 3; 6702 height = (int) strtol(token, &token, 10); 6703 while (*token == ' ') ++token; 6704 if (strncmp(token, "+X ", 3)) return stbi__errpf("unsupported data layout", "Unsupported HDR format"); 6705 token += 3; 6706 width = (int) strtol(token, NULL, 10); 6707 6708 *x = width; 6709 *y = height; 6710 6711 if (comp) *comp = 3; 6712 if (req_comp == 0) req_comp = 3; 6713 6714 if (!stbi__mad4sizes_valid(width, height, req_comp, sizeof(float), 0)) 6715 return stbi__errpf("too large", "HDR image is too large"); 6716 6717 // Read data 6718 hdr_data = (float *) stbi__malloc_mad4(width, height, req_comp, sizeof(float), 0); 6719 if (!hdr_data) 6720 return stbi__errpf("outofmem", "Out of memory"); 6721 6722 // Load image data 6723 // image data is stored as some number of sca 6724 if ( width < 8 || width >= 32768) { 6725 // Read flat data 6726 for (j=0; j < height; ++j) { 6727 for (i=0; i < width; ++i) { 6728 stbi_uc rgbe[4]; 6729 main_decode_loop: 6730 stbi__getn(s, rgbe, 4); 6731 stbi__hdr_convert(hdr_data + j * width * req_comp + i * req_comp, rgbe, req_comp); 6732 } 6733 } 6734 } else { 6735 // Read RLE-encoded data 6736 scanline = NULL; 6737 6738 for (j = 0; j < height; ++j) { 6739 c1 = stbi__get8(s); 6740 c2 = stbi__get8(s); 6741 len = stbi__get8(s); 6742 if (c1 != 2 || c2 != 2 || (len & 0x80)) { 6743 // not run-length encoded, so we have to actually use THIS data as a decoded 6744 // pixel (note this can't be a valid pixel--one of RGB must be >= 128) 6745 stbi_uc rgbe[4]; 6746 rgbe[0] = (stbi_uc) c1; 6747 rgbe[1] = (stbi_uc) c2; 6748 rgbe[2] = (stbi_uc) len; 6749 rgbe[3] = (stbi_uc) stbi__get8(s); 6750 stbi__hdr_convert(hdr_data, rgbe, req_comp); 6751 i = 1; 6752 j = 0; 6753 STBI_FREE(scanline); 6754 goto main_decode_loop; // yes, this makes no sense 6755 } 6756 len <<= 8; 6757 len |= stbi__get8(s); 6758 if (len != width) { STBI_FREE(hdr_data); STBI_FREE(scanline); return stbi__errpf("invalid decoded scanline length", "corrupt HDR"); } 6759 if (scanline == NULL) { 6760 scanline = (stbi_uc *) stbi__malloc_mad2(width, 4, 0); 6761 if (!scanline) { 6762 STBI_FREE(hdr_data); 6763 return stbi__errpf("outofmem", "Out of memory"); 6764 } 6765 } 6766 6767 for (k = 0; k < 4; ++k) { 6768 int nleft; 6769 i = 0; 6770 while ((nleft = width - i) > 0) { 6771 count = stbi__get8(s); 6772 if (count > 128) { 6773 // Run 6774 value = stbi__get8(s); 6775 count -= 128; 6776 if (count > nleft) { STBI_FREE(hdr_data); STBI_FREE(scanline); return stbi__errpf("corrupt", "bad RLE data in HDR"); } 6777 for (z = 0; z < count; ++z) 6778 scanline[i++ * 4 + k] = value; 6779 } else { 6780 // Dump 6781 if (count > nleft) { STBI_FREE(hdr_data); STBI_FREE(scanline); return stbi__errpf("corrupt", "bad RLE data in HDR"); } 6782 for (z = 0; z < count; ++z) 6783 scanline[i++ * 4 + k] = stbi__get8(s); 6784 } 6785 } 6786 } 6787 for (i=0; i < width; ++i) 6788 stbi__hdr_convert(hdr_data+(j*width + i)*req_comp, scanline + i*4, req_comp); 6789 } 6790 if (scanline) 6791 STBI_FREE(scanline); 6792 } 6793 6794 return hdr_data; 6795 } 6796 6797 static int stbi__hdr_info(stbi__context *s, int *x, int *y, int *comp) 6798 { 6799 char buffer[STBI__HDR_BUFLEN]; 6800 char *token; 6801 int valid = 0; 6802 int dummy; 6803 6804 if (!x) x = &dummy; 6805 if (!y) y = &dummy; 6806 if (!comp) comp = &dummy; 6807 6808 if (stbi__hdr_test(s) == 0) { 6809 stbi__rewind( s ); 6810 return 0; 6811 } 6812 6813 for(;;) { 6814 token = stbi__hdr_gettoken(s,buffer); 6815 if (token[0] == 0) break; 6816 if (strcmp(token, "FORMAT=32-bit_rle_rgbe") == 0) valid = 1; 6817 } 6818 6819 if (!valid) { 6820 stbi__rewind( s ); 6821 return 0; 6822 } 6823 token = stbi__hdr_gettoken(s,buffer); 6824 if (strncmp(token, "-Y ", 3)) { 6825 stbi__rewind( s ); 6826 return 0; 6827 } 6828 token += 3; 6829 *y = (int) strtol(token, &token, 10); 6830 while (*token == ' ') ++token; 6831 if (strncmp(token, "+X ", 3)) { 6832 stbi__rewind( s ); 6833 return 0; 6834 } 6835 token += 3; 6836 *x = (int) strtol(token, NULL, 10); 6837 *comp = 3; 6838 return 1; 6839 } 6840 #endif // STBI_NO_HDR 6841 6842 #ifndef STBI_NO_BMP 6843 static int stbi__bmp_info(stbi__context *s, int *x, int *y, int *comp) 6844 { 6845 void *p; 6846 stbi__bmp_data info; 6847 6848 info.all_a = 255; 6849 p = stbi__bmp_parse_header(s, &info); 6850 stbi__rewind( s ); 6851 if (p == NULL) 6852 return 0; 6853 if (x) *x = s->img_x; 6854 if (y) *y = s->img_y; 6855 if (comp) *comp = info.ma ? 4 : 3; 6856 return 1; 6857 } 6858 #endif 6859 6860 #ifndef STBI_NO_PSD 6861 static int stbi__psd_info(stbi__context *s, int *x, int *y, int *comp) 6862 { 6863 int channelCount, dummy, depth; 6864 if (!x) x = &dummy; 6865 if (!y) y = &dummy; 6866 if (!comp) comp = &dummy; 6867 if (stbi__get32be(s) != 0x38425053) { 6868 stbi__rewind( s ); 6869 return 0; 6870 } 6871 if (stbi__get16be(s) != 1) { 6872 stbi__rewind( s ); 6873 return 0; 6874 } 6875 stbi__skip(s, 6); 6876 channelCount = stbi__get16be(s); 6877 if (channelCount < 0 || channelCount > 16) { 6878 stbi__rewind( s ); 6879 return 0; 6880 } 6881 *y = stbi__get32be(s); 6882 *x = stbi__get32be(s); 6883 depth = stbi__get16be(s); 6884 if (depth != 8 && depth != 16) { 6885 stbi__rewind( s ); 6886 return 0; 6887 } 6888 if (stbi__get16be(s) != 3) { 6889 stbi__rewind( s ); 6890 return 0; 6891 } 6892 *comp = 4; 6893 return 1; 6894 } 6895 6896 static int stbi__psd_is16(stbi__context *s) 6897 { 6898 int channelCount, depth; 6899 if (stbi__get32be(s) != 0x38425053) { 6900 stbi__rewind( s ); 6901 return 0; 6902 } 6903 if (stbi__get16be(s) != 1) { 6904 stbi__rewind( s ); 6905 return 0; 6906 } 6907 stbi__skip(s, 6); 6908 channelCount = stbi__get16be(s); 6909 if (channelCount < 0 || channelCount > 16) { 6910 stbi__rewind( s ); 6911 return 0; 6912 } 6913 (void) stbi__get32be(s); 6914 (void) stbi__get32be(s); 6915 depth = stbi__get16be(s); 6916 if (depth != 16) { 6917 stbi__rewind( s ); 6918 return 0; 6919 } 6920 return 1; 6921 } 6922 #endif 6923 6924 #ifndef STBI_NO_PIC 6925 static int stbi__pic_info(stbi__context *s, int *x, int *y, int *comp) 6926 { 6927 int act_comp=0,num_packets=0,chained,dummy; 6928 stbi__pic_packet packets[10]; 6929 6930 if (!x) x = &dummy; 6931 if (!y) y = &dummy; 6932 if (!comp) comp = &dummy; 6933 6934 if (!stbi__pic_is4(s,"\x53\x80\xF6\x34")) { 6935 stbi__rewind(s); 6936 return 0; 6937 } 6938 6939 stbi__skip(s, 88); 6940 6941 *x = stbi__get16be(s); 6942 *y = stbi__get16be(s); 6943 if (stbi__at_eof(s)) { 6944 stbi__rewind( s); 6945 return 0; 6946 } 6947 if ( (*x) != 0 && (1 << 28) / (*x) < (*y)) { 6948 stbi__rewind( s ); 6949 return 0; 6950 } 6951 6952 stbi__skip(s, 8); 6953 6954 do { 6955 stbi__pic_packet *packet; 6956 6957 if (num_packets==sizeof(packets)/sizeof(packets[0])) 6958 return 0; 6959 6960 packet = &packets[num_packets++]; 6961 chained = stbi__get8(s); 6962 packet->size = stbi__get8(s); 6963 packet->type = stbi__get8(s); 6964 packet->channel = stbi__get8(s); 6965 act_comp |= packet->channel; 6966 6967 if (stbi__at_eof(s)) { 6968 stbi__rewind( s ); 6969 return 0; 6970 } 6971 if (packet->size != 8) { 6972 stbi__rewind( s ); 6973 return 0; 6974 } 6975 } while (chained); 6976 6977 *comp = (act_comp & 0x10 ? 4 : 3); 6978 6979 return 1; 6980 } 6981 #endif 6982 6983 // ************************************************************************************************* 6984 // Portable Gray Map and Portable Pixel Map loader 6985 // by Ken Miller 6986 // 6987 // PGM: http://netpbm.sourceforge.net/doc/pgm.html 6988 // PPM: http://netpbm.sourceforge.net/doc/ppm.html 6989 // 6990 // Known limitations: 6991 // Does not support comments in the header section 6992 // Does not support ASCII image data (formats P2 and P3) 6993 // Does not support 16-bit-per-channel 6994 6995 #ifndef STBI_NO_PNM 6996 6997 static int stbi__pnm_test(stbi__context *s) 6998 { 6999 char p, t; 7000 p = (char) stbi__get8(s); 7001 t = (char) stbi__get8(s); 7002 if (p != 'P' || (t != '5' && t != '6')) { 7003 stbi__rewind( s ); 7004 return 0; 7005 } 7006 return 1; 7007 } 7008 7009 static void *stbi__pnm_load(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri) 7010 { 7011 stbi_uc *out; 7012 STBI_NOTUSED(ri); 7013 7014 if (!stbi__pnm_info(s, (int *)&s->img_x, (int *)&s->img_y, (int *)&s->img_n)) 7015 return 0; 7016 7017 *x = s->img_x; 7018 *y = s->img_y; 7019 if (comp) *comp = s->img_n; 7020 7021 if (!stbi__mad3sizes_valid(s->img_n, s->img_x, s->img_y, 0)) 7022 return stbi__errpuc("too large", "PNM too large"); 7023 7024 out = (stbi_uc *) stbi__malloc_mad3(s->img_n, s->img_x, s->img_y, 0); 7025 if (!out) return stbi__errpuc("outofmem", "Out of memory"); 7026 stbi__getn(s, out, s->img_n * s->img_x * s->img_y); 7027 7028 if (req_comp && req_comp != s->img_n) { 7029 out = stbi__convert_format(out, s->img_n, req_comp, s->img_x, s->img_y); 7030 if (out == NULL) return out; // stbi__convert_format frees input on failure 7031 } 7032 return out; 7033 } 7034 7035 static int stbi__pnm_isspace(char c) 7036 { 7037 return c == ' ' || c == '\t' || c == '\n' || c == '\v' || c == '\f' || c == '\r'; 7038 } 7039 7040 static void stbi__pnm_skip_whitespace(stbi__context *s, char *c) 7041 { 7042 for (;;) { 7043 while (!stbi__at_eof(s) && stbi__pnm_isspace(*c)) 7044 *c = (char) stbi__get8(s); 7045 7046 if (stbi__at_eof(s) || *c != '#') 7047 break; 7048 7049 while (!stbi__at_eof(s) && *c != '\n' && *c != '\r' ) 7050 *c = (char) stbi__get8(s); 7051 } 7052 } 7053 7054 static int stbi__pnm_isdigit(char c) 7055 { 7056 return c >= '0' && c <= '9'; 7057 } 7058 7059 static int stbi__pnm_getinteger(stbi__context *s, char *c) 7060 { 7061 int value = 0; 7062 7063 while (!stbi__at_eof(s) && stbi__pnm_isdigit(*c)) { 7064 value = value*10 + (*c - '0'); 7065 *c = (char) stbi__get8(s); 7066 } 7067 7068 return value; 7069 } 7070 7071 static int stbi__pnm_info(stbi__context *s, int *x, int *y, int *comp) 7072 { 7073 int maxv, dummy; 7074 char c, p, t; 7075 7076 if (!x) x = &dummy; 7077 if (!y) y = &dummy; 7078 if (!comp) comp = &dummy; 7079 7080 stbi__rewind(s); 7081 7082 // Get identifier 7083 p = (char) stbi__get8(s); 7084 t = (char) stbi__get8(s); 7085 if (p != 'P' || (t != '5' && t != '6')) { 7086 stbi__rewind(s); 7087 return 0; 7088 } 7089 7090 *comp = (t == '6') ? 3 : 1; // '5' is 1-component .pgm; '6' is 3-component .ppm 7091 7092 c = (char) stbi__get8(s); 7093 stbi__pnm_skip_whitespace(s, &c); 7094 7095 *x = stbi__pnm_getinteger(s, &c); // read width 7096 stbi__pnm_skip_whitespace(s, &c); 7097 7098 *y = stbi__pnm_getinteger(s, &c); // read height 7099 stbi__pnm_skip_whitespace(s, &c); 7100 7101 maxv = stbi__pnm_getinteger(s, &c); // read max value 7102 7103 if (maxv > 255) 7104 return stbi__err("max value > 255", "PPM image not 8-bit"); 7105 else 7106 return 1; 7107 } 7108 #endif 7109 7110 static int stbi__info_main(stbi__context *s, int *x, int *y, int *comp) 7111 { 7112 #ifndef STBI_NO_JPEG 7113 if (stbi__jpeg_info(s, x, y, comp)) return 1; 7114 #endif 7115 7116 #ifndef STBI_NO_PNG 7117 if (stbi__png_info(s, x, y, comp)) return 1; 7118 #endif 7119 7120 #ifndef STBI_NO_GIF 7121 if (stbi__gif_info(s, x, y, comp)) return 1; 7122 #endif 7123 7124 #ifndef STBI_NO_BMP 7125 if (stbi__bmp_info(s, x, y, comp)) return 1; 7126 #endif 7127 7128 #ifndef STBI_NO_PSD 7129 if (stbi__psd_info(s, x, y, comp)) return 1; 7130 #endif 7131 7132 #ifndef STBI_NO_PIC 7133 if (stbi__pic_info(s, x, y, comp)) return 1; 7134 #endif 7135 7136 #ifndef STBI_NO_PNM 7137 if (stbi__pnm_info(s, x, y, comp)) return 1; 7138 #endif 7139 7140 #ifndef STBI_NO_HDR 7141 if (stbi__hdr_info(s, x, y, comp)) return 1; 7142 #endif 7143 7144 // test tga last because it's a crappy test! 7145 #ifndef STBI_NO_TGA 7146 if (stbi__tga_info(s, x, y, comp)) 7147 return 1; 7148 #endif 7149 return stbi__err("unknown image type", "Image not of any known type, or corrupt"); 7150 } 7151 7152 static int stbi__is_16_main(stbi__context *s) 7153 { 7154 #ifndef STBI_NO_PNG 7155 if (stbi__png_is16(s)) return 1; 7156 #endif 7157 7158 #ifndef STBI_NO_PSD 7159 if (stbi__psd_is16(s)) return 1; 7160 #endif 7161 7162 return 0; 7163 } 7164 7165 #ifndef STBI_NO_STDIO 7166 STBIDEF int stbi_info(char const *filename, int *x, int *y, int *comp) 7167 { 7168 FILE *f = stbi__fopen(filename, "rb"); 7169 int result; 7170 if (!f) return stbi__err("can't fopen", "Unable to open file"); 7171 result = stbi_info_from_file(f, x, y, comp); 7172 fclose(f); 7173 return result; 7174 } 7175 7176 STBIDEF int stbi_info_from_file(FILE *f, int *x, int *y, int *comp) 7177 { 7178 int r; 7179 stbi__context s; 7180 long pos = ftell(f); 7181 stbi__start_file(&s, f); 7182 r = stbi__info_main(&s,x,y,comp); 7183 fseek(f,pos,SEEK_SET); 7184 return r; 7185 } 7186 7187 STBIDEF int stbi_is_16_bit(char const *filename) 7188 { 7189 FILE *f = stbi__fopen(filename, "rb"); 7190 int result; 7191 if (!f) return stbi__err("can't fopen", "Unable to open file"); 7192 result = stbi_is_16_bit_from_file(f); 7193 fclose(f); 7194 return result; 7195 } 7196 7197 STBIDEF int stbi_is_16_bit_from_file(FILE *f) 7198 { 7199 int r; 7200 stbi__context s; 7201 long pos = ftell(f); 7202 stbi__start_file(&s, f); 7203 r = stbi__is_16_main(&s); 7204 fseek(f,pos,SEEK_SET); 7205 return r; 7206 } 7207 #endif // !STBI_NO_STDIO 7208 7209 STBIDEF int stbi_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp) 7210 { 7211 stbi__context s; 7212 stbi__start_mem(&s,buffer,len); 7213 return stbi__info_main(&s,x,y,comp); 7214 } 7215 7216 STBIDEF int stbi_info_from_callbacks(stbi_io_callbacks const *c, void *user, int *x, int *y, int *comp) 7217 { 7218 stbi__context s; 7219 stbi__start_callbacks(&s, (stbi_io_callbacks *) c, user); 7220 return stbi__info_main(&s,x,y,comp); 7221 } 7222 7223 STBIDEF int stbi_is_16_bit_from_memory(stbi_uc const *buffer, int len) 7224 { 7225 stbi__context s; 7226 stbi__start_mem(&s,buffer,len); 7227 return stbi__is_16_main(&s); 7228 } 7229 7230 STBIDEF int stbi_is_16_bit_from_callbacks(stbi_io_callbacks const *c, void *user) 7231 { 7232 stbi__context s; 7233 stbi__start_callbacks(&s, (stbi_io_callbacks *) c, user); 7234 return stbi__is_16_main(&s); 7235 } 7236 7237 #endif // STB_IMAGE_IMPLEMENTATION 7238 7239 /* 7240 revision history: 7241 2.19 (2018-02-11) fix warning 7242 2.18 (2018-01-30) fix warnings 7243 2.17 (2018-01-29) change sbti__shiftsigned to avoid clang -O2 bug 7244 1-bit BMP 7245 *_is_16_bit api 7246 avoid warnings 7247 2.16 (2017-07-23) all functions have 16-bit variants; 7248 STBI_NO_STDIO works again; 7249 compilation fixes; 7250 fix rounding in unpremultiply; 7251 optimize vertical flip; 7252 disable raw_len validation; 7253 documentation fixes 7254 2.15 (2017-03-18) fix png-1,2,4 bug; now all Imagenet JPGs decode; 7255 warning fixes; disable run-time SSE detection on gcc; 7256 uniform handling of optional "return" values; 7257 thread-safe initialization of zlib tables 7258 2.14 (2017-03-03) remove deprecated STBI_JPEG_OLD; fixes for Imagenet JPGs 7259 2.13 (2016-11-29) add 16-bit API, only supported for PNG right now 7260 2.12 (2016-04-02) fix typo in 2.11 PSD fix that caused crashes 7261 2.11 (2016-04-02) allocate large structures on the stack 7262 remove white matting for transparent PSD 7263 fix reported channel count for PNG & BMP 7264 re-enable SSE2 in non-gcc 64-bit 7265 support RGB-formatted JPEG 7266 read 16-bit PNGs (only as 8-bit) 7267 2.10 (2016-01-22) avoid warning introduced in 2.09 by STBI_REALLOC_SIZED 7268 2.09 (2016-01-16) allow comments in PNM files 7269 16-bit-per-pixel TGA (not bit-per-component) 7270 info() for TGA could break due to .hdr handling 7271 info() for BMP to shares code instead of sloppy parse 7272 can use STBI_REALLOC_SIZED if allocator doesn't support realloc 7273 code cleanup 7274 2.08 (2015-09-13) fix to 2.07 cleanup, reading RGB PSD as RGBA 7275 2.07 (2015-09-13) fix compiler warnings 7276 partial animated GIF support 7277 limited 16-bpc PSD support 7278 #ifdef unused functions 7279 bug with < 92 byte PIC,PNM,HDR,TGA 7280 2.06 (2015-04-19) fix bug where PSD returns wrong '*comp' value 7281 2.05 (2015-04-19) fix bug in progressive JPEG handling, fix warning 7282 2.04 (2015-04-15) try to re-enable SIMD on MinGW 64-bit 7283 2.03 (2015-04-12) extra corruption checking (mmozeiko) 7284 stbi_set_flip_vertically_on_load (nguillemot) 7285 fix NEON support; fix mingw support 7286 2.02 (2015-01-19) fix incorrect assert, fix warning 7287 2.01 (2015-01-17) fix various warnings; suppress SIMD on gcc 32-bit without -msse2 7288 2.00b (2014-12-25) fix STBI_MALLOC in progressive JPEG 7289 2.00 (2014-12-25) optimize JPG, including x86 SSE2 & NEON SIMD (ryg) 7290 progressive JPEG (stb) 7291 PGM/PPM support (Ken Miller) 7292 STBI_MALLOC,STBI_REALLOC,STBI_FREE 7293 GIF bugfix -- seemingly never worked 7294 STBI_NO_*, STBI_ONLY_* 7295 1.48 (2014-12-14) fix incorrectly-named assert() 7296 1.47 (2014-12-14) 1/2/4-bit PNG support, both direct and paletted (Omar Cornut & stb) 7297 optimize PNG (ryg) 7298 fix bug in interlaced PNG with user-specified channel count (stb) 7299 1.46 (2014-08-26) 7300 fix broken tRNS chunk (colorkey-style transparency) in non-paletted PNG 7301 1.45 (2014-08-16) 7302 fix MSVC-ARM internal compiler error by wrapping malloc 7303 1.44 (2014-08-07) 7304 various warning fixes from Ronny Chevalier 7305 1.43 (2014-07-15) 7306 fix MSVC-only compiler problem in code changed in 1.42 7307 1.42 (2014-07-09) 7308 don't define _CRT_SECURE_NO_WARNINGS (affects user code) 7309 fixes to stbi__cleanup_jpeg path 7310 added STBI_ASSERT to avoid requiring assert.h 7311 1.41 (2014-06-25) 7312 fix search&replace from 1.36 that messed up comments/error messages 7313 1.40 (2014-06-22) 7314 fix gcc struct-initialization warning 7315 1.39 (2014-06-15) 7316 fix to TGA optimization when req_comp != number of components in TGA; 7317 fix to GIF loading because BMP wasn't rewinding (whoops, no GIFs in my test suite) 7318 add support for BMP version 5 (more ignored fields) 7319 1.38 (2014-06-06) 7320 suppress MSVC warnings on integer casts truncating values 7321 fix accidental rename of 'skip' field of I/O 7322 1.37 (2014-06-04) 7323 remove duplicate typedef 7324 1.36 (2014-06-03) 7325 convert to header file single-file library 7326 if de-iphone isn't set, load iphone images color-swapped instead of returning NULL 7327 1.35 (2014-05-27) 7328 various warnings 7329 fix broken STBI_SIMD path 7330 fix bug where stbi_load_from_file no longer left file pointer in correct place 7331 fix broken non-easy path for 32-bit BMP (possibly never used) 7332 TGA optimization by Arseny Kapoulkine 7333 1.34 (unknown) 7334 use STBI_NOTUSED in stbi__resample_row_generic(), fix one more leak in tga failure case 7335 1.33 (2011-07-14) 7336 make stbi_is_hdr work in STBI_NO_HDR (as specified), minor compiler-friendly improvements 7337 1.32 (2011-07-13) 7338 support for "info" function for all supported filetypes (SpartanJ) 7339 1.31 (2011-06-20) 7340 a few more leak fixes, bug in PNG handling (SpartanJ) 7341 1.30 (2011-06-11) 7342 added ability to load files via callbacks to accomidate custom input streams (Ben Wenger) 7343 removed deprecated format-specific test/load functions 7344 removed support for installable file formats (stbi_loader) -- would have been broken for IO callbacks anyway 7345 error cases in bmp and tga give messages and don't leak (Raymond Barbiero, grisha) 7346 fix inefficiency in decoding 32-bit BMP (David Woo) 7347 1.29 (2010-08-16) 7348 various warning fixes from Aurelien Pocheville 7349 1.28 (2010-08-01) 7350 fix bug in GIF palette transparency (SpartanJ) 7351 1.27 (2010-08-01) 7352 cast-to-stbi_uc to fix warnings 7353 1.26 (2010-07-24) 7354 fix bug in file buffering for PNG reported by SpartanJ 7355 1.25 (2010-07-17) 7356 refix trans_data warning (Won Chun) 7357 1.24 (2010-07-12) 7358 perf improvements reading from files on platforms with lock-heavy fgetc() 7359 minor perf improvements for jpeg 7360 deprecated type-specific functions so we'll get feedback if they're needed 7361 attempt to fix trans_data warning (Won Chun) 7362 1.23 fixed bug in iPhone support 7363 1.22 (2010-07-10) 7364 removed image *writing* support 7365 stbi_info support from Jetro Lauha 7366 GIF support from Jean-Marc Lienher 7367 iPhone PNG-extensions from James Brown 7368 warning-fixes from Nicolas Schulz and Janez Zemva (i.stbi__err. Janez (U+017D)emva) 7369 1.21 fix use of 'stbi_uc' in header (reported by jon blow) 7370 1.20 added support for Softimage PIC, by Tom Seddon 7371 1.19 bug in interlaced PNG corruption check (found by ryg) 7372 1.18 (2008-08-02) 7373 fix a threading bug (local mutable static) 7374 1.17 support interlaced PNG 7375 1.16 major bugfix - stbi__convert_format converted one too many pixels 7376 1.15 initialize some fields for thread safety 7377 1.14 fix threadsafe conversion bug 7378 header-file-only version (#define STBI_HEADER_FILE_ONLY before including) 7379 1.13 threadsafe 7380 1.12 const qualifiers in the API 7381 1.11 Support installable IDCT, colorspace conversion routines 7382 1.10 Fixes for 64-bit (don't use "unsigned long") 7383 optimized upsampling by Fabian "ryg" Giesen 7384 1.09 Fix format-conversion for PSD code (bad global variables!) 7385 1.08 Thatcher Ulrich's PSD code integrated by Nicolas Schulz 7386 1.07 attempt to fix C++ warning/errors again 7387 1.06 attempt to fix C++ warning/errors again 7388 1.05 fix TGA loading to return correct *comp and use good luminance calc 7389 1.04 default float alpha is 1, not 255; use 'void *' for stbi_image_free 7390 1.03 bugfixes to STBI_NO_STDIO, STBI_NO_HDR 7391 1.02 support for (subset of) HDR files, float interface for preferred access to them 7392 1.01 fix bug: possible bug in handling right-side up bmps... not sure 7393 fix bug: the stbi__bmp_load() and stbi__tga_load() functions didn't work at all 7394 1.00 interface to zlib that skips zlib header 7395 0.99 correct handling of alpha in palette 7396 0.98 TGA loader by lonesock; dynamically add loaders (untested) 7397 0.97 jpeg errors on too large a file; also catch another malloc failure 7398 0.96 fix detection of invalid v value - particleman@mollyrocket forum 7399 0.95 during header scan, seek to markers in case of padding 7400 0.94 STBI_NO_STDIO to disable stdio usage; rename all #defines the same 7401 0.93 handle jpegtran output; verbose errors 7402 0.92 read 4,8,16,24,32-bit BMP files of several formats 7403 0.91 output 24-bit Windows 3.0 BMP files 7404 0.90 fix a few more warnings; bump version number to approach 1.0 7405 0.61 bugfixes due to Marc LeBlanc, Christopher Lloyd 7406 0.60 fix compiling as c++ 7407 0.59 fix warnings: merge Dave Moore's -Wall fixes 7408 0.58 fix bug: zlib uncompressed mode len/nlen was wrong endian 7409 0.57 fix bug: jpg last huffman symbol before marker was >9 bits but less than 16 available 7410 0.56 fix bug: zlib uncompressed mode len vs. nlen 7411 0.55 fix bug: restart_interval not initialized to 0 7412 0.54 allow NULL for 'int *comp' 7413 0.53 fix bug in png 3->4; speedup png decoding 7414 0.52 png handles req_comp=3,4 directly; minor cleanup; jpeg comments 7415 0.51 obey req_comp requests, 1-component jpegs return as 1-component, 7416 on 'test' only check type, not whether we support this variant 7417 0.50 (2006-11-19) 7418 first released version 7419 */ 7420 7421 7422 /* 7423 ------------------------------------------------------------------------------ 7424 This software is available under 2 licenses -- choose whichever you prefer. 7425 ------------------------------------------------------------------------------ 7426 ALTERNATIVE A - MIT License 7427 Copyright (c) 2017 Sean Barrett 7428 Permission is hereby granted, free of charge, to any person obtaining a copy of 7429 this software and associated documentation files (the "Software"), to deal in 7430 the Software without restriction, including without limitation the rights to 7431 use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies 7432 of the Software, and to permit persons to whom the Software is furnished to do 7433 so, subject to the following conditions: 7434 The above copyright notice and this permission notice shall be included in all 7435 copies or substantial portions of the Software. 7436 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 7437 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 7438 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 7439 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 7440 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 7441 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 7442 SOFTWARE. 7443 ------------------------------------------------------------------------------ 7444 ALTERNATIVE B - Public Domain (www.unlicense.org) 7445 This is free and unencumbered software released into the public domain. 7446 Anyone is free to copy, modify, publish, use, compile, sell, or distribute this 7447 software, either in source code form or as a compiled binary, for any purpose, 7448 commercial or non-commercial, and by any means. 7449 In jurisdictions that recognize copyright laws, the author or authors of this 7450 software dedicate any and all copyright interest in the software to the public 7451 domain. We make this dedication for the benefit of the public at large and to 7452 the detriment of our heirs and successors. We intend this dedication to be an 7453 overt act of relinquishment in perpetuity of all present and future rights to 7454 this software under copyright law. 7455 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 7456 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 7457 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 7458 AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN 7459 ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 7460 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 7461 ------------------------------------------------------------------------------ 7462 */