stb_image.c revision 1.7
1/* stbi-1.29 - public domain JPEG/PNG reader - http://nothings.org/stb_image.c 2 when you control the images you're loading 3 no warranty implied; use at your own risk 4 5 QUICK NOTES: 6 Primarily of interest to game developers and other people who can 7 avoid problematic images and only need the trivial interface 8 9 JPEG baseline (no JPEG progressive) 10 PNG 8-bit only 11 12 TGA (not sure what subset, if a subset) 13 BMP non-1bpp, non-RLE 14 PSD (composited view only, no extra channels) 15 16 GIF (*comp always reports as 4-channel) 17 HDR (radiance rgbE format) 18 PIC (Softimage PIC) 19 20 - decoded from memory or through stdio FILE (define STBI_NO_STDIO to remove code) 21 - supports installable dequantizing-IDCT, YCbCr-to-RGB conversion (define STBI_SIMD) 22 23 Latest revisions: 24 1.29 (2010-08-16) various warning fixes from Aurelien Pocheville 25 1.28 (2010-08-01) fix bug in GIF palette transparency (SpartanJ) 26 1.27 (2010-08-01) cast-to-uint8 to fix warnings (Laurent Gomila) 27 allow trailing 0s at end of image data (Laurent Gomila) 28 1.26 (2010-07-24) fix bug in file buffering for PNG reported by SpartanJ 29 1.25 (2010-07-17) refix trans_data warning (Won Chun) 30 1.24 (2010-07-12) perf improvements reading from files 31 minor perf improvements for jpeg 32 deprecated type-specific functions in hope of feedback 33 attempt to fix trans_data warning (Won Chun) 34 1.23 fixed bug in iPhone support 35 1.22 (2010-07-10) removed image *writing* support to stb_image_write.h 36 stbi_info support from Jetro Lauha 37 GIF support from Jean-Marc Lienher 38 iPhone PNG-extensions from James Brown 39 warning-fixes from Nicolas Schulz and Janez Zemva 40 1.21 fix use of 'uint8' in header (reported by jon blow) 41 1.20 added support for Softimage PIC, by Tom Seddon 42 43 See end of file for full revision history. 44 45 TODO: 46 stbi_info support for BMP,PSD,HDR,PIC 47 rewrite stbi_info and load_file variations to share file handling code 48 (current system allows individual functions to be called directly, 49 since each does all the work, but I doubt anyone uses this in practice) 50 51 52 ============================ Contributors ========================= 53 54 Image formats Optimizations & bugfixes 55 Sean Barrett (jpeg, png, bmp) Fabian "ryg" Giesen 56 Nicolas Schulz (hdr, psd) 57 Jonathan Dummer (tga) Bug fixes & warning fixes 58 Jean-Marc Lienher (gif) Marc LeBlanc 59 Tom Seddon (pic) Christpher Lloyd 60 Thatcher Ulrich (psd) Dave Moore 61 Won Chun 62 the Horde3D community 63 Extensions, features Janez Zemva 64 Jetro Lauha (stbi_info) Jonathan Blow 65 James "moose2000" Brown (iPhone PNG) Laurent Gomila 66 Aruelien Pocheville 67 68 If your name should be here but isn't, let Sean know. 69 70*/ 71 72#ifdef _KERNEL 73#include <dev/stbi/stbiconfig.h> 74#endif 75 76#ifndef STBI_INCLUDE_STB_IMAGE_H 77#define STBI_INCLUDE_STB_IMAGE_H 78 79// To get a header file for this, either cut and paste the header, 80// or create stb_image.h, #define STBI_HEADER_FILE_ONLY, and 81// then include stb_image.c from it. 82 83//// begin header file //////////////////////////////////////////////////// 84// 85// Limitations: 86// - no jpeg progressive support 87// - non-HDR formats support 8-bit samples only (jpeg, png) 88// - no delayed line count (jpeg) -- IJG doesn't support either 89// - no 1-bit BMP 90// - GIF always returns *comp=4 91// 92// Basic usage (see HDR discussion below): 93// int x,y,n; 94// unsigned char *data = stbi_load(filename, &x, &y, &n, 0); 95// // ... process data if not NULL ... 96// // ... x = width, y = height, n = # 8-bit components per pixel ... 97// // ... replace '0' with '1'..'4' to force that many components per pixel 98// stbi_image_free(data) 99// 100// Standard parameters: 101// int *x -- outputs image width in pixels 102// int *y -- outputs image height in pixels 103// int *comp -- outputs # of image components in image file 104// int req_comp -- if non-zero, # of image components requested in result 105// 106// The return value from an image loader is an 'unsigned char *' which points 107// to the pixel data. The pixel data consists of *y scanlines of *x pixels, 108// with each pixel consisting of N interleaved 8-bit components; the first 109// pixel pointed to is top-left-most in the image. There is no padding between 110// image scanlines or between pixels, regardless of format. The number of 111// components N is 'req_comp' if req_comp is non-zero, or *comp otherwise. 112// If req_comp is non-zero, *comp has the number of components that _would_ 113// have been output otherwise. E.g. if you set req_comp to 4, you will always 114// get RGBA output, but you can check *comp to easily see if it's opaque. 115// 116// An output image with N components has the following components interleaved 117// in this order in each pixel: 118// 119// N=#comp components 120// 1 grey 121// 2 grey, alpha 122// 3 red, green, blue 123// 4 red, green, blue, alpha 124// 125// If image loading fails for any reason, the return value will be NULL, 126// and *x, *y, *comp will be unchanged. The function stbi_failure_reason() 127// can be queried for an extremely brief, end-user unfriendly explanation 128// of why the load failed. Define STBI_NO_FAILURE_STRINGS to avoid 129// compiling these strings at all, and STBI_FAILURE_USERMSG to get slightly 130// more user-friendly ones. 131// 132// Paletted PNG, BMP, GIF, and PIC images are automatically depalettized. 133// 134// =========================================================================== 135// 136// iPhone PNG support: 137// 138// By default we convert iphone-formatted PNGs back to RGB; nominally they 139// would silently load as BGR, except the existing code should have just 140// failed on such iPhone PNGs. But you can disable this conversion by 141// by calling stbi_convert_iphone_png_to_rgb(0), in which case 142// you will always just get the native iphone "format" through. 143// 144// Call stbi_set_unpremultiply_on_load(1) as well to force a divide per 145// pixel to remove any premultiplied alpha *only* if the image file explicitly 146// says there's premultiplied data (currently only happens in iPhone images, 147// and only if iPhone convert-to-rgb processing is on). 148// 149// =========================================================================== 150// 151// HDR image support (disable by defining STBI_NO_HDR) 152// 153// stb_image now supports loading HDR images in general, and currently 154// the Radiance .HDR file format, although the support is provided 155// generically. You can still load any file through the existing interface; 156// if you attempt to load an HDR file, it will be automatically remapped to 157// LDR, assuming gamma 2.2 and an arbitrary scale factor defaulting to 1; 158// both of these constants can be reconfigured through this interface: 159// 160// stbi_hdr_to_ldr_gamma(2.2f); 161// stbi_hdr_to_ldr_scale(1.0f); 162// 163// (note, do not use _inverse_ constants; stbi_image will invert them 164// appropriately). 165// 166// Additionally, there is a new, parallel interface for loading files as 167// (linear) floats to preserve the full dynamic range: 168// 169// float *data = stbi_loadf(filename, &x, &y, &n, 0); 170// 171// If you load LDR images through this interface, those images will 172// be promoted to floating point values, run through the inverse of 173// constants corresponding to the above: 174// 175// stbi_ldr_to_hdr_scale(1.0f); 176// stbi_ldr_to_hdr_gamma(2.2f); 177// 178// Finally, given a filename (or an open file or memory block--see header 179// file for details) containing image data, you can query for the "most 180// appropriate" interface to use (that is, whether the image is HDR or 181// not), using: 182// 183// stbi_is_hdr(char *filename); 184 185#ifndef STBI_NO_STDIO 186#include <stdio.h> 187#endif 188 189#define STBI_VERSION 1 190 191enum 192{ 193 STBI_default = 0, // only used for req_comp 194 195 STBI_grey = 1, 196 STBI_grey_alpha = 2, 197 STBI_rgb = 3, 198 STBI_rgb_alpha = 4 199}; 200 201typedef unsigned char stbi_uc; 202 203#ifdef __cplusplus 204extern "C" { 205#endif 206 207// PRIMARY API - works on images of any type 208 209// load image by filename, open file, or memory buffer 210extern stbi_uc *stbi_load_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 211 212#ifndef STBI_NO_STDIO 213extern stbi_uc *stbi_load (char const *filename, int *x, int *y, int *comp, int req_comp); 214extern stbi_uc *stbi_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); 215// for stbi_load_from_file, file pointer is left pointing immediately after image 216#endif 217 218#ifndef STBI_NO_HDR 219 extern float *stbi_loadf_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 220 221 #ifndef STBI_NO_STDIO 222 extern float *stbi_loadf (char const *filename, int *x, int *y, int *comp, int req_comp); 223 extern float *stbi_loadf_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); 224 #endif 225 226 extern void stbi_hdr_to_ldr_gamma(float gamma); 227 extern void stbi_hdr_to_ldr_scale(float scale); 228 229 extern void stbi_ldr_to_hdr_gamma(float gamma); 230 extern void stbi_ldr_to_hdr_scale(float scale); 231#endif // STBI_NO_HDR 232 233// get a VERY brief reason for failure 234// NOT THREADSAFE 235extern const char *stbi_failure_reason (void); 236 237// free the loaded image -- this is just free() 238extern void stbi_image_free (void *retval_from_stbi_load); 239 240// get image dimensions & components without fully decoding 241extern int stbi_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp); 242extern int stbi_is_hdr_from_memory(stbi_uc const *buffer, int len); 243 244#ifndef STBI_NO_STDIO 245extern int stbi_info (char const *filename, int *x, int *y, int *comp); 246extern int stbi_info_from_file (FILE *f, int *x, int *y, int *comp); 247 248extern int stbi_is_hdr (char const *filename); 249extern int stbi_is_hdr_from_file(FILE *f); 250#endif 251 252// for image formats that explicitly notate that they have premultiplied alpha, 253// we just return the colors as stored in the file. set this flag to force 254// unpremultiplication. results are undefined if the unpremultiply overflow. 255extern void stbi_set_unpremultiply_on_load(int flag_true_if_should_unpremultiply); 256 257// indicate whether we should process iphone images back to canonical format, 258// or just pass them through "as-is" 259extern void stbi_convert_iphone_png_to_rgb(int flag_true_if_should_convert); 260 261 262// ZLIB client - used by PNG, available for other purposes 263 264extern char *stbi_zlib_decode_malloc_guesssize(const char *buffer, int len, int initial_size, int *outlen); 265extern char *stbi_zlib_decode_malloc_guesssize_headerflag(const char *buffer, int len, int initial_size, int *outlen, int parse_header); 266extern char *stbi_zlib_decode_malloc(const char *buffer, int len, int *outlen); 267extern int stbi_zlib_decode_buffer(char *obuffer, int olen, const char *ibuffer, int ilen); 268 269extern char *stbi_zlib_decode_noheader_malloc(const char *buffer, int len, int *outlen); 270extern int stbi_zlib_decode_noheader_buffer(char *obuffer, int olen, const char *ibuffer, int ilen); 271 272// define new loaders 273typedef struct 274{ 275 int (*test_memory)(stbi_uc const *buffer, int len); 276 stbi_uc * (*load_from_memory)(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 277 #ifndef STBI_NO_STDIO 278 int (*test_file)(FILE *f); 279 stbi_uc * (*load_from_file)(FILE *f, int *x, int *y, int *comp, int req_comp); 280 #endif 281} stbi_loader; 282 283// register a loader by filling out the above structure (you must define ALL functions) 284// returns 1 if added or already added, 0 if not added (too many loaders) 285// NOT THREADSAFE 286extern int stbi_register_loader(stbi_loader *loader); 287 288// define faster low-level operations (typically SIMD support) 289#ifdef STBI_SIMD 290typedef void (*stbi_idct_8x8)(stbi_uc *out, int out_stride, short data[64], unsigned short *dequantize); 291// compute an integer IDCT on "input" 292// input[x] = data[x] * dequantize[x] 293// write results to 'out': 64 samples, each run of 8 spaced by 'out_stride' 294// CLAMP results to 0..255 295typedef void (*stbi_YCbCr_to_RGB_run)(stbi_uc *output, stbi_uc const *y, stbi_uc const *cb, stbi_uc const *cr, int count, int step); 296// compute a conversion from YCbCr to RGB 297// 'count' pixels 298// write pixels to 'output'; each pixel is 'step' bytes (either 3 or 4; if 4, write '255' as 4th), order R,G,B 299// y: Y input channel 300// cb: Cb input channel; scale/biased to be 0..255 301// cr: Cr input channel; scale/biased to be 0..255 302 303extern void stbi_install_idct(stbi_idct_8x8 func); 304extern void stbi_install_YCbCr_to_RGB(stbi_YCbCr_to_RGB_run func); 305#endif // STBI_SIMD 306 307 308 309 310// TYPE-SPECIFIC ACCESS 311 312#ifdef STBI_TYPE_SPECIFIC_FUNCTIONS 313 314// is it a jpeg? 315extern int stbi_jpeg_test_memory (stbi_uc const *buffer, int len); 316extern stbi_uc *stbi_jpeg_load_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 317extern int stbi_jpeg_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp); 318 319#ifndef STBI_NO_STDIO 320extern stbi_uc *stbi_jpeg_load (char const *filename, int *x, int *y, int *comp, int req_comp); 321extern int stbi_jpeg_test_file (FILE *f); 322extern stbi_uc *stbi_jpeg_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); 323 324extern int stbi_jpeg_info (char const *filename, int *x, int *y, int *comp); 325extern int stbi_jpeg_info_from_file (FILE *f, int *x, int *y, int *comp); 326#endif 327 328// is it a png? 329extern int stbi_png_test_memory (stbi_uc const *buffer, int len); 330extern stbi_uc *stbi_png_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 331extern int stbi_png_info_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp); 332 333#ifndef STBI_NO_STDIO 334extern stbi_uc *stbi_png_load (char const *filename, int *x, int *y, int *comp, int req_comp); 335extern int stbi_png_info (char const *filename, int *x, int *y, int *comp); 336extern int stbi_png_test_file (FILE *f); 337extern stbi_uc *stbi_png_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); 338extern int stbi_png_info_from_file (FILE *f, int *x, int *y, int *comp); 339#endif 340 341// is it a bmp? 342extern int stbi_bmp_test_memory (stbi_uc const *buffer, int len); 343 344extern stbi_uc *stbi_bmp_load (char const *filename, int *x, int *y, int *comp, int req_comp); 345extern stbi_uc *stbi_bmp_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 346#ifndef STBI_NO_STDIO 347extern int stbi_bmp_test_file (FILE *f); 348extern stbi_uc *stbi_bmp_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); 349#endif 350 351// is it a tga? 352extern int stbi_tga_test_memory (stbi_uc const *buffer, int len); 353 354extern stbi_uc *stbi_tga_load (char const *filename, int *x, int *y, int *comp, int req_comp); 355extern stbi_uc *stbi_tga_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 356extern int stbi_tga_info_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp); 357#ifndef STBI_NO_STDIO 358extern int stbi_tga_info_from_file (FILE *f, int *x, int *y, int *comp); 359extern int stbi_tga_test_file (FILE *f); 360extern stbi_uc *stbi_tga_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); 361#endif 362 363// is it a psd? 364extern int stbi_psd_test_memory (stbi_uc const *buffer, int len); 365 366extern stbi_uc *stbi_psd_load (char const *filename, int *x, int *y, int *comp, int req_comp); 367extern stbi_uc *stbi_psd_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 368#ifndef STBI_NO_STDIO 369extern int stbi_psd_test_file (FILE *f); 370extern stbi_uc *stbi_psd_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); 371#endif 372 373// is it an hdr? 374extern int stbi_hdr_test_memory (stbi_uc const *buffer, int len); 375 376extern float * stbi_hdr_load (char const *filename, int *x, int *y, int *comp, int req_comp); 377extern float * stbi_hdr_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 378#ifndef STBI_NO_STDIO 379extern int stbi_hdr_test_file (FILE *f); 380extern float * stbi_hdr_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); 381#endif 382 383// is it a pic? 384extern int stbi_pic_test_memory (stbi_uc const *buffer, int len); 385 386extern stbi_uc *stbi_pic_load (char const *filename, int *x, int *y, int *comp, int req_comp); 387extern stbi_uc *stbi_pic_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 388#ifndef STBI_NO_STDIO 389extern int stbi_pic_test_file (FILE *f); 390extern stbi_uc *stbi_pic_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); 391#endif 392 393// is it a gif? 394extern int stbi_gif_test_memory (stbi_uc const *buffer, int len); 395 396extern stbi_uc *stbi_gif_load (char const *filename, int *x, int *y, int *comp, int req_comp); 397extern stbi_uc *stbi_gif_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 398extern int stbi_gif_info_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp); 399 400#ifndef STBI_NO_STDIO 401extern int stbi_gif_test_file (FILE *f); 402extern stbi_uc *stbi_gif_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); 403extern int stbi_gif_info (char const *filename, int *x, int *y, int *comp); 404extern int stbi_gif_info_from_file (FILE *f, int *x, int *y, int *comp); 405#endif 406 407#endif//STBI_TYPE_SPECIFIC_FUNCTIONS 408 409 410 411 412#ifdef __cplusplus 413} 414#endif 415 416// 417// 418//// end header file ///////////////////////////////////////////////////// 419#endif // STBI_INCLUDE_STB_IMAGE_H 420 421#ifndef STBI_HEADER_FILE_ONLY 422 423#ifndef STBI_NO_HDR 424#include <math.h> // ldexp 425#include <string.h> // strcmp 426#endif 427 428#ifndef STBI_NO_STDIO 429#include <stdio.h> 430#endif 431#ifdef _KERNEL 432#include <sys/cdefs.h> 433__KERNEL_RCSID(0, "$NetBSD: stb_image.c,v 1.7 2016/01/21 17:16:48 christos Exp $"); 434#include <sys/param.h> 435#include <sys/systm.h> 436#include <sys/kernel.h> 437#include <sys/types.h> 438#include <sys/malloc.h> 439#else 440#include <stdlib.h> 441#include <memory.h> 442#include <assert.h> 443#include <stdarg.h> 444#endif 445 446#ifdef _KERNEL 447#define MALLOC(size) malloc((size), M_TEMP, M_WAITOK) 448#define REALLOC(ptr, size) realloc((ptr), (size), M_TEMP, M_WAITOK) 449#define FREE(ptr) \ 450 do { if (ptr) free((ptr), M_TEMP); } while (/*CONSTCOND*/0) 451#else 452#define MALLOC(size) malloc((size)) 453#define REALLOC(ptr, size) realloc((ptr), (size)) 454#define FREE(ptr) free((ptr)) 455#endif 456 457#ifndef _MSC_VER 458 #ifdef __cplusplus 459 #define __forceinline inline 460 #else 461 #define __forceinline 462 #endif 463#endif 464 465 466// implementation: 467typedef unsigned char uint8; 468typedef unsigned short uint16; 469typedef signed short int16; 470typedef unsigned int uint32; 471typedef signed int int32; 472#ifndef __NetBSD__ 473typedef unsigned int uint; 474#endif 475 476// should produce compiler error if size is wrong 477typedef unsigned char validate_uint32[sizeof(uint32)==4 ? 1 : -1]; 478 479#if defined(STBI_NO_STDIO) && !defined(STBI_NO_WRITE) 480#define STBI_NO_WRITE 481#endif 482 483#define STBI_NOTUSED(v) v=v 484 485#ifdef _MSC_VER 486#define STBI_HAS_LRTOL 487#endif 488 489#ifdef STBI_HAS_LRTOL 490 #define stbi_lrot(x,y) _lrotl(x,y) 491#else 492 #define stbi_lrot(x,y) (((x) << (y)) | ((x) >> (32 - (y)))) 493#endif 494 495////////////////////////////////////////////////////////////////////////////// 496// 497// Generic API that works on all image types 498// 499 500// deprecated functions 501 502// is it a jpeg? 503extern int stbi_jpeg_test_memory (stbi_uc const *buffer, int len); 504extern stbi_uc *stbi_jpeg_load_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 505extern int stbi_jpeg_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp); 506 507#ifndef STBI_NO_STDIO 508extern stbi_uc *stbi_jpeg_load (char const *filename, int *x, int *y, int *comp, int req_comp); 509extern int stbi_jpeg_test_file (FILE *f); 510extern stbi_uc *stbi_jpeg_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); 511 512extern int stbi_jpeg_info (char const *filename, int *x, int *y, int *comp); 513extern int stbi_jpeg_info_from_file (FILE *f, int *x, int *y, int *comp); 514#endif 515 516// is it a png? 517extern int stbi_png_test_memory (stbi_uc const *buffer, int len); 518extern stbi_uc *stbi_png_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 519extern int stbi_png_info_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp); 520 521#ifndef STBI_NO_STDIO 522extern stbi_uc *stbi_png_load (char const *filename, int *x, int *y, int *comp, int req_comp); 523extern int stbi_png_info (char const *filename, int *x, int *y, int *comp); 524extern int stbi_png_test_file (FILE *f); 525extern stbi_uc *stbi_png_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); 526extern int stbi_png_info_from_file (FILE *f, int *x, int *y, int *comp); 527#endif 528 529// is it a bmp? 530extern int stbi_bmp_test_memory (stbi_uc const *buffer, int len); 531 532extern stbi_uc *stbi_bmp_load (char const *filename, int *x, int *y, int *comp, int req_comp); 533extern stbi_uc *stbi_bmp_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 534#ifndef STBI_NO_STDIO 535extern int stbi_bmp_test_file (FILE *f); 536extern stbi_uc *stbi_bmp_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); 537#endif 538 539// is it a tga? 540extern int stbi_tga_test_memory (stbi_uc const *buffer, int len); 541 542extern stbi_uc *stbi_tga_load (char const *filename, int *x, int *y, int *comp, int req_comp); 543extern stbi_uc *stbi_tga_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 544#ifndef STBI_NO_STDIO 545extern int stbi_tga_test_file (FILE *f); 546extern stbi_uc *stbi_tga_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); 547#endif 548 549// is it a psd? 550extern int stbi_psd_test_memory (stbi_uc const *buffer, int len); 551 552extern stbi_uc *stbi_psd_load (char const *filename, int *x, int *y, int *comp, int req_comp); 553extern stbi_uc *stbi_psd_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 554#ifndef STBI_NO_STDIO 555extern int stbi_psd_test_file (FILE *f); 556extern stbi_uc *stbi_psd_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); 557#endif 558 559// is it an hdr? 560extern int stbi_hdr_test_memory (stbi_uc const *buffer, int len); 561 562extern float * stbi_hdr_load (char const *filename, int *x, int *y, int *comp, int req_comp); 563extern float * stbi_hdr_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 564#ifndef STBI_NO_STDIO 565extern int stbi_hdr_test_file (FILE *f); 566extern float * stbi_hdr_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); 567#endif 568 569// is it a pic? 570extern int stbi_pic_test_memory (stbi_uc const *buffer, int len); 571 572extern stbi_uc *stbi_pic_load (char const *filename, int *x, int *y, int *comp, int req_comp); 573extern stbi_uc *stbi_pic_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 574#ifndef STBI_NO_STDIO 575extern int stbi_pic_test_file (FILE *f); 576extern stbi_uc *stbi_pic_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); 577#endif 578 579// is it a gif? 580extern int stbi_gif_test_memory (stbi_uc const *buffer, int len); 581 582extern stbi_uc *stbi_gif_load (char const *filename, int *x, int *y, int *comp, int req_comp); 583extern stbi_uc *stbi_gif_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 584extern int stbi_gif_info_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp); 585 586#ifndef STBI_NO_STDIO 587extern int stbi_gif_test_file (FILE *f); 588extern stbi_uc *stbi_gif_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); 589extern int stbi_gif_info (char const *filename, int *x, int *y, int *comp); 590extern int stbi_gif_info_from_file (FILE *f, int *x, int *y, int *comp); 591#endif 592 593 594// this is not threadsafe 595static const char *failure_reason; 596 597const char *stbi_failure_reason(void) 598{ 599 return failure_reason; 600} 601 602#ifndef STBI_NO_FAILURE_STRINGS 603static int e(const char *str) 604{ 605 failure_reason = str; 606 return 0; 607} 608#endif 609 610#ifdef STBI_NO_FAILURE_STRINGS 611 #define e(x,y) 0 612#elif defined(STBI_FAILURE_USERMSG) 613 #define e(x,y) e(y) 614#else 615 #define e(x,y) e(x) 616#endif 617 618#define epf(x,y) ((float *) (e(x,y)?NULL:NULL)) 619#define epuc(x,y) ((unsigned char *) (e(x,y)?NULL:NULL)) 620 621void stbi_image_free(void *retval_from_stbi_load) 622{ 623 FREE(retval_from_stbi_load); 624} 625 626#define MAX_LOADERS 32 627stbi_loader *loaders[MAX_LOADERS]; 628static int max_loaders = 0; 629 630int stbi_register_loader(stbi_loader *loader) 631{ 632 int i; 633 for (i=0; i < MAX_LOADERS; ++i) { 634 // already present? 635 if (loaders[i] == loader) 636 return 1; 637 // end of the list? 638 if (loaders[i] == NULL) { 639 loaders[i] = loader; 640 max_loaders = i+1; 641 return 1; 642 } 643 } 644 // no room for it 645 return 0; 646} 647 648#ifndef STBI_NO_HDR 649static float *ldr_to_hdr(stbi_uc *data, int x, int y, int comp); 650static stbi_uc *hdr_to_ldr(float *data, int x, int y, int comp); 651#endif 652 653#ifndef STBI_NO_STDIO 654unsigned char *stbi_load(char const *filename, int *x, int *y, int *comp, int req_comp) 655{ 656 FILE *f = fopen(filename, "rb"); 657 unsigned char *result; 658 if (!f) return epuc("can't fopen", "Unable to open file"); 659 result = stbi_load_from_file(f,x,y,comp,req_comp); 660 fclose(f); 661 return result; 662} 663 664unsigned char *stbi_load_from_file(FILE *f, int *x, int *y, int *comp, int req_comp) 665{ 666 int i; 667 if (stbi_jpeg_test_file(f)) return stbi_jpeg_load_from_file(f,x,y,comp,req_comp); 668 if (stbi_png_test_file(f)) return stbi_png_load_from_file(f,x,y,comp,req_comp); 669 if (stbi_bmp_test_file(f)) return stbi_bmp_load_from_file(f,x,y,comp,req_comp); 670 if (stbi_gif_test_file(f)) return stbi_gif_load_from_file(f,x,y,comp,req_comp); 671 if (stbi_psd_test_file(f)) return stbi_psd_load_from_file(f,x,y,comp,req_comp); 672 if (stbi_pic_test_file(f)) return stbi_pic_load_from_file(f,x,y,comp,req_comp); 673 674 #ifndef STBI_NO_HDR 675 if (stbi_hdr_test_file(f)) { 676 float *hdr = stbi_hdr_load_from_file(f, x,y,comp,req_comp); 677 return hdr_to_ldr(hdr, *x, *y, req_comp ? req_comp : *comp); 678 } 679 #endif 680 681 for (i=0; i < max_loaders; ++i) 682 if (loaders[i]->test_file(f)) 683 return loaders[i]->load_from_file(f,x,y,comp,req_comp); 684 // test tga last because it's a crappy test! 685 if (stbi_tga_test_file(f)) 686 return stbi_tga_load_from_file(f,x,y,comp,req_comp); 687 return epuc("unknown image type", "Image not of any known type, or corrupt"); 688} 689#endif 690 691unsigned char *stbi_load_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) 692{ 693 int i; 694 if (stbi_jpeg_test_memory(buffer,len)) return stbi_jpeg_load_from_memory(buffer,len,x,y,comp,req_comp); 695 if (stbi_png_test_memory(buffer,len)) return stbi_png_load_from_memory(buffer,len,x,y,comp,req_comp); 696 if (stbi_bmp_test_memory(buffer,len)) return stbi_bmp_load_from_memory(buffer,len,x,y,comp,req_comp); 697 if (stbi_gif_test_memory(buffer,len)) return stbi_gif_load_from_memory(buffer,len,x,y,comp,req_comp); 698 if (stbi_psd_test_memory(buffer,len)) return stbi_psd_load_from_memory(buffer,len,x,y,comp,req_comp); 699 if (stbi_pic_test_memory(buffer,len)) return stbi_pic_load_from_memory(buffer,len,x,y,comp,req_comp); 700 701 #ifndef STBI_NO_HDR 702 if (stbi_hdr_test_memory(buffer, len)) { 703 float *hdr = stbi_hdr_load_from_memory(buffer, len,x,y,comp,req_comp); 704 return hdr_to_ldr(hdr, *x, *y, req_comp ? req_comp : *comp); 705 } 706 #endif 707 708 for (i=0; i < max_loaders; ++i) 709 if (loaders[i]->test_memory(buffer,len)) 710 return loaders[i]->load_from_memory(buffer,len,x,y,comp,req_comp); 711 // test tga last because it's a crappy test! 712 if (stbi_tga_test_memory(buffer,len)) 713 return stbi_tga_load_from_memory(buffer,len,x,y,comp,req_comp); 714 return epuc("unknown image type", "Image not of any known type, or corrupt"); 715} 716 717#ifndef STBI_NO_HDR 718 719#ifndef STBI_NO_STDIO 720float *stbi_loadf(char const *filename, int *x, int *y, int *comp, int req_comp) 721{ 722 FILE *f = fopen(filename, "rb"); 723 float *result; 724 if (!f) return epf("can't fopen", "Unable to open file"); 725 result = stbi_loadf_from_file(f,x,y,comp,req_comp); 726 fclose(f); 727 return result; 728} 729 730float *stbi_loadf_from_file(FILE *f, int *x, int *y, int *comp, int req_comp) 731{ 732 unsigned char *data; 733 #ifndef STBI_NO_HDR 734 if (stbi_hdr_test_file(f)) 735 return stbi_hdr_load_from_file(f,x,y,comp,req_comp); 736 #endif 737 data = stbi_load_from_file(f, x, y, comp, req_comp); 738 if (data) 739 return ldr_to_hdr(data, *x, *y, req_comp ? req_comp : *comp); 740 return epf("unknown image type", "Image not of any known type, or corrupt"); 741} 742#endif 743 744float *stbi_loadf_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) 745{ 746 stbi_uc *data; 747 #ifndef STBI_NO_HDR 748 if (stbi_hdr_test_memory(buffer, len)) 749 return stbi_hdr_load_from_memory(buffer, len,x,y,comp,req_comp); 750 #endif 751 data = stbi_load_from_memory(buffer, len, x, y, comp, req_comp); 752 if (data) 753 return ldr_to_hdr(data, *x, *y, req_comp ? req_comp : *comp); 754 return epf("unknown image type", "Image not of any known type, or corrupt"); 755} 756#endif 757 758// these is-hdr-or-not is defined independent of whether STBI_NO_HDR is 759// defined, for API simplicity; if STBI_NO_HDR is defined, it always 760// reports false! 761 762int stbi_is_hdr_from_memory(stbi_uc const *buffer, int len) 763{ 764 #ifndef STBI_NO_HDR 765 return stbi_hdr_test_memory(buffer, len); 766 #else 767 STBI_NOTUSED(buffer); 768 STBI_NOTUSED(len); 769 return 0; 770 #endif 771} 772 773#ifndef STBI_NO_STDIO 774extern int stbi_is_hdr (char const *filename) 775{ 776 FILE *f = fopen(filename, "rb"); 777 int result=0; 778 if (f) { 779 result = stbi_is_hdr_from_file(f); 780 fclose(f); 781 } 782 return result; 783} 784 785extern int stbi_is_hdr_from_file(FILE *f) 786{ 787 #ifndef STBI_NO_HDR 788 return stbi_hdr_test_file(f); 789 #else 790 return 0; 791 #endif 792} 793 794#endif 795 796#ifndef STBI_NO_HDR 797static float h2l_gamma_i=1.0f/2.2f, h2l_scale_i=1.0f; 798static float l2h_gamma=2.2f, l2h_scale=1.0f; 799 800void stbi_hdr_to_ldr_gamma(float gamma) { h2l_gamma_i = 1/gamma; } 801void stbi_hdr_to_ldr_scale(float scale) { h2l_scale_i = 1/scale; } 802 803void stbi_ldr_to_hdr_gamma(float gamma) { l2h_gamma = gamma; } 804void stbi_ldr_to_hdr_scale(float scale) { l2h_scale = scale; } 805#endif 806 807 808////////////////////////////////////////////////////////////////////////////// 809// 810// Common code used by all image loaders 811// 812 813enum 814{ 815 SCAN_load=0, 816 SCAN_type, 817 SCAN_header 818}; 819 820typedef struct 821{ 822 uint32 img_x, img_y; 823 int img_n, img_out_n; 824 825 #ifndef STBI_NO_STDIO 826 FILE *img_file; 827 int buflen; 828 uint8 buffer_start[128]; 829 int from_file; 830 #endif 831 uint8 const *img_buffer, *img_buffer_end; 832} stbi; 833 834#ifndef STBI_NO_STDIO 835static void start_file(stbi *s, FILE *f) 836{ 837 s->img_file = f; 838 s->buflen = sizeof(s->buffer_start); 839 s->img_buffer_end = s->buffer_start + s->buflen; 840 s->img_buffer = s->img_buffer_end; 841 s->from_file = 1; 842} 843#endif 844 845static void start_mem(stbi *s, uint8 const *buffer, int len) 846{ 847#ifndef STBI_NO_STDIO 848 s->img_file = NULL; 849 s->from_file = 0; 850#endif 851 s->img_buffer = (uint8 const *) buffer; 852 s->img_buffer_end = (uint8 const *) buffer+len; 853} 854 855#ifndef STBI_NO_STDIO 856static void refill_buffer(stbi *s) 857{ 858 int n = fread(s->buffer_start, 1, s->buflen, s->img_file); 859 if (n == 0) { 860 s->from_file = 0; 861 s->img_buffer = s->img_buffer_end-1; 862#if 0 863 *s->img_buffer = 0; 864#endif 865 } else { 866 s->img_buffer = s->buffer_start; 867 s->img_buffer_end = s->buffer_start + n; 868 } 869} 870#endif 871 872__forceinline static int get8(stbi *s) 873{ 874 if (s->img_buffer < s->img_buffer_end) 875 return *s->img_buffer++; 876#ifndef STBI_NO_STDIO 877 if (s->from_file) { 878 refill_buffer(s); 879 return *s->img_buffer++; 880 } 881#endif 882 return 0; 883} 884 885__forceinline static int at_eof(stbi *s) 886{ 887#ifndef STBI_NO_STDIO 888 if (s->img_file) { 889 if (!feof(s->img_file)) return 0; 890 // if feof() is true, check if buffer = end 891 // special case: we've only got the special 0 character at the end 892 if (s->from_file == 0) return 1; 893 } 894#endif 895 return s->img_buffer >= s->img_buffer_end; 896} 897 898__forceinline static uint8 get8u(stbi *s) 899{ 900 return (uint8) get8(s); 901} 902 903static void skip(stbi *s, int n) 904{ 905#ifndef STBI_NO_STDIO 906 if (s->img_file) { 907 int blen = s->img_buffer_end - s->img_buffer; 908 if (blen < n) { 909 s->img_buffer = s->img_buffer_end; 910 fseek(s->img_file, n - blen, SEEK_CUR); 911 return; 912 } 913 } 914#endif 915 s->img_buffer += n; 916} 917 918static int getn(stbi *s, stbi_uc *buffer, int n) 919{ 920#ifndef STBI_NO_STDIO 921 if (s->img_file) { 922 int blen = s->img_buffer_end - s->img_buffer; 923 if (blen < n) { 924 int res; 925 memcpy(buffer, s->img_buffer, blen); 926 res = ((int) fread(buffer + blen, 1, n - blen, s->img_file) == (n-blen)); 927 s->img_buffer = s->img_buffer_end; 928 return res; 929 } 930 } 931#endif 932 if (s->img_buffer+n <= s->img_buffer_end) { 933 memcpy(buffer, s->img_buffer, n); 934 s->img_buffer += n; 935 return 1; 936 } else 937 return 0; 938} 939 940static int get16(stbi *s) 941{ 942 int z = get8(s); 943 return (z << 8) + get8(s); 944} 945 946static uint32 get32(stbi *s) 947{ 948 uint32 z = get16(s); 949 return (z << 16) + get16(s); 950} 951 952static int get16le(stbi *s) 953{ 954 int z = get8(s); 955 return z + (get8(s) << 8); 956} 957 958static uint32 get32le(stbi *s) 959{ 960 uint32 z = get16le(s); 961 return z + (get16le(s) << 16); 962} 963 964////////////////////////////////////////////////////////////////////////////// 965// 966// generic converter from built-in img_n to req_comp 967// individual types do this automatically as much as possible (e.g. jpeg 968// does all cases internally since it needs to colorspace convert anyway, 969// and it never has alpha, so very few cases ). png can automatically 970// interleave an alpha=255 channel, but falls back to this for other cases 971// 972// assume data buffer is malloced, so malloc a new one and free that one 973// only failure mode is malloc failing 974 975static uint8 compute_y(int r, int g, int b) 976{ 977 return (uint8) (((r*77) + (g*150) + (29*b)) >> 8); 978} 979 980static unsigned char *convert_format(unsigned char *data, int img_n, int req_comp, uint x, uint y) 981{ 982 int i,j; 983 unsigned char *good; 984 985 if (req_comp == img_n) return data; 986 assert(req_comp >= 1 && req_comp <= 4); 987 988 good = MALLOC(req_comp * x * y); 989 if (good == NULL) { 990 FREE(data); 991 return epuc("outofmem", "Out of memory"); 992 } 993 994 for (j=0; j < (int) y; ++j) { 995 unsigned char *src = data + j * x * img_n ; 996 unsigned char *dest = good + j * x * req_comp; 997 998 #define COMBO(a,b) ((a)*8+(b)) 999 #define CASE(a,b) case COMBO(a,b): for(i=x-1; i >= 0; --i, src += a, dest += b) 1000 // convert source image with img_n components to one with req_comp components; 1001 // avoid switch per pixel, so use switch per scanline and massive macros 1002 switch (COMBO(img_n, req_comp)) { 1003 CASE(1,2) dest[0]=src[0], dest[1]=255; break; 1004 CASE(1,3) dest[0]=dest[1]=dest[2]=src[0]; break; 1005 CASE(1,4) dest[0]=dest[1]=dest[2]=src[0], dest[3]=255; break; 1006 CASE(2,1) dest[0]=src[0]; break; 1007 CASE(2,3) dest[0]=dest[1]=dest[2]=src[0]; break; 1008 CASE(2,4) dest[0]=dest[1]=dest[2]=src[0], dest[3]=src[1]; break; 1009 CASE(3,4) dest[0]=src[0],dest[1]=src[1],dest[2]=src[2],dest[3]=255; break; 1010 CASE(3,1) dest[0]=compute_y(src[0],src[1],src[2]); break; 1011 CASE(3,2) dest[0]=compute_y(src[0],src[1],src[2]), dest[1] = 255; break; 1012 CASE(4,1) dest[0]=compute_y(src[0],src[1],src[2]); break; 1013 CASE(4,2) dest[0]=compute_y(src[0],src[1],src[2]), dest[1] = src[3]; break; 1014 CASE(4,3) dest[0]=src[0],dest[1]=src[1],dest[2]=src[2]; break; 1015 default: assert(0); 1016 } 1017 #undef CASE 1018 } 1019 1020 FREE(data); 1021 return good; 1022} 1023 1024#ifndef STBI_NO_HDR 1025static float *ldr_to_hdr(stbi_uc *data, int x, int y, int comp) 1026{ 1027 int i,k,n; 1028 float *output = MALLOC(x * y * comp * sizeof(float)); 1029 if (output == NULL) { FREE(data); return epf("outofmem", "Out of memory"); } 1030 // compute number of non-alpha components 1031 if (comp & 1) n = comp; else n = comp-1; 1032 for (i=0; i < x*y; ++i) { 1033 for (k=0; k < n; ++k) { 1034 output[i*comp + k] = (float) pow(data[i*comp+k]/255.0f, l2h_gamma) * l2h_scale; 1035 } 1036 if (k < comp) output[i*comp + k] = data[i*comp+k]/255.0f; 1037 } 1038 FREE(data); 1039 return output; 1040} 1041 1042#define float2int(x) ((int) (x)) 1043static stbi_uc *hdr_to_ldr(float *data, int x, int y, int comp) 1044{ 1045 int i,k,n; 1046 stbi_uc *output = MALLOC(x * y * comp); 1047 if (output == NULL) { FREE(data); return epuc("outofmem", "Out of memory"); } 1048 // compute number of non-alpha components 1049 if (comp & 1) n = comp; else n = comp-1; 1050 for (i=0; i < x*y; ++i) { 1051 for (k=0; k < n; ++k) { 1052 float z = (float) pow(data[i*comp+k]*h2l_scale_i, h2l_gamma_i) * 255 + 0.5f; 1053 if (z < 0) z = 0; 1054 if (z > 255) z = 255; 1055 output[i*comp + k] = (uint8) float2int(z); 1056 } 1057 if (k < comp) { 1058 float z = data[i*comp+k] * 255 + 0.5f; 1059 if (z < 0) z = 0; 1060 if (z > 255) z = 255; 1061 output[i*comp + k] = (uint8) float2int(z); 1062 } 1063 } 1064 FREE(data); 1065 return output; 1066} 1067#endif 1068 1069////////////////////////////////////////////////////////////////////////////// 1070// 1071// "baseline" JPEG/JFIF decoder (not actually fully baseline implementation) 1072// 1073// simple implementation 1074// - channel subsampling of at most 2 in each dimension 1075// - doesn't support delayed output of y-dimension 1076// - simple interface (only one output format: 8-bit interleaved RGB) 1077// - doesn't try to recover corrupt jpegs 1078// - doesn't allow partial loading, loading multiple at once 1079// - still fast on x86 (copying globals into locals doesn't help x86) 1080// - allocates lots of intermediate memory (full size of all components) 1081// - non-interleaved case requires this anyway 1082// - allows good upsampling (see next) 1083// high-quality 1084// - upsampled channels are bilinearly interpolated, even across blocks 1085// - quality integer IDCT derived from IJG's 'slow' 1086// performance 1087// - fast huffman; reasonable integer IDCT 1088// - uses a lot of intermediate memory, could cache poorly 1089// - load http://nothings.org/remote/anemones.jpg 3 times on 2.8Ghz P4 1090// stb_jpeg: 1.34 seconds (MSVC6, default release build) 1091// stb_jpeg: 1.06 seconds (MSVC6, processor = Pentium Pro) 1092// IJL11.dll: 1.08 seconds (compiled by intel) 1093// IJG 1998: 0.98 seconds (MSVC6, makefile provided by IJG) 1094// IJG 1998: 0.95 seconds (MSVC6, makefile + proc=PPro) 1095 1096// huffman decoding acceleration 1097#define FAST_BITS 9 // larger handles more cases; smaller stomps less cache 1098 1099typedef struct 1100{ 1101 uint8 fast[1 << FAST_BITS]; 1102 // weirdly, repacking this into AoS is a 10% speed loss, instead of a win 1103 uint16 code[256]; 1104 uint8 values[256]; 1105 uint8 size[257]; 1106 unsigned int maxcode[18]; 1107 int delta[17]; // old 'firstsymbol' - old 'firstcode' 1108} huffman; 1109 1110typedef struct 1111{ 1112 #ifdef STBI_SIMD 1113 unsigned short dequant2[4][64]; 1114 #endif 1115 stbi s; 1116 huffman huff_dc[4]; 1117 huffman huff_ac[4]; 1118 uint8 dequant[4][64]; 1119 1120// sizes for components, interleaved MCUs 1121 int img_h_max, img_v_max; 1122 int img_mcu_x, img_mcu_y; 1123 int img_mcu_w, img_mcu_h; 1124 1125// definition of jpeg image component 1126 struct 1127 { 1128 int id; 1129 int h,v; 1130 int tq; 1131 int hd,ha; 1132 int dc_pred; 1133 1134 int x,y,w2,h2; 1135 uint8 *data; 1136 void *raw_data; 1137 uint8 *linebuf; 1138 } img_comp[4]; 1139 1140 uint32 code_buffer; // jpeg entropy-coded buffer 1141 int code_bits; // number of valid bits 1142 unsigned char marker; // marker seen while filling entropy buffer 1143 int nomore; // flag if we saw a marker so must stop 1144 1145 int scan_n, order[4]; 1146 int restart_interval, todo; 1147} jpeg; 1148 1149static int build_huffman(huffman *h, int *count) 1150{ 1151 int i,j,k=0,code; 1152 // build size list for each symbol (from JPEG spec) 1153 for (i=0; i < 16; ++i) 1154 for (j=0; j < count[i]; ++j) 1155 h->size[k++] = (uint8) (i+1); 1156 h->size[k] = 0; 1157 1158 // compute actual symbols (from jpeg spec) 1159 code = 0; 1160 k = 0; 1161 for(j=1; j <= 16; ++j) { 1162 // compute delta to add to code to compute symbol id 1163 h->delta[j] = k - code; 1164 if (h->size[k] == j) { 1165 while (h->size[k] == j) 1166 h->code[k++] = (uint16) (code++); 1167 if (code-1 >= (1 << j)) return e("bad code lengths","Corrupt JPEG"); 1168 } 1169 // compute largest code + 1 for this size, preshifted as needed later 1170 h->maxcode[j] = code << (16-j); 1171 code <<= 1; 1172 } 1173 h->maxcode[j] = 0xffffffff; 1174 1175 // build non-spec acceleration table; 255 is flag for not-accelerated 1176 memset(h->fast, 255, 1 << FAST_BITS); 1177 for (i=0; i < k; ++i) { 1178 int s = h->size[i]; 1179 if (s <= FAST_BITS) { 1180 int c = h->code[i] << (FAST_BITS-s); 1181 int m = 1 << (FAST_BITS-s); 1182 for (j=0; j < m; ++j) { 1183 h->fast[c+j] = (uint8) i; 1184 } 1185 } 1186 } 1187 return 1; 1188} 1189 1190static void grow_buffer_unsafe(jpeg *j) 1191{ 1192 do { 1193 int b = j->nomore ? 0 : get8(&j->s); 1194 if (b == 0xff) { 1195 int c = get8(&j->s); 1196 if (c != 0) { 1197 j->marker = (unsigned char) c; 1198 j->nomore = 1; 1199 return; 1200 } 1201 } 1202 j->code_buffer |= b << (24 - j->code_bits); 1203 j->code_bits += 8; 1204 } while (j->code_bits <= 24); 1205} 1206 1207// (1 << n) - 1 1208static uint32 bmask[17]={0,1,3,7,15,31,63,127,255,511,1023,2047,4095,8191,16383,32767,65535}; 1209 1210// decode a jpeg huffman value from the bitstream 1211__forceinline static int decode(jpeg *j, huffman *h) 1212{ 1213 unsigned int temp; 1214 int c,k; 1215 1216 if (j->code_bits < 16) grow_buffer_unsafe(j); 1217 1218 // look at the top FAST_BITS and determine what symbol ID it is, 1219 // if the code is <= FAST_BITS 1220 c = (j->code_buffer >> (32 - FAST_BITS)) & ((1 << FAST_BITS)-1); 1221 k = h->fast[c]; 1222 if (k < 255) { 1223 int s = h->size[k]; 1224 if (s > j->code_bits) 1225 return -1; 1226 j->code_buffer <<= s; 1227 j->code_bits -= s; 1228 return h->values[k]; 1229 } 1230 1231 // naive test is to shift the code_buffer down so k bits are 1232 // valid, then test against maxcode. To speed this up, we've 1233 // preshifted maxcode left so that it has (16-k) 0s at the 1234 // end; in other words, regardless of the number of bits, it 1235 // wants to be compared against something shifted to have 16; 1236 // that way we don't need to shift inside the loop. 1237 temp = j->code_buffer >> 16; 1238 for (k=FAST_BITS+1 ; ; ++k) 1239 if (temp < h->maxcode[k]) 1240 break; 1241 if (k == 17) { 1242 // error! code not found 1243 j->code_bits -= 16; 1244 return -1; 1245 } 1246 1247 if (k > j->code_bits) 1248 return -1; 1249 1250 // convert the huffman code to the symbol id 1251 c = ((j->code_buffer >> (32 - k)) & bmask[k]) + h->delta[k]; 1252 assert((((j->code_buffer) >> (32 - h->size[c])) & bmask[h->size[c]]) == h->code[c]); 1253 1254 // convert the id to a symbol 1255 j->code_bits -= k; 1256 j->code_buffer <<= k; 1257 return h->values[c]; 1258} 1259 1260// combined JPEG 'receive' and JPEG 'extend', since baseline 1261// always extends everything it receives. 1262__forceinline static int extend_receive(jpeg *j, int n) 1263{ 1264 unsigned int m = 1 << (n-1); 1265 unsigned int k; 1266 if (j->code_bits < n) grow_buffer_unsafe(j); 1267 1268 #if 1 1269 k = stbi_lrot(j->code_buffer, n); 1270 j->code_buffer = k & ~bmask[n]; 1271 k &= bmask[n]; 1272 j->code_bits -= n; 1273 #else 1274 k = (j->code_buffer >> (32 - n)) & bmask[n]; 1275 j->code_bits -= n; 1276 j->code_buffer <<= n; 1277 #endif 1278 // the following test is probably a random branch that won't 1279 // predict well. I tried to table accelerate it but failed. 1280 // maybe it's compiling as a conditional move? 1281 if (k < m) 1282 return (-1 << n) + k + 1; 1283 else 1284 return k; 1285} 1286 1287// given a value that's at position X in the zigzag stream, 1288// where does it appear in the 8x8 matrix coded as row-major? 1289static uint8 dezigzag[64+15] = 1290{ 1291 0, 1, 8, 16, 9, 2, 3, 10, 1292 17, 24, 32, 25, 18, 11, 4, 5, 1293 12, 19, 26, 33, 40, 48, 41, 34, 1294 27, 20, 13, 6, 7, 14, 21, 28, 1295 35, 42, 49, 56, 57, 50, 43, 36, 1296 29, 22, 15, 23, 30, 37, 44, 51, 1297 58, 59, 52, 45, 38, 31, 39, 46, 1298 53, 60, 61, 54, 47, 55, 62, 63, 1299 // let corrupt input sample past end 1300 63, 63, 63, 63, 63, 63, 63, 63, 1301 63, 63, 63, 63, 63, 63, 63 1302}; 1303 1304// decode one 64-entry block-- 1305static int decode_block(jpeg *j, short data[64], huffman *hdc, huffman *hac, int b) 1306{ 1307 int diff,dc,k; 1308 int t = decode(j, hdc); 1309 if (t < 0) return e("bad huffman code","Corrupt JPEG"); 1310 1311 // 0 all the ac values now so we can do it 32-bits at a time 1312 memset(data,0,64*sizeof(data[0])); 1313 1314 diff = t ? extend_receive(j, t) : 0; 1315 dc = j->img_comp[b].dc_pred + diff; 1316 j->img_comp[b].dc_pred = dc; 1317 data[0] = (short) dc; 1318 1319 // decode AC components, see JPEG spec 1320 k = 1; 1321 do { 1322 int r,s; 1323 int rs = decode(j, hac); 1324 if (rs < 0) return e("bad huffman code","Corrupt JPEG"); 1325 s = rs & 15; 1326 r = rs >> 4; 1327 if (s == 0) { 1328 if (rs != 0xf0) break; // end block 1329 k += 16; 1330 } else { 1331 k += r; 1332 // decode into unzigzag'd location 1333 data[dezigzag[k++]] = (short) extend_receive(j,s); 1334 } 1335 } while (k < 64); 1336 return 1; 1337} 1338 1339// take a -128..127 value and clamp it and convert to 0..255 1340__forceinline static uint8 clamp(int x) 1341{ 1342 // trick to use a single test to catch both cases 1343 if ((unsigned int) x > 255) { 1344 if (x < 0) return 0; 1345 if (x > 255) return 255; 1346 } 1347 return (uint8) x; 1348} 1349 1350#define f2f(x) (int) (((x) * 4096 + 0.5)) 1351#define fsh(x) ((x) << 12) 1352 1353// derived from jidctint -- DCT_ISLOW 1354#define IDCT_1D(s0,s1,s2,s3,s4,s5,s6,s7) \ 1355 int t0,t1,t2,t3,p1,p2,p3,p4,p5,x0,x1,x2,x3; \ 1356 p2 = s2; \ 1357 p3 = s6; \ 1358 p1 = (p2+p3) * f2f(0.5411961f); \ 1359 t2 = p1 + p3*f2f(-1.847759065f); \ 1360 t3 = p1 + p2*f2f( 0.765366865f); \ 1361 p2 = s0; \ 1362 p3 = s4; \ 1363 t0 = fsh(p2+p3); \ 1364 t1 = fsh(p2-p3); \ 1365 x0 = t0+t3; \ 1366 x3 = t0-t3; \ 1367 x1 = t1+t2; \ 1368 x2 = t1-t2; \ 1369 t0 = s7; \ 1370 t1 = s5; \ 1371 t2 = s3; \ 1372 t3 = s1; \ 1373 p3 = t0+t2; \ 1374 p4 = t1+t3; \ 1375 p1 = t0+t3; \ 1376 p2 = t1+t2; \ 1377 p5 = (p3+p4)*f2f( 1.175875602f); \ 1378 t0 = t0*f2f( 0.298631336f); \ 1379 t1 = t1*f2f( 2.053119869f); \ 1380 t2 = t2*f2f( 3.072711026f); \ 1381 t3 = t3*f2f( 1.501321110f); \ 1382 p1 = p5 + p1*f2f(-0.899976223f); \ 1383 p2 = p5 + p2*f2f(-2.562915447f); \ 1384 p3 = p3*f2f(-1.961570560f); \ 1385 p4 = p4*f2f(-0.390180644f); \ 1386 t3 += p1+p4; \ 1387 t2 += p2+p3; \ 1388 t1 += p2+p4; \ 1389 t0 += p1+p3; 1390 1391#ifdef STBI_SIMD 1392typedef unsigned short stbi_dequantize_t; 1393#else 1394typedef uint8 stbi_dequantize_t; 1395#endif 1396 1397// .344 seconds on 3*anemones.jpg 1398static void idct_block(uint8 *out, int out_stride, short data[64], stbi_dequantize_t *dequantize) 1399{ 1400 int i,val[64],*v=val; 1401 stbi_dequantize_t *dq = dequantize; 1402 uint8 *o; 1403 short *d = data; 1404 1405 // columns 1406 for (i=0; i < 8; ++i,++d,++dq, ++v) { 1407 // if all zeroes, shortcut -- this avoids dequantizing 0s and IDCTing 1408 if (d[ 8]==0 && d[16]==0 && d[24]==0 && d[32]==0 1409 && d[40]==0 && d[48]==0 && d[56]==0) { 1410 // no shortcut 0 seconds 1411 // (1|2|3|4|5|6|7)==0 0 seconds 1412 // all separate -0.047 seconds 1413 // 1 && 2|3 && 4|5 && 6|7: -0.047 seconds 1414 int dcterm = d[0] * dq[0] << 2; 1415 v[0] = v[8] = v[16] = v[24] = v[32] = v[40] = v[48] = v[56] = dcterm; 1416 } else { 1417 IDCT_1D(d[ 0]*dq[ 0],d[ 8]*dq[ 8],d[16]*dq[16],d[24]*dq[24], 1418 d[32]*dq[32],d[40]*dq[40],d[48]*dq[48],d[56]*dq[56]) 1419 // constants scaled things up by 1<<12; let's bring them back 1420 // down, but keep 2 extra bits of precision 1421 x0 += 512; x1 += 512; x2 += 512; x3 += 512; 1422 v[ 0] = (x0+t3) >> 10; 1423 v[56] = (x0-t3) >> 10; 1424 v[ 8] = (x1+t2) >> 10; 1425 v[48] = (x1-t2) >> 10; 1426 v[16] = (x2+t1) >> 10; 1427 v[40] = (x2-t1) >> 10; 1428 v[24] = (x3+t0) >> 10; 1429 v[32] = (x3-t0) >> 10; 1430 } 1431 } 1432 1433 for (i=0, v=val, o=out; i < 8; ++i,v+=8,o+=out_stride) { 1434 // no fast case since the first 1D IDCT spread components out 1435 IDCT_1D(v[0],v[1],v[2],v[3],v[4],v[5],v[6],v[7]) 1436 // constants scaled things up by 1<<12, plus we had 1<<2 from first 1437 // loop, plus horizontal and vertical each scale by sqrt(8) so together 1438 // we've got an extra 1<<3, so 1<<17 total we need to remove. 1439 // so we want to round that, which means adding 0.5 * 1<<17, 1440 // aka 65536. Also, we'll end up with -128 to 127 that we want 1441 // to encode as 0..255 by adding 128, so we'll add that before the shift 1442 x0 += 65536 + (128<<17); 1443 x1 += 65536 + (128<<17); 1444 x2 += 65536 + (128<<17); 1445 x3 += 65536 + (128<<17); 1446 // tried computing the shifts into temps, or'ing the temps to see 1447 // if any were out of range, but that was slower 1448 o[0] = clamp((x0+t3) >> 17); 1449 o[7] = clamp((x0-t3) >> 17); 1450 o[1] = clamp((x1+t2) >> 17); 1451 o[6] = clamp((x1-t2) >> 17); 1452 o[2] = clamp((x2+t1) >> 17); 1453 o[5] = clamp((x2-t1) >> 17); 1454 o[3] = clamp((x3+t0) >> 17); 1455 o[4] = clamp((x3-t0) >> 17); 1456 } 1457} 1458 1459#ifdef STBI_SIMD 1460static stbi_idct_8x8 stbi_idct_installed = idct_block; 1461 1462extern void stbi_install_idct(stbi_idct_8x8 func) 1463{ 1464 stbi_idct_installed = func; 1465} 1466#endif 1467 1468#define MARKER_none 0xff 1469// if there's a pending marker from the entropy stream, return that 1470// otherwise, fetch from the stream and get a marker. if there's no 1471// marker, return 0xff, which is never a valid marker value 1472static uint8 get_marker(jpeg *j) 1473{ 1474 uint8 x; 1475 if (j->marker != MARKER_none) { x = j->marker; j->marker = MARKER_none; return x; } 1476 x = get8u(&j->s); 1477 if (x != 0xff) return MARKER_none; 1478 while (x == 0xff) 1479 x = get8u(&j->s); 1480 return x; 1481} 1482 1483// in each scan, we'll have scan_n components, and the order 1484// of the components is specified by order[] 1485#define RESTART(x) ((x) >= 0xd0 && (x) <= 0xd7) 1486 1487// after a restart interval, reset the entropy decoder and 1488// the dc prediction 1489static void reset(jpeg *j) 1490{ 1491 j->code_bits = 0; 1492 j->code_buffer = 0; 1493 j->nomore = 0; 1494 j->img_comp[0].dc_pred = j->img_comp[1].dc_pred = j->img_comp[2].dc_pred = 0; 1495 j->marker = MARKER_none; 1496 j->todo = j->restart_interval ? j->restart_interval : 0x7fffffff; 1497 // no more than 1<<31 MCUs if no restart_interal? that's plenty safe, 1498 // since we don't even allow 1<<30 pixels 1499} 1500 1501static int parse_entropy_coded_data(jpeg *z) 1502{ 1503 reset(z); 1504 if (z->scan_n == 1) { 1505 int i,j; 1506 #ifdef STBI_SIMD 1507 __declspec(align(16)) 1508 #endif 1509 short data[64]; 1510 int n = z->order[0]; 1511 // non-interleaved data, we just need to process one block at a time, 1512 // in trivial scanline order 1513 // number of blocks to do just depends on how many actual "pixels" this 1514 // component has, independent of interleaved MCU blocking and such 1515 int w = (z->img_comp[n].x+7) >> 3; 1516 int h = (z->img_comp[n].y+7) >> 3; 1517 for (j=0; j < h; ++j) { 1518 for (i=0; i < w; ++i) { 1519 if (!decode_block(z, data, z->huff_dc+z->img_comp[n].hd, z->huff_ac+z->img_comp[n].ha, n)) return 0; 1520 #ifdef STBI_SIMD 1521 stbi_idct_installed(z->img_comp[n].data+z->img_comp[n].w2*j*8+i*8, z->img_comp[n].w2, data, z->dequant2[z->img_comp[n].tq]); 1522 #else 1523 idct_block(z->img_comp[n].data+z->img_comp[n].w2*j*8+i*8, z->img_comp[n].w2, data, z->dequant[z->img_comp[n].tq]); 1524 #endif 1525 // every data block is an MCU, so countdown the restart interval 1526 if (--z->todo <= 0) { 1527 if (z->code_bits < 24) grow_buffer_unsafe(z); 1528 // if it's NOT a restart, then just bail, so we get corrupt data 1529 // rather than no data 1530 if (!RESTART(z->marker)) return 1; 1531 reset(z); 1532 } 1533 } 1534 } 1535 } else { // interleaved! 1536 int i,j,k,x,y; 1537 short data[64]; 1538 for (j=0; j < z->img_mcu_y; ++j) { 1539 for (i=0; i < z->img_mcu_x; ++i) { 1540 // scan an interleaved mcu... process scan_n components in order 1541 for (k=0; k < z->scan_n; ++k) { 1542 int n = z->order[k]; 1543 // scan out an mcu's worth of this component; that's just determined 1544 // by the basic H and V specified for the component 1545 for (y=0; y < z->img_comp[n].v; ++y) { 1546 for (x=0; x < z->img_comp[n].h; ++x) { 1547 int x2 = (i*z->img_comp[n].h + x)*8; 1548 int y2 = (j*z->img_comp[n].v + y)*8; 1549 if (!decode_block(z, data, z->huff_dc+z->img_comp[n].hd, z->huff_ac+z->img_comp[n].ha, n)) return 0; 1550 #ifdef STBI_SIMD 1551 stbi_idct_installed(z->img_comp[n].data+z->img_comp[n].w2*y2+x2, z->img_comp[n].w2, data, z->dequant2[z->img_comp[n].tq]); 1552 #else 1553 idct_block(z->img_comp[n].data+z->img_comp[n].w2*y2+x2, z->img_comp[n].w2, data, z->dequant[z->img_comp[n].tq]); 1554 #endif 1555 } 1556 } 1557 } 1558 // after all interleaved components, that's an interleaved MCU, 1559 // so now count down the restart interval 1560 if (--z->todo <= 0) { 1561 if (z->code_bits < 24) grow_buffer_unsafe(z); 1562 // if it's NOT a restart, then just bail, so we get corrupt data 1563 // rather than no data 1564 if (!RESTART(z->marker)) return 1; 1565 reset(z); 1566 } 1567 } 1568 } 1569 } 1570 return 1; 1571} 1572 1573static int process_marker(jpeg *z, int marker) 1574{ 1575 int L; 1576 switch (marker) { 1577 case MARKER_none: // no marker found 1578 return e("expected marker","Corrupt JPEG"); 1579 1580 case 0xC2: // SOF - progressive 1581 return e("progressive jpeg","JPEG format not supported (progressive)"); 1582 1583 case 0xDD: // DRI - specify restart interval 1584 if (get16(&z->s) != 4) return e("bad DRI len","Corrupt JPEG"); 1585 z->restart_interval = get16(&z->s); 1586 return 1; 1587 1588 case 0xDB: // DQT - define quantization table 1589 L = get16(&z->s)-2; 1590 while (L > 0) { 1591 int q = get8(&z->s); 1592 int p = q >> 4; 1593 int t = q & 15,i; 1594 if (p != 0) return e("bad DQT type","Corrupt JPEG"); 1595 if (t > 3) return e("bad DQT table","Corrupt JPEG"); 1596 for (i=0; i < 64; ++i) 1597 z->dequant[t][dezigzag[i]] = get8u(&z->s); 1598 #ifdef STBI_SIMD 1599 for (i=0; i < 64; ++i) 1600 z->dequant2[t][i] = z->dequant[t][i]; 1601 #endif 1602 L -= 65; 1603 } 1604 return L==0; 1605 1606 case 0xC4: // DHT - define huffman table 1607 L = get16(&z->s)-2; 1608 while (L > 0) { 1609 uint8 *v; 1610 int sizes[16],i,m=0; 1611 int q = get8(&z->s); 1612 int tc = q >> 4; 1613 int th = q & 15; 1614 if (tc > 1 || th > 3) return e("bad DHT header","Corrupt JPEG"); 1615 for (i=0; i < 16; ++i) { 1616 sizes[i] = get8(&z->s); 1617 m += sizes[i]; 1618 } 1619 L -= 17; 1620 if (tc == 0) { 1621 if (!build_huffman(z->huff_dc+th, sizes)) return 0; 1622 v = z->huff_dc[th].values; 1623 } else { 1624 if (!build_huffman(z->huff_ac+th, sizes)) return 0; 1625 v = z->huff_ac[th].values; 1626 } 1627 for (i=0; i < m; ++i) 1628 v[i] = get8u(&z->s); 1629 L -= m; 1630 } 1631 return L==0; 1632 } 1633 // check for comment block or APP blocks 1634 if ((marker >= 0xE0 && marker <= 0xEF) || marker == 0xFE) { 1635 skip(&z->s, get16(&z->s)-2); 1636 return 1; 1637 } 1638 return 0; 1639} 1640 1641// after we see SOS 1642static int process_scan_header(jpeg *z) 1643{ 1644 int i; 1645 int Ls = get16(&z->s); 1646 z->scan_n = get8(&z->s); 1647 if (z->scan_n < 1 || z->scan_n > 4 || z->scan_n > (int) z->s.img_n) return e("bad SOS component count","Corrupt JPEG"); 1648 if (Ls != 6+2*z->scan_n) return e("bad SOS len","Corrupt JPEG"); 1649 for (i=0; i < z->scan_n; ++i) { 1650 int id = get8(&z->s), which; 1651 int q = get8(&z->s); 1652 for (which = 0; which < z->s.img_n; ++which) 1653 if (z->img_comp[which].id == id) 1654 break; 1655 if (which == z->s.img_n) return 0; 1656 z->img_comp[which].hd = q >> 4; if (z->img_comp[which].hd > 3) return e("bad DC huff","Corrupt JPEG"); 1657 z->img_comp[which].ha = q & 15; if (z->img_comp[which].ha > 3) return e("bad AC huff","Corrupt JPEG"); 1658 z->order[i] = which; 1659 } 1660 if (get8(&z->s) != 0) return e("bad SOS","Corrupt JPEG"); 1661 get8(&z->s); // should be 63, but might be 0 1662 if (get8(&z->s) != 0) return e("bad SOS","Corrupt JPEG"); 1663 1664 return 1; 1665} 1666 1667static int process_frame_header(jpeg *z, int scan) 1668{ 1669 stbi *s = &z->s; 1670 int Lf,p,i,q, h_max=1,v_max=1,c; 1671 Lf = get16(s); if (Lf < 11) return e("bad SOF len","Corrupt JPEG"); // JPEG 1672 p = get8(s); if (p != 8) return e("only 8-bit","JPEG format not supported: 8-bit only"); // JPEG baseline 1673 s->img_y = get16(s); if (s->img_y == 0) return e("no header height", "JPEG format not supported: delayed height"); // Legal, but we don't handle it--but neither does IJG 1674 s->img_x = get16(s); if (s->img_x == 0) return e("0 width","Corrupt JPEG"); // JPEG requires 1675 c = get8(s); 1676 if (c != 3 && c != 1) return e("bad component count","Corrupt JPEG"); // JFIF requires 1677 s->img_n = c; 1678 for (i=0; i < c; ++i) { 1679 z->img_comp[i].data = NULL; 1680 z->img_comp[i].linebuf = NULL; 1681 } 1682 1683 if (Lf != 8+3*s->img_n) return e("bad SOF len","Corrupt JPEG"); 1684 1685 for (i=0; i < s->img_n; ++i) { 1686 z->img_comp[i].id = get8(s); 1687 if (z->img_comp[i].id != i+1) // JFIF requires 1688 if (z->img_comp[i].id != i) // some version of jpegtran outputs non-JFIF-compliant files! 1689 return e("bad component ID","Corrupt JPEG"); 1690 q = get8(s); 1691 z->img_comp[i].h = (q >> 4); if (!z->img_comp[i].h || z->img_comp[i].h > 4) return e("bad H","Corrupt JPEG"); 1692 z->img_comp[i].v = q & 15; if (!z->img_comp[i].v || z->img_comp[i].v > 4) return e("bad V","Corrupt JPEG"); 1693 z->img_comp[i].tq = get8(s); if (z->img_comp[i].tq > 3) return e("bad TQ","Corrupt JPEG"); 1694 } 1695 1696 if (scan != SCAN_load) return 1; 1697 1698 if ((1 << 30) / s->img_x / s->img_n < s->img_y) return e("too large", "Image too large to decode"); 1699 1700 for (i=0; i < s->img_n; ++i) { 1701 if (z->img_comp[i].h > h_max) h_max = z->img_comp[i].h; 1702 if (z->img_comp[i].v > v_max) v_max = z->img_comp[i].v; 1703 } 1704 1705 // compute interleaved mcu info 1706 z->img_h_max = h_max; 1707 z->img_v_max = v_max; 1708 z->img_mcu_w = h_max * 8; 1709 z->img_mcu_h = v_max * 8; 1710 z->img_mcu_x = (s->img_x + z->img_mcu_w-1) / z->img_mcu_w; 1711 z->img_mcu_y = (s->img_y + z->img_mcu_h-1) / z->img_mcu_h; 1712 1713 for (i=0; i < s->img_n; ++i) { 1714 // number of effective pixels (e.g. for non-interleaved MCU) 1715 z->img_comp[i].x = (s->img_x * z->img_comp[i].h + h_max-1) / h_max; 1716 z->img_comp[i].y = (s->img_y * z->img_comp[i].v + v_max-1) / v_max; 1717 // to simplify generation, we'll allocate enough memory to decode 1718 // the bogus oversized data from using interleaved MCUs and their 1719 // big blocks (e.g. a 16x16 iMCU on an image of width 33); we won't 1720 // discard the extra data until colorspace conversion 1721 z->img_comp[i].w2 = z->img_mcu_x * z->img_comp[i].h * 8; 1722 z->img_comp[i].h2 = z->img_mcu_y * z->img_comp[i].v * 8; 1723 z->img_comp[i].raw_data = MALLOC(z->img_comp[i].w2 * z->img_comp[i].h2+15); 1724 if (z->img_comp[i].raw_data == NULL) { 1725 for(--i; i >= 0; --i) { 1726 FREE(z->img_comp[i].raw_data); 1727 z->img_comp[i].data = NULL; 1728 } 1729 return e("outofmem", "Out of memory"); 1730 } 1731 // align blocks for installable-idct using mmx/sse 1732 z->img_comp[i].data = (uint8*) (((size_t) z->img_comp[i].raw_data + 15) & ~15); 1733 z->img_comp[i].linebuf = NULL; 1734 } 1735 1736 return 1; 1737} 1738 1739// use comparisons since in some cases we handle more than one case (e.g. SOF) 1740#define DNL(x) ((x) == 0xdc) 1741#define SOI(x) ((x) == 0xd8) 1742#define EOI(x) ((x) == 0xd9) 1743#define SOF(x) ((x) == 0xc0 || (x) == 0xc1) 1744#define SOS(x) ((x) == 0xda) 1745 1746static int decode_jpeg_header(jpeg *z, int scan) 1747{ 1748 int m; 1749 z->marker = MARKER_none; // initialize cached marker to empty 1750 m = get_marker(z); 1751 if (!SOI(m)) return e("no SOI","Corrupt JPEG"); 1752 if (scan == SCAN_type) return 1; 1753 m = get_marker(z); 1754 while (!SOF(m)) { 1755 if (!process_marker(z,m)) return 0; 1756 m = get_marker(z); 1757 while (m == MARKER_none) { 1758 // some files have extra padding after their blocks, so ok, we'll scan 1759 if (at_eof(&z->s)) return e("no SOF", "Corrupt JPEG"); 1760 m = get_marker(z); 1761 } 1762 } 1763 if (!process_frame_header(z, scan)) return 0; 1764 return 1; 1765} 1766 1767static int decode_jpeg_image(jpeg *j) 1768{ 1769 int m; 1770 j->restart_interval = 0; 1771 if (!decode_jpeg_header(j, SCAN_load)) return 0; 1772 m = get_marker(j); 1773 while (!EOI(m)) { 1774 if (SOS(m)) { 1775 if (!process_scan_header(j)) return 0; 1776 if (!parse_entropy_coded_data(j)) return 0; 1777 if (j->marker == MARKER_none ) { 1778 // handle 0s at the end of image data from IP Kamera 9060 1779 while (!at_eof(&j->s)) { 1780 int x = get8(&j->s); 1781 if (x == 255) { 1782 j->marker = get8u(&j->s); 1783 break; 1784 } else if (x != 0) { 1785 return 0; 1786 } 1787 } 1788 // if we reach eof without hitting a marker, get_marker() below will fail and we'll eventually return 0 1789 } 1790 } else { 1791 if (!process_marker(j, m)) return 0; 1792 } 1793 m = get_marker(j); 1794 } 1795 return 1; 1796} 1797 1798// static jfif-centered resampling (across block boundaries) 1799 1800typedef uint8 *(*resample_row_func)(uint8 *out, uint8 *in0, uint8 *in1, 1801 int w, int hs); 1802 1803#define div4(x) ((uint8) ((x) >> 2)) 1804 1805static uint8 *resample_row_1(uint8 *out, uint8 *in_near, uint8 *in_far, int w, int hs) 1806{ 1807 STBI_NOTUSED(out); 1808 STBI_NOTUSED(in_far); 1809 STBI_NOTUSED(w); 1810 STBI_NOTUSED(hs); 1811 return in_near; 1812} 1813 1814static uint8* resample_row_v_2(uint8 *out, uint8 *in_near, uint8 *in_far, int w, int hs) 1815{ 1816 // need to generate two samples vertically for every one in input 1817 int i; 1818 STBI_NOTUSED(hs); 1819 for (i=0; i < w; ++i) 1820 out[i] = div4(3*in_near[i] + in_far[i] + 2); 1821 return out; 1822} 1823 1824static uint8* resample_row_h_2(uint8 *out, uint8 *in_near, uint8 *in_far, int w, int hs) 1825{ 1826 // need to generate two samples horizontally for every one in input 1827 int i; 1828 uint8 *input = in_near; 1829 1830 if (w == 1) { 1831 // if only one sample, can't do any interpolation 1832 out[0] = out[1] = input[0]; 1833 return out; 1834 } 1835 1836 out[0] = input[0]; 1837 out[1] = div4(input[0]*3 + input[1] + 2); 1838 for (i=1; i < w-1; ++i) { 1839 int n = 3*input[i]+2; 1840 out[i*2+0] = div4(n+input[i-1]); 1841 out[i*2+1] = div4(n+input[i+1]); 1842 } 1843 out[i*2+0] = div4(input[w-2]*3 + input[w-1] + 2); 1844 out[i*2+1] = input[w-1]; 1845 1846 STBI_NOTUSED(in_far); 1847 STBI_NOTUSED(hs); 1848 1849 return out; 1850} 1851 1852#define div16(x) ((uint8) ((x) >> 4)) 1853 1854static uint8 *resample_row_hv_2(uint8 *out, uint8 *in_near, uint8 *in_far, int w, int hs) 1855{ 1856 // need to generate 2x2 samples for every one in input 1857 int i,t0,t1; 1858 if (w == 1) { 1859 out[0] = out[1] = div4(3*in_near[0] + in_far[0] + 2); 1860 return out; 1861 } 1862 1863 t1 = 3*in_near[0] + in_far[0]; 1864 out[0] = div4(t1+2); 1865 for (i=1; i < w; ++i) { 1866 t0 = t1; 1867 t1 = 3*in_near[i]+in_far[i]; 1868 out[i*2-1] = div16(3*t0 + t1 + 8); 1869 out[i*2 ] = div16(3*t1 + t0 + 8); 1870 } 1871 out[w*2-1] = div4(t1+2); 1872 1873 STBI_NOTUSED(hs); 1874 1875 return out; 1876} 1877 1878static uint8 *resample_row_generic(uint8 *out, uint8 *in_near, uint8 *in_far, int w, int hs) 1879{ 1880 // resample with nearest-neighbor 1881 int i,j; 1882 in_far = in_far; 1883 for (i=0; i < w; ++i) 1884 for (j=0; j < hs; ++j) 1885 out[i*hs+j] = in_near[i]; 1886 return out; 1887} 1888 1889#define float2fixed(x) ((int) ((x) * 65536 + 0.5)) 1890 1891// 0.38 seconds on 3*anemones.jpg (0.25 with processor = Pro) 1892// VC6 without processor=Pro is generating multiple LEAs per multiply! 1893static void YCbCr_to_RGB_row(uint8 *out, const uint8 *y, const uint8 *pcb, const uint8 *pcr, int count, int step) 1894{ 1895 int i; 1896 for (i=0; i < count; ++i) { 1897 int y_fixed = (y[i] << 16) + 32768; // rounding 1898 int r,g,b; 1899 int cr = pcr[i] - 128; 1900 int cb = pcb[i] - 128; 1901 r = y_fixed + cr*float2fixed(1.40200f); 1902 g = y_fixed - cr*float2fixed(0.71414f) - cb*float2fixed(0.34414f); 1903 b = y_fixed + cb*float2fixed(1.77200f); 1904 r >>= 16; 1905 g >>= 16; 1906 b >>= 16; 1907 if ((unsigned) r > 255) { if (r < 0) r = 0; else r = 255; } 1908 if ((unsigned) g > 255) { if (g < 0) g = 0; else g = 255; } 1909 if ((unsigned) b > 255) { if (b < 0) b = 0; else b = 255; } 1910 out[0] = (uint8)r; 1911 out[1] = (uint8)g; 1912 out[2] = (uint8)b; 1913 out[3] = 255; 1914 out += step; 1915 } 1916} 1917 1918#ifdef STBI_SIMD 1919static stbi_YCbCr_to_RGB_run stbi_YCbCr_installed = YCbCr_to_RGB_row; 1920 1921void stbi_install_YCbCr_to_RGB(stbi_YCbCr_to_RGB_run func) 1922{ 1923 stbi_YCbCr_installed = func; 1924} 1925#endif 1926 1927 1928// clean up the temporary component buffers 1929static void cleanup_jpeg(jpeg *j) 1930{ 1931 int i; 1932 for (i=0; i < j->s.img_n; ++i) { 1933 if (j->img_comp[i].data) { 1934 FREE(j->img_comp[i].raw_data); 1935 j->img_comp[i].data = NULL; 1936 } 1937 if (j->img_comp[i].linebuf) { 1938 FREE(j->img_comp[i].linebuf); 1939 j->img_comp[i].linebuf = NULL; 1940 } 1941 } 1942} 1943 1944typedef struct 1945{ 1946 resample_row_func resample; 1947 uint8 *line0,*line1; 1948 int hs,vs; // expansion factor in each axis 1949 int w_lores; // horizontal pixels pre-expansion 1950 int ystep; // how far through vertical expansion we are 1951 int ypos; // which pre-expansion row we're on 1952} stbi_resample; 1953 1954static uint8 *load_jpeg_image(jpeg *z, int *out_x, int *out_y, int *comp, int req_comp) 1955{ 1956 int n, decode_n; 1957 // validate req_comp 1958 if (req_comp < 0 || req_comp > 4) return epuc("bad req_comp", "Internal error"); 1959 z->s.img_n = 0; 1960 1961 // load a jpeg image from whichever source 1962 if (!decode_jpeg_image(z)) { cleanup_jpeg(z); return NULL; } 1963 1964 // determine actual number of components to generate 1965 n = req_comp ? req_comp : z->s.img_n; 1966 1967 if (z->s.img_n == 3 && n < 3) 1968 decode_n = 1; 1969 else 1970 decode_n = z->s.img_n; 1971 1972 // resample and color-convert 1973 { 1974 int k; 1975 uint i,j; 1976 uint8 *output; 1977 uint8 *coutput[4]; 1978 1979 stbi_resample res_comp[4]; 1980 1981 for (k=0; k < decode_n; ++k) { 1982 stbi_resample *r = &res_comp[k]; 1983 1984 // allocate line buffer big enough for upsampling off the edges 1985 // with upsample factor of 4 1986 z->img_comp[k].linebuf = MALLOC(z->s.img_x + 3); 1987 if (!z->img_comp[k].linebuf) { cleanup_jpeg(z); return epuc("outofmem", "Out of memory"); } 1988 1989 r->hs = z->img_h_max / z->img_comp[k].h; 1990 r->vs = z->img_v_max / z->img_comp[k].v; 1991 r->ystep = r->vs >> 1; 1992 r->w_lores = (z->s.img_x + r->hs-1) / r->hs; 1993 r->ypos = 0; 1994 r->line0 = r->line1 = z->img_comp[k].data; 1995 1996 if (r->hs == 1 && r->vs == 1) r->resample = resample_row_1; 1997 else if (r->hs == 1 && r->vs == 2) r->resample = resample_row_v_2; 1998 else if (r->hs == 2 && r->vs == 1) r->resample = resample_row_h_2; 1999 else if (r->hs == 2 && r->vs == 2) r->resample = resample_row_hv_2; 2000 else r->resample = resample_row_generic; 2001 } 2002 2003 // can't error after this so, this is safe 2004 output = MALLOC(n * z->s.img_x * z->s.img_y + 1); 2005 if (!output) { cleanup_jpeg(z); return epuc("outofmem", "Out of memory"); } 2006 2007 // now go ahead and resample 2008 for (j=0; j < z->s.img_y; ++j) { 2009 uint8 *out = output + n * z->s.img_x * j; 2010 for (k=0; k < decode_n; ++k) { 2011 stbi_resample *r = &res_comp[k]; 2012 int y_bot = r->ystep >= (r->vs >> 1); 2013 coutput[k] = r->resample(z->img_comp[k].linebuf, 2014 y_bot ? r->line1 : r->line0, 2015 y_bot ? r->line0 : r->line1, 2016 r->w_lores, r->hs); 2017 if (++r->ystep >= r->vs) { 2018 r->ystep = 0; 2019 r->line0 = r->line1; 2020 if (++r->ypos < z->img_comp[k].y) 2021 r->line1 += z->img_comp[k].w2; 2022 } 2023 } 2024 if (n >= 3) { 2025 uint8 *y = coutput[0]; 2026 if (z->s.img_n == 3) { 2027 #ifdef STBI_SIMD 2028 stbi_YCbCr_installed(out, y, coutput[1], coutput[2], z->s.img_x, n); 2029 #else 2030 YCbCr_to_RGB_row(out, y, coutput[1], coutput[2], z->s.img_x, n); 2031 #endif 2032 } else 2033 for (i=0; i < z->s.img_x; ++i) { 2034 out[0] = out[1] = out[2] = y[i]; 2035 out[3] = 255; // not used if n==3 2036 out += n; 2037 } 2038 } else { 2039 uint8 *y = coutput[0]; 2040 if (n == 1) 2041 for (i=0; i < z->s.img_x; ++i) out[i] = y[i]; 2042 else 2043 for (i=0; i < z->s.img_x; ++i) *out++ = y[i], *out++ = 255; 2044 } 2045 } 2046 cleanup_jpeg(z); 2047 *out_x = z->s.img_x; 2048 *out_y = z->s.img_y; 2049 if (comp) *comp = z->s.img_n; // report original components, not output 2050 return output; 2051 } 2052} 2053 2054#ifndef STBI_NO_STDIO 2055unsigned char *stbi_jpeg_load_from_file(FILE *f, int *x, int *y, int *comp, int req_comp) 2056{ 2057 jpeg j; 2058 start_file(&j.s, f); 2059 return load_jpeg_image(&j, x,y,comp,req_comp); 2060} 2061 2062unsigned char *stbi_jpeg_load(char const *filename, int *x, int *y, int *comp, int req_comp) 2063{ 2064 unsigned char *data; 2065 FILE *f = fopen(filename, "rb"); 2066 if (!f) return NULL; 2067 data = stbi_jpeg_load_from_file(f,x,y,comp,req_comp); 2068 fclose(f); 2069 return data; 2070} 2071#endif 2072 2073unsigned char *stbi_jpeg_load_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) 2074{ 2075 #ifdef STBI_SMALL_STACK 2076 unsigned char *result; 2077 jpeg *j = MALLOC(sizeof(*j)); 2078 start_mem(&j->s, buffer, len); 2079 result = load_jpeg_image(j,x,y,comp,req_comp); 2080 FREE(j); 2081 return result; 2082 #else 2083 jpeg j; 2084 start_mem(&j.s, buffer,len); 2085 return load_jpeg_image(&j, x,y,comp,req_comp); 2086 #endif 2087} 2088 2089static int stbi_jpeg_info_raw(jpeg *j, int *x, int *y, int *comp) 2090{ 2091 if (!decode_jpeg_header(j, SCAN_header)) 2092 return 0; 2093 if (x) *x = j->s.img_x; 2094 if (y) *y = j->s.img_y; 2095 if (comp) *comp = j->s.img_n; 2096 return 1; 2097} 2098 2099#ifndef STBI_NO_STDIO 2100int stbi_jpeg_test_file(FILE *f) 2101{ 2102 int n,r; 2103 jpeg j; 2104 n = ftell(f); 2105 start_file(&j.s, f); 2106 r = decode_jpeg_header(&j, SCAN_type); 2107 fseek(f,n,SEEK_SET); 2108 return r; 2109} 2110 2111int stbi_jpeg_info_from_file(FILE *f, int *x, int *y, int *comp) 2112{ 2113 jpeg j; 2114 long n = ftell(f); 2115 int res; 2116 start_file(&j.s, f); 2117 res = stbi_jpeg_info_raw(&j, x, y, comp); 2118 fseek(f, n, SEEK_SET); 2119 return res; 2120} 2121 2122int stbi_jpeg_info(char const *filename, int *x, int *y, int *comp) 2123{ 2124 FILE *f = fopen(filename, "rb"); 2125 int result; 2126 if (!f) return e("can't fopen", "Unable to open file"); 2127 result = stbi_jpeg_info_from_file(f, x, y, comp); 2128 fclose(f); 2129 return result; 2130} 2131#endif 2132 2133int stbi_jpeg_test_memory(stbi_uc const *buffer, int len) 2134{ 2135 jpeg j; 2136 start_mem(&j.s, buffer,len); 2137 return decode_jpeg_header(&j, SCAN_type); 2138} 2139 2140int stbi_jpeg_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp) 2141{ 2142 jpeg j; 2143 start_mem(&j.s, buffer, len); 2144 return stbi_jpeg_info_raw(&j, x, y, comp); 2145} 2146 2147#ifndef STBI_NO_STDIO 2148extern int stbi_jpeg_info (char const *filename, int *x, int *y, int *comp); 2149extern int stbi_jpeg_info_from_file (FILE *f, int *x, int *y, int *comp); 2150#endif 2151extern int stbi_jpeg_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp); 2152 2153// public domain zlib decode v0.2 Sean Barrett 2006-11-18 2154// simple implementation 2155// - all input must be provided in an upfront buffer 2156// - all output is written to a single output buffer (can malloc/realloc) 2157// performance 2158// - fast huffman 2159 2160// fast-way is faster to check than jpeg huffman, but slow way is slower 2161#define ZFAST_BITS 9 // accelerate all cases in default tables 2162#define ZFAST_MASK ((1 << ZFAST_BITS) - 1) 2163 2164// zlib-style huffman encoding 2165// (jpegs packs from left, zlib from right, so can't share code) 2166typedef struct 2167{ 2168 uint16 fast[1 << ZFAST_BITS]; 2169 uint16 firstcode[16]; 2170 int maxcode[17]; 2171 uint16 firstsymbol[16]; 2172 uint8 size[288]; 2173 uint16 value[288]; 2174} zhuffman; 2175 2176__forceinline static int bitreverse16(int n) 2177{ 2178 n = ((n & 0xAAAA) >> 1) | ((n & 0x5555) << 1); 2179 n = ((n & 0xCCCC) >> 2) | ((n & 0x3333) << 2); 2180 n = ((n & 0xF0F0) >> 4) | ((n & 0x0F0F) << 4); 2181 n = ((n & 0xFF00) >> 8) | ((n & 0x00FF) << 8); 2182 return n; 2183} 2184 2185__forceinline static int bit_reverse(int v, int bits) 2186{ 2187 assert(bits <= 16); 2188 // to bit reverse n bits, reverse 16 and shift 2189 // e.g. 11 bits, bit reverse and shift away 5 2190 return bitreverse16(v) >> (16-bits); 2191} 2192 2193static int zbuild_huffman(zhuffman *z, uint8 *sizelist, int num) 2194{ 2195 int i,k=0; 2196 int code, next_code[16], sizes[17]; 2197 2198 // DEFLATE spec for generating codes 2199 memset(sizes, 0, sizeof(sizes)); 2200 memset(z->fast, 255, sizeof(z->fast)); 2201 for (i=0; i < num; ++i) 2202 ++sizes[sizelist[i]]; 2203 sizes[0] = 0; 2204 for (i=1; i < 16; ++i) 2205 assert(sizes[i] <= (1 << i)); 2206 code = 0; 2207 for (i=1; i < 16; ++i) { 2208 next_code[i] = code; 2209 z->firstcode[i] = (uint16) code; 2210 z->firstsymbol[i] = (uint16) k; 2211 code = (code + sizes[i]); 2212 if (sizes[i]) 2213 if (code-1 >= (1 << i)) return e("bad codelengths","Corrupt JPEG"); 2214 z->maxcode[i] = code << (16-i); // preshift for inner loop 2215 code <<= 1; 2216 k += sizes[i]; 2217 } 2218 z->maxcode[16] = 0x10000; // sentinel 2219 for (i=0; i < num; ++i) { 2220 int s = sizelist[i]; 2221 if (s) { 2222 int c = next_code[s] - z->firstcode[s] + z->firstsymbol[s]; 2223 z->size[c] = (uint8)s; 2224 z->value[c] = (uint16)i; 2225 if (s <= ZFAST_BITS) { 2226 int m = bit_reverse(next_code[s],s); 2227 while (m < (1 << ZFAST_BITS)) { 2228 z->fast[m] = (uint16) c; 2229 m += (1 << s); 2230 } 2231 } 2232 ++next_code[s]; 2233 } 2234 } 2235 return 1; 2236} 2237 2238// zlib-from-memory implementation for PNG reading 2239// because PNG allows splitting the zlib stream arbitrarily, 2240// and it's annoying structurally to have PNG call ZLIB call PNG, 2241// we require PNG read all the IDATs and combine them into a single 2242// memory buffer 2243 2244typedef struct 2245{ 2246 uint8 const *zbuffer, *zbuffer_end; 2247 int num_bits; 2248 uint32 code_buffer; 2249 2250 char *zout; 2251 char *zout_start; 2252 char *zout_end; 2253 int z_expandable; 2254 2255 zhuffman z_length, z_distance; 2256} zbuf; 2257 2258__forceinline static int zget8(zbuf *z) 2259{ 2260 if (z->zbuffer >= z->zbuffer_end) return 0; 2261 return *z->zbuffer++; 2262} 2263 2264static void fill_bits(zbuf *z) 2265{ 2266 do { 2267 assert(z->code_buffer < (1U << z->num_bits)); 2268 z->code_buffer |= zget8(z) << z->num_bits; 2269 z->num_bits += 8; 2270 } while (z->num_bits <= 24); 2271} 2272 2273__forceinline static unsigned int zreceive(zbuf *z, int n) 2274{ 2275 unsigned int k; 2276 if (z->num_bits < n) fill_bits(z); 2277 k = z->code_buffer & ((1 << n) - 1); 2278 z->code_buffer >>= n; 2279 z->num_bits -= n; 2280 return k; 2281} 2282 2283__forceinline static int zhuffman_decode(zbuf *a, zhuffman *z) 2284{ 2285 int b,s,k; 2286 if (a->num_bits < 16) fill_bits(a); 2287 b = z->fast[a->code_buffer & ZFAST_MASK]; 2288 if (b < 0xffff) { 2289 s = z->size[b]; 2290 a->code_buffer >>= s; 2291 a->num_bits -= s; 2292 return z->value[b]; 2293 } 2294 2295 // not resolved by fast table, so compute it the slow way 2296 // use jpeg approach, which requires MSbits at top 2297 k = bit_reverse(a->code_buffer, 16); 2298 for (s=ZFAST_BITS+1; ; ++s) 2299 if (k < z->maxcode[s]) 2300 break; 2301 if (s == 16) return -1; // invalid code! 2302 // code size is s, so: 2303 b = (k >> (16-s)) - z->firstcode[s] + z->firstsymbol[s]; 2304 assert(z->size[b] == s); 2305 a->code_buffer >>= s; 2306 a->num_bits -= s; 2307 return z->value[b]; 2308} 2309 2310static int expand(zbuf *z, int n) // need to make room for n bytes 2311{ 2312 char *q; 2313 int cur, limit; 2314 if (!z->z_expandable) return e("output buffer limit","Corrupt PNG"); 2315 cur = (int) (z->zout - z->zout_start); 2316 limit = (int) (z->zout_end - z->zout_start); 2317 while (cur + n > limit) 2318 limit *= 2; 2319 q = (char *) REALLOC(z->zout_start, limit); 2320 if (q == NULL) return e("outofmem", "Out of memory"); 2321 z->zout_start = q; 2322 z->zout = q + cur; 2323 z->zout_end = q + limit; 2324 return 1; 2325} 2326 2327static int length_base[31] = { 2328 3,4,5,6,7,8,9,10,11,13, 2329 15,17,19,23,27,31,35,43,51,59, 2330 67,83,99,115,131,163,195,227,258,0,0 }; 2331 2332static int length_extra[31]= 2333{ 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 }; 2334 2335static int dist_base[32] = { 1,2,3,4,5,7,9,13,17,25,33,49,65,97,129,193, 2336257,385,513,769,1025,1537,2049,3073,4097,6145,8193,12289,16385,24577,0,0}; 2337 2338static int dist_extra[32] = 2339{ 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}; 2340 2341static int parse_huffman_block(zbuf *a) 2342{ 2343 for(;;) { 2344 int z = zhuffman_decode(a, &a->z_length); 2345 if (z < 256) { 2346 if (z < 0) return e("bad huffman code","Corrupt PNG"); // error in huffman codes 2347 if (a->zout >= a->zout_end) if (!expand(a, 1)) return 0; 2348 *a->zout++ = (char) z; 2349 } else { 2350 uint8 *p; 2351 int len,dist; 2352 if (z == 256) return 1; 2353 z -= 257; 2354 len = length_base[z]; 2355 if (length_extra[z]) len += zreceive(a, length_extra[z]); 2356 z = zhuffman_decode(a, &a->z_distance); 2357 if (z < 0) return e("bad huffman code","Corrupt PNG"); 2358 dist = dist_base[z]; 2359 if (dist_extra[z]) dist += zreceive(a, dist_extra[z]); 2360 if (a->zout - a->zout_start < dist) return e("bad dist","Corrupt PNG"); 2361 if (a->zout + len > a->zout_end) if (!expand(a, len)) return 0; 2362 p = (uint8 *) (a->zout - dist); 2363 while (len--) 2364 *a->zout++ = *p++; 2365 } 2366 } 2367} 2368 2369static int compute_huffman_codes(zbuf *a) 2370{ 2371 static uint8 length_dezigzag[19] = { 16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15 }; 2372 zhuffman z_codelength; 2373 uint8 lencodes[286+32+137];//padding for maximum single op 2374 uint8 codelength_sizes[19]; 2375 int i,n; 2376 2377 int hlit = zreceive(a,5) + 257; 2378 int hdist = zreceive(a,5) + 1; 2379 int hclen = zreceive(a,4) + 4; 2380 2381 memset(codelength_sizes, 0, sizeof(codelength_sizes)); 2382 for (i=0; i < hclen; ++i) { 2383 int s = zreceive(a,3); 2384 codelength_sizes[length_dezigzag[i]] = (uint8) s; 2385 } 2386 if (!zbuild_huffman(&z_codelength, codelength_sizes, 19)) return 0; 2387 2388 n = 0; 2389 while (n < hlit + hdist) { 2390 int c = zhuffman_decode(a, &z_codelength); 2391 assert(c >= 0 && c < 19); 2392 if (c < 16) 2393 lencodes[n++] = (uint8) c; 2394 else if (c == 16) { 2395 c = zreceive(a,2)+3; 2396 memset(lencodes+n, lencodes[n-1], c); 2397 n += c; 2398 } else if (c == 17) { 2399 c = zreceive(a,3)+3; 2400 memset(lencodes+n, 0, c); 2401 n += c; 2402 } else { 2403 assert(c == 18); 2404 c = zreceive(a,7)+11; 2405 memset(lencodes+n, 0, c); 2406 n += c; 2407 } 2408 } 2409 if (n != hlit+hdist) return e("bad codelengths","Corrupt PNG"); 2410 if (!zbuild_huffman(&a->z_length, lencodes, hlit)) return 0; 2411 if (!zbuild_huffman(&a->z_distance, lencodes+hlit, hdist)) return 0; 2412 return 1; 2413} 2414 2415static int parse_uncompressed_block(zbuf *a) 2416{ 2417 uint8 header[4]; 2418 int len,nlen,k; 2419 if (a->num_bits & 7) 2420 zreceive(a, a->num_bits & 7); // discard 2421 // drain the bit-packed data into header 2422 k = 0; 2423 while (a->num_bits > 0) { 2424 header[k++] = (uint8) (a->code_buffer & 255); // wtf this warns? 2425 a->code_buffer >>= 8; 2426 a->num_bits -= 8; 2427 } 2428 assert(a->num_bits == 0); 2429 // now fill header the normal way 2430 while (k < 4) 2431 header[k++] = (uint8) zget8(a); 2432 len = header[1] * 256 + header[0]; 2433 nlen = header[3] * 256 + header[2]; 2434 if (nlen != (len ^ 0xffff)) return e("zlib corrupt","Corrupt PNG"); 2435 if (a->zbuffer + len > a->zbuffer_end) return e("read past buffer","Corrupt PNG"); 2436 if (a->zout + len > a->zout_end) 2437 if (!expand(a, len)) return 0; 2438 memcpy(a->zout, a->zbuffer, len); 2439 a->zbuffer += len; 2440 a->zout += len; 2441 return 1; 2442} 2443 2444static int parse_zlib_header(zbuf *a) 2445{ 2446 int cmf = zget8(a); 2447 int cm = cmf & 15; 2448 /* int cinfo = cmf >> 4; */ 2449 int flg = zget8(a); 2450 if ((cmf*256+flg) % 31 != 0) return e("bad zlib header","Corrupt PNG"); // zlib spec 2451 if (flg & 32) return e("no preset dict","Corrupt PNG"); // preset dictionary not allowed in png 2452 if (cm != 8) return e("bad compression","Corrupt PNG"); // DEFLATE required for png 2453 // window = 1 << (8 + cinfo)... but who cares, we fully buffer output 2454 return 1; 2455} 2456 2457// @TODO: should statically initialize these for optimal thread safety 2458static uint8 default_length[288], default_distance[32]; 2459static void init_defaults(void) 2460{ 2461 int i; // use <= to match clearly with spec 2462 for (i=0; i <= 143; ++i) default_length[i] = 8; 2463 for ( ; i <= 255; ++i) default_length[i] = 9; 2464 for ( ; i <= 279; ++i) default_length[i] = 7; 2465 for ( ; i <= 287; ++i) default_length[i] = 8; 2466 2467 for (i=0; i <= 31; ++i) default_distance[i] = 5; 2468} 2469 2470int stbi_png_partial; // a quick hack to only allow decoding some of a PNG... I should implement real streaming support instead 2471static int parse_zlib(zbuf *a, int parse_header) 2472{ 2473 int final, type; 2474 if (parse_header) 2475 if (!parse_zlib_header(a)) return 0; 2476 a->num_bits = 0; 2477 a->code_buffer = 0; 2478 do { 2479 final = zreceive(a,1); 2480 type = zreceive(a,2); 2481 if (type == 0) { 2482 if (!parse_uncompressed_block(a)) return 0; 2483 } else if (type == 3) { 2484 return 0; 2485 } else { 2486 if (type == 1) { 2487 // use fixed code lengths 2488 if (!default_distance[31]) init_defaults(); 2489 if (!zbuild_huffman(&a->z_length , default_length , 288)) return 0; 2490 if (!zbuild_huffman(&a->z_distance, default_distance, 32)) return 0; 2491 } else { 2492 if (!compute_huffman_codes(a)) return 0; 2493 } 2494 if (!parse_huffman_block(a)) return 0; 2495 } 2496 if (stbi_png_partial && a->zout - a->zout_start > 65536) 2497 break; 2498 } while (!final); 2499 return 1; 2500} 2501 2502static int do_zlib(zbuf *a, char *obuf, int olen, int exp, int parse_header) 2503{ 2504 a->zout_start = obuf; 2505 a->zout = obuf; 2506 a->zout_end = obuf + olen; 2507 a->z_expandable = exp; 2508 2509 return parse_zlib(a, parse_header); 2510} 2511 2512char *stbi_zlib_decode_malloc_guesssize(const char * buffer, int len, int initial_size, int *outlen) 2513{ 2514 zbuf a; 2515 char *p = MALLOC(initial_size); 2516 if (p == NULL) return NULL; 2517 a.zbuffer = (uint8 const *) buffer; 2518 a.zbuffer_end = (uint8 const *) buffer + len; 2519 if (do_zlib(&a, p, initial_size, 1, 1)) { 2520 if (outlen) *outlen = (int) (a.zout - a.zout_start); 2521 return a.zout_start; 2522 } else { 2523 FREE(a.zout_start); 2524 return NULL; 2525 } 2526} 2527 2528char *stbi_zlib_decode_malloc(char const *buffer, int len, int *outlen) 2529{ 2530 return stbi_zlib_decode_malloc_guesssize(buffer, len, 16384, outlen); 2531} 2532 2533char *stbi_zlib_decode_malloc_guesssize_headerflag(const char *buffer, int len, int initial_size, int *outlen, int parse_header) 2534{ 2535 zbuf a; 2536 char *p = MALLOC(initial_size); 2537 if (p == NULL) return NULL; 2538 a.zbuffer = (uint8 const *) buffer; 2539 a.zbuffer_end = (uint8 const *) buffer + len; 2540 if (do_zlib(&a, p, initial_size, 1, parse_header)) { 2541 if (outlen) *outlen = (int) (a.zout - a.zout_start); 2542 return a.zout_start; 2543 } else { 2544 FREE(a.zout_start); 2545 return NULL; 2546 } 2547} 2548 2549int stbi_zlib_decode_buffer(char *obuffer, int olen, char const *ibuffer, int ilen) 2550{ 2551 zbuf a; 2552 a.zbuffer = (uint8 const *) ibuffer; 2553 a.zbuffer_end = (uint8 const *) ibuffer + ilen; 2554 if (do_zlib(&a, obuffer, olen, 0, 1)) 2555 return (int) (a.zout - a.zout_start); 2556 else 2557 return -1; 2558} 2559 2560char *stbi_zlib_decode_noheader_malloc(char const *buffer, int len, int *outlen) 2561{ 2562 zbuf a; 2563 char *p = MALLOC(16384); 2564 if (p == NULL) return NULL; 2565 a.zbuffer = (uint8 const *) buffer; 2566 a.zbuffer_end = (uint8 const *) buffer+len; 2567 if (do_zlib(&a, p, 16384, 1, 0)) { 2568 if (outlen) *outlen = (int) (a.zout - a.zout_start); 2569 return a.zout_start; 2570 } else { 2571 FREE(a.zout_start); 2572 return NULL; 2573 } 2574} 2575 2576int stbi_zlib_decode_noheader_buffer(char *obuffer, int olen, const char *ibuffer, int ilen) 2577{ 2578 zbuf a; 2579 a.zbuffer = (uint8 const *) ibuffer; 2580 a.zbuffer_end = (uint8 const *) ibuffer + ilen; 2581 if (do_zlib(&a, obuffer, olen, 0, 0)) 2582 return (int) (a.zout - a.zout_start); 2583 else 2584 return -1; 2585} 2586 2587// public domain "baseline" PNG decoder v0.10 Sean Barrett 2006-11-18 2588// simple implementation 2589// - only 8-bit samples 2590// - no CRC checking 2591// - allocates lots of intermediate memory 2592// - avoids problem of streaming data between subsystems 2593// - avoids explicit window management 2594// performance 2595// - uses stb_zlib, a PD zlib implementation with fast huffman decoding 2596 2597 2598typedef struct 2599{ 2600 uint32 length; 2601 uint32 type; 2602} chunk; 2603 2604#define PNG_TYPE(a,b,c,d) (((a) << 24) + ((b) << 16) + ((c) << 8) + (d)) 2605 2606static chunk get_chunk_header(stbi *s) 2607{ 2608 chunk c; 2609 c.length = get32(s); 2610 c.type = get32(s); 2611 return c; 2612} 2613 2614static int check_png_header(stbi *s) 2615{ 2616 static uint8 png_sig[8] = { 137,80,78,71,13,10,26,10 }; 2617 int i; 2618 for (i=0; i < 8; ++i) 2619 if (get8(s) != png_sig[i]) return e("bad png sig","Not a PNG"); 2620 return 1; 2621} 2622 2623typedef struct 2624{ 2625 stbi s; 2626 uint8 *idata, *expanded, *out; 2627} png; 2628 2629 2630enum { 2631 F_none=0, F_sub=1, F_up=2, F_avg=3, F_paeth=4, 2632 F_avg_first, F_paeth_first 2633}; 2634 2635static uint8 first_row_filter[5] = 2636{ 2637 F_none, F_sub, F_none, F_avg_first, F_paeth_first 2638}; 2639 2640static int paeth(int a, int b, int c) 2641{ 2642 int p = a + b - c; 2643 int pa = abs(p-a); 2644 int pb = abs(p-b); 2645 int pc = abs(p-c); 2646 if (pa <= pb && pa <= pc) return a; 2647 if (pb <= pc) return b; 2648 return c; 2649} 2650 2651// create the png data from post-deflated data 2652static int create_png_image_raw(png *a, uint8 *raw, uint32 raw_len, int out_n, uint32 x, uint32 y) 2653{ 2654 stbi *s = &a->s; 2655 uint32 i,j,stride = x*out_n; 2656 int k; 2657 int img_n = s->img_n; // copy it into a local for later 2658 assert(out_n == s->img_n || out_n == s->img_n+1); 2659 if (stbi_png_partial) y = 1; 2660 a->out = MALLOC(x * y * out_n); 2661 if (!a->out) return e("outofmem", "Out of memory"); 2662 if (!stbi_png_partial) { 2663 if (s->img_x == x && s->img_y == y) { 2664 if (raw_len != (img_n * x + 1) * y) return e("not enough pixels","Corrupt PNG"); 2665 } else { // interlaced: 2666 if (raw_len < (img_n * x + 1) * y) return e("not enough pixels","Corrupt PNG"); 2667 } 2668 } 2669 for (j=0; j < y; ++j) { 2670 uint8 *cur = a->out + stride*j; 2671 uint8 *prior = cur - stride; 2672 int filter = *raw++; 2673 if (filter > 4) return e("invalid filter","Corrupt PNG"); 2674 // if first row, use special filter that doesn't sample previous row 2675 if (j == 0) filter = first_row_filter[filter]; 2676 // handle first pixel explicitly 2677 for (k=0; k < img_n; ++k) { 2678 switch (filter) { 2679 case F_none : cur[k] = raw[k]; break; 2680 case F_sub : cur[k] = raw[k]; break; 2681 case F_up : cur[k] = raw[k] + prior[k]; break; 2682 case F_avg : cur[k] = raw[k] + (prior[k]>>1); break; 2683 case F_paeth : cur[k] = (uint8) (raw[k] + paeth(0,prior[k],0)); break; 2684 case F_avg_first : cur[k] = raw[k]; break; 2685 case F_paeth_first: cur[k] = raw[k]; break; 2686 } 2687 } 2688 if (img_n != out_n) cur[img_n] = 255; 2689 raw += img_n; 2690 cur += out_n; 2691 prior += out_n; 2692 // this is a little gross, so that we don't switch per-pixel or per-component 2693 if (img_n == out_n) { 2694 #define CASE(f) \ 2695 case f: \ 2696 for (i=x-1; i >= 1; --i, raw+=img_n,cur+=img_n,prior+=img_n) \ 2697 for (k=0; k < img_n; ++k) 2698 switch (filter) { 2699 CASE(F_none) cur[k] = raw[k]; break; 2700 CASE(F_sub) cur[k] = raw[k] + cur[k-img_n]; break; 2701 CASE(F_up) cur[k] = raw[k] + prior[k]; break; 2702 CASE(F_avg) cur[k] = raw[k] + ((prior[k] + cur[k-img_n])>>1); break; 2703 CASE(F_paeth) cur[k] = (uint8) (raw[k] + paeth(cur[k-img_n],prior[k],prior[k-img_n])); break; 2704 CASE(F_avg_first) cur[k] = raw[k] + (cur[k-img_n] >> 1); break; 2705 CASE(F_paeth_first) cur[k] = (uint8) (raw[k] + paeth(cur[k-img_n],0,0)); break; 2706 } 2707 #undef CASE 2708 } else { 2709 assert(img_n+1 == out_n); 2710 #define CASE(f) \ 2711 case f: \ 2712 for (i=x-1; i >= 1; --i, cur[img_n]=255,raw+=img_n,cur+=out_n,prior+=out_n) \ 2713 for (k=0; k < img_n; ++k) 2714 switch (filter) { 2715 CASE(F_none) cur[k] = raw[k]; break; 2716 CASE(F_sub) cur[k] = raw[k] + cur[k-out_n]; break; 2717 CASE(F_up) cur[k] = raw[k] + prior[k]; break; 2718 CASE(F_avg) cur[k] = raw[k] + ((prior[k] + cur[k-out_n])>>1); break; 2719 CASE(F_paeth) cur[k] = (uint8) (raw[k] + paeth(cur[k-out_n],prior[k],prior[k-out_n])); break; 2720 CASE(F_avg_first) cur[k] = raw[k] + (cur[k-out_n] >> 1); break; 2721 CASE(F_paeth_first) cur[k] = (uint8) (raw[k] + paeth(cur[k-out_n],0,0)); break; 2722 } 2723 #undef CASE 2724 } 2725 } 2726 return 1; 2727} 2728 2729static int create_png_image(png *a, uint8 *raw, uint32 raw_len, int out_n, int interlaced) 2730{ 2731 uint8 *final; 2732 int p; 2733 int save; 2734 if (!interlaced) 2735 return create_png_image_raw(a, raw, raw_len, out_n, a->s.img_x, a->s.img_y); 2736 save = stbi_png_partial; 2737 stbi_png_partial = 0; 2738 2739 // de-interlacing 2740 final = MALLOC(a->s.img_x * a->s.img_y * out_n); 2741 for (p=0; p < 7; ++p) { 2742 int xorig[] = { 0,4,0,2,0,1,0 }; 2743 int yorig[] = { 0,0,4,0,2,0,1 }; 2744 int xspc[] = { 8,8,4,4,2,2,1 }; 2745 int yspc[] = { 8,8,8,4,4,2,2 }; 2746 int i,j,x,y; 2747 // pass1_x[4] = 0, pass1_x[5] = 1, pass1_x[12] = 1 2748 x = (a->s.img_x - xorig[p] + xspc[p]-1) / xspc[p]; 2749 y = (a->s.img_y - yorig[p] + yspc[p]-1) / yspc[p]; 2750 if (x && y) { 2751 if (!create_png_image_raw(a, raw, raw_len, out_n, x, y)) { 2752 FREE(final); 2753 return 0; 2754 } 2755 for (j=0; j < y; ++j) 2756 for (i=0; i < x; ++i) 2757 memcpy(final + (j*yspc[p]+yorig[p])*a->s.img_x*out_n + (i*xspc[p]+xorig[p])*out_n, 2758 a->out + (j*x+i)*out_n, out_n); 2759 FREE(a->out); 2760 raw += (x*out_n+1)*y; 2761 raw_len -= (x*out_n+1)*y; 2762 } 2763 } 2764 a->out = final; 2765 2766 stbi_png_partial = save; 2767 return 1; 2768} 2769 2770static int compute_transparency(png *z, uint8 tc[3], int out_n) 2771{ 2772 stbi *s = &z->s; 2773 uint32 i, pixel_count = s->img_x * s->img_y; 2774 uint8 *p = z->out; 2775 2776 // compute color-based transparency, assuming we've 2777 // already got 255 as the alpha value in the output 2778 assert(out_n == 2 || out_n == 4); 2779 2780 if (out_n == 2) { 2781 for (i=0; i < pixel_count; ++i) { 2782 p[1] = (p[0] == tc[0] ? 0 : 255); 2783 p += 2; 2784 } 2785 } else { 2786 for (i=0; i < pixel_count; ++i) { 2787 if (p[0] == tc[0] && p[1] == tc[1] && p[2] == tc[2]) 2788 p[3] = 0; 2789 p += 4; 2790 } 2791 } 2792 return 1; 2793} 2794 2795static int expand_palette(png *a, uint8 *palette, int len, int pal_img_n) 2796{ 2797 uint32 i, pixel_count = a->s.img_x * a->s.img_y; 2798 uint8 *p, *temp_out, *orig = a->out; 2799 2800 p = MALLOC(pixel_count * pal_img_n); 2801 if (p == NULL) return e("outofmem", "Out of memory"); 2802 2803 // between here and FREE(out) below, exiting would leak 2804 temp_out = p; 2805 2806 if (pal_img_n == 3) { 2807 for (i=0; i < pixel_count; ++i) { 2808 int n = orig[i]*4; 2809 p[0] = palette[n ]; 2810 p[1] = palette[n+1]; 2811 p[2] = palette[n+2]; 2812 p += 3; 2813 } 2814 } else { 2815 for (i=0; i < pixel_count; ++i) { 2816 int n = orig[i]*4; 2817 p[0] = palette[n ]; 2818 p[1] = palette[n+1]; 2819 p[2] = palette[n+2]; 2820 p[3] = palette[n+3]; 2821 p += 4; 2822 } 2823 } 2824 FREE(a->out); 2825 a->out = temp_out; 2826 2827 STBI_NOTUSED(len); 2828 2829 return 1; 2830} 2831 2832static int stbi_unpremultiply_on_load = 0; 2833static int stbi_de_iphone_flag = 0; 2834 2835void stbi_set_unpremultiply_on_load(int flag_true_if_should_unpremultiply) 2836{ 2837 stbi_unpremultiply_on_load = flag_true_if_should_unpremultiply; 2838} 2839void stbi_convert_iphone_png_to_rgb(int flag_true_if_should_convert) 2840{ 2841 stbi_de_iphone_flag = flag_true_if_should_convert; 2842} 2843 2844static void stbi_de_iphone(png *z) 2845{ 2846 stbi *s = &z->s; 2847 uint32 i, pixel_count = s->img_x * s->img_y; 2848 uint8 *p = z->out; 2849 2850 if (s->img_out_n == 3) { // convert bgr to rgb 2851 for (i=0; i < pixel_count; ++i) { 2852 uint8 t = p[0]; 2853 p[0] = p[2]; 2854 p[2] = t; 2855 p += 3; 2856 } 2857 } else { 2858 assert(s->img_out_n == 4); 2859 if (stbi_unpremultiply_on_load) { 2860 // convert bgr to rgb and unpremultiply 2861 for (i=0; i < pixel_count; ++i) { 2862 uint8 a = p[3]; 2863 uint8 t = p[0]; 2864 if (a) { 2865 p[0] = p[2] * 255 / a; 2866 p[1] = p[1] * 255 / a; 2867 p[2] = t * 255 / a; 2868 } else { 2869 p[0] = p[2]; 2870 p[2] = t; 2871 } 2872 p += 4; 2873 } 2874 } else { 2875 // convert bgr to rgb 2876 for (i=0; i < pixel_count; ++i) { 2877 uint8 t = p[0]; 2878 p[0] = p[2]; 2879 p[2] = t; 2880 p += 4; 2881 } 2882 } 2883 } 2884} 2885 2886static int parse_png_file(png *z, int scan, int req_comp) 2887{ 2888 uint8 palette[1024], pal_img_n=0; 2889 uint8 has_trans=0, tc[3]; 2890 uint32 ioff=0, idata_limit=0, i, pal_len=0; 2891 int first=1,k,interlace=0, iphone=0; 2892 stbi *s = &z->s; 2893 2894 if (!check_png_header(s)) return 0; 2895 2896 if (scan == SCAN_type) return 1; 2897 2898 for (;;) { 2899 chunk c = get_chunk_header(s); 2900 switch (c.type) { 2901 case PNG_TYPE('C','g','B','I'): 2902 iphone = stbi_de_iphone_flag; 2903 skip(s, c.length); 2904 break; 2905 case PNG_TYPE('I','H','D','R'): { 2906 int depth,color,comp,filter; 2907 if (!first) return e("multiple IHDR","Corrupt PNG"); 2908 first = 0; 2909 if (c.length != 13) return e("bad IHDR len","Corrupt PNG"); 2910 s->img_x = get32(s); if (s->img_x > (1 << 24)) return e("too large","Very large image (corrupt?)"); 2911 s->img_y = get32(s); if (s->img_y > (1 << 24)) return e("too large","Very large image (corrupt?)"); 2912 depth = get8(s); if (depth != 8) return e("8bit only","PNG not supported: 8-bit only"); 2913 color = get8(s); if (color > 6) return e("bad ctype","Corrupt PNG"); 2914 if (color == 3) pal_img_n = 3; else if (color & 1) return e("bad ctype","Corrupt PNG"); 2915 comp = get8(s); if (comp) return e("bad comp method","Corrupt PNG"); 2916 filter= get8(s); if (filter) return e("bad filter method","Corrupt PNG"); 2917 interlace = get8(s); if (interlace>1) return e("bad interlace method","Corrupt PNG"); 2918 if (!s->img_x || !s->img_y) return e("0-pixel image","Corrupt PNG"); 2919 if (!pal_img_n) { 2920 s->img_n = (color & 2 ? 3 : 1) + (color & 4 ? 1 : 0); 2921 if ((1 << 30) / s->img_x / s->img_n < s->img_y) return e("too large", "Image too large to decode"); 2922 if (scan == SCAN_header) return 1; 2923 } else { 2924 // if paletted, then pal_n is our final components, and 2925 // img_n is # components to decompress/filter. 2926 s->img_n = 1; 2927 if ((1 << 30) / s->img_x / 4 < s->img_y) return e("too large","Corrupt PNG"); 2928 // if SCAN_header, have to scan to see if we have a tRNS 2929 } 2930 break; 2931 } 2932 2933 case PNG_TYPE('P','L','T','E'): { 2934 if (first) return e("first not IHDR", "Corrupt PNG"); 2935 if (c.length > 256*3) return e("invalid PLTE","Corrupt PNG"); 2936 pal_len = c.length / 3; 2937 if (pal_len * 3 != c.length) return e("invalid PLTE","Corrupt PNG"); 2938 for (i=0; i < pal_len; ++i) { 2939 palette[i*4+0] = get8u(s); 2940 palette[i*4+1] = get8u(s); 2941 palette[i*4+2] = get8u(s); 2942 palette[i*4+3] = 255; 2943 } 2944 break; 2945 } 2946 2947 case PNG_TYPE('t','R','N','S'): { 2948 if (first) return e("first not IHDR", "Corrupt PNG"); 2949 if (z->idata) return e("tRNS after IDAT","Corrupt PNG"); 2950 if (pal_img_n) { 2951 if (scan == SCAN_header) { s->img_n = 4; return 1; } 2952 if (pal_len == 0) return e("tRNS before PLTE","Corrupt PNG"); 2953 if (c.length > pal_len) return e("bad tRNS len","Corrupt PNG"); 2954 pal_img_n = 4; 2955 for (i=0; i < c.length; ++i) 2956 palette[i*4+3] = get8u(s); 2957 } else { 2958 if (!(s->img_n & 1)) return e("tRNS with alpha","Corrupt PNG"); 2959 if (c.length != (uint32) s->img_n*2) return e("bad tRNS len","Corrupt PNG"); 2960 has_trans = 1; 2961 for (k=0; k < s->img_n; ++k) 2962 tc[k] = (uint8) get16(s); // non 8-bit images will be larger 2963 } 2964 break; 2965 } 2966 2967 case PNG_TYPE('I','D','A','T'): { 2968 if (first) return e("first not IHDR", "Corrupt PNG"); 2969 if (pal_img_n && !pal_len) return e("no PLTE","Corrupt PNG"); 2970 if (scan == SCAN_header) { s->img_n = pal_img_n; return 1; } 2971 if (ioff + c.length > idata_limit) { 2972 uint8 *p; 2973 if (idata_limit == 0) idata_limit = c.length > 4096 ? c.length : 4096; 2974 while (ioff + c.length > idata_limit) 2975 idata_limit *= 2; 2976 p = (uint8 *) REALLOC(z->idata, idata_limit); if (p == NULL) return e("outofmem", "Out of memory"); 2977 z->idata = p; 2978 } 2979 if (!getn(s, z->idata+ioff,c.length)) return e("outofdata","Corrupt PNG"); 2980 ioff += c.length; 2981 break; 2982 } 2983 2984 case PNG_TYPE('I','E','N','D'): { 2985 uint32 raw_len; 2986 if (first) return e("first not IHDR", "Corrupt PNG"); 2987 if (scan != SCAN_load) return 1; 2988 if (z->idata == NULL) return e("no IDAT","Corrupt PNG"); 2989 z->expanded = (uint8 *) stbi_zlib_decode_malloc_guesssize_headerflag((char *) z->idata, ioff, 16384, (int *) &raw_len, !iphone); 2990 if (z->expanded == NULL) return 0; // zlib should set error 2991 FREE(z->idata); z->idata = NULL; 2992 if ((req_comp == s->img_n+1 && req_comp != 3 && !pal_img_n) || has_trans) 2993 s->img_out_n = s->img_n+1; 2994 else 2995 s->img_out_n = s->img_n; 2996 if (!create_png_image(z, z->expanded, raw_len, s->img_out_n, interlace)) return 0; 2997 if (has_trans) 2998 if (!compute_transparency(z, tc, s->img_out_n)) return 0; 2999 if (iphone && s->img_out_n > 2) 3000 stbi_de_iphone(z); 3001 if (pal_img_n) { 3002 // pal_img_n == 3 or 4 3003 s->img_n = pal_img_n; // record the actual colors we had 3004 s->img_out_n = pal_img_n; 3005 if (req_comp >= 3) s->img_out_n = req_comp; 3006 if (!expand_palette(z, palette, pal_len, s->img_out_n)) 3007 return 0; 3008 } 3009 FREE(z->expanded); z->expanded = NULL; 3010 return 1; 3011 } 3012 3013 default: 3014 // if critical, fail 3015 if (first) return e("first not IHDR", "Corrupt PNG"); 3016 if ((c.type & (1 << 29)) == 0) { 3017 #ifndef STBI_NO_FAILURE_STRINGS 3018 // not threadsafe 3019 static char invalid_chunk[] = "XXXX chunk not known"; 3020 invalid_chunk[0] = (uint8) (c.type >> 24); 3021 invalid_chunk[1] = (uint8) (c.type >> 16); 3022 invalid_chunk[2] = (uint8) (c.type >> 8); 3023 invalid_chunk[3] = (uint8) (c.type >> 0); 3024 #endif 3025 return e(invalid_chunk, "PNG not supported: unknown chunk type"); 3026 } 3027 skip(s, c.length); 3028 break; 3029 } 3030 // end of chunk, read and skip CRC 3031 get32(s); 3032 } 3033} 3034 3035static unsigned char *do_png(png *p, int *x, int *y, int *n, int req_comp) 3036{ 3037 unsigned char *result=NULL; 3038 p->expanded = NULL; 3039 p->idata = NULL; 3040 p->out = NULL; 3041 if (req_comp < 0 || req_comp > 4) return epuc("bad req_comp", "Internal error"); 3042 if (parse_png_file(p, SCAN_load, req_comp)) { 3043 result = p->out; 3044 p->out = NULL; 3045 if (req_comp && req_comp != p->s.img_out_n) { 3046 result = convert_format(result, p->s.img_out_n, req_comp, p->s.img_x, p->s.img_y); 3047 p->s.img_out_n = req_comp; 3048 if (result == NULL) return result; 3049 } 3050 *x = p->s.img_x; 3051 *y = p->s.img_y; 3052 if (n) *n = p->s.img_n; 3053 } 3054 FREE(p->expanded); p->expanded = NULL; 3055 FREE(p->idata); p->idata = NULL; 3056 3057 return result; 3058} 3059 3060#ifndef STBI_NO_STDIO 3061unsigned char *stbi_png_load_from_file(FILE *f, int *x, int *y, int *comp, int req_comp) 3062{ 3063 png p; 3064 start_file(&p.s, f); 3065 return do_png(&p, x,y,comp,req_comp); 3066} 3067 3068unsigned char *stbi_png_load(char const *filename, int *x, int *y, int *comp, int req_comp) 3069{ 3070 unsigned char *data; 3071 FILE *f = fopen(filename, "rb"); 3072 if (!f) return NULL; 3073 data = stbi_png_load_from_file(f,x,y,comp,req_comp); 3074 fclose(f); 3075 return data; 3076} 3077#endif 3078 3079unsigned char *stbi_png_load_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) 3080{ 3081 png p; 3082 start_mem(&p.s, buffer,len); 3083 return do_png(&p, x,y,comp,req_comp); 3084} 3085 3086#ifndef STBI_NO_STDIO 3087int stbi_png_test_file(FILE *f) 3088{ 3089 png p; 3090 int n,r; 3091 n = ftell(f); 3092 start_file(&p.s, f); 3093 r = parse_png_file(&p, SCAN_type,STBI_default); 3094 fseek(f,n,SEEK_SET); 3095 return r; 3096} 3097#endif 3098 3099int stbi_png_test_memory(stbi_uc const *buffer, int len) 3100{ 3101 png p; 3102 start_mem(&p.s, buffer, len); 3103 return parse_png_file(&p, SCAN_type,STBI_default); 3104} 3105 3106static int stbi_png_info_raw(png *p, int *x, int *y, int *comp) 3107{ 3108 if (!parse_png_file(p, SCAN_header, 0)) 3109 return 0; 3110 if (x) *x = p->s.img_x; 3111 if (y) *y = p->s.img_y; 3112 if (comp) *comp = p->s.img_n; 3113 return 1; 3114} 3115 3116#ifndef STBI_NO_STDIO 3117int stbi_png_info (char const *filename, int *x, int *y, int *comp) 3118{ 3119 int res; 3120 FILE *f = fopen(filename, "rb"); 3121 if (!f) return 0; 3122 res = stbi_png_info_from_file(f, x, y, comp); 3123 fclose(f); 3124 return res; 3125} 3126 3127int stbi_png_info_from_file(FILE *f, int *x, int *y, int *comp) 3128{ 3129 png p; 3130 int res; 3131 long n = ftell(f); 3132 start_file(&p.s, f); 3133 res = stbi_png_info_raw(&p, x, y, comp); 3134 fseek(f, n, SEEK_SET); 3135 return res; 3136} 3137#endif // !STBI_NO_STDIO 3138 3139int stbi_png_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp) 3140{ 3141 png p; 3142 start_mem(&p.s, buffer, len); 3143 return stbi_png_info_raw(&p, x, y, comp); 3144} 3145 3146// Microsoft/Windows BMP image 3147 3148static int bmp_test(stbi *s) 3149{ 3150 int sz; 3151 if (get8(s) != 'B') return 0; 3152 if (get8(s) != 'M') return 0; 3153 get32le(s); // discard filesize 3154 get16le(s); // discard reserved 3155 get16le(s); // discard reserved 3156 get32le(s); // discard data offset 3157 sz = get32le(s); 3158 if (sz == 12 || sz == 40 || sz == 56 || sz == 108) return 1; 3159 return 0; 3160} 3161 3162#ifndef STBI_NO_STDIO 3163int stbi_bmp_test_file (FILE *f) 3164{ 3165 stbi s; 3166 int r,n = ftell(f); 3167 start_file(&s,f); 3168 r = bmp_test(&s); 3169 fseek(f,n,SEEK_SET); 3170 return r; 3171} 3172#endif 3173 3174int stbi_bmp_test_memory (stbi_uc const *buffer, int len) 3175{ 3176 stbi s; 3177 start_mem(&s, buffer, len); 3178 return bmp_test(&s); 3179} 3180 3181// returns 0..31 for the highest set bit 3182static int high_bit(unsigned int z) 3183{ 3184 int n=0; 3185 if (z == 0) return -1; 3186 if (z >= 0x10000) n += 16, z >>= 16; 3187 if (z >= 0x00100) n += 8, z >>= 8; 3188 if (z >= 0x00010) n += 4, z >>= 4; 3189 if (z >= 0x00004) n += 2, z >>= 2; 3190 if (z >= 0x00002) n += 1, z >>= 1; 3191 return n; 3192} 3193 3194static int bitcount(unsigned int a) 3195{ 3196 a = (a & 0x55555555) + ((a >> 1) & 0x55555555); // max 2 3197 a = (a & 0x33333333) + ((a >> 2) & 0x33333333); // max 4 3198 a = (a + (a >> 4)) & 0x0f0f0f0f; // max 8 per 4, now 8 bits 3199 a = (a + (a >> 8)); // max 16 per 8 bits 3200 a = (a + (a >> 16)); // max 32 per 8 bits 3201 return a & 0xff; 3202} 3203 3204static int shiftsigned(int v, int shift, int bits) 3205{ 3206 int result; 3207 int z=0; 3208 3209 if (shift < 0) v <<= -shift; 3210 else v >>= shift; 3211 result = v; 3212 3213 z = bits; 3214 while (z < 8) { 3215 result += v >> z; 3216 z += bits; 3217 } 3218 return result; 3219} 3220 3221static stbi_uc *bmp_load(stbi *s, int *x, int *y, int *comp, int req_comp) 3222{ 3223 uint8 *out; 3224 unsigned int mr=0,mg=0,mb=0,ma=0; 3225 stbi_uc pal[256][4]; 3226 int psize=0,i,j,compress=0,width; 3227 int bpp, flip_vertically, pad, target, offset, hsz; 3228 if (get8(s) != 'B' || get8(s) != 'M') return epuc("not BMP", "Corrupt BMP"); 3229 get32le(s); // discard filesize 3230 get16le(s); // discard reserved 3231 get16le(s); // discard reserved 3232 offset = get32le(s); 3233 hsz = get32le(s); 3234 if (hsz != 12 && hsz != 40 && hsz != 56 && hsz != 108) return epuc("unknown BMP", "BMP type not supported: unknown"); 3235 if (hsz == 12) { 3236 s->img_x = get16le(s); 3237 s->img_y = get16le(s); 3238 } else { 3239 s->img_x = get32le(s); 3240 s->img_y = get32le(s); 3241 } 3242 if (get16le(s) != 1) return epuc("bad BMP", "bad BMP"); 3243 bpp = get16le(s); 3244 if (bpp == 1) return epuc("monochrome", "BMP type not supported: 1-bit"); 3245 flip_vertically = ((int) s->img_y) > 0; 3246 s->img_y = abs((int) s->img_y); 3247 if (hsz == 12) { 3248 if (bpp < 24) 3249 psize = (offset - 14 - 24) / 3; 3250 } else { 3251 compress = get32le(s); 3252 if (compress == 1 || compress == 2) return epuc("BMP RLE", "BMP type not supported: RLE"); 3253 get32le(s); // discard sizeof 3254 get32le(s); // discard hres 3255 get32le(s); // discard vres 3256 get32le(s); // discard colorsused 3257 get32le(s); // discard max important 3258 if (hsz == 40 || hsz == 56) { 3259 if (hsz == 56) { 3260 get32le(s); 3261 get32le(s); 3262 get32le(s); 3263 get32le(s); 3264 } 3265 if (bpp == 16 || bpp == 32) { 3266 mr = mg = mb = 0; 3267 if (compress == 0) { 3268 if (bpp == 32) { 3269 mr = 0xffu << 16; 3270 mg = 0xffu << 8; 3271 mb = 0xffu << 0; 3272 ma = 0xffu << 24; 3273 } else { 3274 mr = 31u << 10; 3275 mg = 31u << 5; 3276 mb = 31u << 0; 3277 } 3278 } else if (compress == 3) { 3279 mr = get32le(s); 3280 mg = get32le(s); 3281 mb = get32le(s); 3282 // not documented, but generated by photoshop and handled by mspaint 3283 if (mr == mg && mg == mb) { 3284 // ?!?!? 3285 return epuc("bad BMP", "bad BMP"); 3286 } 3287 } else 3288 return epuc("bad BMP", "bad BMP"); 3289 } 3290 } else { 3291 assert(hsz == 108); 3292 mr = get32le(s); 3293 mg = get32le(s); 3294 mb = get32le(s); 3295 ma = get32le(s); 3296 get32le(s); // discard color space 3297 for (i=0; i < 12; ++i) 3298 get32le(s); // discard color space parameters 3299 } 3300 if (bpp < 16) 3301 psize = (offset - 14 - hsz) >> 2; 3302 } 3303 s->img_n = ma ? 4 : 3; 3304 if (req_comp && req_comp >= 3) // we can directly decode 3 or 4 3305 target = req_comp; 3306 else 3307 target = s->img_n; // if they want monochrome, we'll post-convert 3308 out = MALLOC(target * s->img_x * s->img_y); 3309 if (!out) return epuc("outofmem", "Out of memory"); 3310 if (bpp < 16) { 3311 int z=0; 3312 if (psize == 0 || psize > 256) { FREE(out); return epuc("invalid", "Corrupt BMP"); } 3313 for (i=0; i < psize; ++i) { 3314 pal[i][2] = get8u(s); 3315 pal[i][1] = get8u(s); 3316 pal[i][0] = get8u(s); 3317 if (hsz != 12) get8(s); 3318 pal[i][3] = 255; 3319 } 3320 skip(s, offset - 14 - hsz - psize * (hsz == 12 ? 3 : 4)); 3321 if (bpp == 4) width = (s->img_x + 1) >> 1; 3322 else if (bpp == 8) width = s->img_x; 3323 else { FREE(out); return epuc("bad bpp", "Corrupt BMP"); } 3324 pad = (-width)&3; 3325 for (j=0; j < (int) s->img_y; ++j) { 3326 for (i=0; i < (int) s->img_x; i += 2) { 3327 int v=get8(s),v2=0; 3328 if (bpp == 4) { 3329 v2 = v & 15; 3330 v >>= 4; 3331 } 3332 out[z++] = pal[v][0]; 3333 out[z++] = pal[v][1]; 3334 out[z++] = pal[v][2]; 3335 if (target == 4) out[z++] = 255; 3336 if (i+1 == (int) s->img_x) break; 3337 v = (bpp == 8) ? get8(s) : v2; 3338 out[z++] = pal[v][0]; 3339 out[z++] = pal[v][1]; 3340 out[z++] = pal[v][2]; 3341 if (target == 4) out[z++] = 255; 3342 } 3343 skip(s, pad); 3344 } 3345 } else { 3346 int rshift=0,gshift=0,bshift=0,ashift=0,rcount=0,gcount=0,bcount=0,acount=0; 3347 int z = 0; 3348 int easy=0; 3349 skip(s, offset - 14 - hsz); 3350 if (bpp == 24) width = 3 * s->img_x; 3351 else if (bpp == 16) width = 2*s->img_x; 3352 else /* bpp = 32 and pad = 0 */ width=0; 3353 pad = (-width) & 3; 3354 if (bpp == 24) { 3355 easy = 1; 3356 } else if (bpp == 32) { 3357 if (mb == 0xff && mg == 0xff00 && mr == 0xff000000 && ma == 0xff000000) 3358 easy = 2; 3359 } 3360 if (!easy) { 3361 if (!mr || !mg || !mb) return epuc("bad masks", "Corrupt BMP"); 3362 // right shift amt to put high bit in position #7 3363 rshift = high_bit(mr)-7; rcount = bitcount(mr); 3364 gshift = high_bit(mg)-7; gcount = bitcount(mr); 3365 bshift = high_bit(mb)-7; bcount = bitcount(mr); 3366 ashift = high_bit(ma)-7; acount = bitcount(mr); 3367 } 3368 for (j=0; j < (int) s->img_y; ++j) { 3369 if (easy) { 3370 for (i=0; i < (int) s->img_x; ++i) { 3371 int a; 3372 out[z+2] = get8u(s); 3373 out[z+1] = get8u(s); 3374 out[z+0] = get8u(s); 3375 z += 3; 3376 a = (easy == 2 ? get8(s) : 255); 3377 if (target == 4) out[z++] = (uint8) a; 3378 } 3379 } else { 3380 for (i=0; i < (int) s->img_x; ++i) { 3381 uint32 v = (bpp == 16 ? get16le(s) : get32le(s)); 3382 int a; 3383 out[z++] = (uint8) shiftsigned(v & mr, rshift, rcount); 3384 out[z++] = (uint8) shiftsigned(v & mg, gshift, gcount); 3385 out[z++] = (uint8) shiftsigned(v & mb, bshift, bcount); 3386 a = (ma ? shiftsigned(v & ma, ashift, acount) : 255); 3387 if (target == 4) out[z++] = (uint8) a; 3388 } 3389 } 3390 skip(s, pad); 3391 } 3392 } 3393 if (flip_vertically) { 3394 stbi_uc t; 3395 for (j=0; j < (int) s->img_y>>1; ++j) { 3396 stbi_uc *p1 = out + j *s->img_x*target; 3397 stbi_uc *p2 = out + (s->img_y-1-j)*s->img_x*target; 3398 for (i=0; i < (int) s->img_x*target; ++i) { 3399 t = p1[i], p1[i] = p2[i], p2[i] = t; 3400 } 3401 } 3402 } 3403 3404 if (req_comp && req_comp != target) { 3405 out = convert_format(out, target, req_comp, s->img_x, s->img_y); 3406 if (out == NULL) return out; // convert_format frees input on failure 3407 } 3408 3409 *x = s->img_x; 3410 *y = s->img_y; 3411 if (comp) *comp = target; 3412 return out; 3413} 3414 3415#ifndef STBI_NO_STDIO 3416stbi_uc *stbi_bmp_load (char const *filename, int *x, int *y, int *comp, int req_comp) 3417{ 3418 stbi_uc *data; 3419 FILE *f = fopen(filename, "rb"); 3420 if (!f) return NULL; 3421 data = stbi_bmp_load_from_file(f, x,y,comp,req_comp); 3422 fclose(f); 3423 return data; 3424} 3425 3426stbi_uc *stbi_bmp_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp) 3427{ 3428 stbi s; 3429 start_file(&s, f); 3430 return bmp_load(&s, x,y,comp,req_comp); 3431} 3432#endif 3433 3434stbi_uc *stbi_bmp_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) 3435{ 3436 stbi s; 3437 start_mem(&s, buffer, len); 3438 return bmp_load(&s, x,y,comp,req_comp); 3439} 3440 3441// Targa Truevision - TGA 3442// by Jonathan Dummer 3443 3444static int tga_info(stbi *s, int *x, int *y, int *comp) 3445{ 3446 int tga_w, tga_h, tga_comp; 3447 int sz; 3448 get8u(s); // discard Offset 3449 sz = get8u(s); // color type 3450 if( sz > 1 ) return 0; // only RGB or indexed allowed 3451 sz = get8u(s); // image type 3452 // only RGB or grey allowed, +/- RLE 3453 if ((sz != 1) && (sz != 2) && (sz != 3) && (sz != 9) && (sz != 10) && (sz != 11)) return 0; 3454 get16le(s); // discard palette start 3455 get16le(s); // discard palette length 3456 get8(s); // discard bits per palette color entry 3457 get16le(s); // discard x origin 3458 get16le(s); // discard y origin 3459 tga_w = get16le(s); 3460 if( tga_w < 1 ) return 0; // test width 3461 tga_h = get16le(s); 3462 if( tga_h < 1 ) return 0; // test height 3463 sz = get8(s); // bits per pixel 3464 // only RGB or RGBA or grey allowed 3465 if ((sz != 8) && (sz != 16) && (sz != 24) && (sz != 32)) return 0; 3466 tga_comp = sz; 3467 if (x) *x = tga_w; 3468 if (y) *y = tga_h; 3469 if (comp) *comp = tga_comp / 8; 3470 return 1; // seems to have passed everything 3471} 3472 3473#ifndef STBI_NO_STDIO 3474int stbi_tga_info_from_file(FILE *f, int *x, int *y, int *comp) 3475{ 3476 stbi s; 3477 int r; 3478 long n = ftell(f); 3479 start_file(&s, f); 3480 r = tga_info(&s, x, y, comp); 3481 fseek(f, n, SEEK_SET); 3482 return r; 3483} 3484#endif 3485 3486int stbi_tga_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp) 3487{ 3488 stbi s; 3489 start_mem(&s, buffer, len); 3490 return tga_info(&s, x, y, comp); 3491} 3492 3493static int tga_test(stbi *s) 3494{ 3495 int sz; 3496 get8u(s); // discard Offset 3497 sz = get8u(s); // color type 3498 if ( sz > 1 ) return 0; // only RGB or indexed allowed 3499 sz = get8u(s); // image type 3500 if ( (sz != 1) && (sz != 2) && (sz != 3) && (sz != 9) && (sz != 10) && (sz != 11) ) return 0; // only RGB or grey allowed, +/- RLE 3501 get16(s); // discard palette start 3502 get16(s); // discard palette length 3503 get8(s); // discard bits per palette color entry 3504 get16(s); // discard x origin 3505 get16(s); // discard y origin 3506 if ( get16(s) < 1 ) return 0; // test width 3507 if ( get16(s) < 1 ) return 0; // test height 3508 sz = get8(s); // bits per pixel 3509 if ( (sz != 8) && (sz != 16) && (sz != 24) && (sz != 32) ) return 0; // only RGB or RGBA or grey allowed 3510 return 1; // seems to have passed everything 3511} 3512 3513#ifndef STBI_NO_STDIO 3514int stbi_tga_test_file (FILE *f) 3515{ 3516 stbi s; 3517 int r,n = ftell(f); 3518 start_file(&s, f); 3519 r = tga_test(&s); 3520 fseek(f,n,SEEK_SET); 3521 return r; 3522} 3523#endif 3524 3525int stbi_tga_test_memory (stbi_uc const *buffer, int len) 3526{ 3527 stbi s; 3528 start_mem(&s, buffer, len); 3529 return tga_test(&s); 3530} 3531 3532static stbi_uc *tga_load(stbi *s, int *x, int *y, int *comp, int req_comp) 3533{ 3534 // read in the TGA header stuff 3535 int tga_offset = get8u(s); 3536 int tga_indexed = get8u(s); 3537 int tga_image_type = get8u(s); 3538 int tga_is_RLE = 0; 3539 int tga_palette_start = get16le(s); 3540 int tga_palette_len = get16le(s); 3541 int tga_palette_bits = get8u(s); 3542 int tga_x_origin = get16le(s); 3543 int tga_y_origin = get16le(s); 3544 int tga_width = get16le(s); 3545 int tga_height = get16le(s); 3546 int tga_bits_per_pixel = get8u(s); 3547 int tga_inverted = get8u(s); 3548 // image data 3549 unsigned char *tga_data; 3550 unsigned char *tga_palette = NULL; 3551 int i, j; 3552 unsigned char raw_data[4]; 3553 unsigned char trans_data[4]; 3554 int RLE_count = 0; 3555 int RLE_repeating = 0; 3556 int read_next_pixel = 1; 3557 3558 // do a tiny bit of precessing 3559 if ( tga_image_type >= 8 ) 3560 { 3561 tga_image_type -= 8; 3562 tga_is_RLE = 1; 3563 } 3564 /* int tga_alpha_bits = tga_inverted & 15; */ 3565 tga_inverted = 1 - ((tga_inverted >> 5) & 1); 3566 3567 // error check 3568 if ( //(tga_indexed) || 3569 (tga_width < 1) || (tga_height < 1) || 3570 (tga_image_type < 1) || (tga_image_type > 3) || 3571 ((tga_bits_per_pixel != 8) && (tga_bits_per_pixel != 16) && 3572 (tga_bits_per_pixel != 24) && (tga_bits_per_pixel != 32)) 3573 ) 3574 { 3575 return NULL; 3576 } 3577 3578 // If I'm paletted, then I'll use the number of bits from the palette 3579 if ( tga_indexed ) 3580 { 3581 tga_bits_per_pixel = tga_palette_bits; 3582 } 3583 3584 // tga info 3585 *x = tga_width; 3586 *y = tga_height; 3587 if ( (req_comp < 1) || (req_comp > 4) ) 3588 { 3589 // just use whatever the file was 3590 req_comp = tga_bits_per_pixel / 8; 3591 *comp = req_comp; 3592 } else 3593 { 3594 // force a new number of components 3595 *comp = tga_bits_per_pixel/8; 3596 } 3597 tga_data = MALLOC( tga_width * tga_height * req_comp ); 3598 3599 // skip to the data's starting position (offset usually = 0) 3600 skip(s, tga_offset ); 3601 // do I need to load a palette? 3602 if ( tga_indexed ) 3603 { 3604 // any data to skip? (offset usually = 0) 3605 skip(s, tga_palette_start ); 3606 // load the palette 3607 tga_palette = MALLOC( tga_palette_len * tga_palette_bits / 8 ); 3608 if (!getn(s, tga_palette, tga_palette_len * tga_palette_bits / 8 )) 3609 return NULL; 3610 } 3611 // load the data 3612 trans_data[0] = trans_data[1] = trans_data[2] = trans_data[3] = 0; 3613 for (i=0; i < tga_width * tga_height; ++i) 3614 { 3615 // if I'm in RLE mode, do I need to get a RLE chunk? 3616 if ( tga_is_RLE ) 3617 { 3618 if ( RLE_count == 0 ) 3619 { 3620 // yep, get the next byte as a RLE command 3621 int RLE_cmd = get8u(s); 3622 RLE_count = 1 + (RLE_cmd & 127); 3623 RLE_repeating = RLE_cmd >> 7; 3624 read_next_pixel = 1; 3625 } else if ( !RLE_repeating ) 3626 { 3627 read_next_pixel = 1; 3628 } 3629 } else 3630 { 3631 read_next_pixel = 1; 3632 } 3633 // OK, if I need to read a pixel, do it now 3634 if ( read_next_pixel ) 3635 { 3636 // load however much data we did have 3637 if ( tga_indexed ) 3638 { 3639 // read in 1 byte, then perform the lookup 3640 int pal_idx = get8u(s); 3641 if ( pal_idx >= tga_palette_len ) 3642 { 3643 // invalid index 3644 pal_idx = 0; 3645 } 3646 pal_idx *= tga_bits_per_pixel / 8; 3647 for (j = 0; j*8 < tga_bits_per_pixel; ++j) 3648 { 3649 raw_data[j] = tga_palette[pal_idx+j]; 3650 } 3651 } else 3652 { 3653 // read in the data raw 3654 for (j = 0; j*8 < tga_bits_per_pixel; ++j) 3655 { 3656 raw_data[j] = get8u(s); 3657 } 3658 } 3659 // convert raw to the intermediate format 3660 switch (tga_bits_per_pixel) 3661 { 3662 case 8: 3663 // Luminous => RGBA 3664 trans_data[0] = raw_data[0]; 3665 trans_data[1] = raw_data[0]; 3666 trans_data[2] = raw_data[0]; 3667 trans_data[3] = 255; 3668 break; 3669 case 16: 3670 // Luminous,Alpha => RGBA 3671 trans_data[0] = raw_data[0]; 3672 trans_data[1] = raw_data[0]; 3673 trans_data[2] = raw_data[0]; 3674 trans_data[3] = raw_data[1]; 3675 break; 3676 case 24: 3677 // BGR => RGBA 3678 trans_data[0] = raw_data[2]; 3679 trans_data[1] = raw_data[1]; 3680 trans_data[2] = raw_data[0]; 3681 trans_data[3] = 255; 3682 break; 3683 case 32: 3684 // BGRA => RGBA 3685 trans_data[0] = raw_data[2]; 3686 trans_data[1] = raw_data[1]; 3687 trans_data[2] = raw_data[0]; 3688 trans_data[3] = raw_data[3]; 3689 break; 3690 } 3691 // clear the reading flag for the next pixel 3692 read_next_pixel = 0; 3693 } // end of reading a pixel 3694 // convert to final format 3695 switch (req_comp) 3696 { 3697 case 1: 3698 // RGBA => Luminance 3699 tga_data[i*req_comp+0] = compute_y(trans_data[0],trans_data[1],trans_data[2]); 3700 break; 3701 case 2: 3702 // RGBA => Luminance,Alpha 3703 tga_data[i*req_comp+0] = compute_y(trans_data[0],trans_data[1],trans_data[2]); 3704 tga_data[i*req_comp+1] = trans_data[3]; 3705 break; 3706 case 3: 3707 // RGBA => RGB 3708 tga_data[i*req_comp+0] = trans_data[0]; 3709 tga_data[i*req_comp+1] = trans_data[1]; 3710 tga_data[i*req_comp+2] = trans_data[2]; 3711 break; 3712 case 4: 3713 // RGBA => RGBA 3714 tga_data[i*req_comp+0] = trans_data[0]; 3715 tga_data[i*req_comp+1] = trans_data[1]; 3716 tga_data[i*req_comp+2] = trans_data[2]; 3717 tga_data[i*req_comp+3] = trans_data[3]; 3718 break; 3719 } 3720 // in case we're in RLE mode, keep counting down 3721 --RLE_count; 3722 } 3723 // do I need to invert the image? 3724 if ( tga_inverted ) 3725 { 3726 for (j = 0; j*2 < tga_height; ++j) 3727 { 3728 int index1 = j * tga_width * req_comp; 3729 int index2 = (tga_height - 1 - j) * tga_width * req_comp; 3730 for (i = tga_width * req_comp; i > 0; --i) 3731 { 3732 unsigned char temp = tga_data[index1]; 3733 tga_data[index1] = tga_data[index2]; 3734 tga_data[index2] = temp; 3735 ++index1; 3736 ++index2; 3737 } 3738 } 3739 } 3740 // clear my palette, if I had one 3741 if ( tga_palette != NULL ) 3742 { 3743 FREE( tga_palette ); 3744 } 3745 // the things I do to get rid of an error message, and yet keep 3746 // Microsoft's C compilers happy... [8^( 3747 tga_palette_start = tga_palette_len = tga_palette_bits = 3748 tga_x_origin = tga_y_origin = 0; 3749 // OK, done 3750 return tga_data; 3751} 3752 3753#ifndef STBI_NO_STDIO 3754stbi_uc *stbi_tga_load (char const *filename, int *x, int *y, int *comp, int req_comp) 3755{ 3756 stbi_uc *data; 3757 FILE *f = fopen(filename, "rb"); 3758 if (!f) return NULL; 3759 data = stbi_tga_load_from_file(f, x,y,comp,req_comp); 3760 fclose(f); 3761 return data; 3762} 3763 3764stbi_uc *stbi_tga_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp) 3765{ 3766 stbi s; 3767 start_file(&s, f); 3768 return tga_load(&s, x,y,comp,req_comp); 3769} 3770#endif 3771 3772stbi_uc *stbi_tga_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) 3773{ 3774 stbi s; 3775 start_mem(&s, buffer, len); 3776 return tga_load(&s, x,y,comp,req_comp); 3777} 3778 3779 3780// ************************************************************************************************* 3781// Photoshop PSD loader -- PD by Thatcher Ulrich, integration by Nicolas Schulz, tweaked by STB 3782 3783static int psd_test(stbi *s) 3784{ 3785 if (get32(s) != 0x38425053) return 0; // "8BPS" 3786 else return 1; 3787} 3788 3789#ifndef STBI_NO_STDIO 3790int stbi_psd_test_file(FILE *f) 3791{ 3792 stbi s; 3793 int r,n = ftell(f); 3794 start_file(&s, f); 3795 r = psd_test(&s); 3796 fseek(f,n,SEEK_SET); 3797 return r; 3798} 3799#endif 3800 3801int stbi_psd_test_memory(stbi_uc const *buffer, int len) 3802{ 3803 stbi s; 3804 start_mem(&s, buffer, len); 3805 return psd_test(&s); 3806} 3807 3808static stbi_uc *psd_load(stbi *s, int *x, int *y, int *comp, int req_comp) 3809{ 3810 int pixelCount; 3811 int channelCount, compression; 3812 int channel, i, count, len; 3813 int w,h; 3814 uint8 *out; 3815 3816 // Check identifier 3817 if (get32(s) != 0x38425053) // "8BPS" 3818 return epuc("not PSD", "Corrupt PSD image"); 3819 3820 // Check file type version. 3821 if (get16(s) != 1) 3822 return epuc("wrong version", "Unsupported version of PSD image"); 3823 3824 // Skip 6 reserved bytes. 3825 skip(s, 6 ); 3826 3827 // Read the number of channels (R, G, B, A, etc). 3828 channelCount = get16(s); 3829 if (channelCount < 0 || channelCount > 16) 3830 return epuc("wrong channel count", "Unsupported number of channels in PSD image"); 3831 3832 // Read the rows and columns of the image. 3833 h = get32(s); 3834 w = get32(s); 3835 3836 // Make sure the depth is 8 bits. 3837 if (get16(s) != 8) 3838 return epuc("unsupported bit depth", "PSD bit depth is not 8 bit"); 3839 3840 // Make sure the color mode is RGB. 3841 // Valid options are: 3842 // 0: Bitmap 3843 // 1: Grayscale 3844 // 2: Indexed color 3845 // 3: RGB color 3846 // 4: CMYK color 3847 // 7: Multichannel 3848 // 8: Duotone 3849 // 9: Lab color 3850 if (get16(s) != 3) 3851 return epuc("wrong color format", "PSD is not in RGB color format"); 3852 3853 // Skip the Mode Data. (It's the palette for indexed color; other info for other modes.) 3854 skip(s,get32(s) ); 3855 3856 // Skip the image resources. (resolution, pen tool paths, etc) 3857 skip(s, get32(s) ); 3858 3859 // Skip the reserved data. 3860 skip(s, get32(s) ); 3861 3862 // Find out if the data is compressed. 3863 // Known values: 3864 // 0: no compression 3865 // 1: RLE compressed 3866 compression = get16(s); 3867 if (compression > 1) 3868 return epuc("bad compression", "PSD has an unknown compression format"); 3869 3870 // Create the destination image. 3871 out = MALLOC(4 * w*h); 3872 if (!out) return epuc("outofmem", "Out of memory"); 3873 pixelCount = w*h; 3874 3875 // Initialize the data to zero. 3876 //memset( out, 0, pixelCount * 4 ); 3877 3878 // Finally, the image data. 3879 if (compression) { 3880 // RLE as used by .PSD and .TIFF 3881 // Loop until you get the number of unpacked bytes you are expecting: 3882 // Read the next source byte into n. 3883 // If n is between 0 and 127 inclusive, copy the next n+1 bytes literally. 3884 // Else if n is between -127 and -1 inclusive, copy the next byte -n+1 times. 3885 // Else if n is 128, noop. 3886 // Endloop 3887 3888 // The RLE-compressed data is preceeded by a 2-byte data count for each row in the data, 3889 // which we're going to just skip. 3890 skip(s, h * channelCount * 2 ); 3891 3892 // Read the RLE data by channel. 3893 for (channel = 0; channel < 4; channel++) { 3894 uint8 *p; 3895 3896 p = out+channel; 3897 if (channel >= channelCount) { 3898 // Fill this channel with default data. 3899 for (i = 0; i < pixelCount; i++) *p = (channel == 3 ? 255 : 0), p += 4; 3900 } else { 3901 // Read the RLE data. 3902 count = 0; 3903 while (count < pixelCount) { 3904 len = get8(s); 3905 if (len == 128) { 3906 // No-op. 3907 } else if (len < 128) { 3908 // Copy next len+1 bytes literally. 3909 len++; 3910 count += len; 3911 while (len) { 3912 *p = get8u(s); 3913 p += 4; 3914 len--; 3915 } 3916 } else if (len > 128) { 3917 uint8 val; 3918 // Next -len+1 bytes in the dest are replicated from next source byte. 3919 // (Interpret len as a negative 8-bit int.) 3920 len ^= 0x0FF; 3921 len += 2; 3922 val = get8u(s); 3923 count += len; 3924 while (len) { 3925 *p = val; 3926 p += 4; 3927 len--; 3928 } 3929 } 3930 } 3931 } 3932 } 3933 3934 } else { 3935 // We're at the raw image data. It's each channel in order (Red, Green, Blue, Alpha, ...) 3936 // where each channel consists of an 8-bit value for each pixel in the image. 3937 3938 // Read the data by channel. 3939 for (channel = 0; channel < 4; channel++) { 3940 uint8 *p; 3941 3942 p = out + channel; 3943 if (channel > channelCount) { 3944 // Fill this channel with default data. 3945 for (i = 0; i < pixelCount; i++) *p = channel == 3 ? 255 : 0, p += 4; 3946 } else { 3947 // Read the data. 3948 for (i = 0; i < pixelCount; i++) 3949 *p = get8u(s), p += 4; 3950 } 3951 } 3952 } 3953 3954 if (req_comp && req_comp != 4) { 3955 out = convert_format(out, 4, req_comp, w, h); 3956 if (out == NULL) return out; // convert_format frees input on failure 3957 } 3958 3959 if (comp) *comp = channelCount; 3960 *y = h; 3961 *x = w; 3962 3963 return out; 3964} 3965 3966#ifndef STBI_NO_STDIO 3967stbi_uc *stbi_psd_load(char const *filename, int *x, int *y, int *comp, int req_comp) 3968{ 3969 stbi_uc *data; 3970 FILE *f = fopen(filename, "rb"); 3971 if (!f) return NULL; 3972 data = stbi_psd_load_from_file(f, x,y,comp,req_comp); 3973 fclose(f); 3974 return data; 3975} 3976 3977stbi_uc *stbi_psd_load_from_file(FILE *f, int *x, int *y, int *comp, int req_comp) 3978{ 3979 stbi s; 3980 start_file(&s, f); 3981 return psd_load(&s, x,y,comp,req_comp); 3982} 3983#endif 3984 3985stbi_uc *stbi_psd_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) 3986{ 3987 stbi s; 3988 start_mem(&s, buffer, len); 3989 return psd_load(&s, x,y,comp,req_comp); 3990} 3991 3992// ************************************************************************************************* 3993// Softimage PIC loader 3994// by Tom Seddon 3995// 3996// See http://softimage.wiki.softimage.com/index.php/INFO:_PIC_file_format 3997// See http://ozviz.wasp.uwa.edu.au/~pbourke/dataformats/softimagepic/ 3998 3999static int pic_is4(stbi *s,const char *str) 4000{ 4001 int i; 4002 for (i=0; i<4; ++i) 4003 if (get8(s) != (stbi_uc)str[i]) 4004 return 0; 4005 4006 return 1; 4007} 4008 4009static int pic_test(stbi *s) 4010{ 4011 int i; 4012 4013 if (!pic_is4(s,"\x53\x80\xF6\x34")) 4014 return 0; 4015 4016 for(i=0;i<84;++i) 4017 get8(s); 4018 4019 if (!pic_is4(s,"PICT")) 4020 return 0; 4021 4022 return 1; 4023} 4024 4025typedef struct 4026{ 4027 stbi_uc size,type,channel; 4028} pic_packet_t; 4029 4030static stbi_uc *pic_readval(stbi *s, int channel, stbi_uc *dest) 4031{ 4032 int mask=0x80, i; 4033 4034 for (i=0; i<4; ++i, mask>>=1) { 4035 if (channel & mask) { 4036 if (at_eof(s)) return epuc("bad file","PIC file too short"); 4037 dest[i]=get8u(s); 4038 } 4039 } 4040 4041 return dest; 4042} 4043 4044static void pic_copyval(int channel,stbi_uc *dest,const stbi_uc *src) 4045{ 4046 int mask=0x80,i; 4047 4048 for (i=0;i<4; ++i, mask>>=1) 4049 if (channel&mask) 4050 dest[i]=src[i]; 4051} 4052 4053static stbi_uc *pic_load2(stbi *s,int width,int height,int *comp, stbi_uc *result) 4054{ 4055 int act_comp=0,num_packets=0,y,chained; 4056 pic_packet_t packets[10]; 4057 4058 // this will (should...) cater for even some bizarre stuff like having data 4059 // for the same channel in multiple packets. 4060 do { 4061 pic_packet_t *packet; 4062 4063 if (num_packets==sizeof(packets)/sizeof(packets[0])) 4064 return epuc("bad format","too many packets"); 4065 4066 packet = &packets[num_packets++]; 4067 4068 chained = get8(s); 4069 packet->size = get8u(s); 4070 packet->type = get8u(s); 4071 packet->channel = get8u(s); 4072 4073 act_comp |= packet->channel; 4074 4075 if (at_eof(s)) return epuc("bad file","file too short (reading packets)"); 4076 if (packet->size != 8) return epuc("bad format","packet isn't 8bpp"); 4077 } while (chained); 4078 4079 *comp = (act_comp & 0x10 ? 4 : 3); // has alpha channel? 4080 4081 for(y=0; y<height; ++y) { 4082 int packet_idx; 4083 4084 for(packet_idx=0; packet_idx < num_packets; ++packet_idx) { 4085 pic_packet_t *packet = &packets[packet_idx]; 4086 stbi_uc *dest = result+y*width*4; 4087 4088 switch (packet->type) { 4089 default: 4090 return epuc("bad format","packet has bad compression type"); 4091 4092 case 0: {//uncompressed 4093 int x; 4094 4095 for(x=0;x<width;++x, dest+=4) 4096 if (!pic_readval(s,packet->channel,dest)) 4097 return 0; 4098 break; 4099 } 4100 4101 case 1://Pure RLE 4102 { 4103 int left=width, i; 4104 4105 while (left>0) { 4106 stbi_uc count,value[4]; 4107 4108 count=get8u(s); 4109 if (at_eof(s)) return epuc("bad file","file too short (pure read count)"); 4110 4111 if (count > left) 4112 count = (uint8) left; 4113 4114 if (!pic_readval(s,packet->channel,value)) return 0; 4115 4116 for(i=0; i<count; ++i,dest+=4) 4117 pic_copyval(packet->channel,dest,value); 4118 left -= count; 4119 } 4120 } 4121 break; 4122 4123 case 2: {//Mixed RLE 4124 int left=width; 4125 while (left>0) { 4126 int count = get8(s), i; 4127 if (at_eof(s)) return epuc("bad file","file too short (mixed read count)"); 4128 4129 if (count >= 128) { // Repeated 4130 stbi_uc value[4]; 4131 4132 if (count==128) 4133 count = get16(s); 4134 else 4135 count -= 127; 4136 if (count > left) 4137 return epuc("bad file","scanline overrun"); 4138 4139 if (!pic_readval(s,packet->channel,value)) 4140 return 0; 4141 4142 for(i=0;i<count;++i, dest += 4) 4143 pic_copyval(packet->channel,dest,value); 4144 } else { // Raw 4145 ++count; 4146 if (count>left) return epuc("bad file","scanline overrun"); 4147 4148 for(i=0;i<count;++i, dest+=4) 4149 if (!pic_readval(s,packet->channel,dest)) 4150 return 0; 4151 } 4152 left-=count; 4153 } 4154 break; 4155 } 4156 } 4157 } 4158 } 4159 4160 return result; 4161} 4162 4163static stbi_uc *pic_load(stbi *s,int *px,int *py,int *comp,int req_comp) 4164{ 4165 stbi_uc *result; 4166 int i, x,y; 4167 4168 for (i=0; i<92; ++i) 4169 get8(s); 4170 4171 x = get16(s); 4172 y = get16(s); 4173 if (at_eof(s)) return epuc("bad file","file too short (pic header)"); 4174 if ((1 << 28) / x < y) return epuc("too large", "Image too large to decode"); 4175 4176 get32(s); //skip `ratio' 4177 get16(s); //skip `fields' 4178 get16(s); //skip `pad' 4179 4180 // intermediate buffer is RGBA 4181 result = MALLOC(x*y*4); 4182 memset(result, 0xff, x*y*4); 4183 4184 if (!pic_load2(s,x,y,comp, result)) { 4185 FREE(result); 4186 result=0; 4187 } 4188 *px = x; 4189 *py = y; 4190 if (req_comp == 0) req_comp = *comp; 4191 result=convert_format(result,4,req_comp,x,y); 4192 4193 return result; 4194} 4195 4196int stbi_pic_test_memory(stbi_uc const *buffer, int len) 4197{ 4198 stbi s; 4199 start_mem(&s,buffer,len); 4200 return pic_test(&s); 4201} 4202 4203stbi_uc *stbi_pic_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) 4204{ 4205 stbi s; 4206 start_mem(&s,buffer,len); 4207 return pic_load(&s,x,y,comp,req_comp); 4208} 4209 4210#ifndef STBI_NO_STDIO 4211int stbi_pic_test_file(FILE *f) 4212{ 4213 int result; 4214 long l = ftell(f); 4215 stbi s; 4216 start_file(&s,f); 4217 result = pic_test(&s); 4218 fseek(f,l,SEEK_SET); 4219 return result; 4220} 4221 4222stbi_uc *stbi_pic_load(char const *filename,int *x, int *y, int *comp, int req_comp) 4223{ 4224 stbi_uc *result; 4225 FILE *f=fopen(filename,"rb"); 4226 if (!f) return 0; 4227 result = stbi_pic_load_from_file(f,x,y,comp,req_comp); 4228 fclose(f); 4229 return result; 4230} 4231 4232stbi_uc *stbi_pic_load_from_file(FILE *f,int *x, int *y, int *comp, int req_comp) 4233{ 4234 stbi s; 4235 start_file(&s,f); 4236 return pic_load(&s,x,y,comp,req_comp); 4237} 4238#endif 4239 4240// ************************************************************************************************* 4241// GIF loader -- public domain by Jean-Marc Lienher -- simplified/shrunk by stb 4242typedef struct stbi_gif_lzw_struct { 4243 int16 prefix; 4244 uint8 first; 4245 uint8 suffix; 4246} stbi_gif_lzw; 4247 4248typedef struct stbi_gif_struct 4249{ 4250 int w,h; 4251 stbi_uc *out; // output buffer (always 4 components) 4252 int flags, bgindex, ratio, transparent, eflags; 4253 uint8 pal[256][4]; 4254 uint8 lpal[256][4]; 4255 stbi_gif_lzw codes[4096]; 4256 uint8 *color_table; 4257 int parse, step; 4258 int lflags; 4259 int start_x, start_y; 4260 int max_x, max_y; 4261 int cur_x, cur_y; 4262 int line_size; 4263} stbi_gif; 4264 4265static int gif_test(stbi *s) 4266{ 4267 int sz; 4268 if (get8(s) != 'G' || get8(s) != 'I' || get8(s) != 'F' || get8(s) != '8') return 0; 4269 sz = get8(s); 4270 if (sz != '9' && sz != '7') return 0; 4271 if (get8(s) != 'a') return 0; 4272 return 1; 4273} 4274 4275#ifndef STBI_NO_STDIO 4276int stbi_gif_test_file (FILE *f) 4277{ 4278 stbi s; 4279 int r,n = ftell(f); 4280 start_file(&s,f); 4281 r = gif_test(&s); 4282 fseek(f,n,SEEK_SET); 4283 return r; 4284} 4285#endif 4286 4287int stbi_gif_test_memory (stbi_uc const *buffer, int len) 4288{ 4289 stbi s; 4290 start_mem(&s, buffer, len); 4291 return gif_test(&s); 4292} 4293 4294static void stbi_gif_parse_colortable(stbi *s, uint8 pal[256][4], int num_entries, int transp) 4295{ 4296 int i; 4297 for (i=0; i < num_entries; ++i) { 4298 pal[i][2] = get8u(s); 4299 pal[i][1] = get8u(s); 4300 pal[i][0] = get8u(s); 4301 pal[i][3] = transp ? 0 : 255; 4302 } 4303} 4304 4305static int stbi_gif_header(stbi *s, stbi_gif *g, int *comp, int is_info) 4306{ 4307 uint8 ver; 4308 if (get8(s) != 'G' || get8(s) != 'I' || get8(s) != 'F' || get8(s) != '8') 4309 return e("not GIF", "Corrupt GIF"); 4310 4311 ver = get8u(s); 4312 if (ver != '7' && ver != '9') return e("not GIF", "Corrupt GIF"); 4313 if (get8(s) != 'a') return e("not GIF", "Corrupt GIF"); 4314 4315 failure_reason = ""; 4316 g->w = get16le(s); 4317 g->h = get16le(s); 4318 g->flags = get8(s); 4319 g->bgindex = get8(s); 4320 g->ratio = get8(s); 4321 g->transparent = -1; 4322 4323 if (comp != 0) *comp = 4; // can't actually tell whether it's 3 or 4 until we parse the comments 4324 4325 if (is_info) return 1; 4326 4327 if (g->flags & 0x80) 4328 stbi_gif_parse_colortable(s,g->pal, 2 << (g->flags & 7), -1); 4329 4330 return 1; 4331} 4332 4333static int stbi_gif_info_raw(stbi *s, int *x, int *y, int *comp) 4334{ 4335 stbi_gif g; 4336 if (!stbi_gif_header(s, &g, comp, 1)) return 0; 4337 if (x) *x = g.w; 4338 if (y) *y = g.h; 4339 return 1; 4340} 4341 4342static void stbi_out_gif_code(stbi_gif *g, uint16 code) 4343{ 4344 uint8 *p, *c; 4345 4346 // recurse to decode the prefixes, since the linked-list is backwards, 4347 // and working backwards through an interleaved image would be nasty 4348 if (g->codes[code].prefix >= 0) 4349 stbi_out_gif_code(g, g->codes[code].prefix); 4350 4351 if (g->cur_y >= g->max_y) return; 4352 4353 p = &g->out[g->cur_x + g->cur_y]; 4354 c = &g->color_table[g->codes[code].suffix * 4]; 4355 4356 if (c[3] >= 128) { 4357 p[0] = c[2]; 4358 p[1] = c[1]; 4359 p[2] = c[0]; 4360 p[3] = c[3]; 4361 } 4362 g->cur_x += 4; 4363 4364 if (g->cur_x >= g->max_x) { 4365 g->cur_x = g->start_x; 4366 g->cur_y += g->step; 4367 4368 while (g->cur_y >= g->max_y && g->parse > 0) { 4369 g->step = (1 << g->parse) * g->line_size; 4370 g->cur_y = g->start_y + (g->step >> 1); 4371 --g->parse; 4372 } 4373 } 4374} 4375 4376static uint8 *stbi_process_gif_raster(stbi *s, stbi_gif *g) 4377{ 4378 uint8 lzw_cs; 4379 int32 len, code; 4380 uint32 first; 4381 int32 codesize, codemask, avail, oldcode, bits, valid_bits, clear; 4382 stbi_gif_lzw *p; 4383 4384 lzw_cs = get8u(s); 4385 clear = 1 << lzw_cs; 4386 first = 1; 4387 codesize = lzw_cs + 1; 4388 codemask = (1 << codesize) - 1; 4389 bits = 0; 4390 valid_bits = 0; 4391 for (code = 0; code < clear; code++) { 4392 g->codes[code].prefix = -1; 4393 g->codes[code].first = (uint8) code; 4394 g->codes[code].suffix = (uint8) code; 4395 } 4396 4397 // support no starting clear code 4398 avail = clear+2; 4399 oldcode = -1; 4400 4401 len = 0; 4402 for(;;) { 4403 if (valid_bits < codesize) { 4404 if (len == 0) { 4405 len = get8(s); // start new block 4406 if (len == 0) 4407 return g->out; 4408 } 4409 --len; 4410 bits |= (int32) get8(s) << valid_bits; 4411 valid_bits += 8; 4412 } else { 4413 code = bits & codemask; 4414 bits >>= codesize; 4415 valid_bits -= codesize; 4416 // @OPTIMIZE: is there some way we can accelerate the non-clear path? 4417 if (code == clear) { // clear code 4418 codesize = lzw_cs + 1; 4419 codemask = (1 << codesize) - 1; 4420 avail = clear + 2; 4421 oldcode = -1; 4422 first = 0; 4423 } else if (code == clear + 1) { // end of stream code 4424 skip(s, len); 4425 while ((len = get8(s)) > 0) 4426 skip(s,len); 4427 return g->out; 4428 } else if (code <= avail) { 4429 if (first) return epuc("no clear code", "Corrupt GIF"); 4430 4431 if (oldcode >= 0) { 4432 p = &g->codes[avail++]; 4433 if (avail > 4096) return epuc("too many codes", "Corrupt GIF"); 4434 p->prefix = (int16) oldcode; 4435 p->first = g->codes[oldcode].first; 4436 p->suffix = (code == avail) ? p->first : g->codes[code].first; 4437 } else if (code == avail) 4438 return epuc("illegal code in raster", "Corrupt GIF"); 4439 4440 stbi_out_gif_code(g, (uint16) code); 4441 4442 if ((avail & codemask) == 0 && avail <= 0x0FFF) { 4443 codesize++; 4444 codemask = (1 << codesize) - 1; 4445 } 4446 4447 oldcode = code; 4448 } else { 4449 return epuc("illegal code in raster", "Corrupt GIF"); 4450 } 4451 } 4452 } 4453} 4454 4455static void stbi_fill_gif_background(stbi_gif *g) 4456{ 4457 int i; 4458 uint8 *c = g->pal[g->bgindex]; 4459 // @OPTIMIZE: write a dword at a time 4460 for (i = 0; i < g->w * g->h * 4; i += 4) { 4461 uint8 *p = &g->out[i]; 4462 p[0] = c[2]; 4463 p[1] = c[1]; 4464 p[2] = c[0]; 4465 p[3] = c[3]; 4466 } 4467} 4468 4469// this function is designed to support animated gifs, although stb_image doesn't support it 4470static uint8 *stbi_gif_load_next(stbi *s, stbi_gif *g, int *comp, int req_comp) 4471{ 4472 int i; 4473 uint8 *old_out = 0; 4474 4475 if (g->out == 0) { 4476 if (!stbi_gif_header(s, g, comp,0)) return 0; // failure_reason set by stbi_gif_header 4477 g->out = MALLOC(4 * g->w * g->h); 4478 if (g->out == 0) return epuc("outofmem", "Out of memory"); 4479 stbi_fill_gif_background(g); 4480 } else { 4481 // animated-gif-only path 4482 if (((g->eflags & 0x1C) >> 2) == 3) { 4483 old_out = g->out; 4484 g->out = MALLOC(4 * g->w * g->h); 4485 if (g->out == 0) return epuc("outofmem", "Out of memory"); 4486 memcpy(g->out, old_out, g->w*g->h*4); 4487 } 4488 } 4489 4490 for (;;) { 4491 switch (get8(s)) { 4492 case 0x2C: /* Image Descriptor */ 4493 { 4494 int32 x, y, w, h; 4495 uint8 *o; 4496 4497 x = get16le(s); 4498 y = get16le(s); 4499 w = get16le(s); 4500 h = get16le(s); 4501 if (((x + w) > (g->w)) || ((y + h) > (g->h))) 4502 return epuc("bad Image Descriptor", "Corrupt GIF"); 4503 4504 g->line_size = g->w * 4; 4505 g->start_x = x * 4; 4506 g->start_y = y * g->line_size; 4507 g->max_x = g->start_x + w * 4; 4508 g->max_y = g->start_y + h * g->line_size; 4509 g->cur_x = g->start_x; 4510 g->cur_y = g->start_y; 4511 4512 g->lflags = get8(s); 4513 4514 if (g->lflags & 0x40) { 4515 g->step = 8 * g->line_size; // first interlaced spacing 4516 g->parse = 3; 4517 } else { 4518 g->step = g->line_size; 4519 g->parse = 0; 4520 } 4521 4522 if (g->lflags & 0x80) { 4523 stbi_gif_parse_colortable(s,g->lpal, 2 << (g->lflags & 7), g->eflags & 0x01 ? g->transparent : -1); 4524 g->color_table = (uint8 *) g->lpal; 4525 } else if (g->flags & 0x80) { 4526 for (i=0; i < 256; ++i) // @OPTIMIZE: reset only the previous transparent 4527 g->pal[i][3] = 255; 4528 if (g->transparent >= 0 && (g->eflags & 0x01)) 4529 g->pal[g->transparent][3] = 0; 4530 g->color_table = (uint8 *) g->pal; 4531 } else 4532 return epuc("missing color table", "Corrupt GIF"); 4533 4534 o = stbi_process_gif_raster(s, g); 4535 if (o == NULL) return NULL; 4536 4537 if (req_comp && req_comp != 4) 4538 o = convert_format(o, 4, req_comp, g->w, g->h); 4539 return o; 4540 } 4541 4542 case 0x21: // Comment Extension. 4543 { 4544 int len; 4545 if (get8(s) == 0xF9) { // Graphic Control Extension. 4546 len = get8(s); 4547 if (len == 4) { 4548 g->eflags = get8(s); 4549 get16le(s); // delay 4550 g->transparent = get8(s); 4551 } else { 4552 skip(s, len); 4553 break; 4554 } 4555 } 4556 while ((len = get8(s)) != 0) 4557 skip(s, len); 4558 break; 4559 } 4560 4561 case 0x3B: // gif stream termination code 4562 return (uint8 *) 1; 4563 4564 default: 4565 return epuc("unknown code", "Corrupt GIF"); 4566 } 4567 } 4568} 4569 4570#ifndef STBI_NO_STDIO 4571stbi_uc *stbi_gif_load (char const *filename, int *x, int *y, int *comp, int req_comp) 4572{ 4573 uint8 *data; 4574 FILE *f = fopen(filename, "rb"); 4575 if (!f) return NULL; 4576 data = stbi_gif_load_from_file(f, x,y,comp,req_comp); 4577 fclose(f); 4578 return data; 4579} 4580 4581stbi_uc *stbi_gif_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp) 4582{ 4583 uint8 *u = 0; 4584 stbi s; 4585 stbi_gif g={0}; 4586 start_file(&s, f); 4587 4588 u = stbi_gif_load_next(&s, &g, comp, req_comp); 4589 if (u == (void *) 1) u = 0; // end of animated gif marker 4590 if (u) { 4591 *x = g.w; 4592 *y = g.h; 4593 } 4594 4595 return u; 4596} 4597#endif 4598 4599stbi_uc *stbi_gif_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) 4600{ 4601 uint8 *u = 0; 4602 stbi s; 4603 stbi_gif *pg; 4604 4605 #ifdef STBI_SMALL_STACK 4606 pg = MALLOC(sizeof(*pg)); 4607 if (pg == NULL) 4608 return NULL; 4609 #else 4610 stbi_gif g; 4611 pg = &g; 4612 #endif 4613 4614 memset(pg, 0, sizeof(*pg)); 4615 start_mem(&s, buffer, len); 4616 u = stbi_gif_load_next(&s, pg, comp, req_comp); 4617 if (u == (void *) 1) u = 0; // end of animated gif marker 4618 if (u) { 4619 *x = pg->w; 4620 *y = pg->h; 4621 } 4622 4623 #ifdef STBI_SMALL_STACK 4624 FREE(pg); 4625 #endif 4626 4627 return u; 4628} 4629 4630#ifndef STBI_NO_STDIO 4631int stbi_gif_info (char const *filename, int *x, int *y, int *comp) 4632{ 4633 int res; 4634 FILE *f = fopen(filename, "rb"); 4635 if (!f) return 0; 4636 res = stbi_gif_info_from_file(f, x, y, comp); 4637 fclose(f); 4638 return res; 4639} 4640 4641int stbi_gif_info_from_file(FILE *f, int *x, int *y, int *comp) 4642{ 4643 stbi s; 4644 int res; 4645 long n = ftell(f); 4646 start_file(&s, f); 4647 res = stbi_gif_info_raw(&s, x, y, comp); 4648 fseek(f, n, SEEK_SET); 4649 return res; 4650} 4651#endif // !STBI_NO_STDIO 4652 4653int stbi_gif_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp) 4654{ 4655 stbi s; 4656 start_mem(&s, buffer, len); 4657 return stbi_gif_info_raw(&s, x, y, comp); 4658} 4659 4660 4661 4662 4663// ************************************************************************************************* 4664// Radiance RGBE HDR loader 4665// originally by Nicolas Schulz 4666#ifndef STBI_NO_HDR 4667static int hdr_test(stbi *s) 4668{ 4669 const char *signature = "#?RADIANCE\n"; 4670 int i; 4671 for (i=0; signature[i]; ++i) 4672 if (get8(s) != signature[i]) 4673 return 0; 4674 return 1; 4675} 4676 4677int stbi_hdr_test_memory(stbi_uc const *buffer, int len) 4678{ 4679 stbi s; 4680 start_mem(&s, buffer, len); 4681 return hdr_test(&s); 4682} 4683 4684#ifndef STBI_NO_STDIO 4685int stbi_hdr_test_file(FILE *f) 4686{ 4687 stbi s; 4688 int r,n = ftell(f); 4689 start_file(&s, f); 4690 r = hdr_test(&s); 4691 fseek(f,n,SEEK_SET); 4692 return r; 4693} 4694#endif 4695 4696#define HDR_BUFLEN 1024 4697static char *hdr_gettoken(stbi *z, char *buffer) 4698{ 4699 int len=0; 4700 char c = '\0'; 4701 4702 c = (char) get8(z); 4703 4704 while (!at_eof(z) && c != '\n') { 4705 buffer[len++] = c; 4706 if (len == HDR_BUFLEN-1) { 4707 // flush to end of line 4708 while (!at_eof(z) && get8(z) != '\n') 4709 ; 4710 break; 4711 } 4712 c = (char) get8(z); 4713 } 4714 4715 buffer[len] = 0; 4716 return buffer; 4717} 4718 4719static void hdr_convert(float *output, stbi_uc *input, int req_comp) 4720{ 4721 if ( input[3] != 0 ) { 4722 float f1; 4723 // Exponent 4724 f1 = (float) ldexp(1.0f, input[3] - (int)(128 + 8)); 4725 if (req_comp <= 2) 4726 output[0] = (input[0] + input[1] + input[2]) * f1 / 3; 4727 else { 4728 output[0] = input[0] * f1; 4729 output[1] = input[1] * f1; 4730 output[2] = input[2] * f1; 4731 } 4732 if (req_comp == 2) output[1] = 1; 4733 if (req_comp == 4) output[3] = 1; 4734 } else { 4735 switch (req_comp) { 4736 case 4: output[3] = 1; /* fallthrough */ 4737 case 3: output[0] = output[1] = output[2] = 0; 4738 break; 4739 case 2: output[1] = 1; /* fallthrough */ 4740 case 1: output[0] = 0; 4741 break; 4742 } 4743 } 4744} 4745 4746 4747static float *hdr_load(stbi *s, int *x, int *y, int *comp, int req_comp) 4748{ 4749 char buffer[HDR_BUFLEN]; 4750 char *token; 4751 int valid = 0; 4752 int width, height; 4753 stbi_uc *scanline; 4754 float *hdr_data; 4755 int len; 4756 unsigned char count, value; 4757 int i, j, k, c1,c2, z; 4758 4759 4760 // Check identifier 4761 if (strcmp(hdr_gettoken(s,buffer), "#?RADIANCE") != 0) 4762 return epf("not HDR", "Corrupt HDR image"); 4763 4764 // Parse header 4765 for(;;) { 4766 token = hdr_gettoken(s,buffer); 4767 if (token[0] == 0) break; 4768 if (strcmp(token, "FORMAT=32-bit_rle_rgbe") == 0) valid = 1; 4769 } 4770 4771 if (!valid) return epf("unsupported format", "Unsupported HDR format"); 4772 4773 // Parse width and height 4774 // can't use sscanf() if we're not using stdio! 4775 token = hdr_gettoken(s,buffer); 4776 if (strncmp(token, "-Y ", 3)) return epf("unsupported data layout", "Unsupported HDR format"); 4777 token += 3; 4778 height = strtol(token, &token, 10); 4779 while (*token == ' ') ++token; 4780 if (strncmp(token, "+X ", 3)) return epf("unsupported data layout", "Unsupported HDR format"); 4781 token += 3; 4782 width = strtol(token, NULL, 10); 4783 4784 *x = width; 4785 *y = height; 4786 4787 *comp = 3; 4788 if (req_comp == 0) req_comp = 3; 4789 4790 // Read data 4791 hdr_data = MALLOC(height * width * req_comp * sizeof(float)); 4792 4793 // Load image data 4794 // image data is stored as some number of sca 4795 if ( width < 8 || width >= 32768) { 4796 // Read flat data 4797 for (j=0; j < height; ++j) { 4798 for (i=0; i < width; ++i) { 4799 stbi_uc rgbe[4]; 4800 main_decode_loop: 4801 getn(s, rgbe, 4); 4802 hdr_convert(hdr_data + j * width * req_comp + i * req_comp, rgbe, req_comp); 4803 } 4804 } 4805 } else { 4806 // Read RLE-encoded data 4807 scanline = NULL; 4808 4809 for (j = 0; j < height; ++j) { 4810 c1 = get8(s); 4811 c2 = get8(s); 4812 len = get8(s); 4813 if (c1 != 2 || c2 != 2 || (len & 0x80)) { 4814 // not run-length encoded, so we have to actually use THIS data as a decoded 4815 // pixel (note this can't be a valid pixel--one of RGB must be >= 128) 4816 uint8 rgbe[4]; 4817 rgbe[0] = (uint8) c1; 4818 rgbe[1] = (uint8) c2; 4819 rgbe[2] = (uint8) len; 4820 rgbe[3] = (uint8) get8u(s); 4821 hdr_convert(hdr_data, rgbe, req_comp); 4822 i = 1; 4823 j = 0; 4824 FREE(scanline); 4825 goto main_decode_loop; // yes, this makes no sense 4826 } 4827 len <<= 8; 4828 len |= get8(s); 4829 if (len != width) { FREE(hdr_data); FREE(scanline); return epf("invalid decoded scanline length", "corrupt HDR"); } 4830 if (scanline == NULL) scanline = MALLOC(width * 4); 4831 4832 for (k = 0; k < 4; ++k) { 4833 i = 0; 4834 while (i < width) { 4835 count = get8u(s); 4836 if (count > 128) { 4837 // Run 4838 value = get8u(s); 4839 count -= 128; 4840 for (z = 0; z < count; ++z) 4841 scanline[i++ * 4 + k] = value; 4842 } else { 4843 // Dump 4844 for (z = 0; z < count; ++z) 4845 scanline[i++ * 4 + k] = get8u(s); 4846 } 4847 } 4848 } 4849 for (i=0; i < width; ++i) 4850 hdr_convert(hdr_data+(j*width + i)*req_comp, scanline + i*4, req_comp); 4851 } 4852 FREE(scanline); 4853 } 4854 4855 return hdr_data; 4856} 4857 4858#ifndef STBI_NO_STDIO 4859float *stbi_hdr_load_from_file(FILE *f, int *x, int *y, int *comp, int req_comp) 4860{ 4861 stbi s; 4862 start_file(&s,f); 4863 return hdr_load(&s,x,y,comp,req_comp); 4864} 4865#endif 4866 4867float *stbi_hdr_load_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) 4868{ 4869 stbi s; 4870 start_mem(&s,buffer, len); 4871 return hdr_load(&s,x,y,comp,req_comp); 4872} 4873 4874#endif // STBI_NO_HDR 4875 4876 4877#ifndef STBI_NO_STDIO 4878int stbi_info(char const *filename, int *x, int *y, int *comp) 4879{ 4880 FILE *f = fopen(filename, "rb"); 4881 int result; 4882 if (!f) return e("can't fopen", "Unable to open file"); 4883 result = stbi_info_from_file(f, x, y, comp); 4884 fclose(f); 4885 return result; 4886} 4887 4888int stbi_info_from_file(FILE *f, int *x, int *y, int *comp) 4889{ 4890 if (stbi_jpeg_info_from_file(f, x, y, comp)) 4891 return 1; 4892 if (stbi_png_info_from_file(f, x, y, comp)) 4893 return 1; 4894 if (stbi_gif_info_from_file(f, x, y, comp)) 4895 return 1; 4896 // @TODO: stbi_bmp_info_from_file 4897 // @TODO: stbi_psd_info_from_file 4898 #ifndef STBI_NO_HDR 4899 // @TODO: stbi_hdr_info_from_file 4900 #endif 4901 // test tga last because it's a crappy test! 4902 if (stbi_tga_info_from_file(f, x, y, comp)) 4903 return 1; 4904 return e("unknown image type", "Image not of any known type, or corrupt"); 4905} 4906#endif // !STBI_NO_STDIO 4907 4908int stbi_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp) 4909{ 4910 if (stbi_jpeg_info_from_memory(buffer, len, x, y, comp)) 4911 return 1; 4912 if (stbi_png_info_from_memory(buffer, len, x, y, comp)) 4913 return 1; 4914 if (stbi_gif_info_from_memory(buffer, len, x, y, comp)) 4915 return 1; 4916 // @TODO: stbi_bmp_info_from_memory 4917 // @TODO: stbi_psd_info_from_memory 4918 #ifndef STBI_NO_HDR 4919 // @TODO: stbi_hdr_info_from_memory 4920 #endif 4921 // test tga last because it's a crappy test! 4922 if (stbi_tga_info_from_memory(buffer, len, x, y, comp)) 4923 return 1; 4924 return e("unknown image type", "Image not of any known type, or corrupt"); 4925} 4926 4927#endif // STBI_HEADER_FILE_ONLY 4928 4929/* 4930 revision history: 4931 1.29 (2010-08-16) various warning fixes from Aurelien Pocheville 4932 1.28 (2010-08-01) fix bug in GIF palette transparency (SpartanJ) 4933 1.27 (2010-08-01) 4934 cast-to-uint8 to fix warnings 4935 1.26 (2010-07-24) 4936 fix bug in file buffering for PNG reported by SpartanJ 4937 1.25 (2010-07-17) 4938 refix trans_data warning (Won Chun) 4939 1.24 (2010-07-12) 4940 perf improvements reading from files on platforms with lock-heavy fgetc() 4941 minor perf improvements for jpeg 4942 deprecated type-specific functions so we'll get feedback if they're needed 4943 attempt to fix trans_data warning (Won Chun) 4944 1.23 fixed bug in iPhone support 4945 1.22 (2010-07-10) 4946 removed image *writing* support 4947 removed image *writing* support 4948 stbi_info support from Jetro Lauha 4949 GIF support from Jean-Marc Lienher 4950 iPhone PNG-extensions from James Brown 4951 warning-fixes from Nicolas Schulz and Janez Zemva (i.e. Janez (U+017D)emva) 4952 1.21 fix use of 'uint8' in header (reported by jon blow) 4953 1.20 added support for Softimage PIC, by Tom Seddon 4954 1.19 bug in interlaced PNG corruption check (found by ryg) 4955 1.18 2008-08-02 4956 fix a threading bug (local mutable static) 4957 1.17 support interlaced PNG 4958 1.16 major bugfix - convert_format converted one too many pixels 4959 1.15 initialize some fields for thread safety 4960 1.14 fix threadsafe conversion bug 4961 header-file-only version (#define STBI_HEADER_FILE_ONLY before including) 4962 1.13 threadsafe 4963 1.12 const qualifiers in the API 4964 1.11 Support installable IDCT, colorspace conversion routines 4965 1.10 Fixes for 64-bit (don't use "unsigned long") 4966 optimized upsampling by Fabian "ryg" Giesen 4967 1.09 Fix format-conversion for PSD code (bad global variables!) 4968 1.08 Thatcher Ulrich's PSD code integrated by Nicolas Schulz 4969 1.07 attempt to fix C++ warning/errors again 4970 1.06 attempt to fix C++ warning/errors again 4971 1.05 fix TGA loading to return correct *comp and use good luminance calc 4972 1.04 default float alpha is 1, not 255; use 'void *' for stbi_image_free 4973 1.03 bugfixes to STBI_NO_STDIO, STBI_NO_HDR 4974 1.02 support for (subset of) HDR files, float interface for preferred access to them 4975 1.01 fix bug: possible bug in handling right-side up bmps... not sure 4976 fix bug: the stbi_bmp_load() and stbi_tga_load() functions didn't work at all 4977 1.00 interface to zlib that skips zlib header 4978 0.99 correct handling of alpha in palette 4979 0.98 TGA loader by lonesock; dynamically add loaders (untested) 4980 0.97 jpeg errors on too large a file; also catch another malloc failure 4981 0.96 fix detection of invalid v value - particleman@mollyrocket forum 4982 0.95 during header scan, seek to markers in case of padding 4983 0.94 STBI_NO_STDIO to disable stdio usage; rename all #defines the same 4984 0.93 handle jpegtran output; verbose errors 4985 0.92 read 4,8,16,24,32-bit BMP files of several formats 4986 0.91 output 24-bit Windows 3.0 BMP files 4987 0.90 fix a few more warnings; bump version number to approach 1.0 4988 0.61 bugfixes due to Marc LeBlanc, Christopher Lloyd 4989 0.60 fix compiling as c++ 4990 0.59 fix warnings: merge Dave Moore's -Wall fixes 4991 0.58 fix bug: zlib uncompressed mode len/nlen was wrong endian 4992 0.57 fix bug: jpg last huffman symbol before marker was >9 bits but less 4993 than 16 available 4994 0.56 fix bug: zlib uncompressed mode len vs. nlen 4995 0.55 fix bug: restart_interval not initialized to 0 4996 0.54 allow NULL for 'int *comp' 4997 0.53 fix bug in png 3->4; speedup png decoding 4998 0.52 png handles req_comp=3,4 directly; minor cleanup; jpeg comments 4999 0.51 obey req_comp requests, 1-component jpegs return as 1-component, 5000 on 'test' only check type, not whether we support this variant 5001*/ 5002
