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Remove building with NOCRYPTO option
[minix.git] / sys / dev / stbi / stb_image.c
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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
191 enum
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
201 typedef unsigned char stbi_uc;
202
203 #ifdef __cplusplus
204 extern "C" {
205 #endif
206
207 // PRIMARY API - works on images of any type
208
209 // load image by filename, open file, or memory buffer
210 extern 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
213 extern stbi_uc *stbi_load (char const *filename, int *x, int *y, int *comp, int req_comp);
214 extern 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
235 extern const char *stbi_failure_reason (void);
236
237 // free the loaded image -- this is just free()
238 extern void stbi_image_free (void *retval_from_stbi_load);
239
240 // get image dimensions & components without fully decoding
241 extern int stbi_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp);
242 extern int stbi_is_hdr_from_memory(stbi_uc const *buffer, int len);
243
244 #ifndef STBI_NO_STDIO
245 extern int stbi_info (char const *filename, int *x, int *y, int *comp);
246 extern int stbi_info_from_file (FILE *f, int *x, int *y, int *comp);
247
248 extern int stbi_is_hdr (char const *filename);
249 extern 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.
255 extern 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"
259 extern 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
264 extern char *stbi_zlib_decode_malloc_guesssize(const char *buffer, int len, int initial_size, int *outlen);
265 extern char *stbi_zlib_decode_malloc_guesssize_headerflag(const char *buffer, int len, int initial_size, int *outlen, int parse_header);
266 extern char *stbi_zlib_decode_malloc(const char *buffer, int len, int *outlen);
267 extern int stbi_zlib_decode_buffer(char *obuffer, int olen, const char *ibuffer, int ilen);
268
269 extern char *stbi_zlib_decode_noheader_malloc(const char *buffer, int len, int *outlen);
270 extern int stbi_zlib_decode_noheader_buffer(char *obuffer, int olen, const char *ibuffer, int ilen);
271
272 // define new loaders
273 typedef 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
286 extern int stbi_register_loader(stbi_loader *loader);
287
288 // define faster low-level operations (typically SIMD support)
289 #ifdef STBI_SIMD
290 typedef 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
295 typedef 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
303 extern void stbi_install_idct(stbi_idct_8x8 func);
304 extern 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?
315 extern int stbi_jpeg_test_memory (stbi_uc const *buffer, int len);
316 extern stbi_uc *stbi_jpeg_load_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp);
317 extern int stbi_jpeg_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp);
318
319 #ifndef STBI_NO_STDIO
320 extern stbi_uc *stbi_jpeg_load (char const *filename, int *x, int *y, int *comp, int req_comp);
321 extern int stbi_jpeg_test_file (FILE *f);
322 extern stbi_uc *stbi_jpeg_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
323
324 extern int stbi_jpeg_info (char const *filename, int *x, int *y, int *comp);
325 extern int stbi_jpeg_info_from_file (FILE *f, int *x, int *y, int *comp);
326 #endif
327
328 // is it a png?
329 extern int stbi_png_test_memory (stbi_uc const *buffer, int len);
330 extern stbi_uc *stbi_png_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp);
331 extern int stbi_png_info_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp);
332
333 #ifndef STBI_NO_STDIO
334 extern stbi_uc *stbi_png_load (char const *filename, int *x, int *y, int *comp, int req_comp);
335 extern int stbi_png_info (char const *filename, int *x, int *y, int *comp);
336 extern int stbi_png_test_file (FILE *f);
337 extern stbi_uc *stbi_png_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
338 extern int stbi_png_info_from_file (FILE *f, int *x, int *y, int *comp);
339 #endif
340
341 // is it a bmp?
342 extern int stbi_bmp_test_memory (stbi_uc const *buffer, int len);
343
344 extern stbi_uc *stbi_bmp_load (char const *filename, int *x, int *y, int *comp, int req_comp);
345 extern 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
347 extern int stbi_bmp_test_file (FILE *f);
348 extern 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?
352 extern int stbi_tga_test_memory (stbi_uc const *buffer, int len);
353
354 extern stbi_uc *stbi_tga_load (char const *filename, int *x, int *y, int *comp, int req_comp);
355 extern stbi_uc *stbi_tga_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp);
356 extern int stbi_tga_info_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp);
357 #ifndef STBI_NO_STDIO
358 extern int stbi_tga_info_from_file (FILE *f, int *x, int *y, int *comp);
359 extern int stbi_tga_test_file (FILE *f);
360 extern 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?
364 extern int stbi_psd_test_memory (stbi_uc const *buffer, int len);
365
366 extern stbi_uc *stbi_psd_load (char const *filename, int *x, int *y, int *comp, int req_comp);
367 extern 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
369 extern int stbi_psd_test_file (FILE *f);
370 extern 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?
374 extern int stbi_hdr_test_memory (stbi_uc const *buffer, int len);
375
376 extern float * stbi_hdr_load (char const *filename, int *x, int *y, int *comp, int req_comp);
377 extern 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
379 extern int stbi_hdr_test_file (FILE *f);
380 extern 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?
384 extern int stbi_pic_test_memory (stbi_uc const *buffer, int len);
385
386 extern stbi_uc *stbi_pic_load (char const *filename, int *x, int *y, int *comp, int req_comp);
387 extern 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
389 extern int stbi_pic_test_file (FILE *f);
390 extern 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?
394 extern int stbi_gif_test_memory (stbi_uc const *buffer, int len);
395
396 extern stbi_uc *stbi_gif_load (char const *filename, int *x, int *y, int *comp, int req_comp);
397 extern stbi_uc *stbi_gif_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp);
398 extern int stbi_gif_info_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp);
399
400 #ifndef STBI_NO_STDIO
401 extern int stbi_gif_test_file (FILE *f);
402 extern stbi_uc *stbi_gif_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
403 extern int stbi_gif_info (char const *filename, int *x, int *y, int *comp);
404 extern 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 1.6 2013/09/15 14:06:10 martin 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:
467 typedef unsigned char uint8;
468 typedef unsigned short uint16;
469 typedef signed short int16;
470 typedef unsigned int uint32;
471 typedef signed int int32;
472 #ifndef __NetBSD__
473 typedef unsigned int uint;
474 #endif
475
476 // should produce compiler error if size is wrong
477 typedef 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?
503 extern int stbi_jpeg_test_memory (stbi_uc const *buffer, int len);
504 extern stbi_uc *stbi_jpeg_load_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp);
505 extern int stbi_jpeg_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp);
506
507 #ifndef STBI_NO_STDIO
508 extern stbi_uc *stbi_jpeg_load (char const *filename, int *x, int *y, int *comp, int req_comp);
509 extern int stbi_jpeg_test_file (FILE *f);
510 extern stbi_uc *stbi_jpeg_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
511
512 extern int stbi_jpeg_info (char const *filename, int *x, int *y, int *comp);
513 extern int stbi_jpeg_info_from_file (FILE *f, int *x, int *y, int *comp);
514 #endif
515
516 // is it a png?
517 extern int stbi_png_test_memory (stbi_uc const *buffer, int len);
518 extern stbi_uc *stbi_png_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp);
519 extern int stbi_png_info_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp);
520
521 #ifndef STBI_NO_STDIO
522 extern stbi_uc *stbi_png_load (char const *filename, int *x, int *y, int *comp, int req_comp);
523 extern int stbi_png_info (char const *filename, int *x, int *y, int *comp);
524 extern int stbi_png_test_file (FILE *f);
525 extern stbi_uc *stbi_png_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
526 extern int stbi_png_info_from_file (FILE *f, int *x, int *y, int *comp);
527 #endif
528
529 // is it a bmp?
530 extern int stbi_bmp_test_memory (stbi_uc const *buffer, int len);
531
532 extern stbi_uc *stbi_bmp_load (char const *filename, int *x, int *y, int *comp, int req_comp);
533 extern 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
535 extern int stbi_bmp_test_file (FILE *f);
536 extern 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?
540 extern int stbi_tga_test_memory (stbi_uc const *buffer, int len);
541
542 extern stbi_uc *stbi_tga_load (char const *filename, int *x, int *y, int *comp, int req_comp);
543 extern 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
545 extern int stbi_tga_test_file (FILE *f);
546 extern 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?
550 extern int stbi_psd_test_memory (stbi_uc const *buffer, int len);
551
552 extern stbi_uc *stbi_psd_load (char const *filename, int *x, int *y, int *comp, int req_comp);
553 extern 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
555 extern int stbi_psd_test_file (FILE *f);
556 extern 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?
560 extern int stbi_hdr_test_memory (stbi_uc const *buffer, int len);
561
562 extern float * stbi_hdr_load (char const *filename, int *x, int *y, int *comp, int req_comp);
563 extern 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
565 extern int stbi_hdr_test_file (FILE *f);
566 extern 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?
570 extern int stbi_pic_test_memory (stbi_uc const *buffer, int len);
571
572 extern stbi_uc *stbi_pic_load (char const *filename, int *x, int *y, int *comp, int req_comp);
573 extern 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
575 extern int stbi_pic_test_file (FILE *f);
576 extern 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?
580 extern int stbi_gif_test_memory (stbi_uc const *buffer, int len);
581
582 extern stbi_uc *stbi_gif_load (char const *filename, int *x, int *y, int *comp, int req_comp);
583 extern stbi_uc *stbi_gif_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp);
584 extern int stbi_gif_info_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp);
585
586 #ifndef STBI_NO_STDIO
587 extern int stbi_gif_test_file (FILE *f);
588 extern stbi_uc *stbi_gif_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
589 extern int stbi_gif_info (char const *filename, int *x, int *y, int *comp);
590 extern int stbi_gif_info_from_file (FILE *f, int *x, int *y, int *comp);
591 #endif
592
593
594 // this is not threadsafe
595 static const char *failure_reason;
596
597 const char *stbi_failure_reason(void)
598 {
599 return failure_reason;
600 }
601
602 #ifndef STBI_NO_FAILURE_STRINGS
603 static 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
621 void stbi_image_free(void *retval_from_stbi_load)
622 {
623 FREE(retval_from_stbi_load);
624 }
625
626 #define MAX_LOADERS 32
627 stbi_loader *loaders[MAX_LOADERS];
628 static int max_loaders = 0;
629
630 int 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
649 static float *ldr_to_hdr(stbi_uc *data, int x, int y, int comp);
650 static stbi_uc *hdr_to_ldr(float *data, int x, int y, int comp);
651 #endif
652
653 #ifndef STBI_NO_STDIO
654 unsigned 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
664 unsigned 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
691 unsigned 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
720 float *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
730 float *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
744 float *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
762 int 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
774 extern 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
785 extern 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
797 static float h2l_gamma_i=1.0f/2.2f, h2l_scale_i=1.0f;
798 static float l2h_gamma=2.2f, l2h_scale=1.0f;
799
800 void stbi_hdr_to_ldr_gamma(float gamma) { h2l_gamma_i = 1/gamma; }
801 void stbi_hdr_to_ldr_scale(float scale) { h2l_scale_i = 1/scale; }
802
803 void stbi_ldr_to_hdr_gamma(float gamma) { l2h_gamma = gamma; }
804 void 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
813 enum
814 {
815 SCAN_load=0,
816 SCAN_type,
817 SCAN_header
818 };
819
820 typedef 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
835 static 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
845 static 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
856 static 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
903 static 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
918 static 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
940 static int get16(stbi *s)
941 {
942 int z = get8(s);
943 return (z << 8) + get8(s);
944 }
945
946 static uint32 get32(stbi *s)
947 {
948 uint32 z = get16(s);
949 return (z << 16) + get16(s);
950 }
951
952 static int get16le(stbi *s)
953 {
954 int z = get8(s);
955 return z + (get8(s) << 8);
956 }
957
958 static 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
975 static uint8 compute_y(int r, int g, int b)
976 {
977 return (uint8) (((r*77) + (g*150) + (29*b)) >> 8);
978 }
979
980 static 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 = (unsigned char *) 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
1025 static float *ldr_to_hdr(stbi_uc *data, int x, int y, int comp)
1026 {
1027 int i,k,n;
1028 float *output = (float *) 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))
1043 static stbi_uc *hdr_to_ldr(float *data, int x, int y, int comp)
1044 {
1045 int i,k,n;
1046 stbi_uc *output = (stbi_uc *) 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
1099 typedef 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
1110 typedef 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
1149 static 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
1190 static 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
1208 static 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?
1289 static 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--
1305 static 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
1392 typedef unsigned short stbi_dequantize_t;
1393 #else
1394 typedef uint8 stbi_dequantize_t;
1395 #endif
1396
1397 // .344 seconds on 3*anemones.jpg
1398 static 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
1460 static stbi_idct_8x8 stbi_idct_installed = idct_block;
1461
1462 extern 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
1472 static 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
1489 static 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
1501 static 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
1573 static 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
1642 static 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
1667 static 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
1746 static 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
1767 static 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
1800 typedef uint8 *(*resample_row_func)(uint8 *out, uint8 *in0, uint8 *in1,
1801 int w, int hs);
1802
1803 #define div4(x) ((uint8) ((x) >> 2))
1804
1805 static 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
1814 static 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
1824 static 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
1854 static 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
1878 static 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!
1893 static 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
1919 static stbi_YCbCr_to_RGB_run stbi_YCbCr_installed = YCbCr_to_RGB_row;
1920
1921 void 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
1929 static 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
1944 typedef 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
1954 static 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 = (uint8 *) 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 = (uint8 *) 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
2055 unsigned 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
2062 unsigned 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
2073 unsigned 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 = (jpeg *) 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
2089 static 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
2100 int 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
2111 int 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
2122 int 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
2133 int 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
2140 int 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
2148 extern int stbi_jpeg_info (char const *filename, int *x, int *y, int *comp);
2149 extern int stbi_jpeg_info_from_file (FILE *f, int *x, int *y, int *comp);
2150 #endif
2151 extern 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)
2166 typedef 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
2193 static 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
2244 typedef 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
2264 static 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
2310 static 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
2327 static 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
2332 static 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
2335 static int dist_base[32] = { 1,2,3,4,5,7,9,13,17,25,33,49,65,97,129,193,
2336 257,385,513,769,1025,1537,2049,3073,4097,6145,8193,12289,16385,24577,0,0};
2337
2338 static 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
2341 static 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
2369 static 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
2415 static 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
2444 static 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
2458 static uint8 default_length[288], default_distance[32];
2459 static 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
2470 int stbi_png_partial; // a quick hack to only allow decoding some of a PNG... I should implement real streaming support instead
2471 static 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
2502 static 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
2512 char *stbi_zlib_decode_malloc_guesssize(const char * buffer, int len, int initial_size, int *outlen)
2513 {
2514 zbuf a;
2515 char *p = (char *) 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
2528 char *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
2533 char *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 = (char *) 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
2549 int 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
2560 char *stbi_zlib_decode_noheader_malloc(char const *buffer, int len, int *outlen)
2561 {
2562 zbuf a;
2563 char *p = (char *) 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
2576 int 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
2598 typedef 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
2606 static 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
2614 static 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
2623 typedef struct
2624 {
2625 stbi s;
2626 uint8 *idata, *expanded, *out;
2627 } png;
2628
2629
2630 enum {
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
2635 static uint8 first_row_filter[5] =
2636 {
2637 F_none, F_sub, F_none, F_avg_first, F_paeth_first
2638 };
2639
2640 static 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
2652 static 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 = (uint8 *) 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
2729 static 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 = (uint8 *) 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
2770 static 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
2795 static 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 = (uint8 *) 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
2832 static int stbi_unpremultiply_on_load = 0;
2833 static int stbi_de_iphone_flag = 0;
2834
2835 void stbi_set_unpremultiply_on_load(int flag_true_if_should_unpremultiply)
2836 {
2837 stbi_unpremultiply_on_load = flag_true_if_should_unpremultiply;
2838 }
2839 void 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
2844 static 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
2886 static 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
3035 static 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
3061 unsigned 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
3068 unsigned 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
3079 unsigned 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
3087 int 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
3099 int 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
3106 static 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
3117 int 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
3127 int 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
3139 int 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
3148 static 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
3163 int 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
3174 int 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
3182 static 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
3194 static 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
3204 static 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
3221 static 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 = (stbi_uc *) 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
3416 stbi_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
3426 stbi_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
3434 stbi_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
3444 static 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
3474 int 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
3486 int 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
3493 static 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
3514 int 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
3525 int 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
3532 static 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 = (unsigned char*)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 = (unsigned char*)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
3754 stbi_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
3764 stbi_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
3772 stbi_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
3783 static 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
3790 int 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
3801 int 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
3808 static 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 = (stbi_uc *) 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
3967 stbi_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
3977 stbi_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
3985 stbi_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
3999 static 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
4009 static 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
4025 typedef struct
4026 {
4027 stbi_uc size,type,channel;
4028 } pic_packet_t;
4029
4030 static 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
4044 static 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
4053 static 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
4163 static 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 = (stbi_uc *) 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
4196 int 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
4203 stbi_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
4211 int 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
4222 stbi_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
4232 stbi_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
4242 typedef struct stbi_gif_lzw_struct {
4243 int16 prefix;
4244 uint8 first;
4245 uint8 suffix;
4246 } stbi_gif_lzw;
4247
4248 typedef 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
4265 static 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
4276 int 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
4287 int 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
4294 static 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
4305 static 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
4333 static 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
4342 static 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
4376 static 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
4455 static 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
4470 static 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 = (uint8 *) 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 = (uint8 *) 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
4571 stbi_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
4581 stbi_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
4599 stbi_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 = (stbi_gif *) 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
4631 int 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
4641 int 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
4653 int 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
4667 static 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
4677 int 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
4685 int 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
4697 static 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
4719 static 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
4747 static 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 = (float *) 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 = (stbi_uc *) 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
4859 float *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
4867 float *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
4878 int 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
4888 int 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
4908 int 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 */
MINIX 3 (repo.or.cz mirror)