diff options
Diffstat (limited to 'libraries/irrlicht-1.8/source/Irrlicht/libpng/pngrtran.c')
-rw-r--r-- | libraries/irrlicht-1.8/source/Irrlicht/libpng/pngrtran.c | 5023 |
1 files changed, 0 insertions, 5023 deletions
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngrtran.c b/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngrtran.c deleted file mode 100644 index 1079595..0000000 --- a/libraries/irrlicht-1.8/source/Irrlicht/libpng/pngrtran.c +++ /dev/null | |||
@@ -1,5023 +0,0 @@ | |||
1 | |||
2 | /* pngrtran.c - transforms the data in a row for PNG readers | ||
3 | * | ||
4 | * Last changed in libpng 1.5.7 [December 15, 2011] | ||
5 | * Copyright (c) 1998-2011 Glenn Randers-Pehrson | ||
6 | * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) | ||
7 | * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) | ||
8 | * | ||
9 | * This code is released under the libpng license. | ||
10 | * For conditions of distribution and use, see the disclaimer | ||
11 | * and license in png.h | ||
12 | * | ||
13 | * This file contains functions optionally called by an application | ||
14 | * in order to tell libpng how to handle data when reading a PNG. | ||
15 | * Transformations that are used in both reading and writing are | ||
16 | * in pngtrans.c. | ||
17 | */ | ||
18 | |||
19 | #include "pngpriv.h" | ||
20 | |||
21 | #ifdef PNG_READ_SUPPORTED | ||
22 | |||
23 | /* Set the action on getting a CRC error for an ancillary or critical chunk. */ | ||
24 | void PNGAPI | ||
25 | png_set_crc_action(png_structp png_ptr, int crit_action, int ancil_action) | ||
26 | { | ||
27 | png_debug(1, "in png_set_crc_action"); | ||
28 | |||
29 | if (png_ptr == NULL) | ||
30 | return; | ||
31 | |||
32 | /* Tell libpng how we react to CRC errors in critical chunks */ | ||
33 | switch (crit_action) | ||
34 | { | ||
35 | case PNG_CRC_NO_CHANGE: /* Leave setting as is */ | ||
36 | break; | ||
37 | |||
38 | case PNG_CRC_WARN_USE: /* Warn/use data */ | ||
39 | png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; | ||
40 | png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE; | ||
41 | break; | ||
42 | |||
43 | case PNG_CRC_QUIET_USE: /* Quiet/use data */ | ||
44 | png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; | ||
45 | png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE | | ||
46 | PNG_FLAG_CRC_CRITICAL_IGNORE; | ||
47 | break; | ||
48 | |||
49 | case PNG_CRC_WARN_DISCARD: /* Not a valid action for critical data */ | ||
50 | png_warning(png_ptr, | ||
51 | "Can't discard critical data on CRC error"); | ||
52 | case PNG_CRC_ERROR_QUIT: /* Error/quit */ | ||
53 | |||
54 | case PNG_CRC_DEFAULT: | ||
55 | default: | ||
56 | png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; | ||
57 | break; | ||
58 | } | ||
59 | |||
60 | /* Tell libpng how we react to CRC errors in ancillary chunks */ | ||
61 | switch (ancil_action) | ||
62 | { | ||
63 | case PNG_CRC_NO_CHANGE: /* Leave setting as is */ | ||
64 | break; | ||
65 | |||
66 | case PNG_CRC_WARN_USE: /* Warn/use data */ | ||
67 | png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; | ||
68 | png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE; | ||
69 | break; | ||
70 | |||
71 | case PNG_CRC_QUIET_USE: /* Quiet/use data */ | ||
72 | png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; | ||
73 | png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE | | ||
74 | PNG_FLAG_CRC_ANCILLARY_NOWARN; | ||
75 | break; | ||
76 | |||
77 | case PNG_CRC_ERROR_QUIT: /* Error/quit */ | ||
78 | png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; | ||
79 | png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_NOWARN; | ||
80 | break; | ||
81 | |||
82 | case PNG_CRC_WARN_DISCARD: /* Warn/discard data */ | ||
83 | |||
84 | case PNG_CRC_DEFAULT: | ||
85 | default: | ||
86 | png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; | ||
87 | break; | ||
88 | } | ||
89 | } | ||
90 | |||
91 | #ifdef PNG_READ_BACKGROUND_SUPPORTED | ||
92 | /* Handle alpha and tRNS via a background color */ | ||
93 | void PNGFAPI | ||
94 | png_set_background_fixed(png_structp png_ptr, | ||
95 | png_const_color_16p background_color, int background_gamma_code, | ||
96 | int need_expand, png_fixed_point background_gamma) | ||
97 | { | ||
98 | png_debug(1, "in png_set_background_fixed"); | ||
99 | |||
100 | if (png_ptr == NULL) | ||
101 | return; | ||
102 | |||
103 | if (background_gamma_code == PNG_BACKGROUND_GAMMA_UNKNOWN) | ||
104 | { | ||
105 | png_warning(png_ptr, "Application must supply a known background gamma"); | ||
106 | return; | ||
107 | } | ||
108 | |||
109 | png_ptr->transformations |= PNG_COMPOSE | PNG_STRIP_ALPHA; | ||
110 | png_ptr->transformations &= ~PNG_ENCODE_ALPHA; | ||
111 | png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; | ||
112 | |||
113 | png_memcpy(&(png_ptr->background), background_color, | ||
114 | png_sizeof(png_color_16)); | ||
115 | png_ptr->background_gamma = background_gamma; | ||
116 | png_ptr->background_gamma_type = (png_byte)(background_gamma_code); | ||
117 | if (need_expand) | ||
118 | png_ptr->transformations |= PNG_BACKGROUND_EXPAND; | ||
119 | else | ||
120 | png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND; | ||
121 | } | ||
122 | |||
123 | # ifdef PNG_FLOATING_POINT_SUPPORTED | ||
124 | void PNGAPI | ||
125 | png_set_background(png_structp png_ptr, | ||
126 | png_const_color_16p background_color, int background_gamma_code, | ||
127 | int need_expand, double background_gamma) | ||
128 | { | ||
129 | png_set_background_fixed(png_ptr, background_color, background_gamma_code, | ||
130 | need_expand, png_fixed(png_ptr, background_gamma, "png_set_background")); | ||
131 | } | ||
132 | # endif /* FLOATING_POINT */ | ||
133 | #endif /* READ_BACKGROUND */ | ||
134 | |||
135 | /* Scale 16-bit depth files to 8-bit depth. If both of these are set then the | ||
136 | * one that pngrtran does first (scale) happens. This is necessary to allow the | ||
137 | * TRANSFORM and API behavior to be somewhat consistent, and it's simpler. | ||
138 | */ | ||
139 | #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED | ||
140 | void PNGAPI | ||
141 | png_set_scale_16(png_structp png_ptr) | ||
142 | { | ||
143 | png_debug(1, "in png_set_scale_16"); | ||
144 | |||
145 | if (png_ptr == NULL) | ||
146 | return; | ||
147 | |||
148 | png_ptr->transformations |= PNG_SCALE_16_TO_8; | ||
149 | } | ||
150 | #endif | ||
151 | |||
152 | #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED | ||
153 | /* Chop 16-bit depth files to 8-bit depth */ | ||
154 | void PNGAPI | ||
155 | png_set_strip_16(png_structp png_ptr) | ||
156 | { | ||
157 | png_debug(1, "in png_set_strip_16"); | ||
158 | |||
159 | if (png_ptr == NULL) | ||
160 | return; | ||
161 | |||
162 | png_ptr->transformations |= PNG_16_TO_8; | ||
163 | } | ||
164 | #endif | ||
165 | |||
166 | #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED | ||
167 | void PNGAPI | ||
168 | png_set_strip_alpha(png_structp png_ptr) | ||
169 | { | ||
170 | png_debug(1, "in png_set_strip_alpha"); | ||
171 | |||
172 | if (png_ptr == NULL) | ||
173 | return; | ||
174 | |||
175 | png_ptr->transformations |= PNG_STRIP_ALPHA; | ||
176 | } | ||
177 | #endif | ||
178 | |||
179 | #if defined(PNG_READ_ALPHA_MODE_SUPPORTED) || defined(PNG_READ_GAMMA_SUPPORTED) | ||
180 | static png_fixed_point | ||
181 | translate_gamma_flags(png_structp png_ptr, png_fixed_point output_gamma, | ||
182 | int is_screen) | ||
183 | { | ||
184 | /* Check for flag values. The main reason for having the old Mac value as a | ||
185 | * flag is that it is pretty near impossible to work out what the correct | ||
186 | * value is from Apple documentation - a working Mac system is needed to | ||
187 | * discover the value! | ||
188 | */ | ||
189 | if (output_gamma == PNG_DEFAULT_sRGB || | ||
190 | output_gamma == PNG_FP_1 / PNG_DEFAULT_sRGB) | ||
191 | { | ||
192 | /* If there is no sRGB support this just sets the gamma to the standard | ||
193 | * sRGB value. (This is a side effect of using this function!) | ||
194 | */ | ||
195 | # ifdef PNG_READ_sRGB_SUPPORTED | ||
196 | png_ptr->flags |= PNG_FLAG_ASSUME_sRGB; | ||
197 | # endif | ||
198 | if (is_screen) | ||
199 | output_gamma = PNG_GAMMA_sRGB; | ||
200 | else | ||
201 | output_gamma = PNG_GAMMA_sRGB_INVERSE; | ||
202 | } | ||
203 | |||
204 | else if (output_gamma == PNG_GAMMA_MAC_18 || | ||
205 | output_gamma == PNG_FP_1 / PNG_GAMMA_MAC_18) | ||
206 | { | ||
207 | if (is_screen) | ||
208 | output_gamma = PNG_GAMMA_MAC_OLD; | ||
209 | else | ||
210 | output_gamma = PNG_GAMMA_MAC_INVERSE; | ||
211 | } | ||
212 | |||
213 | return output_gamma; | ||
214 | } | ||
215 | |||
216 | # ifdef PNG_FLOATING_POINT_SUPPORTED | ||
217 | static png_fixed_point | ||
218 | convert_gamma_value(png_structp png_ptr, double output_gamma) | ||
219 | { | ||
220 | /* The following silently ignores cases where fixed point (times 100,000) | ||
221 | * gamma values are passed to the floating point API. This is safe and it | ||
222 | * means the fixed point constants work just fine with the floating point | ||
223 | * API. The alternative would just lead to undetected errors and spurious | ||
224 | * bug reports. Negative values fail inside the _fixed API unless they | ||
225 | * correspond to the flag values. | ||
226 | */ | ||
227 | if (output_gamma > 0 && output_gamma < 128) | ||
228 | output_gamma *= PNG_FP_1; | ||
229 | |||
230 | /* This preserves -1 and -2 exactly: */ | ||
231 | output_gamma = floor(output_gamma + .5); | ||
232 | |||
233 | if (output_gamma > PNG_FP_MAX || output_gamma < PNG_FP_MIN) | ||
234 | png_fixed_error(png_ptr, "gamma value"); | ||
235 | |||
236 | return (png_fixed_point)output_gamma; | ||
237 | } | ||
238 | # endif | ||
239 | #endif /* READ_ALPHA_MODE || READ_GAMMA */ | ||
240 | |||
241 | #ifdef PNG_READ_ALPHA_MODE_SUPPORTED | ||
242 | void PNGFAPI | ||
243 | png_set_alpha_mode_fixed(png_structp png_ptr, int mode, | ||
244 | png_fixed_point output_gamma) | ||
245 | { | ||
246 | int compose = 0; | ||
247 | png_fixed_point file_gamma; | ||
248 | |||
249 | png_debug(1, "in png_set_alpha_mode"); | ||
250 | |||
251 | if (png_ptr == NULL) | ||
252 | return; | ||
253 | |||
254 | output_gamma = translate_gamma_flags(png_ptr, output_gamma, 1/*screen*/); | ||
255 | |||
256 | /* Validate the value to ensure it is in a reasonable range. The value | ||
257 | * is expected to be 1 or greater, but this range test allows for some | ||
258 | * viewing correction values. The intent is to weed out users of this API | ||
259 | * who use the inverse of the gamma value accidentally! Since some of these | ||
260 | * values are reasonable this may have to be changed. | ||
261 | */ | ||
262 | if (output_gamma < 70000 || output_gamma > 300000) | ||
263 | png_error(png_ptr, "output gamma out of expected range"); | ||
264 | |||
265 | /* The default file gamma is the inverse of the output gamma; the output | ||
266 | * gamma may be changed below so get the file value first: | ||
267 | */ | ||
268 | file_gamma = png_reciprocal(output_gamma); | ||
269 | |||
270 | /* There are really 8 possibilities here, composed of any combination | ||
271 | * of: | ||
272 | * | ||
273 | * premultiply the color channels | ||
274 | * do not encode non-opaque pixels | ||
275 | * encode the alpha as well as the color channels | ||
276 | * | ||
277 | * The differences disappear if the input/output ('screen') gamma is 1.0, | ||
278 | * because then the encoding is a no-op and there is only the choice of | ||
279 | * premultiplying the color channels or not. | ||
280 | * | ||
281 | * png_set_alpha_mode and png_set_background interact because both use | ||
282 | * png_compose to do the work. Calling both is only useful when | ||
283 | * png_set_alpha_mode is used to set the default mode - PNG_ALPHA_PNG - along | ||
284 | * with a default gamma value. Otherwise PNG_COMPOSE must not be set. | ||
285 | */ | ||
286 | switch (mode) | ||
287 | { | ||
288 | case PNG_ALPHA_PNG: /* default: png standard */ | ||
289 | /* No compose, but it may be set by png_set_background! */ | ||
290 | png_ptr->transformations &= ~PNG_ENCODE_ALPHA; | ||
291 | png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; | ||
292 | break; | ||
293 | |||
294 | case PNG_ALPHA_ASSOCIATED: /* color channels premultiplied */ | ||
295 | compose = 1; | ||
296 | png_ptr->transformations &= ~PNG_ENCODE_ALPHA; | ||
297 | png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; | ||
298 | /* The output is linear: */ | ||
299 | output_gamma = PNG_FP_1; | ||
300 | break; | ||
301 | |||
302 | case PNG_ALPHA_OPTIMIZED: /* associated, non-opaque pixels linear */ | ||
303 | compose = 1; | ||
304 | png_ptr->transformations &= ~PNG_ENCODE_ALPHA; | ||
305 | png_ptr->flags |= PNG_FLAG_OPTIMIZE_ALPHA; | ||
306 | /* output_gamma records the encoding of opaque pixels! */ | ||
307 | break; | ||
308 | |||
309 | case PNG_ALPHA_BROKEN: /* associated, non-linear, alpha encoded */ | ||
310 | compose = 1; | ||
311 | png_ptr->transformations |= PNG_ENCODE_ALPHA; | ||
312 | png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; | ||
313 | break; | ||
314 | |||
315 | default: | ||
316 | png_error(png_ptr, "invalid alpha mode"); | ||
317 | } | ||
318 | |||
319 | /* Only set the default gamma if the file gamma has not been set (this has | ||
320 | * the side effect that the gamma in a second call to png_set_alpha_mode will | ||
321 | * be ignored.) | ||
322 | */ | ||
323 | if (png_ptr->gamma == 0) | ||
324 | png_ptr->gamma = file_gamma; | ||
325 | |||
326 | /* But always set the output gamma: */ | ||
327 | png_ptr->screen_gamma = output_gamma; | ||
328 | |||
329 | /* Finally, if pre-multiplying, set the background fields to achieve the | ||
330 | * desired result. | ||
331 | */ | ||
332 | if (compose) | ||
333 | { | ||
334 | /* And obtain alpha pre-multiplication by composing on black: */ | ||
335 | png_memset(&png_ptr->background, 0, sizeof png_ptr->background); | ||
336 | png_ptr->background_gamma = png_ptr->gamma; /* just in case */ | ||
337 | png_ptr->background_gamma_type = PNG_BACKGROUND_GAMMA_FILE; | ||
338 | png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND; | ||
339 | |||
340 | if (png_ptr->transformations & PNG_COMPOSE) | ||
341 | png_error(png_ptr, | ||
342 | "conflicting calls to set alpha mode and background"); | ||
343 | |||
344 | png_ptr->transformations |= PNG_COMPOSE; | ||
345 | } | ||
346 | |||
347 | /* New API, make sure apps call the correct initializers: */ | ||
348 | png_ptr->flags |= PNG_FLAG_DETECT_UNINITIALIZED; | ||
349 | } | ||
350 | |||
351 | # ifdef PNG_FLOATING_POINT_SUPPORTED | ||
352 | void PNGAPI | ||
353 | png_set_alpha_mode(png_structp png_ptr, int mode, double output_gamma) | ||
354 | { | ||
355 | png_set_alpha_mode_fixed(png_ptr, mode, convert_gamma_value(png_ptr, | ||
356 | output_gamma)); | ||
357 | } | ||
358 | # endif | ||
359 | #endif | ||
360 | |||
361 | #ifdef PNG_READ_QUANTIZE_SUPPORTED | ||
362 | /* Dither file to 8-bit. Supply a palette, the current number | ||
363 | * of elements in the palette, the maximum number of elements | ||
364 | * allowed, and a histogram if possible. If the current number | ||
365 | * of colors is greater then the maximum number, the palette will be | ||
366 | * modified to fit in the maximum number. "full_quantize" indicates | ||
367 | * whether we need a quantizing cube set up for RGB images, or if we | ||
368 | * simply are reducing the number of colors in a paletted image. | ||
369 | */ | ||
370 | |||
371 | typedef struct png_dsort_struct | ||
372 | { | ||
373 | struct png_dsort_struct FAR * next; | ||
374 | png_byte left; | ||
375 | png_byte right; | ||
376 | } png_dsort; | ||
377 | typedef png_dsort FAR * png_dsortp; | ||
378 | typedef png_dsort FAR * FAR * png_dsortpp; | ||
379 | |||
380 | void PNGAPI | ||
381 | png_set_quantize(png_structp png_ptr, png_colorp palette, | ||
382 | int num_palette, int maximum_colors, png_const_uint_16p histogram, | ||
383 | int full_quantize) | ||
384 | { | ||
385 | png_debug(1, "in png_set_quantize"); | ||
386 | |||
387 | if (png_ptr == NULL) | ||
388 | return; | ||
389 | |||
390 | png_ptr->transformations |= PNG_QUANTIZE; | ||
391 | |||
392 | if (!full_quantize) | ||
393 | { | ||
394 | int i; | ||
395 | |||
396 | png_ptr->quantize_index = (png_bytep)png_malloc(png_ptr, | ||
397 | (png_uint_32)(num_palette * png_sizeof(png_byte))); | ||
398 | for (i = 0; i < num_palette; i++) | ||
399 | png_ptr->quantize_index[i] = (png_byte)i; | ||
400 | } | ||
401 | |||
402 | if (num_palette > maximum_colors) | ||
403 | { | ||
404 | if (histogram != NULL) | ||
405 | { | ||
406 | /* This is easy enough, just throw out the least used colors. | ||
407 | * Perhaps not the best solution, but good enough. | ||
408 | */ | ||
409 | |||
410 | int i; | ||
411 | |||
412 | /* Initialize an array to sort colors */ | ||
413 | png_ptr->quantize_sort = (png_bytep)png_malloc(png_ptr, | ||
414 | (png_uint_32)(num_palette * png_sizeof(png_byte))); | ||
415 | |||
416 | /* Initialize the quantize_sort array */ | ||
417 | for (i = 0; i < num_palette; i++) | ||
418 | png_ptr->quantize_sort[i] = (png_byte)i; | ||
419 | |||
420 | /* Find the least used palette entries by starting a | ||
421 | * bubble sort, and running it until we have sorted | ||
422 | * out enough colors. Note that we don't care about | ||
423 | * sorting all the colors, just finding which are | ||
424 | * least used. | ||
425 | */ | ||
426 | |||
427 | for (i = num_palette - 1; i >= maximum_colors; i--) | ||
428 | { | ||
429 | int done; /* To stop early if the list is pre-sorted */ | ||
430 | int j; | ||
431 | |||
432 | done = 1; | ||
433 | for (j = 0; j < i; j++) | ||
434 | { | ||
435 | if (histogram[png_ptr->quantize_sort[j]] | ||
436 | < histogram[png_ptr->quantize_sort[j + 1]]) | ||
437 | { | ||
438 | png_byte t; | ||
439 | |||
440 | t = png_ptr->quantize_sort[j]; | ||
441 | png_ptr->quantize_sort[j] = png_ptr->quantize_sort[j + 1]; | ||
442 | png_ptr->quantize_sort[j + 1] = t; | ||
443 | done = 0; | ||
444 | } | ||
445 | } | ||
446 | |||
447 | if (done) | ||
448 | break; | ||
449 | } | ||
450 | |||
451 | /* Swap the palette around, and set up a table, if necessary */ | ||
452 | if (full_quantize) | ||
453 | { | ||
454 | int j = num_palette; | ||
455 | |||
456 | /* Put all the useful colors within the max, but don't | ||
457 | * move the others. | ||
458 | */ | ||
459 | for (i = 0; i < maximum_colors; i++) | ||
460 | { | ||
461 | if ((int)png_ptr->quantize_sort[i] >= maximum_colors) | ||
462 | { | ||
463 | do | ||
464 | j--; | ||
465 | while ((int)png_ptr->quantize_sort[j] >= maximum_colors); | ||
466 | |||
467 | palette[i] = palette[j]; | ||
468 | } | ||
469 | } | ||
470 | } | ||
471 | else | ||
472 | { | ||
473 | int j = num_palette; | ||
474 | |||
475 | /* Move all the used colors inside the max limit, and | ||
476 | * develop a translation table. | ||
477 | */ | ||
478 | for (i = 0; i < maximum_colors; i++) | ||
479 | { | ||
480 | /* Only move the colors we need to */ | ||
481 | if ((int)png_ptr->quantize_sort[i] >= maximum_colors) | ||
482 | { | ||
483 | png_color tmp_color; | ||
484 | |||
485 | do | ||
486 | j--; | ||
487 | while ((int)png_ptr->quantize_sort[j] >= maximum_colors); | ||
488 | |||
489 | tmp_color = palette[j]; | ||
490 | palette[j] = palette[i]; | ||
491 | palette[i] = tmp_color; | ||
492 | /* Indicate where the color went */ | ||
493 | png_ptr->quantize_index[j] = (png_byte)i; | ||
494 | png_ptr->quantize_index[i] = (png_byte)j; | ||
495 | } | ||
496 | } | ||
497 | |||
498 | /* Find closest color for those colors we are not using */ | ||
499 | for (i = 0; i < num_palette; i++) | ||
500 | { | ||
501 | if ((int)png_ptr->quantize_index[i] >= maximum_colors) | ||
502 | { | ||
503 | int min_d, k, min_k, d_index; | ||
504 | |||
505 | /* Find the closest color to one we threw out */ | ||
506 | d_index = png_ptr->quantize_index[i]; | ||
507 | min_d = PNG_COLOR_DIST(palette[d_index], palette[0]); | ||
508 | for (k = 1, min_k = 0; k < maximum_colors; k++) | ||
509 | { | ||
510 | int d; | ||
511 | |||
512 | d = PNG_COLOR_DIST(palette[d_index], palette[k]); | ||
513 | |||
514 | if (d < min_d) | ||
515 | { | ||
516 | min_d = d; | ||
517 | min_k = k; | ||
518 | } | ||
519 | } | ||
520 | /* Point to closest color */ | ||
521 | png_ptr->quantize_index[i] = (png_byte)min_k; | ||
522 | } | ||
523 | } | ||
524 | } | ||
525 | png_free(png_ptr, png_ptr->quantize_sort); | ||
526 | png_ptr->quantize_sort = NULL; | ||
527 | } | ||
528 | else | ||
529 | { | ||
530 | /* This is much harder to do simply (and quickly). Perhaps | ||
531 | * we need to go through a median cut routine, but those | ||
532 | * don't always behave themselves with only a few colors | ||
533 | * as input. So we will just find the closest two colors, | ||
534 | * and throw out one of them (chosen somewhat randomly). | ||
535 | * [We don't understand this at all, so if someone wants to | ||
536 | * work on improving it, be our guest - AED, GRP] | ||
537 | */ | ||
538 | int i; | ||
539 | int max_d; | ||
540 | int num_new_palette; | ||
541 | png_dsortp t; | ||
542 | png_dsortpp hash; | ||
543 | |||
544 | t = NULL; | ||
545 | |||
546 | /* Initialize palette index arrays */ | ||
547 | png_ptr->index_to_palette = (png_bytep)png_malloc(png_ptr, | ||
548 | (png_uint_32)(num_palette * png_sizeof(png_byte))); | ||
549 | png_ptr->palette_to_index = (png_bytep)png_malloc(png_ptr, | ||
550 | (png_uint_32)(num_palette * png_sizeof(png_byte))); | ||
551 | |||
552 | /* Initialize the sort array */ | ||
553 | for (i = 0; i < num_palette; i++) | ||
554 | { | ||
555 | png_ptr->index_to_palette[i] = (png_byte)i; | ||
556 | png_ptr->palette_to_index[i] = (png_byte)i; | ||
557 | } | ||
558 | |||
559 | hash = (png_dsortpp)png_calloc(png_ptr, (png_uint_32)(769 * | ||
560 | png_sizeof(png_dsortp))); | ||
561 | |||
562 | num_new_palette = num_palette; | ||
563 | |||
564 | /* Initial wild guess at how far apart the farthest pixel | ||
565 | * pair we will be eliminating will be. Larger | ||
566 | * numbers mean more areas will be allocated, Smaller | ||
567 | * numbers run the risk of not saving enough data, and | ||
568 | * having to do this all over again. | ||
569 | * | ||
570 | * I have not done extensive checking on this number. | ||
571 | */ | ||
572 | max_d = 96; | ||
573 | |||
574 | while (num_new_palette > maximum_colors) | ||
575 | { | ||
576 | for (i = 0; i < num_new_palette - 1; i++) | ||
577 | { | ||
578 | int j; | ||
579 | |||
580 | for (j = i + 1; j < num_new_palette; j++) | ||
581 | { | ||
582 | int d; | ||
583 | |||
584 | d = PNG_COLOR_DIST(palette[i], palette[j]); | ||
585 | |||
586 | if (d <= max_d) | ||
587 | { | ||
588 | |||
589 | t = (png_dsortp)png_malloc_warn(png_ptr, | ||
590 | (png_uint_32)(png_sizeof(png_dsort))); | ||
591 | |||
592 | if (t == NULL) | ||
593 | break; | ||
594 | |||
595 | t->next = hash[d]; | ||
596 | t->left = (png_byte)i; | ||
597 | t->right = (png_byte)j; | ||
598 | hash[d] = t; | ||
599 | } | ||
600 | } | ||
601 | if (t == NULL) | ||
602 | break; | ||
603 | } | ||
604 | |||
605 | if (t != NULL) | ||
606 | for (i = 0; i <= max_d; i++) | ||
607 | { | ||
608 | if (hash[i] != NULL) | ||
609 | { | ||
610 | png_dsortp p; | ||
611 | |||
612 | for (p = hash[i]; p; p = p->next) | ||
613 | { | ||
614 | if ((int)png_ptr->index_to_palette[p->left] | ||
615 | < num_new_palette && | ||
616 | (int)png_ptr->index_to_palette[p->right] | ||
617 | < num_new_palette) | ||
618 | { | ||
619 | int j, next_j; | ||
620 | |||
621 | if (num_new_palette & 0x01) | ||
622 | { | ||
623 | j = p->left; | ||
624 | next_j = p->right; | ||
625 | } | ||
626 | else | ||
627 | { | ||
628 | j = p->right; | ||
629 | next_j = p->left; | ||
630 | } | ||
631 | |||
632 | num_new_palette--; | ||
633 | palette[png_ptr->index_to_palette[j]] | ||
634 | = palette[num_new_palette]; | ||
635 | if (!full_quantize) | ||
636 | { | ||
637 | int k; | ||
638 | |||
639 | for (k = 0; k < num_palette; k++) | ||
640 | { | ||
641 | if (png_ptr->quantize_index[k] == | ||
642 | png_ptr->index_to_palette[j]) | ||
643 | png_ptr->quantize_index[k] = | ||
644 | png_ptr->index_to_palette[next_j]; | ||
645 | |||
646 | if ((int)png_ptr->quantize_index[k] == | ||
647 | num_new_palette) | ||
648 | png_ptr->quantize_index[k] = | ||
649 | png_ptr->index_to_palette[j]; | ||
650 | } | ||
651 | } | ||
652 | |||
653 | png_ptr->index_to_palette[png_ptr->palette_to_index | ||
654 | [num_new_palette]] = png_ptr->index_to_palette[j]; | ||
655 | |||
656 | png_ptr->palette_to_index[png_ptr->index_to_palette[j]] | ||
657 | = png_ptr->palette_to_index[num_new_palette]; | ||
658 | |||
659 | png_ptr->index_to_palette[j] = | ||
660 | (png_byte)num_new_palette; | ||
661 | |||
662 | png_ptr->palette_to_index[num_new_palette] = | ||
663 | (png_byte)j; | ||
664 | } | ||
665 | if (num_new_palette <= maximum_colors) | ||
666 | break; | ||
667 | } | ||
668 | if (num_new_palette <= maximum_colors) | ||
669 | break; | ||
670 | } | ||
671 | } | ||
672 | |||
673 | for (i = 0; i < 769; i++) | ||
674 | { | ||
675 | if (hash[i] != NULL) | ||
676 | { | ||
677 | png_dsortp p = hash[i]; | ||
678 | while (p) | ||
679 | { | ||
680 | t = p->next; | ||
681 | png_free(png_ptr, p); | ||
682 | p = t; | ||
683 | } | ||
684 | } | ||
685 | hash[i] = 0; | ||
686 | } | ||
687 | max_d += 96; | ||
688 | } | ||
689 | png_free(png_ptr, hash); | ||
690 | png_free(png_ptr, png_ptr->palette_to_index); | ||
691 | png_free(png_ptr, png_ptr->index_to_palette); | ||
692 | png_ptr->palette_to_index = NULL; | ||
693 | png_ptr->index_to_palette = NULL; | ||
694 | } | ||
695 | num_palette = maximum_colors; | ||
696 | } | ||
697 | if (png_ptr->palette == NULL) | ||
698 | { | ||
699 | png_ptr->palette = palette; | ||
700 | } | ||
701 | png_ptr->num_palette = (png_uint_16)num_palette; | ||
702 | |||
703 | if (full_quantize) | ||
704 | { | ||
705 | int i; | ||
706 | png_bytep distance; | ||
707 | int total_bits = PNG_QUANTIZE_RED_BITS + PNG_QUANTIZE_GREEN_BITS + | ||
708 | PNG_QUANTIZE_BLUE_BITS; | ||
709 | int num_red = (1 << PNG_QUANTIZE_RED_BITS); | ||
710 | int num_green = (1 << PNG_QUANTIZE_GREEN_BITS); | ||
711 | int num_blue = (1 << PNG_QUANTIZE_BLUE_BITS); | ||
712 | png_size_t num_entries = ((png_size_t)1 << total_bits); | ||
713 | |||
714 | png_ptr->palette_lookup = (png_bytep)png_calloc(png_ptr, | ||
715 | (png_uint_32)(num_entries * png_sizeof(png_byte))); | ||
716 | |||
717 | distance = (png_bytep)png_malloc(png_ptr, (png_uint_32)(num_entries * | ||
718 | png_sizeof(png_byte))); | ||
719 | |||
720 | png_memset(distance, 0xff, num_entries * png_sizeof(png_byte)); | ||
721 | |||
722 | for (i = 0; i < num_palette; i++) | ||
723 | { | ||
724 | int ir, ig, ib; | ||
725 | int r = (palette[i].red >> (8 - PNG_QUANTIZE_RED_BITS)); | ||
726 | int g = (palette[i].green >> (8 - PNG_QUANTIZE_GREEN_BITS)); | ||
727 | int b = (palette[i].blue >> (8 - PNG_QUANTIZE_BLUE_BITS)); | ||
728 | |||
729 | for (ir = 0; ir < num_red; ir++) | ||
730 | { | ||
731 | /* int dr = abs(ir - r); */ | ||
732 | int dr = ((ir > r) ? ir - r : r - ir); | ||
733 | int index_r = (ir << (PNG_QUANTIZE_BLUE_BITS + | ||
734 | PNG_QUANTIZE_GREEN_BITS)); | ||
735 | |||
736 | for (ig = 0; ig < num_green; ig++) | ||
737 | { | ||
738 | /* int dg = abs(ig - g); */ | ||
739 | int dg = ((ig > g) ? ig - g : g - ig); | ||
740 | int dt = dr + dg; | ||
741 | int dm = ((dr > dg) ? dr : dg); | ||
742 | int index_g = index_r | (ig << PNG_QUANTIZE_BLUE_BITS); | ||
743 | |||
744 | for (ib = 0; ib < num_blue; ib++) | ||
745 | { | ||
746 | int d_index = index_g | ib; | ||
747 | /* int db = abs(ib - b); */ | ||
748 | int db = ((ib > b) ? ib - b : b - ib); | ||
749 | int dmax = ((dm > db) ? dm : db); | ||
750 | int d = dmax + dt + db; | ||
751 | |||
752 | if (d < (int)distance[d_index]) | ||
753 | { | ||
754 | distance[d_index] = (png_byte)d; | ||
755 | png_ptr->palette_lookup[d_index] = (png_byte)i; | ||
756 | } | ||
757 | } | ||
758 | } | ||
759 | } | ||
760 | } | ||
761 | |||
762 | png_free(png_ptr, distance); | ||
763 | } | ||
764 | } | ||
765 | #endif /* PNG_READ_QUANTIZE_SUPPORTED */ | ||
766 | |||
767 | #ifdef PNG_READ_GAMMA_SUPPORTED | ||
768 | void PNGFAPI | ||
769 | png_set_gamma_fixed(png_structp png_ptr, png_fixed_point scrn_gamma, | ||
770 | png_fixed_point file_gamma) | ||
771 | { | ||
772 | png_debug(1, "in png_set_gamma_fixed"); | ||
773 | |||
774 | if (png_ptr == NULL) | ||
775 | return; | ||
776 | |||
777 | /* New in libpng-1.5.4 - reserve particular negative values as flags. */ | ||
778 | scrn_gamma = translate_gamma_flags(png_ptr, scrn_gamma, 1/*screen*/); | ||
779 | file_gamma = translate_gamma_flags(png_ptr, file_gamma, 0/*file*/); | ||
780 | |||
781 | #if PNG_LIBPNG_VER >= 10600 | ||
782 | /* Checking the gamma values for being >0 was added in 1.5.4 along with the | ||
783 | * premultiplied alpha support; this actually hides an undocumented feature | ||
784 | * of the previous implementation which allowed gamma processing to be | ||
785 | * disabled in background handling. There is no evidence (so far) that this | ||
786 | * was being used; however, png_set_background itself accepted and must still | ||
787 | * accept '0' for the gamma value it takes, because it isn't always used. | ||
788 | * | ||
789 | * Since this is an API change (albeit a very minor one that removes an | ||
790 | * undocumented API feature) it will not be made until libpng-1.6.0. | ||
791 | */ | ||
792 | if (file_gamma <= 0) | ||
793 | png_error(png_ptr, "invalid file gamma in png_set_gamma"); | ||
794 | |||
795 | if (scrn_gamma <= 0) | ||
796 | png_error(png_ptr, "invalid screen gamma in png_set_gamma"); | ||
797 | #endif | ||
798 | |||
799 | /* Set the gamma values unconditionally - this overrides the value in the PNG | ||
800 | * file if a gAMA chunk was present. png_set_alpha_mode provides a | ||
801 | * different, easier, way to default the file gamma. | ||
802 | */ | ||
803 | png_ptr->gamma = file_gamma; | ||
804 | png_ptr->screen_gamma = scrn_gamma; | ||
805 | } | ||
806 | |||
807 | # ifdef PNG_FLOATING_POINT_SUPPORTED | ||
808 | void PNGAPI | ||
809 | png_set_gamma(png_structp png_ptr, double scrn_gamma, double file_gamma) | ||
810 | { | ||
811 | png_set_gamma_fixed(png_ptr, convert_gamma_value(png_ptr, scrn_gamma), | ||
812 | convert_gamma_value(png_ptr, file_gamma)); | ||
813 | } | ||
814 | # endif /* FLOATING_POINT_SUPPORTED */ | ||
815 | #endif /* READ_GAMMA */ | ||
816 | |||
817 | #ifdef PNG_READ_EXPAND_SUPPORTED | ||
818 | /* Expand paletted images to RGB, expand grayscale images of | ||
819 | * less than 8-bit depth to 8-bit depth, and expand tRNS chunks | ||
820 | * to alpha channels. | ||
821 | */ | ||
822 | void PNGAPI | ||
823 | png_set_expand(png_structp png_ptr) | ||
824 | { | ||
825 | png_debug(1, "in png_set_expand"); | ||
826 | |||
827 | if (png_ptr == NULL) | ||
828 | return; | ||
829 | |||
830 | png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); | ||
831 | png_ptr->flags &= ~PNG_FLAG_ROW_INIT; | ||
832 | } | ||
833 | |||
834 | /* GRR 19990627: the following three functions currently are identical | ||
835 | * to png_set_expand(). However, it is entirely reasonable that someone | ||
836 | * might wish to expand an indexed image to RGB but *not* expand a single, | ||
837 | * fully transparent palette entry to a full alpha channel--perhaps instead | ||
838 | * convert tRNS to the grayscale/RGB format (16-bit RGB value), or replace | ||
839 | * the transparent color with a particular RGB value, or drop tRNS entirely. | ||
840 | * IOW, a future version of the library may make the transformations flag | ||
841 | * a bit more fine-grained, with separate bits for each of these three | ||
842 | * functions. | ||
843 | * | ||
844 | * More to the point, these functions make it obvious what libpng will be | ||
845 | * doing, whereas "expand" can (and does) mean any number of things. | ||
846 | * | ||
847 | * GRP 20060307: In libpng-1.2.9, png_set_gray_1_2_4_to_8() was modified | ||
848 | * to expand only the sample depth but not to expand the tRNS to alpha | ||
849 | * and its name was changed to png_set_expand_gray_1_2_4_to_8(). | ||
850 | */ | ||
851 | |||
852 | /* Expand paletted images to RGB. */ | ||
853 | void PNGAPI | ||
854 | png_set_palette_to_rgb(png_structp png_ptr) | ||
855 | { | ||
856 | png_debug(1, "in png_set_palette_to_rgb"); | ||
857 | |||
858 | if (png_ptr == NULL) | ||
859 | return; | ||
860 | |||
861 | png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); | ||
862 | png_ptr->flags &= ~PNG_FLAG_ROW_INIT; | ||
863 | } | ||
864 | |||
865 | /* Expand grayscale images of less than 8-bit depth to 8 bits. */ | ||
866 | void PNGAPI | ||
867 | png_set_expand_gray_1_2_4_to_8(png_structp png_ptr) | ||
868 | { | ||
869 | png_debug(1, "in png_set_expand_gray_1_2_4_to_8"); | ||
870 | |||
871 | if (png_ptr == NULL) | ||
872 | return; | ||
873 | |||
874 | png_ptr->transformations |= PNG_EXPAND; | ||
875 | png_ptr->flags &= ~PNG_FLAG_ROW_INIT; | ||
876 | } | ||
877 | |||
878 | |||
879 | |||
880 | /* Expand tRNS chunks to alpha channels. */ | ||
881 | void PNGAPI | ||
882 | png_set_tRNS_to_alpha(png_structp png_ptr) | ||
883 | { | ||
884 | png_debug(1, "in png_set_tRNS_to_alpha"); | ||
885 | |||
886 | png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); | ||
887 | png_ptr->flags &= ~PNG_FLAG_ROW_INIT; | ||
888 | } | ||
889 | #endif /* defined(PNG_READ_EXPAND_SUPPORTED) */ | ||
890 | |||
891 | #ifdef PNG_READ_EXPAND_16_SUPPORTED | ||
892 | /* Expand to 16-bit channels, expand the tRNS chunk too (because otherwise | ||
893 | * it may not work correctly.) | ||
894 | */ | ||
895 | void PNGAPI | ||
896 | png_set_expand_16(png_structp png_ptr) | ||
897 | { | ||
898 | png_debug(1, "in png_set_expand_16"); | ||
899 | |||
900 | if (png_ptr == NULL) | ||
901 | return; | ||
902 | |||
903 | png_ptr->transformations |= (PNG_EXPAND_16 | PNG_EXPAND | PNG_EXPAND_tRNS); | ||
904 | png_ptr->flags &= ~PNG_FLAG_ROW_INIT; | ||
905 | |||
906 | /* New API, make sure apps call the correct initializers: */ | ||
907 | png_ptr->flags |= PNG_FLAG_DETECT_UNINITIALIZED; | ||
908 | } | ||
909 | #endif | ||
910 | |||
911 | #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED | ||
912 | void PNGAPI | ||
913 | png_set_gray_to_rgb(png_structp png_ptr) | ||
914 | { | ||
915 | png_debug(1, "in png_set_gray_to_rgb"); | ||
916 | |||
917 | if (png_ptr != NULL) | ||
918 | { | ||
919 | /* Because rgb must be 8 bits or more: */ | ||
920 | png_set_expand_gray_1_2_4_to_8(png_ptr); | ||
921 | png_ptr->transformations |= PNG_GRAY_TO_RGB; | ||
922 | png_ptr->flags &= ~PNG_FLAG_ROW_INIT; | ||
923 | } | ||
924 | } | ||
925 | #endif | ||
926 | |||
927 | #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED | ||
928 | void PNGFAPI | ||
929 | png_set_rgb_to_gray_fixed(png_structp png_ptr, int error_action, | ||
930 | png_fixed_point red, png_fixed_point green) | ||
931 | { | ||
932 | png_debug(1, "in png_set_rgb_to_gray"); | ||
933 | |||
934 | if (png_ptr == NULL) | ||
935 | return; | ||
936 | |||
937 | switch(error_action) | ||
938 | { | ||
939 | case PNG_ERROR_ACTION_NONE: | ||
940 | png_ptr->transformations |= PNG_RGB_TO_GRAY; | ||
941 | break; | ||
942 | |||
943 | case PNG_ERROR_ACTION_WARN: | ||
944 | png_ptr->transformations |= PNG_RGB_TO_GRAY_WARN; | ||
945 | break; | ||
946 | |||
947 | case PNG_ERROR_ACTION_ERROR: | ||
948 | png_ptr->transformations |= PNG_RGB_TO_GRAY_ERR; | ||
949 | break; | ||
950 | |||
951 | default: | ||
952 | png_error(png_ptr, "invalid error action to rgb_to_gray"); | ||
953 | break; | ||
954 | } | ||
955 | if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) | ||
956 | #ifdef PNG_READ_EXPAND_SUPPORTED | ||
957 | png_ptr->transformations |= PNG_EXPAND; | ||
958 | #else | ||
959 | { | ||
960 | png_warning(png_ptr, | ||
961 | "Cannot do RGB_TO_GRAY without EXPAND_SUPPORTED"); | ||
962 | |||
963 | png_ptr->transformations &= ~PNG_RGB_TO_GRAY; | ||
964 | } | ||
965 | #endif | ||
966 | { | ||
967 | if (red >= 0 && green >= 0 && red + green <= PNG_FP_1) | ||
968 | { | ||
969 | png_uint_16 red_int, green_int; | ||
970 | |||
971 | /* NOTE: this calculation does not round, but this behavior is retained | ||
972 | * for consistency, the inaccuracy is very small. The code here always | ||
973 | * overwrites the coefficients, regardless of whether they have been | ||
974 | * defaulted or set already. | ||
975 | */ | ||
976 | red_int = (png_uint_16)(((png_uint_32)red*32768)/100000); | ||
977 | green_int = (png_uint_16)(((png_uint_32)green*32768)/100000); | ||
978 | |||
979 | png_ptr->rgb_to_gray_red_coeff = red_int; | ||
980 | png_ptr->rgb_to_gray_green_coeff = green_int; | ||
981 | png_ptr->rgb_to_gray_coefficients_set = 1; | ||
982 | } | ||
983 | |||
984 | else | ||
985 | { | ||
986 | if (red >= 0 && green >= 0) | ||
987 | png_warning(png_ptr, | ||
988 | "ignoring out of range rgb_to_gray coefficients"); | ||
989 | |||
990 | /* Use the defaults, from the cHRM chunk if set, else the historical | ||
991 | * values which are close to the sRGB/HDTV/ITU-Rec 709 values. See | ||
992 | * png_do_rgb_to_gray for more discussion of the values. In this case | ||
993 | * the coefficients are not marked as 'set' and are not overwritten if | ||
994 | * something has already provided a default. | ||
995 | */ | ||
996 | if (png_ptr->rgb_to_gray_red_coeff == 0 && | ||
997 | png_ptr->rgb_to_gray_green_coeff == 0) | ||
998 | { | ||
999 | png_ptr->rgb_to_gray_red_coeff = 6968; | ||
1000 | png_ptr->rgb_to_gray_green_coeff = 23434; | ||
1001 | /* png_ptr->rgb_to_gray_blue_coeff = 2366; */ | ||
1002 | } | ||
1003 | } | ||
1004 | } | ||
1005 | } | ||
1006 | |||
1007 | #ifdef PNG_FLOATING_POINT_SUPPORTED | ||
1008 | /* Convert a RGB image to a grayscale of the same width. This allows us, | ||
1009 | * for example, to convert a 24 bpp RGB image into an 8 bpp grayscale image. | ||
1010 | */ | ||
1011 | |||
1012 | void PNGAPI | ||
1013 | png_set_rgb_to_gray(png_structp png_ptr, int error_action, double red, | ||
1014 | double green) | ||
1015 | { | ||
1016 | if (png_ptr == NULL) | ||
1017 | return; | ||
1018 | |||
1019 | png_set_rgb_to_gray_fixed(png_ptr, error_action, | ||
1020 | png_fixed(png_ptr, red, "rgb to gray red coefficient"), | ||
1021 | png_fixed(png_ptr, green, "rgb to gray green coefficient")); | ||
1022 | } | ||
1023 | #endif /* FLOATING POINT */ | ||
1024 | |||
1025 | #endif | ||
1026 | |||
1027 | #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ | ||
1028 | defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) | ||
1029 | void PNGAPI | ||
1030 | png_set_read_user_transform_fn(png_structp png_ptr, png_user_transform_ptr | ||
1031 | read_user_transform_fn) | ||
1032 | { | ||
1033 | png_debug(1, "in png_set_read_user_transform_fn"); | ||
1034 | |||
1035 | if (png_ptr == NULL) | ||
1036 | return; | ||
1037 | |||
1038 | #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED | ||
1039 | png_ptr->transformations |= PNG_USER_TRANSFORM; | ||
1040 | png_ptr->read_user_transform_fn = read_user_transform_fn; | ||
1041 | #endif | ||
1042 | } | ||
1043 | #endif | ||
1044 | |||
1045 | #ifdef PNG_READ_TRANSFORMS_SUPPORTED | ||
1046 | #ifdef PNG_READ_GAMMA_SUPPORTED | ||
1047 | /* In the case of gamma transformations only do transformations on images where | ||
1048 | * the [file] gamma and screen_gamma are not close reciprocals, otherwise it | ||
1049 | * slows things down slightly, and also needlessly introduces small errors. | ||
1050 | */ | ||
1051 | static int /* PRIVATE */ | ||
1052 | png_gamma_threshold(png_fixed_point screen_gamma, png_fixed_point file_gamma) | ||
1053 | { | ||
1054 | /* PNG_GAMMA_THRESHOLD is the threshold for performing gamma | ||
1055 | * correction as a difference of the overall transform from 1.0 | ||
1056 | * | ||
1057 | * We want to compare the threshold with s*f - 1, if we get | ||
1058 | * overflow here it is because of wacky gamma values so we | ||
1059 | * turn on processing anyway. | ||
1060 | */ | ||
1061 | png_fixed_point gtest; | ||
1062 | return !png_muldiv(>est, screen_gamma, file_gamma, PNG_FP_1) || | ||
1063 | png_gamma_significant(gtest); | ||
1064 | } | ||
1065 | #endif | ||
1066 | |||
1067 | /* Initialize everything needed for the read. This includes modifying | ||
1068 | * the palette. | ||
1069 | */ | ||
1070 | |||
1071 | /*For the moment 'png_init_palette_transformations' and | ||
1072 | * 'png_init_rgb_transformations' only do some flag canceling optimizations. | ||
1073 | * The intent is that these two routines should have palette or rgb operations | ||
1074 | * extracted from 'png_init_read_transformations'. | ||
1075 | */ | ||
1076 | static void /* PRIVATE */ | ||
1077 | png_init_palette_transformations(png_structp png_ptr) | ||
1078 | { | ||
1079 | /* Called to handle the (input) palette case. In png_do_read_transformations | ||
1080 | * the first step is to expand the palette if requested, so this code must | ||
1081 | * take care to only make changes that are invariant with respect to the | ||
1082 | * palette expansion, or only do them if there is no expansion. | ||
1083 | * | ||
1084 | * STRIP_ALPHA has already been handled in the caller (by setting num_trans | ||
1085 | * to 0.) | ||
1086 | */ | ||
1087 | int input_has_alpha = 0; | ||
1088 | int input_has_transparency = 0; | ||
1089 | |||
1090 | if (png_ptr->num_trans > 0) | ||
1091 | { | ||
1092 | int i; | ||
1093 | |||
1094 | /* Ignore if all the entries are opaque (unlikely!) */ | ||
1095 | for (i=0; i<png_ptr->num_trans; ++i) | ||
1096 | if (png_ptr->trans_alpha[i] == 255) | ||
1097 | continue; | ||
1098 | else if (png_ptr->trans_alpha[i] == 0) | ||
1099 | input_has_transparency = 1; | ||
1100 | else | ||
1101 | input_has_alpha = 1; | ||
1102 | } | ||
1103 | |||
1104 | /* If no alpha we can optimize. */ | ||
1105 | if (!input_has_alpha) | ||
1106 | { | ||
1107 | /* Any alpha means background and associative alpha processing is | ||
1108 | * required, however if the alpha is 0 or 1 throughout OPTIIMIZE_ALPHA | ||
1109 | * and ENCODE_ALPHA are irrelevant. | ||
1110 | */ | ||
1111 | png_ptr->transformations &= ~PNG_ENCODE_ALPHA; | ||
1112 | png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; | ||
1113 | |||
1114 | if (!input_has_transparency) | ||
1115 | png_ptr->transformations &= ~(PNG_COMPOSE | PNG_BACKGROUND_EXPAND); | ||
1116 | } | ||
1117 | |||
1118 | #if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED) | ||
1119 | /* png_set_background handling - deals with the complexity of whether the | ||
1120 | * background color is in the file format or the screen format in the case | ||
1121 | * where an 'expand' will happen. | ||
1122 | */ | ||
1123 | |||
1124 | /* The following code cannot be entered in the alpha pre-multiplication case | ||
1125 | * because PNG_BACKGROUND_EXPAND is cancelled below. | ||
1126 | */ | ||
1127 | if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) && | ||
1128 | (png_ptr->transformations & PNG_EXPAND)) | ||
1129 | { | ||
1130 | { | ||
1131 | png_ptr->background.red = | ||
1132 | png_ptr->palette[png_ptr->background.index].red; | ||
1133 | png_ptr->background.green = | ||
1134 | png_ptr->palette[png_ptr->background.index].green; | ||
1135 | png_ptr->background.blue = | ||
1136 | png_ptr->palette[png_ptr->background.index].blue; | ||
1137 | |||
1138 | #ifdef PNG_READ_INVERT_ALPHA_SUPPORTED | ||
1139 | if (png_ptr->transformations & PNG_INVERT_ALPHA) | ||
1140 | { | ||
1141 | if (!(png_ptr->transformations & PNG_EXPAND_tRNS)) | ||
1142 | { | ||
1143 | /* Invert the alpha channel (in tRNS) unless the pixels are | ||
1144 | * going to be expanded, in which case leave it for later | ||
1145 | */ | ||
1146 | int i, istop = png_ptr->num_trans; | ||
1147 | |||
1148 | for (i=0; i<istop; i++) | ||
1149 | png_ptr->trans_alpha[i] = (png_byte)(255 - | ||
1150 | png_ptr->trans_alpha[i]); | ||
1151 | } | ||
1152 | } | ||
1153 | #endif /* PNG_READ_INVERT_ALPHA_SUPPORTED */ | ||
1154 | } | ||
1155 | } /* background expand and (therefore) no alpha association. */ | ||
1156 | #endif /* PNG_READ_EXPAND_SUPPORTED && PNG_READ_BACKGROUND_SUPPORTED */ | ||
1157 | } | ||
1158 | |||
1159 | static void /* PRIVATE */ | ||
1160 | png_init_rgb_transformations(png_structp png_ptr) | ||
1161 | { | ||
1162 | /* Added to libpng-1.5.4: check the color type to determine whether there | ||
1163 | * is any alpha or transparency in the image and simply cancel the | ||
1164 | * background and alpha mode stuff if there isn't. | ||
1165 | */ | ||
1166 | int input_has_alpha = (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0; | ||
1167 | int input_has_transparency = png_ptr->num_trans > 0; | ||
1168 | |||
1169 | /* If no alpha we can optimize. */ | ||
1170 | if (!input_has_alpha) | ||
1171 | { | ||
1172 | /* Any alpha means background and associative alpha processing is | ||
1173 | * required, however if the alpha is 0 or 1 throughout OPTIIMIZE_ALPHA | ||
1174 | * and ENCODE_ALPHA are irrelevant. | ||
1175 | */ | ||
1176 | # ifdef PNG_READ_ALPHA_MODE_SUPPORTED | ||
1177 | png_ptr->transformations &= ~PNG_ENCODE_ALPHA; | ||
1178 | png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; | ||
1179 | # endif | ||
1180 | |||
1181 | if (!input_has_transparency) | ||
1182 | png_ptr->transformations &= ~(PNG_COMPOSE | PNG_BACKGROUND_EXPAND); | ||
1183 | } | ||
1184 | |||
1185 | #if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED) | ||
1186 | /* png_set_background handling - deals with the complexity of whether the | ||
1187 | * background color is in the file format or the screen format in the case | ||
1188 | * where an 'expand' will happen. | ||
1189 | */ | ||
1190 | |||
1191 | /* The following code cannot be entered in the alpha pre-multiplication case | ||
1192 | * because PNG_BACKGROUND_EXPAND is cancelled below. | ||
1193 | */ | ||
1194 | if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) && | ||
1195 | (png_ptr->transformations & PNG_EXPAND) && | ||
1196 | !(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) | ||
1197 | /* i.e., GRAY or GRAY_ALPHA */ | ||
1198 | { | ||
1199 | { | ||
1200 | /* Expand background and tRNS chunks */ | ||
1201 | int gray = png_ptr->background.gray; | ||
1202 | int trans_gray = png_ptr->trans_color.gray; | ||
1203 | |||
1204 | switch (png_ptr->bit_depth) | ||
1205 | { | ||
1206 | case 1: | ||
1207 | gray *= 0xff; | ||
1208 | trans_gray *= 0xff; | ||
1209 | break; | ||
1210 | |||
1211 | case 2: | ||
1212 | gray *= 0x55; | ||
1213 | trans_gray *= 0x55; | ||
1214 | break; | ||
1215 | |||
1216 | case 4: | ||
1217 | gray *= 0x11; | ||
1218 | trans_gray *= 0x11; | ||
1219 | break; | ||
1220 | |||
1221 | default: | ||
1222 | |||
1223 | case 8: | ||
1224 | /* Already 8 bits, fall through */ | ||
1225 | |||
1226 | case 16: | ||
1227 | /* Already a full 16 bits */ | ||
1228 | break; | ||
1229 | } | ||
1230 | |||
1231 | png_ptr->background.red = png_ptr->background.green = | ||
1232 | png_ptr->background.blue = (png_uint_16)gray; | ||
1233 | |||
1234 | if (!(png_ptr->transformations & PNG_EXPAND_tRNS)) | ||
1235 | { | ||
1236 | png_ptr->trans_color.red = png_ptr->trans_color.green = | ||
1237 | png_ptr->trans_color.blue = (png_uint_16)trans_gray; | ||
1238 | } | ||
1239 | } | ||
1240 | } /* background expand and (therefore) no alpha association. */ | ||
1241 | #endif /* PNG_READ_EXPAND_SUPPORTED && PNG_READ_BACKGROUND_SUPPORTED */ | ||
1242 | } | ||
1243 | |||
1244 | void /* PRIVATE */ | ||
1245 | png_init_read_transformations(png_structp png_ptr) | ||
1246 | { | ||
1247 | png_debug(1, "in png_init_read_transformations"); | ||
1248 | |||
1249 | /* This internal function is called from png_read_start_row in pngrutil.c | ||
1250 | * and it is called before the 'rowbytes' calculation is done, so the code | ||
1251 | * in here can change or update the transformations flags. | ||
1252 | * | ||
1253 | * First do updates that do not depend on the details of the PNG image data | ||
1254 | * being processed. | ||
1255 | */ | ||
1256 | |||
1257 | #ifdef PNG_READ_GAMMA_SUPPORTED | ||
1258 | /* Prior to 1.5.4 these tests were performed from png_set_gamma, 1.5.4 adds | ||
1259 | * png_set_alpha_mode and this is another source for a default file gamma so | ||
1260 | * the test needs to be performed later - here. In addition prior to 1.5.4 | ||
1261 | * the tests were repeated for the PALETTE color type here - this is no | ||
1262 | * longer necessary (and doesn't seem to have been necessary before.) | ||
1263 | */ | ||
1264 | { | ||
1265 | /* The following temporary indicates if overall gamma correction is | ||
1266 | * required. | ||
1267 | */ | ||
1268 | int gamma_correction = 0; | ||
1269 | |||
1270 | if (png_ptr->gamma != 0) /* has been set */ | ||
1271 | { | ||
1272 | if (png_ptr->screen_gamma != 0) /* screen set too */ | ||
1273 | gamma_correction = png_gamma_threshold(png_ptr->gamma, | ||
1274 | png_ptr->screen_gamma); | ||
1275 | |||
1276 | else | ||
1277 | /* Assume the output matches the input; a long time default behavior | ||
1278 | * of libpng, although the standard has nothing to say about this. | ||
1279 | */ | ||
1280 | png_ptr->screen_gamma = png_reciprocal(png_ptr->gamma); | ||
1281 | } | ||
1282 | |||
1283 | else if (png_ptr->screen_gamma != 0) | ||
1284 | /* The converse - assume the file matches the screen, note that this | ||
1285 | * perhaps undesireable default can (from 1.5.4) be changed by calling | ||
1286 | * png_set_alpha_mode (even if the alpha handling mode isn't required | ||
1287 | * or isn't changed from the default.) | ||
1288 | */ | ||
1289 | png_ptr->gamma = png_reciprocal(png_ptr->screen_gamma); | ||
1290 | |||
1291 | else /* neither are set */ | ||
1292 | /* Just in case the following prevents any processing - file and screen | ||
1293 | * are both assumed to be linear and there is no way to introduce a | ||
1294 | * third gamma value other than png_set_background with 'UNIQUE', and, | ||
1295 | * prior to 1.5.4 | ||
1296 | */ | ||
1297 | png_ptr->screen_gamma = png_ptr->gamma = PNG_FP_1; | ||
1298 | |||
1299 | /* Now turn the gamma transformation on or off as appropriate. Notice | ||
1300 | * that PNG_GAMMA just refers to the file->screen correction. Alpha | ||
1301 | * composition may independently cause gamma correction because it needs | ||
1302 | * linear data (e.g. if the file has a gAMA chunk but the screen gamma | ||
1303 | * hasn't been specified.) In any case this flag may get turned off in | ||
1304 | * the code immediately below if the transform can be handled outside the | ||
1305 | * row loop. | ||
1306 | */ | ||
1307 | if (gamma_correction) | ||
1308 | png_ptr->transformations |= PNG_GAMMA; | ||
1309 | |||
1310 | else | ||
1311 | png_ptr->transformations &= ~PNG_GAMMA; | ||
1312 | } | ||
1313 | #endif | ||
1314 | |||
1315 | /* Certain transformations have the effect of preventing other | ||
1316 | * transformations that happen afterward in png_do_read_transformations, | ||
1317 | * resolve the interdependencies here. From the code of | ||
1318 | * png_do_read_transformations the order is: | ||
1319 | * | ||
1320 | * 1) PNG_EXPAND (including PNG_EXPAND_tRNS) | ||
1321 | * 2) PNG_STRIP_ALPHA (if no compose) | ||
1322 | * 3) PNG_RGB_TO_GRAY | ||
1323 | * 4) PNG_GRAY_TO_RGB iff !PNG_BACKGROUND_IS_GRAY | ||
1324 | * 5) PNG_COMPOSE | ||
1325 | * 6) PNG_GAMMA | ||
1326 | * 7) PNG_STRIP_ALPHA (if compose) | ||
1327 | * 8) PNG_ENCODE_ALPHA | ||
1328 | * 9) PNG_SCALE_16_TO_8 | ||
1329 | * 10) PNG_16_TO_8 | ||
1330 | * 11) PNG_QUANTIZE (converts to palette) | ||
1331 | * 12) PNG_EXPAND_16 | ||
1332 | * 13) PNG_GRAY_TO_RGB iff PNG_BACKGROUND_IS_GRAY | ||
1333 | * 14) PNG_INVERT_MONO | ||
1334 | * 15) PNG_SHIFT | ||
1335 | * 16) PNG_PACK | ||
1336 | * 17) PNG_BGR | ||
1337 | * 18) PNG_PACKSWAP | ||
1338 | * 19) PNG_FILLER (includes PNG_ADD_ALPHA) | ||
1339 | * 20) PNG_INVERT_ALPHA | ||
1340 | * 21) PNG_SWAP_ALPHA | ||
1341 | * 22) PNG_SWAP_BYTES | ||
1342 | * 23) PNG_USER_TRANSFORM [must be last] | ||
1343 | */ | ||
1344 | #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED | ||
1345 | if ((png_ptr->transformations & PNG_STRIP_ALPHA) && | ||
1346 | !(png_ptr->transformations & PNG_COMPOSE)) | ||
1347 | { | ||
1348 | /* Stripping the alpha channel happens immediately after the 'expand' | ||
1349 | * transformations, before all other transformation, so it cancels out | ||
1350 | * the alpha handling. It has the side effect negating the effect of | ||
1351 | * PNG_EXPAND_tRNS too: | ||
1352 | */ | ||
1353 | png_ptr->transformations &= ~(PNG_BACKGROUND_EXPAND | PNG_ENCODE_ALPHA | | ||
1354 | PNG_EXPAND_tRNS); | ||
1355 | png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; | ||
1356 | |||
1357 | /* Kill the tRNS chunk itself too. Prior to 1.5.4 this did not happen | ||
1358 | * so transparency information would remain just so long as it wasn't | ||
1359 | * expanded. This produces unexpected API changes if the set of things | ||
1360 | * that do PNG_EXPAND_tRNS changes (perfectly possible given the | ||
1361 | * documentation - which says ask for what you want, accept what you | ||
1362 | * get.) This makes the behavior consistent from 1.5.4: | ||
1363 | */ | ||
1364 | png_ptr->num_trans = 0; | ||
1365 | } | ||
1366 | #endif /* STRIP_ALPHA supported, no COMPOSE */ | ||
1367 | |||
1368 | #ifdef PNG_READ_ALPHA_MODE_SUPPORTED | ||
1369 | /* If the screen gamma is about 1.0 then the OPTIMIZE_ALPHA and ENCODE_ALPHA | ||
1370 | * settings will have no effect. | ||
1371 | */ | ||
1372 | if (!png_gamma_significant(png_ptr->screen_gamma)) | ||
1373 | { | ||
1374 | png_ptr->transformations &= ~PNG_ENCODE_ALPHA; | ||
1375 | png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; | ||
1376 | } | ||
1377 | #endif | ||
1378 | |||
1379 | #if defined(PNG_READ_EXPAND_SUPPORTED) && \ | ||
1380 | defined(PNG_READ_BACKGROUND_SUPPORTED) && \ | ||
1381 | defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) | ||
1382 | /* Detect gray background and attempt to enable optimization for | ||
1383 | * gray --> RGB case. | ||
1384 | * | ||
1385 | * Note: if PNG_BACKGROUND_EXPAND is set and color_type is either RGB or | ||
1386 | * RGB_ALPHA (in which case need_expand is superfluous anyway), the | ||
1387 | * background color might actually be gray yet not be flagged as such. | ||
1388 | * This is not a problem for the current code, which uses | ||
1389 | * PNG_BACKGROUND_IS_GRAY only to decide when to do the | ||
1390 | * png_do_gray_to_rgb() transformation. | ||
1391 | * | ||
1392 | * TODO: this code needs to be revised to avoid the complexity and | ||
1393 | * interdependencies. The color type of the background should be recorded in | ||
1394 | * png_set_background, along with the bit depth, then the code has a record | ||
1395 | * of exactly what color space the background is currently in. | ||
1396 | */ | ||
1397 | if (png_ptr->transformations & PNG_BACKGROUND_EXPAND) | ||
1398 | { | ||
1399 | /* PNG_BACKGROUND_EXPAND: the background is in the file color space, so if | ||
1400 | * the file was grayscale the background value is gray. | ||
1401 | */ | ||
1402 | if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) | ||
1403 | png_ptr->mode |= PNG_BACKGROUND_IS_GRAY; | ||
1404 | } | ||
1405 | |||
1406 | else if (png_ptr->transformations & PNG_COMPOSE) | ||
1407 | { | ||
1408 | /* PNG_COMPOSE: png_set_background was called with need_expand false, | ||
1409 | * so the color is in the color space of the output or png_set_alpha_mode | ||
1410 | * was called and the color is black. Ignore RGB_TO_GRAY because that | ||
1411 | * happens before GRAY_TO_RGB. | ||
1412 | */ | ||
1413 | if (png_ptr->transformations & PNG_GRAY_TO_RGB) | ||
1414 | { | ||
1415 | if (png_ptr->background.red == png_ptr->background.green && | ||
1416 | png_ptr->background.red == png_ptr->background.blue) | ||
1417 | { | ||
1418 | png_ptr->mode |= PNG_BACKGROUND_IS_GRAY; | ||
1419 | png_ptr->background.gray = png_ptr->background.red; | ||
1420 | } | ||
1421 | } | ||
1422 | } | ||
1423 | #endif /* PNG_READ_GRAY_TO_RGB_SUPPORTED (etc) */ | ||
1424 | |||
1425 | /* For indexed PNG data (PNG_COLOR_TYPE_PALETTE) many of the transformations | ||
1426 | * can be performed directly on the palette, and some (such as rgb to gray) | ||
1427 | * can be optimized inside the palette. This is particularly true of the | ||
1428 | * composite (background and alpha) stuff, which can be pretty much all done | ||
1429 | * in the palette even if the result is expanded to RGB or gray afterward. | ||
1430 | * | ||
1431 | * NOTE: this is Not Yet Implemented, the code behaves as in 1.5.1 and | ||
1432 | * earlier and the palette stuff is actually handled on the first row. This | ||
1433 | * leads to the reported bug that the palette returned by png_get_PLTE is not | ||
1434 | * updated. | ||
1435 | */ | ||
1436 | if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) | ||
1437 | png_init_palette_transformations(png_ptr); | ||
1438 | |||
1439 | else | ||
1440 | png_init_rgb_transformations(png_ptr); | ||
1441 | |||
1442 | #if defined(PNG_READ_BACKGROUND_SUPPORTED) && \ | ||
1443 | defined(PNG_READ_EXPAND_16_SUPPORTED) | ||
1444 | if ((png_ptr->transformations & PNG_EXPAND_16) && | ||
1445 | (png_ptr->transformations & PNG_COMPOSE) && | ||
1446 | !(png_ptr->transformations & PNG_BACKGROUND_EXPAND) && | ||
1447 | png_ptr->bit_depth != 16) | ||
1448 | { | ||
1449 | /* TODO: fix this. Because the expand_16 operation is after the compose | ||
1450 | * handling the background color must be 8, not 16, bits deep, but the | ||
1451 | * application will supply a 16-bit value so reduce it here. | ||
1452 | * | ||
1453 | * The PNG_BACKGROUND_EXPAND code above does not expand to 16 bits at | ||
1454 | * present, so that case is ok (until do_expand_16 is moved.) | ||
1455 | * | ||
1456 | * NOTE: this discards the low 16 bits of the user supplied background | ||
1457 | * color, but until expand_16 works properly there is no choice! | ||
1458 | */ | ||
1459 | # define CHOP(x) (x)=((png_uint_16)(((png_uint_32)(x)*255+32895) >> 16)) | ||
1460 | CHOP(png_ptr->background.red); | ||
1461 | CHOP(png_ptr->background.green); | ||
1462 | CHOP(png_ptr->background.blue); | ||
1463 | CHOP(png_ptr->background.gray); | ||
1464 | # undef CHOP | ||
1465 | } | ||
1466 | #endif /* PNG_READ_BACKGROUND_SUPPORTED && PNG_READ_EXPAND_16_SUPPORTED */ | ||
1467 | |||
1468 | #if defined(PNG_READ_BACKGROUND_SUPPORTED) && \ | ||
1469 | (defined(PNG_READ_SCALE_16_TO_8_SUPPORTED) || \ | ||
1470 | defined(PNG_READ_STRIP_16_TO_8_SUPPORTED)) | ||
1471 | if ((png_ptr->transformations & (PNG_16_TO_8|PNG_SCALE_16_TO_8)) && | ||
1472 | (png_ptr->transformations & PNG_COMPOSE) && | ||
1473 | !(png_ptr->transformations & PNG_BACKGROUND_EXPAND) && | ||
1474 | png_ptr->bit_depth == 16) | ||
1475 | { | ||
1476 | /* On the other hand, if a 16-bit file is to be reduced to 8-bits per | ||
1477 | * component this will also happen after PNG_COMPOSE and so the background | ||
1478 | * color must be pre-expanded here. | ||
1479 | * | ||
1480 | * TODO: fix this too. | ||
1481 | */ | ||
1482 | png_ptr->background.red = (png_uint_16)(png_ptr->background.red * 257); | ||
1483 | png_ptr->background.green = | ||
1484 | (png_uint_16)(png_ptr->background.green * 257); | ||
1485 | png_ptr->background.blue = (png_uint_16)(png_ptr->background.blue * 257); | ||
1486 | png_ptr->background.gray = (png_uint_16)(png_ptr->background.gray * 257); | ||
1487 | } | ||
1488 | #endif | ||
1489 | |||
1490 | /* NOTE: below 'PNG_READ_ALPHA_MODE_SUPPORTED' is presumed to also enable the | ||
1491 | * background support (see the comments in scripts/pnglibconf.dfa), this | ||
1492 | * allows pre-multiplication of the alpha channel to be implemented as | ||
1493 | * compositing on black. This is probably sub-optimal and has been done in | ||
1494 | * 1.5.4 betas simply to enable external critique and testing (i.e. to | ||
1495 | * implement the new API quickly, without lots of internal changes.) | ||
1496 | */ | ||
1497 | |||
1498 | #ifdef PNG_READ_GAMMA_SUPPORTED | ||
1499 | # ifdef PNG_READ_BACKGROUND_SUPPORTED | ||
1500 | /* Includes ALPHA_MODE */ | ||
1501 | png_ptr->background_1 = png_ptr->background; | ||
1502 | # endif | ||
1503 | |||
1504 | /* This needs to change - in the palette image case a whole set of tables are | ||
1505 | * built when it would be quicker to just calculate the correct value for | ||
1506 | * each palette entry directly. Also, the test is too tricky - why check | ||
1507 | * PNG_RGB_TO_GRAY if PNG_GAMMA is not set? The answer seems to be that | ||
1508 | * PNG_GAMMA is cancelled even if the gamma is known? The test excludes the | ||
1509 | * PNG_COMPOSE case, so apparently if there is no *overall* gamma correction | ||
1510 | * the gamma tables will not be built even if composition is required on a | ||
1511 | * gamma encoded value. | ||
1512 | * | ||
1513 | * In 1.5.4 this is addressed below by an additional check on the individual | ||
1514 | * file gamma - if it is not 1.0 both RGB_TO_GRAY and COMPOSE need the | ||
1515 | * tables. | ||
1516 | */ | ||
1517 | if ((png_ptr->transformations & PNG_GAMMA) | ||
1518 | || ((png_ptr->transformations & PNG_RGB_TO_GRAY) | ||
1519 | && (png_gamma_significant(png_ptr->gamma) || | ||
1520 | png_gamma_significant(png_ptr->screen_gamma))) | ||
1521 | || ((png_ptr->transformations & PNG_COMPOSE) | ||
1522 | && (png_gamma_significant(png_ptr->gamma) | ||
1523 | || png_gamma_significant(png_ptr->screen_gamma) | ||
1524 | # ifdef PNG_READ_BACKGROUND_SUPPORTED | ||
1525 | || (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_UNIQUE | ||
1526 | && png_gamma_significant(png_ptr->background_gamma)) | ||
1527 | # endif | ||
1528 | )) || ((png_ptr->transformations & PNG_ENCODE_ALPHA) | ||
1529 | && png_gamma_significant(png_ptr->screen_gamma)) | ||
1530 | ) | ||
1531 | { | ||
1532 | png_build_gamma_table(png_ptr, png_ptr->bit_depth); | ||
1533 | |||
1534 | #ifdef PNG_READ_BACKGROUND_SUPPORTED | ||
1535 | if (png_ptr->transformations & PNG_COMPOSE) | ||
1536 | { | ||
1537 | /* Issue a warning about this combination: because RGB_TO_GRAY is | ||
1538 | * optimized to do the gamma transform if present yet do_background has | ||
1539 | * to do the same thing if both options are set a | ||
1540 | * double-gamma-correction happens. This is true in all versions of | ||
1541 | * libpng to date. | ||
1542 | */ | ||
1543 | if (png_ptr->transformations & PNG_RGB_TO_GRAY) | ||
1544 | png_warning(png_ptr, | ||
1545 | "libpng does not support gamma+background+rgb_to_gray"); | ||
1546 | |||
1547 | if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) | ||
1548 | { | ||
1549 | /* We don't get to here unless there is a tRNS chunk with non-opaque | ||
1550 | * entries - see the checking code at the start of this function. | ||
1551 | */ | ||
1552 | png_color back, back_1; | ||
1553 | png_colorp palette = png_ptr->palette; | ||
1554 | int num_palette = png_ptr->num_palette; | ||
1555 | int i; | ||
1556 | if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE) | ||
1557 | { | ||
1558 | |||
1559 | back.red = png_ptr->gamma_table[png_ptr->background.red]; | ||
1560 | back.green = png_ptr->gamma_table[png_ptr->background.green]; | ||
1561 | back.blue = png_ptr->gamma_table[png_ptr->background.blue]; | ||
1562 | |||
1563 | back_1.red = png_ptr->gamma_to_1[png_ptr->background.red]; | ||
1564 | back_1.green = png_ptr->gamma_to_1[png_ptr->background.green]; | ||
1565 | back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue]; | ||
1566 | } | ||
1567 | else | ||
1568 | { | ||
1569 | png_fixed_point g, gs; | ||
1570 | |||
1571 | switch (png_ptr->background_gamma_type) | ||
1572 | { | ||
1573 | case PNG_BACKGROUND_GAMMA_SCREEN: | ||
1574 | g = (png_ptr->screen_gamma); | ||
1575 | gs = PNG_FP_1; | ||
1576 | break; | ||
1577 | |||
1578 | case PNG_BACKGROUND_GAMMA_FILE: | ||
1579 | g = png_reciprocal(png_ptr->gamma); | ||
1580 | gs = png_reciprocal2(png_ptr->gamma, | ||
1581 | png_ptr->screen_gamma); | ||
1582 | break; | ||
1583 | |||
1584 | case PNG_BACKGROUND_GAMMA_UNIQUE: | ||
1585 | g = png_reciprocal(png_ptr->background_gamma); | ||
1586 | gs = png_reciprocal2(png_ptr->background_gamma, | ||
1587 | png_ptr->screen_gamma); | ||
1588 | break; | ||
1589 | default: | ||
1590 | g = PNG_FP_1; /* back_1 */ | ||
1591 | gs = PNG_FP_1; /* back */ | ||
1592 | break; | ||
1593 | } | ||
1594 | |||
1595 | if (png_gamma_significant(gs)) | ||
1596 | { | ||
1597 | back.red = png_gamma_8bit_correct(png_ptr->background.red, | ||
1598 | gs); | ||
1599 | back.green = png_gamma_8bit_correct(png_ptr->background.green, | ||
1600 | gs); | ||
1601 | back.blue = png_gamma_8bit_correct(png_ptr->background.blue, | ||
1602 | gs); | ||
1603 | } | ||
1604 | |||
1605 | else | ||
1606 | { | ||
1607 | back.red = (png_byte)png_ptr->background.red; | ||
1608 | back.green = (png_byte)png_ptr->background.green; | ||
1609 | back.blue = (png_byte)png_ptr->background.blue; | ||
1610 | } | ||
1611 | |||
1612 | if (png_gamma_significant(g)) | ||
1613 | { | ||
1614 | back_1.red = png_gamma_8bit_correct(png_ptr->background.red, | ||
1615 | g); | ||
1616 | back_1.green = png_gamma_8bit_correct( | ||
1617 | png_ptr->background.green, g); | ||
1618 | back_1.blue = png_gamma_8bit_correct(png_ptr->background.blue, | ||
1619 | g); | ||
1620 | } | ||
1621 | |||
1622 | else | ||
1623 | { | ||
1624 | back_1.red = (png_byte)png_ptr->background.red; | ||
1625 | back_1.green = (png_byte)png_ptr->background.green; | ||
1626 | back_1.blue = (png_byte)png_ptr->background.blue; | ||
1627 | } | ||
1628 | } | ||
1629 | |||
1630 | for (i = 0; i < num_palette; i++) | ||
1631 | { | ||
1632 | if (i < (int)png_ptr->num_trans && | ||
1633 | png_ptr->trans_alpha[i] != 0xff) | ||
1634 | { | ||
1635 | if (png_ptr->trans_alpha[i] == 0) | ||
1636 | { | ||
1637 | palette[i] = back; | ||
1638 | } | ||
1639 | else /* if (png_ptr->trans_alpha[i] != 0xff) */ | ||
1640 | { | ||
1641 | png_byte v, w; | ||
1642 | |||
1643 | v = png_ptr->gamma_to_1[palette[i].red]; | ||
1644 | png_composite(w, v, png_ptr->trans_alpha[i], back_1.red); | ||
1645 | palette[i].red = png_ptr->gamma_from_1[w]; | ||
1646 | |||
1647 | v = png_ptr->gamma_to_1[palette[i].green]; | ||
1648 | png_composite(w, v, png_ptr->trans_alpha[i], back_1.green); | ||
1649 | palette[i].green = png_ptr->gamma_from_1[w]; | ||
1650 | |||
1651 | v = png_ptr->gamma_to_1[palette[i].blue]; | ||
1652 | png_composite(w, v, png_ptr->trans_alpha[i], back_1.blue); | ||
1653 | palette[i].blue = png_ptr->gamma_from_1[w]; | ||
1654 | } | ||
1655 | } | ||
1656 | else | ||
1657 | { | ||
1658 | palette[i].red = png_ptr->gamma_table[palette[i].red]; | ||
1659 | palette[i].green = png_ptr->gamma_table[palette[i].green]; | ||
1660 | palette[i].blue = png_ptr->gamma_table[palette[i].blue]; | ||
1661 | } | ||
1662 | } | ||
1663 | |||
1664 | /* Prevent the transformations being done again. | ||
1665 | * | ||
1666 | * NOTE: this is highly dubious; it removes the transformations in | ||
1667 | * place. This seems inconsistent with the general treatment of the | ||
1668 | * transformations elsewhere. | ||
1669 | */ | ||
1670 | png_ptr->transformations &= ~(PNG_COMPOSE | PNG_GAMMA); | ||
1671 | } /* color_type == PNG_COLOR_TYPE_PALETTE */ | ||
1672 | |||
1673 | /* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN) */ | ||
1674 | else /* color_type != PNG_COLOR_TYPE_PALETTE */ | ||
1675 | { | ||
1676 | int gs_sig, g_sig; | ||
1677 | png_fixed_point g = PNG_FP_1; /* Correction to linear */ | ||
1678 | png_fixed_point gs = PNG_FP_1; /* Correction to screen */ | ||
1679 | |||
1680 | switch (png_ptr->background_gamma_type) | ||
1681 | { | ||
1682 | case PNG_BACKGROUND_GAMMA_SCREEN: | ||
1683 | g = png_ptr->screen_gamma; | ||
1684 | /* gs = PNG_FP_1; */ | ||
1685 | break; | ||
1686 | |||
1687 | case PNG_BACKGROUND_GAMMA_FILE: | ||
1688 | g = png_reciprocal(png_ptr->gamma); | ||
1689 | gs = png_reciprocal2(png_ptr->gamma, png_ptr->screen_gamma); | ||
1690 | break; | ||
1691 | |||
1692 | case PNG_BACKGROUND_GAMMA_UNIQUE: | ||
1693 | g = png_reciprocal(png_ptr->background_gamma); | ||
1694 | gs = png_reciprocal2(png_ptr->background_gamma, | ||
1695 | png_ptr->screen_gamma); | ||
1696 | break; | ||
1697 | |||
1698 | default: | ||
1699 | png_error(png_ptr, "invalid background gamma type"); | ||
1700 | } | ||
1701 | |||
1702 | g_sig = png_gamma_significant(g); | ||
1703 | gs_sig = png_gamma_significant(gs); | ||
1704 | |||
1705 | if (g_sig) | ||
1706 | png_ptr->background_1.gray = png_gamma_correct(png_ptr, | ||
1707 | png_ptr->background.gray, g); | ||
1708 | |||
1709 | if (gs_sig) | ||
1710 | png_ptr->background.gray = png_gamma_correct(png_ptr, | ||
1711 | png_ptr->background.gray, gs); | ||
1712 | |||
1713 | if ((png_ptr->background.red != png_ptr->background.green) || | ||
1714 | (png_ptr->background.red != png_ptr->background.blue) || | ||
1715 | (png_ptr->background.red != png_ptr->background.gray)) | ||
1716 | { | ||
1717 | /* RGB or RGBA with color background */ | ||
1718 | if (g_sig) | ||
1719 | { | ||
1720 | png_ptr->background_1.red = png_gamma_correct(png_ptr, | ||
1721 | png_ptr->background.red, g); | ||
1722 | |||
1723 | png_ptr->background_1.green = png_gamma_correct(png_ptr, | ||
1724 | png_ptr->background.green, g); | ||
1725 | |||
1726 | png_ptr->background_1.blue = png_gamma_correct(png_ptr, | ||
1727 | png_ptr->background.blue, g); | ||
1728 | } | ||
1729 | |||
1730 | if (gs_sig) | ||
1731 | { | ||
1732 | png_ptr->background.red = png_gamma_correct(png_ptr, | ||
1733 | png_ptr->background.red, gs); | ||
1734 | |||
1735 | png_ptr->background.green = png_gamma_correct(png_ptr, | ||
1736 | png_ptr->background.green, gs); | ||
1737 | |||
1738 | png_ptr->background.blue = png_gamma_correct(png_ptr, | ||
1739 | png_ptr->background.blue, gs); | ||
1740 | } | ||
1741 | } | ||
1742 | |||
1743 | else | ||
1744 | { | ||
1745 | /* GRAY, GRAY ALPHA, RGB, or RGBA with gray background */ | ||
1746 | png_ptr->background_1.red = png_ptr->background_1.green | ||
1747 | = png_ptr->background_1.blue = png_ptr->background_1.gray; | ||
1748 | |||
1749 | png_ptr->background.red = png_ptr->background.green | ||
1750 | = png_ptr->background.blue = png_ptr->background.gray; | ||
1751 | } | ||
1752 | |||
1753 | /* The background is now in screen gamma: */ | ||
1754 | png_ptr->background_gamma_type = PNG_BACKGROUND_GAMMA_SCREEN; | ||
1755 | } /* color_type != PNG_COLOR_TYPE_PALETTE */ | ||
1756 | }/* png_ptr->transformations & PNG_BACKGROUND */ | ||
1757 | |||
1758 | else | ||
1759 | /* Transformation does not include PNG_BACKGROUND */ | ||
1760 | #endif /* PNG_READ_BACKGROUND_SUPPORTED */ | ||
1761 | if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE | ||
1762 | #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED | ||
1763 | /* RGB_TO_GRAY needs to have non-gamma-corrected values! */ | ||
1764 | && ((png_ptr->transformations & PNG_EXPAND) == 0 || | ||
1765 | (png_ptr->transformations & PNG_RGB_TO_GRAY) == 0) | ||
1766 | #endif | ||
1767 | ) | ||
1768 | { | ||
1769 | png_colorp palette = png_ptr->palette; | ||
1770 | int num_palette = png_ptr->num_palette; | ||
1771 | int i; | ||
1772 | |||
1773 | /*NOTE: there are other transformations that should probably be in here | ||
1774 | * too. | ||
1775 | */ | ||
1776 | for (i = 0; i < num_palette; i++) | ||
1777 | { | ||
1778 | palette[i].red = png_ptr->gamma_table[palette[i].red]; | ||
1779 | palette[i].green = png_ptr->gamma_table[palette[i].green]; | ||
1780 | palette[i].blue = png_ptr->gamma_table[palette[i].blue]; | ||
1781 | } | ||
1782 | |||
1783 | /* Done the gamma correction. */ | ||
1784 | png_ptr->transformations &= ~PNG_GAMMA; | ||
1785 | } /* color_type == PALETTE && !PNG_BACKGROUND transformation */ | ||
1786 | } | ||
1787 | #ifdef PNG_READ_BACKGROUND_SUPPORTED | ||
1788 | else | ||
1789 | #endif | ||
1790 | #endif /* PNG_READ_GAMMA_SUPPORTED */ | ||
1791 | |||
1792 | #ifdef PNG_READ_BACKGROUND_SUPPORTED | ||
1793 | /* No GAMMA transformation (see the hanging else 4 lines above) */ | ||
1794 | if ((png_ptr->transformations & PNG_COMPOSE) && | ||
1795 | (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)) | ||
1796 | { | ||
1797 | int i; | ||
1798 | int istop = (int)png_ptr->num_trans; | ||
1799 | png_color back; | ||
1800 | png_colorp palette = png_ptr->palette; | ||
1801 | |||
1802 | back.red = (png_byte)png_ptr->background.red; | ||
1803 | back.green = (png_byte)png_ptr->background.green; | ||
1804 | back.blue = (png_byte)png_ptr->background.blue; | ||
1805 | |||
1806 | for (i = 0; i < istop; i++) | ||
1807 | { | ||
1808 | if (png_ptr->trans_alpha[i] == 0) | ||
1809 | { | ||
1810 | palette[i] = back; | ||
1811 | } | ||
1812 | |||
1813 | else if (png_ptr->trans_alpha[i] != 0xff) | ||
1814 | { | ||
1815 | /* The png_composite() macro is defined in png.h */ | ||
1816 | png_composite(palette[i].red, palette[i].red, | ||
1817 | png_ptr->trans_alpha[i], back.red); | ||
1818 | |||
1819 | png_composite(palette[i].green, palette[i].green, | ||
1820 | png_ptr->trans_alpha[i], back.green); | ||
1821 | |||
1822 | png_composite(palette[i].blue, palette[i].blue, | ||
1823 | png_ptr->trans_alpha[i], back.blue); | ||
1824 | } | ||
1825 | } | ||
1826 | |||
1827 | png_ptr->transformations &= ~PNG_COMPOSE; | ||
1828 | } | ||
1829 | #endif /* PNG_READ_BACKGROUND_SUPPORTED */ | ||
1830 | |||
1831 | #ifdef PNG_READ_SHIFT_SUPPORTED | ||
1832 | if ((png_ptr->transformations & PNG_SHIFT) && | ||
1833 | (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)) | ||
1834 | { | ||
1835 | int i; | ||
1836 | int istop = png_ptr->num_palette; | ||
1837 | int shift = 8 - png_ptr->sig_bit.red; | ||
1838 | |||
1839 | /* significant bits can be in the range 1 to 7 for a meaninful result, if | ||
1840 | * the number of significant bits is 0 then no shift is done (this is an | ||
1841 | * error condition which is silently ignored.) | ||
1842 | */ | ||
1843 | if (shift > 0 && shift < 8) for (i=0; i<istop; ++i) | ||
1844 | { | ||
1845 | int component = png_ptr->palette[i].red; | ||
1846 | |||
1847 | component >>= shift; | ||
1848 | png_ptr->palette[i].red = (png_byte)component; | ||
1849 | } | ||
1850 | |||
1851 | shift = 8 - png_ptr->sig_bit.green; | ||
1852 | if (shift > 0 && shift < 8) for (i=0; i<istop; ++i) | ||
1853 | { | ||
1854 | int component = png_ptr->palette[i].green; | ||
1855 | |||
1856 | component >>= shift; | ||
1857 | png_ptr->palette[i].green = (png_byte)component; | ||
1858 | } | ||
1859 | |||
1860 | shift = 8 - png_ptr->sig_bit.blue; | ||
1861 | if (shift > 0 && shift < 8) for (i=0; i<istop; ++i) | ||
1862 | { | ||
1863 | int component = png_ptr->palette[i].blue; | ||
1864 | |||
1865 | component >>= shift; | ||
1866 | png_ptr->palette[i].blue = (png_byte)component; | ||
1867 | } | ||
1868 | } | ||
1869 | #endif /* PNG_READ_SHIFT_SUPPORTED */ | ||
1870 | } | ||
1871 | |||
1872 | /* Modify the info structure to reflect the transformations. The | ||
1873 | * info should be updated so a PNG file could be written with it, | ||
1874 | * assuming the transformations result in valid PNG data. | ||
1875 | */ | ||
1876 | void /* PRIVATE */ | ||
1877 | png_read_transform_info(png_structp png_ptr, png_infop info_ptr) | ||
1878 | { | ||
1879 | png_debug(1, "in png_read_transform_info"); | ||
1880 | |||
1881 | #ifdef PNG_READ_EXPAND_SUPPORTED | ||
1882 | if (png_ptr->transformations & PNG_EXPAND) | ||
1883 | { | ||
1884 | if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) | ||
1885 | { | ||
1886 | /* This check must match what actually happens in | ||
1887 | * png_do_expand_palette; if it ever checks the tRNS chunk to see if | ||
1888 | * it is all opaque we must do the same (at present it does not.) | ||
1889 | */ | ||
1890 | if (png_ptr->num_trans > 0) | ||
1891 | info_ptr->color_type = PNG_COLOR_TYPE_RGB_ALPHA; | ||
1892 | |||
1893 | else | ||
1894 | info_ptr->color_type = PNG_COLOR_TYPE_RGB; | ||
1895 | |||
1896 | info_ptr->bit_depth = 8; | ||
1897 | info_ptr->num_trans = 0; | ||
1898 | } | ||
1899 | else | ||
1900 | { | ||
1901 | if (png_ptr->num_trans) | ||
1902 | { | ||
1903 | if (png_ptr->transformations & PNG_EXPAND_tRNS) | ||
1904 | info_ptr->color_type |= PNG_COLOR_MASK_ALPHA; | ||
1905 | } | ||
1906 | if (info_ptr->bit_depth < 8) | ||
1907 | info_ptr->bit_depth = 8; | ||
1908 | |||
1909 | info_ptr->num_trans = 0; | ||
1910 | } | ||
1911 | } | ||
1912 | #endif | ||
1913 | |||
1914 | #if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\ | ||
1915 | defined(PNG_READ_ALPHA_MODE_SUPPORTED) | ||
1916 | /* The following is almost certainly wrong unless the background value is in | ||
1917 | * the screen space! | ||
1918 | */ | ||
1919 | if (png_ptr->transformations & PNG_COMPOSE) | ||
1920 | info_ptr->background = png_ptr->background; | ||
1921 | #endif | ||
1922 | |||
1923 | #ifdef PNG_READ_GAMMA_SUPPORTED | ||
1924 | /* The following used to be conditional on PNG_GAMMA (prior to 1.5.4), | ||
1925 | * however it seems that the code in png_init_read_transformations, which has | ||
1926 | * been called before this from png_read_update_info->png_read_start_row | ||
1927 | * sometimes does the gamma transform and cancels the flag. | ||
1928 | */ | ||
1929 | info_ptr->gamma = png_ptr->gamma; | ||
1930 | #endif | ||
1931 | |||
1932 | if (info_ptr->bit_depth == 16) | ||
1933 | { | ||
1934 | # ifdef PNG_READ_16BIT_SUPPORTED | ||
1935 | # ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED | ||
1936 | if (png_ptr->transformations & PNG_SCALE_16_TO_8) | ||
1937 | info_ptr->bit_depth = 8; | ||
1938 | # endif | ||
1939 | |||
1940 | # ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED | ||
1941 | if (png_ptr->transformations & PNG_16_TO_8) | ||
1942 | info_ptr->bit_depth = 8; | ||
1943 | # endif | ||
1944 | |||
1945 | # else | ||
1946 | /* No 16 bit support: force chopping 16-bit input down to 8, in this case | ||
1947 | * the app program can chose if both APIs are available by setting the | ||
1948 | * correct scaling to use. | ||
1949 | */ | ||
1950 | # ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED | ||
1951 | /* For compatibility with previous versions use the strip method by | ||
1952 | * default. This code works because if PNG_SCALE_16_TO_8 is already | ||
1953 | * set the code below will do that in preference to the chop. | ||
1954 | */ | ||
1955 | png_ptr->transformations |= PNG_16_TO_8; | ||
1956 | info_ptr->bit_depth = 8; | ||
1957 | # else | ||
1958 | |||
1959 | # ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED | ||
1960 | png_ptr->transformations |= PNG_SCALE_16_TO_8; | ||
1961 | info_ptr->bit_depth = 8; | ||
1962 | # else | ||
1963 | |||
1964 | CONFIGURATION ERROR: you must enable at least one 16 to 8 method | ||
1965 | # endif | ||
1966 | # endif | ||
1967 | #endif /* !READ_16BIT_SUPPORTED */ | ||
1968 | } | ||
1969 | |||
1970 | #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED | ||
1971 | if (png_ptr->transformations & PNG_GRAY_TO_RGB) | ||
1972 | info_ptr->color_type = (png_byte)(info_ptr->color_type | | ||
1973 | PNG_COLOR_MASK_COLOR); | ||
1974 | #endif | ||
1975 | |||
1976 | #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED | ||
1977 | if (png_ptr->transformations & PNG_RGB_TO_GRAY) | ||
1978 | info_ptr->color_type = (png_byte)(info_ptr->color_type & | ||
1979 | ~PNG_COLOR_MASK_COLOR); | ||
1980 | #endif | ||
1981 | |||
1982 | #ifdef PNG_READ_QUANTIZE_SUPPORTED | ||
1983 | if (png_ptr->transformations & PNG_QUANTIZE) | ||
1984 | { | ||
1985 | if (((info_ptr->color_type == PNG_COLOR_TYPE_RGB) || | ||
1986 | (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)) && | ||
1987 | png_ptr->palette_lookup && info_ptr->bit_depth == 8) | ||
1988 | { | ||
1989 | info_ptr->color_type = PNG_COLOR_TYPE_PALETTE; | ||
1990 | } | ||
1991 | } | ||
1992 | #endif | ||
1993 | |||
1994 | #ifdef PNG_READ_EXPAND_16_SUPPORTED | ||
1995 | if (png_ptr->transformations & PNG_EXPAND_16 && info_ptr->bit_depth == 8 && | ||
1996 | info_ptr->color_type != PNG_COLOR_TYPE_PALETTE) | ||
1997 | { | ||
1998 | info_ptr->bit_depth = 16; | ||
1999 | } | ||
2000 | #endif | ||
2001 | |||
2002 | #ifdef PNG_READ_PACK_SUPPORTED | ||
2003 | if ((png_ptr->transformations & PNG_PACK) && (info_ptr->bit_depth < 8)) | ||
2004 | info_ptr->bit_depth = 8; | ||
2005 | #endif | ||
2006 | |||
2007 | if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) | ||
2008 | info_ptr->channels = 1; | ||
2009 | |||
2010 | else if (info_ptr->color_type & PNG_COLOR_MASK_COLOR) | ||
2011 | info_ptr->channels = 3; | ||
2012 | |||
2013 | else | ||
2014 | info_ptr->channels = 1; | ||
2015 | |||
2016 | #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED | ||
2017 | if (png_ptr->transformations & PNG_STRIP_ALPHA) | ||
2018 | { | ||
2019 | info_ptr->color_type = (png_byte)(info_ptr->color_type & | ||
2020 | ~PNG_COLOR_MASK_ALPHA); | ||
2021 | info_ptr->num_trans = 0; | ||
2022 | } | ||
2023 | #endif | ||
2024 | |||
2025 | if (info_ptr->color_type & PNG_COLOR_MASK_ALPHA) | ||
2026 | info_ptr->channels++; | ||
2027 | |||
2028 | #ifdef PNG_READ_FILLER_SUPPORTED | ||
2029 | /* STRIP_ALPHA and FILLER allowed: MASK_ALPHA bit stripped above */ | ||
2030 | if ((png_ptr->transformations & PNG_FILLER) && | ||
2031 | ((info_ptr->color_type == PNG_COLOR_TYPE_RGB) || | ||
2032 | (info_ptr->color_type == PNG_COLOR_TYPE_GRAY))) | ||
2033 | { | ||
2034 | info_ptr->channels++; | ||
2035 | /* If adding a true alpha channel not just filler */ | ||
2036 | if (png_ptr->transformations & PNG_ADD_ALPHA) | ||
2037 | info_ptr->color_type |= PNG_COLOR_MASK_ALPHA; | ||
2038 | } | ||
2039 | #endif | ||
2040 | |||
2041 | #if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) && \ | ||
2042 | defined(PNG_READ_USER_TRANSFORM_SUPPORTED) | ||
2043 | if (png_ptr->transformations & PNG_USER_TRANSFORM) | ||
2044 | { | ||
2045 | if (info_ptr->bit_depth < png_ptr->user_transform_depth) | ||
2046 | info_ptr->bit_depth = png_ptr->user_transform_depth; | ||
2047 | |||
2048 | if (info_ptr->channels < png_ptr->user_transform_channels) | ||
2049 | info_ptr->channels = png_ptr->user_transform_channels; | ||
2050 | } | ||
2051 | #endif | ||
2052 | |||
2053 | info_ptr->pixel_depth = (png_byte)(info_ptr->channels * | ||
2054 | info_ptr->bit_depth); | ||
2055 | |||
2056 | info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, info_ptr->width); | ||
2057 | |||
2058 | /* Adding in 1.5.4: cache the above value in png_struct so that we can later | ||
2059 | * check in png_rowbytes that the user buffer won't get overwritten. Note | ||
2060 | * that the field is not always set - if png_read_update_info isn't called | ||
2061 | * the application has to either not do any transforms or get the calculation | ||
2062 | * right itself. | ||
2063 | */ | ||
2064 | png_ptr->info_rowbytes = info_ptr->rowbytes; | ||
2065 | |||
2066 | #ifndef PNG_READ_EXPAND_SUPPORTED | ||
2067 | if (png_ptr) | ||
2068 | return; | ||
2069 | #endif | ||
2070 | } | ||
2071 | |||
2072 | /* Transform the row. The order of transformations is significant, | ||
2073 | * and is very touchy. If you add a transformation, take care to | ||
2074 | * decide how it fits in with the other transformations here. | ||
2075 | */ | ||
2076 | void /* PRIVATE */ | ||
2077 | png_do_read_transformations(png_structp png_ptr, png_row_infop row_info) | ||
2078 | { | ||
2079 | png_debug(1, "in png_do_read_transformations"); | ||
2080 | |||
2081 | if (png_ptr->row_buf == NULL) | ||
2082 | { | ||
2083 | /* Prior to 1.5.4 this output row/pass where the NULL pointer is, but this | ||
2084 | * error is incredibly rare and incredibly easy to debug without this | ||
2085 | * information. | ||
2086 | */ | ||
2087 | png_error(png_ptr, "NULL row buffer"); | ||
2088 | } | ||
2089 | |||
2090 | /* The following is debugging; prior to 1.5.4 the code was never compiled in; | ||
2091 | * in 1.5.4 PNG_FLAG_DETECT_UNINITIALIZED was added and the macro | ||
2092 | * PNG_WARN_UNINITIALIZED_ROW removed. In 1.5 the new flag is set only for | ||
2093 | * selected new APIs to ensure that there is no API change. | ||
2094 | */ | ||
2095 | if ((png_ptr->flags & PNG_FLAG_DETECT_UNINITIALIZED) != 0 && | ||
2096 | !(png_ptr->flags & PNG_FLAG_ROW_INIT)) | ||
2097 | { | ||
2098 | /* Application has failed to call either png_read_start_image() or | ||
2099 | * png_read_update_info() after setting transforms that expand pixels. | ||
2100 | * This check added to libpng-1.2.19 (but not enabled until 1.5.4). | ||
2101 | */ | ||
2102 | png_error(png_ptr, "Uninitialized row"); | ||
2103 | } | ||
2104 | |||
2105 | #ifdef PNG_READ_EXPAND_SUPPORTED | ||
2106 | if (png_ptr->transformations & PNG_EXPAND) | ||
2107 | { | ||
2108 | if (row_info->color_type == PNG_COLOR_TYPE_PALETTE) | ||
2109 | { | ||
2110 | png_do_expand_palette(row_info, png_ptr->row_buf + 1, | ||
2111 | png_ptr->palette, png_ptr->trans_alpha, png_ptr->num_trans); | ||
2112 | } | ||
2113 | |||
2114 | else | ||
2115 | { | ||
2116 | if (png_ptr->num_trans && | ||
2117 | (png_ptr->transformations & PNG_EXPAND_tRNS)) | ||
2118 | png_do_expand(row_info, png_ptr->row_buf + 1, | ||
2119 | &(png_ptr->trans_color)); | ||
2120 | |||
2121 | else | ||
2122 | png_do_expand(row_info, png_ptr->row_buf + 1, | ||
2123 | NULL); | ||
2124 | } | ||
2125 | } | ||
2126 | #endif | ||
2127 | |||
2128 | #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED | ||
2129 | if ((png_ptr->transformations & PNG_STRIP_ALPHA) && | ||
2130 | !(png_ptr->transformations & PNG_COMPOSE) && | ||
2131 | (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA || | ||
2132 | row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)) | ||
2133 | png_do_strip_channel(row_info, png_ptr->row_buf + 1, | ||
2134 | 0 /* at_start == false, because SWAP_ALPHA happens later */); | ||
2135 | #endif | ||
2136 | |||
2137 | #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED | ||
2138 | if (png_ptr->transformations & PNG_RGB_TO_GRAY) | ||
2139 | { | ||
2140 | int rgb_error = | ||
2141 | png_do_rgb_to_gray(png_ptr, row_info, | ||
2142 | png_ptr->row_buf + 1); | ||
2143 | |||
2144 | if (rgb_error) | ||
2145 | { | ||
2146 | png_ptr->rgb_to_gray_status=1; | ||
2147 | if ((png_ptr->transformations & PNG_RGB_TO_GRAY) == | ||
2148 | PNG_RGB_TO_GRAY_WARN) | ||
2149 | png_warning(png_ptr, "png_do_rgb_to_gray found nongray pixel"); | ||
2150 | |||
2151 | if ((png_ptr->transformations & PNG_RGB_TO_GRAY) == | ||
2152 | PNG_RGB_TO_GRAY_ERR) | ||
2153 | png_error(png_ptr, "png_do_rgb_to_gray found nongray pixel"); | ||
2154 | } | ||
2155 | } | ||
2156 | #endif | ||
2157 | |||
2158 | /* From Andreas Dilger e-mail to png-implement, 26 March 1998: | ||
2159 | * | ||
2160 | * In most cases, the "simple transparency" should be done prior to doing | ||
2161 | * gray-to-RGB, or you will have to test 3x as many bytes to check if a | ||
2162 | * pixel is transparent. You would also need to make sure that the | ||
2163 | * transparency information is upgraded to RGB. | ||
2164 | * | ||
2165 | * To summarize, the current flow is: | ||
2166 | * - Gray + simple transparency -> compare 1 or 2 gray bytes and composite | ||
2167 | * with background "in place" if transparent, | ||
2168 | * convert to RGB if necessary | ||
2169 | * - Gray + alpha -> composite with gray background and remove alpha bytes, | ||
2170 | * convert to RGB if necessary | ||
2171 | * | ||
2172 | * To support RGB backgrounds for gray images we need: | ||
2173 | * - Gray + simple transparency -> convert to RGB + simple transparency, | ||
2174 | * compare 3 or 6 bytes and composite with | ||
2175 | * background "in place" if transparent | ||
2176 | * (3x compare/pixel compared to doing | ||
2177 | * composite with gray bkgrnd) | ||
2178 | * - Gray + alpha -> convert to RGB + alpha, composite with background and | ||
2179 | * remove alpha bytes (3x float | ||
2180 | * operations/pixel compared with composite | ||
2181 | * on gray background) | ||
2182 | * | ||
2183 | * Greg's change will do this. The reason it wasn't done before is for | ||
2184 | * performance, as this increases the per-pixel operations. If we would check | ||
2185 | * in advance if the background was gray or RGB, and position the gray-to-RGB | ||
2186 | * transform appropriately, then it would save a lot of work/time. | ||
2187 | */ | ||
2188 | |||
2189 | #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED | ||
2190 | /* If gray -> RGB, do so now only if background is non-gray; else do later | ||
2191 | * for performance reasons | ||
2192 | */ | ||
2193 | if ((png_ptr->transformations & PNG_GRAY_TO_RGB) && | ||
2194 | !(png_ptr->mode & PNG_BACKGROUND_IS_GRAY)) | ||
2195 | png_do_gray_to_rgb(row_info, png_ptr->row_buf + 1); | ||
2196 | #endif | ||
2197 | |||
2198 | #if (defined PNG_READ_BACKGROUND_SUPPORTED) ||\ | ||
2199 | (defined PNG_READ_ALPHA_MODE_SUPPORTED) | ||
2200 | if (png_ptr->transformations & PNG_COMPOSE) | ||
2201 | png_do_compose(row_info, png_ptr->row_buf + 1, png_ptr); | ||
2202 | #endif | ||
2203 | |||
2204 | #ifdef PNG_READ_GAMMA_SUPPORTED | ||
2205 | if ((png_ptr->transformations & PNG_GAMMA) && | ||
2206 | #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED | ||
2207 | /* Because RGB_TO_GRAY does the gamma transform. */ | ||
2208 | !(png_ptr->transformations & PNG_RGB_TO_GRAY) && | ||
2209 | #endif | ||
2210 | #if (defined PNG_READ_BACKGROUND_SUPPORTED) ||\ | ||
2211 | (defined PNG_READ_ALPHA_MODE_SUPPORTED) | ||
2212 | /* Because PNG_COMPOSE does the gamma transform if there is something to | ||
2213 | * do (if there is an alpha channel or transparency.) | ||
2214 | */ | ||
2215 | !((png_ptr->transformations & PNG_COMPOSE) && | ||
2216 | ((png_ptr->num_trans != 0) || | ||
2217 | (png_ptr->color_type & PNG_COLOR_MASK_ALPHA))) && | ||
2218 | #endif | ||
2219 | /* Because png_init_read_transformations transforms the palette, unless | ||
2220 | * RGB_TO_GRAY will do the transform. | ||
2221 | */ | ||
2222 | (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)) | ||
2223 | png_do_gamma(row_info, png_ptr->row_buf + 1, png_ptr); | ||
2224 | #endif | ||
2225 | |||
2226 | #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED | ||
2227 | if ((png_ptr->transformations & PNG_STRIP_ALPHA) && | ||
2228 | (png_ptr->transformations & PNG_COMPOSE) && | ||
2229 | (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA || | ||
2230 | row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)) | ||
2231 | png_do_strip_channel(row_info, png_ptr->row_buf + 1, | ||
2232 | 0 /* at_start == false, because SWAP_ALPHA happens later */); | ||
2233 | #endif | ||
2234 | |||
2235 | #ifdef PNG_READ_ALPHA_MODE_SUPPORTED | ||
2236 | if ((png_ptr->transformations & PNG_ENCODE_ALPHA) && | ||
2237 | (row_info->color_type & PNG_COLOR_MASK_ALPHA)) | ||
2238 | png_do_encode_alpha(row_info, png_ptr->row_buf + 1, png_ptr); | ||
2239 | #endif | ||
2240 | |||
2241 | #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED | ||
2242 | if (png_ptr->transformations & PNG_SCALE_16_TO_8) | ||
2243 | png_do_scale_16_to_8(row_info, png_ptr->row_buf + 1); | ||
2244 | #endif | ||
2245 | |||
2246 | #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED | ||
2247 | /* There is no harm in doing both of these because only one has any effect, | ||
2248 | * by putting the 'scale' option first if the app asks for scale (either by | ||
2249 | * calling the API or in a TRANSFORM flag) this is what happens. | ||
2250 | */ | ||
2251 | if (png_ptr->transformations & PNG_16_TO_8) | ||
2252 | png_do_chop(row_info, png_ptr->row_buf + 1); | ||
2253 | #endif | ||
2254 | |||
2255 | #ifdef PNG_READ_QUANTIZE_SUPPORTED | ||
2256 | if (png_ptr->transformations & PNG_QUANTIZE) | ||
2257 | { | ||
2258 | png_do_quantize(row_info, png_ptr->row_buf + 1, | ||
2259 | png_ptr->palette_lookup, png_ptr->quantize_index); | ||
2260 | |||
2261 | if (row_info->rowbytes == 0) | ||
2262 | png_error(png_ptr, "png_do_quantize returned rowbytes=0"); | ||
2263 | } | ||
2264 | #endif /* PNG_READ_QUANTIZE_SUPPORTED */ | ||
2265 | |||
2266 | #ifdef PNG_READ_EXPAND_16_SUPPORTED | ||
2267 | /* Do the expansion now, after all the arithmetic has been done. Notice | ||
2268 | * that previous transformations can handle the PNG_EXPAND_16 flag if this | ||
2269 | * is efficient (particularly true in the case of gamma correction, where | ||
2270 | * better accuracy results faster!) | ||
2271 | */ | ||
2272 | if (png_ptr->transformations & PNG_EXPAND_16) | ||
2273 | png_do_expand_16(row_info, png_ptr->row_buf + 1); | ||
2274 | #endif | ||
2275 | |||
2276 | #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED | ||
2277 | /*NOTE: moved here in 1.5.4 (from much later in this list.) */ | ||
2278 | if ((png_ptr->transformations & PNG_GRAY_TO_RGB) && | ||
2279 | (png_ptr->mode & PNG_BACKGROUND_IS_GRAY)) | ||
2280 | png_do_gray_to_rgb(row_info, png_ptr->row_buf + 1); | ||
2281 | #endif | ||
2282 | |||
2283 | #ifdef PNG_READ_INVERT_SUPPORTED | ||
2284 | if (png_ptr->transformations & PNG_INVERT_MONO) | ||
2285 | png_do_invert(row_info, png_ptr->row_buf + 1); | ||
2286 | #endif | ||
2287 | |||
2288 | #ifdef PNG_READ_SHIFT_SUPPORTED | ||
2289 | if (png_ptr->transformations & PNG_SHIFT) | ||
2290 | png_do_unshift(row_info, png_ptr->row_buf + 1, | ||
2291 | &(png_ptr->shift)); | ||
2292 | #endif | ||
2293 | |||
2294 | #ifdef PNG_READ_PACK_SUPPORTED | ||
2295 | if (png_ptr->transformations & PNG_PACK) | ||
2296 | png_do_unpack(row_info, png_ptr->row_buf + 1); | ||
2297 | #endif | ||
2298 | |||
2299 | #ifdef PNG_READ_BGR_SUPPORTED | ||
2300 | if (png_ptr->transformations & PNG_BGR) | ||
2301 | png_do_bgr(row_info, png_ptr->row_buf + 1); | ||
2302 | #endif | ||
2303 | |||
2304 | #ifdef PNG_READ_PACKSWAP_SUPPORTED | ||
2305 | if (png_ptr->transformations & PNG_PACKSWAP) | ||
2306 | png_do_packswap(row_info, png_ptr->row_buf + 1); | ||
2307 | #endif | ||
2308 | |||
2309 | #ifdef PNG_READ_FILLER_SUPPORTED | ||
2310 | if (png_ptr->transformations & PNG_FILLER) | ||
2311 | png_do_read_filler(row_info, png_ptr->row_buf + 1, | ||
2312 | (png_uint_32)png_ptr->filler, png_ptr->flags); | ||
2313 | #endif | ||
2314 | |||
2315 | #ifdef PNG_READ_INVERT_ALPHA_SUPPORTED | ||
2316 | if (png_ptr->transformations & PNG_INVERT_ALPHA) | ||
2317 | png_do_read_invert_alpha(row_info, png_ptr->row_buf + 1); | ||
2318 | #endif | ||
2319 | |||
2320 | #ifdef PNG_READ_SWAP_ALPHA_SUPPORTED | ||
2321 | if (png_ptr->transformations & PNG_SWAP_ALPHA) | ||
2322 | png_do_read_swap_alpha(row_info, png_ptr->row_buf + 1); | ||
2323 | #endif | ||
2324 | |||
2325 | #ifdef PNG_READ_16BIT_SUPPORTED | ||
2326 | #ifdef PNG_READ_SWAP_SUPPORTED | ||
2327 | if (png_ptr->transformations & PNG_SWAP_BYTES) | ||
2328 | png_do_swap(row_info, png_ptr->row_buf + 1); | ||
2329 | #endif | ||
2330 | #endif | ||
2331 | |||
2332 | #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED | ||
2333 | if (png_ptr->transformations & PNG_USER_TRANSFORM) | ||
2334 | { | ||
2335 | if (png_ptr->read_user_transform_fn != NULL) | ||
2336 | (*(png_ptr->read_user_transform_fn)) /* User read transform function */ | ||
2337 | (png_ptr, /* png_ptr */ | ||
2338 | row_info, /* row_info: */ | ||
2339 | /* png_uint_32 width; width of row */ | ||
2340 | /* png_size_t rowbytes; number of bytes in row */ | ||
2341 | /* png_byte color_type; color type of pixels */ | ||
2342 | /* png_byte bit_depth; bit depth of samples */ | ||
2343 | /* png_byte channels; number of channels (1-4) */ | ||
2344 | /* png_byte pixel_depth; bits per pixel (depth*channels) */ | ||
2345 | png_ptr->row_buf + 1); /* start of pixel data for row */ | ||
2346 | #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED | ||
2347 | if (png_ptr->user_transform_depth) | ||
2348 | row_info->bit_depth = png_ptr->user_transform_depth; | ||
2349 | |||
2350 | if (png_ptr->user_transform_channels) | ||
2351 | row_info->channels = png_ptr->user_transform_channels; | ||
2352 | #endif | ||
2353 | row_info->pixel_depth = (png_byte)(row_info->bit_depth * | ||
2354 | row_info->channels); | ||
2355 | |||
2356 | row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_info->width); | ||
2357 | } | ||
2358 | #endif | ||
2359 | } | ||
2360 | |||
2361 | #ifdef PNG_READ_PACK_SUPPORTED | ||
2362 | /* Unpack pixels of 1, 2, or 4 bits per pixel into 1 byte per pixel, | ||
2363 | * without changing the actual values. Thus, if you had a row with | ||
2364 | * a bit depth of 1, you would end up with bytes that only contained | ||
2365 | * the numbers 0 or 1. If you would rather they contain 0 and 255, use | ||
2366 | * png_do_shift() after this. | ||
2367 | */ | ||
2368 | void /* PRIVATE */ | ||
2369 | png_do_unpack(png_row_infop row_info, png_bytep row) | ||
2370 | { | ||
2371 | png_debug(1, "in png_do_unpack"); | ||
2372 | |||
2373 | if (row_info->bit_depth < 8) | ||
2374 | { | ||
2375 | png_uint_32 i; | ||
2376 | png_uint_32 row_width=row_info->width; | ||
2377 | |||
2378 | switch (row_info->bit_depth) | ||
2379 | { | ||
2380 | case 1: | ||
2381 | { | ||
2382 | png_bytep sp = row + (png_size_t)((row_width - 1) >> 3); | ||
2383 | png_bytep dp = row + (png_size_t)row_width - 1; | ||
2384 | png_uint_32 shift = 7 - (int)((row_width + 7) & 0x07); | ||
2385 | for (i = 0; i < row_width; i++) | ||
2386 | { | ||
2387 | *dp = (png_byte)((*sp >> shift) & 0x01); | ||
2388 | |||
2389 | if (shift == 7) | ||
2390 | { | ||
2391 | shift = 0; | ||
2392 | sp--; | ||
2393 | } | ||
2394 | |||
2395 | else | ||
2396 | shift++; | ||
2397 | |||
2398 | dp--; | ||
2399 | } | ||
2400 | break; | ||
2401 | } | ||
2402 | |||
2403 | case 2: | ||
2404 | { | ||
2405 | |||
2406 | png_bytep sp = row + (png_size_t)((row_width - 1) >> 2); | ||
2407 | png_bytep dp = row + (png_size_t)row_width - 1; | ||
2408 | png_uint_32 shift = (int)((3 - ((row_width + 3) & 0x03)) << 1); | ||
2409 | for (i = 0; i < row_width; i++) | ||
2410 | { | ||
2411 | *dp = (png_byte)((*sp >> shift) & 0x03); | ||
2412 | |||
2413 | if (shift == 6) | ||
2414 | { | ||
2415 | shift = 0; | ||
2416 | sp--; | ||
2417 | } | ||
2418 | |||
2419 | else | ||
2420 | shift += 2; | ||
2421 | |||
2422 | dp--; | ||
2423 | } | ||
2424 | break; | ||
2425 | } | ||
2426 | |||
2427 | case 4: | ||
2428 | { | ||
2429 | png_bytep sp = row + (png_size_t)((row_width - 1) >> 1); | ||
2430 | png_bytep dp = row + (png_size_t)row_width - 1; | ||
2431 | png_uint_32 shift = (int)((1 - ((row_width + 1) & 0x01)) << 2); | ||
2432 | for (i = 0; i < row_width; i++) | ||
2433 | { | ||
2434 | *dp = (png_byte)((*sp >> shift) & 0x0f); | ||
2435 | |||
2436 | if (shift == 4) | ||
2437 | { | ||
2438 | shift = 0; | ||
2439 | sp--; | ||
2440 | } | ||
2441 | |||
2442 | else | ||
2443 | shift = 4; | ||
2444 | |||
2445 | dp--; | ||
2446 | } | ||
2447 | break; | ||
2448 | } | ||
2449 | |||
2450 | default: | ||
2451 | break; | ||
2452 | } | ||
2453 | row_info->bit_depth = 8; | ||
2454 | row_info->pixel_depth = (png_byte)(8 * row_info->channels); | ||
2455 | row_info->rowbytes = row_width * row_info->channels; | ||
2456 | } | ||
2457 | } | ||
2458 | #endif | ||
2459 | |||
2460 | #ifdef PNG_READ_SHIFT_SUPPORTED | ||
2461 | /* Reverse the effects of png_do_shift. This routine merely shifts the | ||
2462 | * pixels back to their significant bits values. Thus, if you have | ||
2463 | * a row of bit depth 8, but only 5 are significant, this will shift | ||
2464 | * the values back to 0 through 31. | ||
2465 | */ | ||
2466 | void /* PRIVATE */ | ||
2467 | png_do_unshift(png_row_infop row_info, png_bytep row, | ||
2468 | png_const_color_8p sig_bits) | ||
2469 | { | ||
2470 | int color_type; | ||
2471 | |||
2472 | png_debug(1, "in png_do_unshift"); | ||
2473 | |||
2474 | /* The palette case has already been handled in the _init routine. */ | ||
2475 | color_type = row_info->color_type; | ||
2476 | |||
2477 | if (color_type != PNG_COLOR_TYPE_PALETTE) | ||
2478 | { | ||
2479 | int shift[4]; | ||
2480 | int channels = 0; | ||
2481 | int bit_depth = row_info->bit_depth; | ||
2482 | |||
2483 | if (color_type & PNG_COLOR_MASK_COLOR) | ||
2484 | { | ||
2485 | shift[channels++] = bit_depth - sig_bits->red; | ||
2486 | shift[channels++] = bit_depth - sig_bits->green; | ||
2487 | shift[channels++] = bit_depth - sig_bits->blue; | ||
2488 | } | ||
2489 | |||
2490 | else | ||
2491 | { | ||
2492 | shift[channels++] = bit_depth - sig_bits->gray; | ||
2493 | } | ||
2494 | |||
2495 | if (color_type & PNG_COLOR_MASK_ALPHA) | ||
2496 | { | ||
2497 | shift[channels++] = bit_depth - sig_bits->alpha; | ||
2498 | } | ||
2499 | |||
2500 | { | ||
2501 | int c, have_shift; | ||
2502 | |||
2503 | for (c = have_shift = 0; c < channels; ++c) | ||
2504 | { | ||
2505 | /* A shift of more than the bit depth is an error condition but it | ||
2506 | * gets ignored here. | ||
2507 | */ | ||
2508 | if (shift[c] <= 0 || shift[c] >= bit_depth) | ||
2509 | shift[c] = 0; | ||
2510 | |||
2511 | else | ||
2512 | have_shift = 1; | ||
2513 | } | ||
2514 | |||
2515 | if (!have_shift) | ||
2516 | return; | ||
2517 | } | ||
2518 | |||
2519 | switch (bit_depth) | ||
2520 | { | ||
2521 | default: | ||
2522 | /* Must be 1bpp gray: should not be here! */ | ||
2523 | /* NOTREACHED */ | ||
2524 | break; | ||
2525 | |||
2526 | case 2: | ||
2527 | /* Must be 2bpp gray */ | ||
2528 | /* assert(channels == 1 && shift[0] == 1) */ | ||
2529 | { | ||
2530 | png_bytep bp = row; | ||
2531 | png_bytep bp_end = bp + row_info->rowbytes; | ||
2532 | |||
2533 | while (bp < bp_end) | ||
2534 | { | ||
2535 | int b = (*bp >> 1) & 0x55; | ||
2536 | *bp++ = (png_byte)b; | ||
2537 | } | ||
2538 | break; | ||
2539 | } | ||
2540 | |||
2541 | case 4: | ||
2542 | /* Must be 4bpp gray */ | ||
2543 | /* assert(channels == 1) */ | ||
2544 | { | ||
2545 | png_bytep bp = row; | ||
2546 | png_bytep bp_end = bp + row_info->rowbytes; | ||
2547 | int gray_shift = shift[0]; | ||
2548 | int mask = 0xf >> gray_shift; | ||
2549 | |||
2550 | mask |= mask << 4; | ||
2551 | |||
2552 | while (bp < bp_end) | ||
2553 | { | ||
2554 | int b = (*bp >> gray_shift) & mask; | ||
2555 | *bp++ = (png_byte)b; | ||
2556 | } | ||
2557 | break; | ||
2558 | } | ||
2559 | |||
2560 | case 8: | ||
2561 | /* Single byte components, G, GA, RGB, RGBA */ | ||
2562 | { | ||
2563 | png_bytep bp = row; | ||
2564 | png_bytep bp_end = bp + row_info->rowbytes; | ||
2565 | int channel = 0; | ||
2566 | |||
2567 | while (bp < bp_end) | ||
2568 | { | ||
2569 | int b = *bp >> shift[channel]; | ||
2570 | if (++channel >= channels) | ||
2571 | channel = 0; | ||
2572 | *bp++ = (png_byte)b; | ||
2573 | } | ||
2574 | break; | ||
2575 | } | ||
2576 | |||
2577 | #ifdef PNG_READ_16BIT_SUPPORTED | ||
2578 | case 16: | ||
2579 | /* Double byte components, G, GA, RGB, RGBA */ | ||
2580 | { | ||
2581 | png_bytep bp = row; | ||
2582 | png_bytep bp_end = bp + row_info->rowbytes; | ||
2583 | int channel = 0; | ||
2584 | |||
2585 | while (bp < bp_end) | ||
2586 | { | ||
2587 | int value = (bp[0] << 8) + bp[1]; | ||
2588 | |||
2589 | value >>= shift[channel]; | ||
2590 | if (++channel >= channels) | ||
2591 | channel = 0; | ||
2592 | *bp++ = (png_byte)(value >> 8); | ||
2593 | *bp++ = (png_byte)(value & 0xff); | ||
2594 | } | ||
2595 | break; | ||
2596 | } | ||
2597 | #endif | ||
2598 | } | ||
2599 | } | ||
2600 | } | ||
2601 | #endif | ||
2602 | |||
2603 | #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED | ||
2604 | /* Scale rows of bit depth 16 down to 8 accurately */ | ||
2605 | void /* PRIVATE */ | ||
2606 | png_do_scale_16_to_8(png_row_infop row_info, png_bytep row) | ||
2607 | { | ||
2608 | png_debug(1, "in png_do_scale_16_to_8"); | ||
2609 | |||
2610 | if (row_info->bit_depth == 16) | ||
2611 | { | ||
2612 | png_bytep sp = row; /* source */ | ||
2613 | png_bytep dp = row; /* destination */ | ||
2614 | png_bytep ep = sp + row_info->rowbytes; /* end+1 */ | ||
2615 | |||
2616 | while (sp < ep) | ||
2617 | { | ||
2618 | /* The input is an array of 16 bit components, these must be scaled to | ||
2619 | * 8 bits each. For a 16 bit value V the required value (from the PNG | ||
2620 | * specification) is: | ||
2621 | * | ||
2622 | * (V * 255) / 65535 | ||
2623 | * | ||
2624 | * This reduces to round(V / 257), or floor((V + 128.5)/257) | ||
2625 | * | ||
2626 | * Represent V as the two byte value vhi.vlo. Make a guess that the | ||
2627 | * result is the top byte of V, vhi, then the correction to this value | ||
2628 | * is: | ||
2629 | * | ||
2630 | * error = floor(((V-vhi.vhi) + 128.5) / 257) | ||
2631 | * = floor(((vlo-vhi) + 128.5) / 257) | ||
2632 | * | ||
2633 | * This can be approximated using integer arithmetic (and a signed | ||
2634 | * shift): | ||
2635 | * | ||
2636 | * error = (vlo-vhi+128) >> 8; | ||
2637 | * | ||
2638 | * The approximate differs from the exact answer only when (vlo-vhi) is | ||
2639 | * 128; it then gives a correction of +1 when the exact correction is | ||
2640 | * 0. This gives 128 errors. The exact answer (correct for all 16 bit | ||
2641 | * input values) is: | ||
2642 | * | ||
2643 | * error = (vlo-vhi+128)*65535 >> 24; | ||
2644 | * | ||
2645 | * An alternative arithmetic calculation which also gives no errors is: | ||
2646 | * | ||
2647 | * (V * 255 + 32895) >> 16 | ||
2648 | */ | ||
2649 | |||
2650 | png_int_32 tmp = *sp++; /* must be signed! */ | ||
2651 | tmp += (((int)*sp++ - tmp + 128) * 65535) >> 24; | ||
2652 | *dp++ = (png_byte)tmp; | ||
2653 | } | ||
2654 | |||
2655 | row_info->bit_depth = 8; | ||
2656 | row_info->pixel_depth = (png_byte)(8 * row_info->channels); | ||
2657 | row_info->rowbytes = row_info->width * row_info->channels; | ||
2658 | } | ||
2659 | } | ||
2660 | #endif | ||
2661 | |||
2662 | #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED | ||
2663 | void /* PRIVATE */ | ||
2664 | /* Simply discard the low byte. This was the default behavior prior | ||
2665 | * to libpng-1.5.4. | ||
2666 | */ | ||
2667 | png_do_chop(png_row_infop row_info, png_bytep row) | ||
2668 | { | ||
2669 | png_debug(1, "in png_do_chop"); | ||
2670 | |||
2671 | if (row_info->bit_depth == 16) | ||
2672 | { | ||
2673 | png_bytep sp = row; /* source */ | ||
2674 | png_bytep dp = row; /* destination */ | ||
2675 | png_bytep ep = sp + row_info->rowbytes; /* end+1 */ | ||
2676 | |||
2677 | while (sp < ep) | ||
2678 | { | ||
2679 | *dp++ = *sp; | ||
2680 | sp += 2; /* skip low byte */ | ||
2681 | } | ||
2682 | |||
2683 | row_info->bit_depth = 8; | ||
2684 | row_info->pixel_depth = (png_byte)(8 * row_info->channels); | ||
2685 | row_info->rowbytes = row_info->width * row_info->channels; | ||
2686 | } | ||
2687 | } | ||
2688 | #endif | ||
2689 | |||
2690 | #ifdef PNG_READ_SWAP_ALPHA_SUPPORTED | ||
2691 | void /* PRIVATE */ | ||
2692 | png_do_read_swap_alpha(png_row_infop row_info, png_bytep row) | ||
2693 | { | ||
2694 | png_debug(1, "in png_do_read_swap_alpha"); | ||
2695 | |||
2696 | { | ||
2697 | png_uint_32 row_width = row_info->width; | ||
2698 | if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) | ||
2699 | { | ||
2700 | /* This converts from RGBA to ARGB */ | ||
2701 | if (row_info->bit_depth == 8) | ||
2702 | { | ||
2703 | png_bytep sp = row + row_info->rowbytes; | ||
2704 | png_bytep dp = sp; | ||
2705 | png_byte save; | ||
2706 | png_uint_32 i; | ||
2707 | |||
2708 | for (i = 0; i < row_width; i++) | ||
2709 | { | ||
2710 | save = *(--sp); | ||
2711 | *(--dp) = *(--sp); | ||
2712 | *(--dp) = *(--sp); | ||
2713 | *(--dp) = *(--sp); | ||
2714 | *(--dp) = save; | ||
2715 | } | ||
2716 | } | ||
2717 | |||
2718 | #ifdef PNG_READ_16BIT_SUPPORTED | ||
2719 | /* This converts from RRGGBBAA to AARRGGBB */ | ||
2720 | else | ||
2721 | { | ||
2722 | png_bytep sp = row + row_info->rowbytes; | ||
2723 | png_bytep dp = sp; | ||
2724 | png_byte save[2]; | ||
2725 | png_uint_32 i; | ||
2726 | |||
2727 | for (i = 0; i < row_width; i++) | ||
2728 | { | ||
2729 | save[0] = *(--sp); | ||
2730 | save[1] = *(--sp); | ||
2731 | *(--dp) = *(--sp); | ||
2732 | *(--dp) = *(--sp); | ||
2733 | *(--dp) = *(--sp); | ||
2734 | *(--dp) = *(--sp); | ||
2735 | *(--dp) = *(--sp); | ||
2736 | *(--dp) = *(--sp); | ||
2737 | *(--dp) = save[0]; | ||
2738 | *(--dp) = save[1]; | ||
2739 | } | ||
2740 | } | ||
2741 | #endif | ||
2742 | } | ||
2743 | |||
2744 | else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) | ||
2745 | { | ||
2746 | /* This converts from GA to AG */ | ||
2747 | if (row_info->bit_depth == 8) | ||
2748 | { | ||
2749 | png_bytep sp = row + row_info->rowbytes; | ||
2750 | png_bytep dp = sp; | ||
2751 | png_byte save; | ||
2752 | png_uint_32 i; | ||
2753 | |||
2754 | for (i = 0; i < row_width; i++) | ||
2755 | { | ||
2756 | save = *(--sp); | ||
2757 | *(--dp) = *(--sp); | ||
2758 | *(--dp) = save; | ||
2759 | } | ||
2760 | } | ||
2761 | |||
2762 | #ifdef PNG_READ_16BIT_SUPPORTED | ||
2763 | /* This converts from GGAA to AAGG */ | ||
2764 | else | ||
2765 | { | ||
2766 | png_bytep sp = row + row_info->rowbytes; | ||
2767 | png_bytep dp = sp; | ||
2768 | png_byte save[2]; | ||
2769 | png_uint_32 i; | ||
2770 | |||
2771 | for (i = 0; i < row_width; i++) | ||
2772 | { | ||
2773 | save[0] = *(--sp); | ||
2774 | save[1] = *(--sp); | ||
2775 | *(--dp) = *(--sp); | ||
2776 | *(--dp) = *(--sp); | ||
2777 | *(--dp) = save[0]; | ||
2778 | *(--dp) = save[1]; | ||
2779 | } | ||
2780 | } | ||
2781 | #endif | ||
2782 | } | ||
2783 | } | ||
2784 | } | ||
2785 | #endif | ||
2786 | |||
2787 | #ifdef PNG_READ_INVERT_ALPHA_SUPPORTED | ||
2788 | void /* PRIVATE */ | ||
2789 | png_do_read_invert_alpha(png_row_infop row_info, png_bytep row) | ||
2790 | { | ||
2791 | png_uint_32 row_width; | ||
2792 | png_debug(1, "in png_do_read_invert_alpha"); | ||
2793 | |||
2794 | row_width = row_info->width; | ||
2795 | if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) | ||
2796 | { | ||
2797 | if (row_info->bit_depth == 8) | ||
2798 | { | ||
2799 | /* This inverts the alpha channel in RGBA */ | ||
2800 | png_bytep sp = row + row_info->rowbytes; | ||
2801 | png_bytep dp = sp; | ||
2802 | png_uint_32 i; | ||
2803 | |||
2804 | for (i = 0; i < row_width; i++) | ||
2805 | { | ||
2806 | *(--dp) = (png_byte)(255 - *(--sp)); | ||
2807 | |||
2808 | /* This does nothing: | ||
2809 | *(--dp) = *(--sp); | ||
2810 | *(--dp) = *(--sp); | ||
2811 | *(--dp) = *(--sp); | ||
2812 | We can replace it with: | ||
2813 | */ | ||
2814 | sp-=3; | ||
2815 | dp=sp; | ||
2816 | } | ||
2817 | } | ||
2818 | |||
2819 | #ifdef PNG_READ_16BIT_SUPPORTED | ||
2820 | /* This inverts the alpha channel in RRGGBBAA */ | ||
2821 | else | ||
2822 | { | ||
2823 | png_bytep sp = row + row_info->rowbytes; | ||
2824 | png_bytep dp = sp; | ||
2825 | png_uint_32 i; | ||
2826 | |||
2827 | for (i = 0; i < row_width; i++) | ||
2828 | { | ||
2829 | *(--dp) = (png_byte)(255 - *(--sp)); | ||
2830 | *(--dp) = (png_byte)(255 - *(--sp)); | ||
2831 | |||
2832 | /* This does nothing: | ||
2833 | *(--dp) = *(--sp); | ||
2834 | *(--dp) = *(--sp); | ||
2835 | *(--dp) = *(--sp); | ||
2836 | *(--dp) = *(--sp); | ||
2837 | *(--dp) = *(--sp); | ||
2838 | *(--dp) = *(--sp); | ||
2839 | We can replace it with: | ||
2840 | */ | ||
2841 | sp-=6; | ||
2842 | dp=sp; | ||
2843 | } | ||
2844 | } | ||
2845 | #endif | ||
2846 | } | ||
2847 | else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) | ||
2848 | { | ||
2849 | if (row_info->bit_depth == 8) | ||
2850 | { | ||
2851 | /* This inverts the alpha channel in GA */ | ||
2852 | png_bytep sp = row + row_info->rowbytes; | ||
2853 | png_bytep dp = sp; | ||
2854 | png_uint_32 i; | ||
2855 | |||
2856 | for (i = 0; i < row_width; i++) | ||
2857 | { | ||
2858 | *(--dp) = (png_byte)(255 - *(--sp)); | ||
2859 | *(--dp) = *(--sp); | ||
2860 | } | ||
2861 | } | ||
2862 | |||
2863 | #ifdef PNG_READ_16BIT_SUPPORTED | ||
2864 | else | ||
2865 | { | ||
2866 | /* This inverts the alpha channel in GGAA */ | ||
2867 | png_bytep sp = row + row_info->rowbytes; | ||
2868 | png_bytep dp = sp; | ||
2869 | png_uint_32 i; | ||
2870 | |||
2871 | for (i = 0; i < row_width; i++) | ||
2872 | { | ||
2873 | *(--dp) = (png_byte)(255 - *(--sp)); | ||
2874 | *(--dp) = (png_byte)(255 - *(--sp)); | ||
2875 | /* | ||
2876 | *(--dp) = *(--sp); | ||
2877 | *(--dp) = *(--sp); | ||
2878 | */ | ||
2879 | sp-=2; | ||
2880 | dp=sp; | ||
2881 | } | ||
2882 | } | ||
2883 | #endif | ||
2884 | } | ||
2885 | } | ||
2886 | #endif | ||
2887 | |||
2888 | #ifdef PNG_READ_FILLER_SUPPORTED | ||
2889 | /* Add filler channel if we have RGB color */ | ||
2890 | void /* PRIVATE */ | ||
2891 | png_do_read_filler(png_row_infop row_info, png_bytep row, | ||
2892 | png_uint_32 filler, png_uint_32 flags) | ||
2893 | { | ||
2894 | png_uint_32 i; | ||
2895 | png_uint_32 row_width = row_info->width; | ||
2896 | |||
2897 | #ifdef PNG_READ_16BIT_SUPPORTED | ||
2898 | png_byte hi_filler = (png_byte)((filler>>8) & 0xff); | ||
2899 | #endif | ||
2900 | png_byte lo_filler = (png_byte)(filler & 0xff); | ||
2901 | |||
2902 | png_debug(1, "in png_do_read_filler"); | ||
2903 | |||
2904 | if ( | ||
2905 | row_info->color_type == PNG_COLOR_TYPE_GRAY) | ||
2906 | { | ||
2907 | if (row_info->bit_depth == 8) | ||
2908 | { | ||
2909 | if (flags & PNG_FLAG_FILLER_AFTER) | ||
2910 | { | ||
2911 | /* This changes the data from G to GX */ | ||
2912 | png_bytep sp = row + (png_size_t)row_width; | ||
2913 | png_bytep dp = sp + (png_size_t)row_width; | ||
2914 | for (i = 1; i < row_width; i++) | ||
2915 | { | ||
2916 | *(--dp) = lo_filler; | ||
2917 | *(--dp) = *(--sp); | ||
2918 | } | ||
2919 | *(--dp) = lo_filler; | ||
2920 | row_info->channels = 2; | ||
2921 | row_info->pixel_depth = 16; | ||
2922 | row_info->rowbytes = row_width * 2; | ||
2923 | } | ||
2924 | |||
2925 | else | ||
2926 | { | ||
2927 | /* This changes the data from G to XG */ | ||
2928 | png_bytep sp = row + (png_size_t)row_width; | ||
2929 | png_bytep dp = sp + (png_size_t)row_width; | ||
2930 | for (i = 0; i < row_width; i++) | ||
2931 | { | ||
2932 | *(--dp) = *(--sp); | ||
2933 | *(--dp) = lo_filler; | ||
2934 | } | ||
2935 | row_info->channels = 2; | ||
2936 | row_info->pixel_depth = 16; | ||
2937 | row_info->rowbytes = row_width * 2; | ||
2938 | } | ||
2939 | } | ||
2940 | |||
2941 | #ifdef PNG_READ_16BIT_SUPPORTED | ||
2942 | else if (row_info->bit_depth == 16) | ||
2943 | { | ||
2944 | if (flags & PNG_FLAG_FILLER_AFTER) | ||
2945 | { | ||
2946 | /* This changes the data from GG to GGXX */ | ||
2947 | png_bytep sp = row + (png_size_t)row_width * 2; | ||
2948 | png_bytep dp = sp + (png_size_t)row_width * 2; | ||
2949 | for (i = 1; i < row_width; i++) | ||
2950 | { | ||
2951 | *(--dp) = hi_filler; | ||
2952 | *(--dp) = lo_filler; | ||
2953 | *(--dp) = *(--sp); | ||
2954 | *(--dp) = *(--sp); | ||
2955 | } | ||
2956 | *(--dp) = hi_filler; | ||
2957 | *(--dp) = lo_filler; | ||
2958 | row_info->channels = 2; | ||
2959 | row_info->pixel_depth = 32; | ||
2960 | row_info->rowbytes = row_width * 4; | ||
2961 | } | ||
2962 | |||
2963 | else | ||
2964 | { | ||
2965 | /* This changes the data from GG to XXGG */ | ||
2966 | png_bytep sp = row + (png_size_t)row_width * 2; | ||
2967 | png_bytep dp = sp + (png_size_t)row_width * 2; | ||
2968 | for (i = 0; i < row_width; i++) | ||
2969 | { | ||
2970 | *(--dp) = *(--sp); | ||
2971 | *(--dp) = *(--sp); | ||
2972 | *(--dp) = hi_filler; | ||
2973 | *(--dp) = lo_filler; | ||
2974 | } | ||
2975 | row_info->channels = 2; | ||
2976 | row_info->pixel_depth = 32; | ||
2977 | row_info->rowbytes = row_width * 4; | ||
2978 | } | ||
2979 | } | ||
2980 | #endif | ||
2981 | } /* COLOR_TYPE == GRAY */ | ||
2982 | else if (row_info->color_type == PNG_COLOR_TYPE_RGB) | ||
2983 | { | ||
2984 | if (row_info->bit_depth == 8) | ||
2985 | { | ||
2986 | if (flags & PNG_FLAG_FILLER_AFTER) | ||
2987 | { | ||
2988 | /* This changes the data from RGB to RGBX */ | ||
2989 | png_bytep sp = row + (png_size_t)row_width * 3; | ||
2990 | png_bytep dp = sp + (png_size_t)row_width; | ||
2991 | for (i = 1; i < row_width; i++) | ||
2992 | { | ||
2993 | *(--dp) = lo_filler; | ||
2994 | *(--dp) = *(--sp); | ||
2995 | *(--dp) = *(--sp); | ||
2996 | *(--dp) = *(--sp); | ||
2997 | } | ||
2998 | *(--dp) = lo_filler; | ||
2999 | row_info->channels = 4; | ||
3000 | row_info->pixel_depth = 32; | ||
3001 | row_info->rowbytes = row_width * 4; | ||
3002 | } | ||
3003 | |||
3004 | else | ||
3005 | { | ||
3006 | /* This changes the data from RGB to XRGB */ | ||
3007 | png_bytep sp = row + (png_size_t)row_width * 3; | ||
3008 | png_bytep dp = sp + (png_size_t)row_width; | ||
3009 | for (i = 0; i < row_width; i++) | ||
3010 | { | ||
3011 | *(--dp) = *(--sp); | ||
3012 | *(--dp) = *(--sp); | ||
3013 | *(--dp) = *(--sp); | ||
3014 | *(--dp) = lo_filler; | ||
3015 | } | ||
3016 | row_info->channels = 4; | ||
3017 | row_info->pixel_depth = 32; | ||
3018 | row_info->rowbytes = row_width * 4; | ||
3019 | } | ||
3020 | } | ||
3021 | |||
3022 | #ifdef PNG_READ_16BIT_SUPPORTED | ||
3023 | else if (row_info->bit_depth == 16) | ||
3024 | { | ||
3025 | if (flags & PNG_FLAG_FILLER_AFTER) | ||
3026 | { | ||
3027 | /* This changes the data from RRGGBB to RRGGBBXX */ | ||
3028 | png_bytep sp = row + (png_size_t)row_width * 6; | ||
3029 | png_bytep dp = sp + (png_size_t)row_width * 2; | ||
3030 | for (i = 1; i < row_width; i++) | ||
3031 | { | ||
3032 | *(--dp) = hi_filler; | ||
3033 | *(--dp) = lo_filler; | ||
3034 | *(--dp) = *(--sp); | ||
3035 | *(--dp) = *(--sp); | ||
3036 | *(--dp) = *(--sp); | ||
3037 | *(--dp) = *(--sp); | ||
3038 | *(--dp) = *(--sp); | ||
3039 | *(--dp) = *(--sp); | ||
3040 | } | ||
3041 | *(--dp) = hi_filler; | ||
3042 | *(--dp) = lo_filler; | ||
3043 | row_info->channels = 4; | ||
3044 | row_info->pixel_depth = 64; | ||
3045 | row_info->rowbytes = row_width * 8; | ||
3046 | } | ||
3047 | |||
3048 | else | ||
3049 | { | ||
3050 | /* This changes the data from RRGGBB to XXRRGGBB */ | ||
3051 | png_bytep sp = row + (png_size_t)row_width * 6; | ||
3052 | png_bytep dp = sp + (png_size_t)row_width * 2; | ||
3053 | for (i = 0; i < row_width; i++) | ||
3054 | { | ||
3055 | *(--dp) = *(--sp); | ||
3056 | *(--dp) = *(--sp); | ||
3057 | *(--dp) = *(--sp); | ||
3058 | *(--dp) = *(--sp); | ||
3059 | *(--dp) = *(--sp); | ||
3060 | *(--dp) = *(--sp); | ||
3061 | *(--dp) = hi_filler; | ||
3062 | *(--dp) = lo_filler; | ||
3063 | } | ||
3064 | |||
3065 | row_info->channels = 4; | ||
3066 | row_info->pixel_depth = 64; | ||
3067 | row_info->rowbytes = row_width * 8; | ||
3068 | } | ||
3069 | } | ||
3070 | #endif | ||
3071 | } /* COLOR_TYPE == RGB */ | ||
3072 | } | ||
3073 | #endif | ||
3074 | |||
3075 | #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED | ||
3076 | /* Expand grayscale files to RGB, with or without alpha */ | ||
3077 | void /* PRIVATE */ | ||
3078 | png_do_gray_to_rgb(png_row_infop row_info, png_bytep row) | ||
3079 | { | ||
3080 | png_uint_32 i; | ||
3081 | png_uint_32 row_width = row_info->width; | ||
3082 | |||
3083 | png_debug(1, "in png_do_gray_to_rgb"); | ||
3084 | |||
3085 | if (row_info->bit_depth >= 8 && | ||
3086 | !(row_info->color_type & PNG_COLOR_MASK_COLOR)) | ||
3087 | { | ||
3088 | if (row_info->color_type == PNG_COLOR_TYPE_GRAY) | ||
3089 | { | ||
3090 | if (row_info->bit_depth == 8) | ||
3091 | { | ||
3092 | /* This changes G to RGB */ | ||
3093 | png_bytep sp = row + (png_size_t)row_width - 1; | ||
3094 | png_bytep dp = sp + (png_size_t)row_width * 2; | ||
3095 | for (i = 0; i < row_width; i++) | ||
3096 | { | ||
3097 | *(dp--) = *sp; | ||
3098 | *(dp--) = *sp; | ||
3099 | *(dp--) = *(sp--); | ||
3100 | } | ||
3101 | } | ||
3102 | |||
3103 | else | ||
3104 | { | ||
3105 | /* This changes GG to RRGGBB */ | ||
3106 | png_bytep sp = row + (png_size_t)row_width * 2 - 1; | ||
3107 | png_bytep dp = sp + (png_size_t)row_width * 4; | ||
3108 | for (i = 0; i < row_width; i++) | ||
3109 | { | ||
3110 | *(dp--) = *sp; | ||
3111 | *(dp--) = *(sp - 1); | ||
3112 | *(dp--) = *sp; | ||
3113 | *(dp--) = *(sp - 1); | ||
3114 | *(dp--) = *(sp--); | ||
3115 | *(dp--) = *(sp--); | ||
3116 | } | ||
3117 | } | ||
3118 | } | ||
3119 | |||
3120 | else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) | ||
3121 | { | ||
3122 | if (row_info->bit_depth == 8) | ||
3123 | { | ||
3124 | /* This changes GA to RGBA */ | ||
3125 | png_bytep sp = row + (png_size_t)row_width * 2 - 1; | ||
3126 | png_bytep dp = sp + (png_size_t)row_width * 2; | ||
3127 | for (i = 0; i < row_width; i++) | ||
3128 | { | ||
3129 | *(dp--) = *(sp--); | ||
3130 | *(dp--) = *sp; | ||
3131 | *(dp--) = *sp; | ||
3132 | *(dp--) = *(sp--); | ||
3133 | } | ||
3134 | } | ||
3135 | |||
3136 | else | ||
3137 | { | ||
3138 | /* This changes GGAA to RRGGBBAA */ | ||
3139 | png_bytep sp = row + (png_size_t)row_width * 4 - 1; | ||
3140 | png_bytep dp = sp + (png_size_t)row_width * 4; | ||
3141 | for (i = 0; i < row_width; i++) | ||
3142 | { | ||
3143 | *(dp--) = *(sp--); | ||
3144 | *(dp--) = *(sp--); | ||
3145 | *(dp--) = *sp; | ||
3146 | *(dp--) = *(sp - 1); | ||
3147 | *(dp--) = *sp; | ||
3148 | *(dp--) = *(sp - 1); | ||
3149 | *(dp--) = *(sp--); | ||
3150 | *(dp--) = *(sp--); | ||
3151 | } | ||
3152 | } | ||
3153 | } | ||
3154 | row_info->channels = (png_byte)(row_info->channels + 2); | ||
3155 | row_info->color_type |= PNG_COLOR_MASK_COLOR; | ||
3156 | row_info->pixel_depth = (png_byte)(row_info->channels * | ||
3157 | row_info->bit_depth); | ||
3158 | row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); | ||
3159 | } | ||
3160 | } | ||
3161 | #endif | ||
3162 | |||
3163 | #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED | ||
3164 | /* Reduce RGB files to grayscale, with or without alpha | ||
3165 | * using the equation given in Poynton's ColorFAQ of 1998-01-04 at | ||
3166 | * <http://www.inforamp.net/~poynton/> (THIS LINK IS DEAD June 2008 but | ||
3167 | * versions dated 1998 through November 2002 have been archived at | ||
3168 | * http://web.archive.org/web/20000816232553/http://www.inforamp.net/ | ||
3169 | * ~poynton/notes/colour_and_gamma/ColorFAQ.txt ) | ||
3170 | * Charles Poynton poynton at poynton.com | ||
3171 | * | ||
3172 | * Y = 0.212671 * R + 0.715160 * G + 0.072169 * B | ||
3173 | * | ||
3174 | * which can be expressed with integers as | ||
3175 | * | ||
3176 | * Y = (6969 * R + 23434 * G + 2365 * B)/32768 | ||
3177 | * | ||
3178 | * Poynton's current link (as of January 2003 through July 2011): | ||
3179 | * <http://www.poynton.com/notes/colour_and_gamma/> | ||
3180 | * has changed the numbers slightly: | ||
3181 | * | ||
3182 | * Y = 0.2126*R + 0.7152*G + 0.0722*B | ||
3183 | * | ||
3184 | * which can be expressed with integers as | ||
3185 | * | ||
3186 | * Y = (6966 * R + 23436 * G + 2366 * B)/32768 | ||
3187 | * | ||
3188 | * Historically, however, libpng uses numbers derived from the ITU-R Rec 709 | ||
3189 | * end point chromaticities and the D65 white point. Depending on the | ||
3190 | * precision used for the D65 white point this produces a variety of different | ||
3191 | * numbers, however if the four decimal place value used in ITU-R Rec 709 is | ||
3192 | * used (0.3127,0.3290) the Y calculation would be: | ||
3193 | * | ||
3194 | * Y = (6968 * R + 23435 * G + 2366 * B)/32768 | ||
3195 | * | ||
3196 | * While this is correct the rounding results in an overflow for white, because | ||
3197 | * the sum of the rounded coefficients is 32769, not 32768. Consequently | ||
3198 | * libpng uses, instead, the closest non-overflowing approximation: | ||
3199 | * | ||
3200 | * Y = (6968 * R + 23434 * G + 2366 * B)/32768 | ||
3201 | * | ||
3202 | * Starting with libpng-1.5.5, if the image being converted has a cHRM chunk | ||
3203 | * (including an sRGB chunk) then the chromaticities are used to calculate the | ||
3204 | * coefficients. See the chunk handling in pngrutil.c for more information. | ||
3205 | * | ||
3206 | * In all cases the calculation is to be done in a linear colorspace. If no | ||
3207 | * gamma information is available to correct the encoding of the original RGB | ||
3208 | * values this results in an implicit assumption that the original PNG RGB | ||
3209 | * values were linear. | ||
3210 | * | ||
3211 | * Other integer coefficents can be used via png_set_rgb_to_gray(). Because | ||
3212 | * the API takes just red and green coefficients the blue coefficient is | ||
3213 | * calculated to make the sum 32768. This will result in different rounding | ||
3214 | * to that used above. | ||
3215 | */ | ||
3216 | int /* PRIVATE */ | ||
3217 | png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row) | ||
3218 | |||
3219 | { | ||
3220 | int rgb_error = 0; | ||
3221 | |||
3222 | png_debug(1, "in png_do_rgb_to_gray"); | ||
3223 | |||
3224 | if (!(row_info->color_type & PNG_COLOR_MASK_PALETTE) && | ||
3225 | (row_info->color_type & PNG_COLOR_MASK_COLOR)) | ||
3226 | { | ||
3227 | PNG_CONST png_uint_32 rc = png_ptr->rgb_to_gray_red_coeff; | ||
3228 | PNG_CONST png_uint_32 gc = png_ptr->rgb_to_gray_green_coeff; | ||
3229 | PNG_CONST png_uint_32 bc = 32768 - rc - gc; | ||
3230 | PNG_CONST png_uint_32 row_width = row_info->width; | ||
3231 | PNG_CONST int have_alpha = | ||
3232 | (row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0; | ||
3233 | |||
3234 | if (row_info->bit_depth == 8) | ||
3235 | { | ||
3236 | #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) | ||
3237 | /* Notice that gamma to/from 1 are not necessarily inverses (if | ||
3238 | * there is an overall gamma correction). Prior to 1.5.5 this code | ||
3239 | * checked the linearized values for equality; this doesn't match | ||
3240 | * the documentation, the original values must be checked. | ||
3241 | */ | ||
3242 | if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL) | ||
3243 | { | ||
3244 | png_bytep sp = row; | ||
3245 | png_bytep dp = row; | ||
3246 | png_uint_32 i; | ||
3247 | |||
3248 | for (i = 0; i < row_width; i++) | ||
3249 | { | ||
3250 | png_byte red = *(sp++); | ||
3251 | png_byte green = *(sp++); | ||
3252 | png_byte blue = *(sp++); | ||
3253 | |||
3254 | if (red != green || red != blue) | ||
3255 | { | ||
3256 | red = png_ptr->gamma_to_1[red]; | ||
3257 | green = png_ptr->gamma_to_1[green]; | ||
3258 | blue = png_ptr->gamma_to_1[blue]; | ||
3259 | |||
3260 | rgb_error |= 1; | ||
3261 | *(dp++) = png_ptr->gamma_from_1[ | ||
3262 | (rc*red + gc*green + bc*blue + 16384)>>15]; | ||
3263 | } | ||
3264 | |||
3265 | else | ||
3266 | { | ||
3267 | /* If there is no overall correction the table will not be | ||
3268 | * set. | ||
3269 | */ | ||
3270 | if (png_ptr->gamma_table != NULL) | ||
3271 | red = png_ptr->gamma_table[red]; | ||
3272 | |||
3273 | *(dp++) = red; | ||
3274 | } | ||
3275 | |||
3276 | if (have_alpha) | ||
3277 | *(dp++) = *(sp++); | ||
3278 | } | ||
3279 | } | ||
3280 | else | ||
3281 | #endif | ||
3282 | { | ||
3283 | png_bytep sp = row; | ||
3284 | png_bytep dp = row; | ||
3285 | png_uint_32 i; | ||
3286 | |||
3287 | for (i = 0; i < row_width; i++) | ||
3288 | { | ||
3289 | png_byte red = *(sp++); | ||
3290 | png_byte green = *(sp++); | ||
3291 | png_byte blue = *(sp++); | ||
3292 | |||
3293 | if (red != green || red != blue) | ||
3294 | { | ||
3295 | rgb_error |= 1; | ||
3296 | /*NOTE: this is the historical approach which simply | ||
3297 | * truncates the results. | ||
3298 | */ | ||
3299 | *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15); | ||
3300 | } | ||
3301 | |||
3302 | else | ||
3303 | *(dp++) = red; | ||
3304 | |||
3305 | if (have_alpha) | ||
3306 | *(dp++) = *(sp++); | ||
3307 | } | ||
3308 | } | ||
3309 | } | ||
3310 | |||
3311 | else /* RGB bit_depth == 16 */ | ||
3312 | { | ||
3313 | #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) | ||
3314 | if (png_ptr->gamma_16_to_1 != NULL && png_ptr->gamma_16_from_1 != NULL) | ||
3315 | { | ||
3316 | png_bytep sp = row; | ||
3317 | png_bytep dp = row; | ||
3318 | png_uint_32 i; | ||
3319 | |||
3320 | for (i = 0; i < row_width; i++) | ||
3321 | { | ||
3322 | png_uint_16 red, green, blue, w; | ||
3323 | |||
3324 | red = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; | ||
3325 | green = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; | ||
3326 | blue = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; | ||
3327 | |||
3328 | if (red == green && red == blue) | ||
3329 | { | ||
3330 | if (png_ptr->gamma_16_table != NULL) | ||
3331 | w = png_ptr->gamma_16_table[(red&0xff) | ||
3332 | >> png_ptr->gamma_shift][red>>8]; | ||
3333 | |||
3334 | else | ||
3335 | w = red; | ||
3336 | } | ||
3337 | |||
3338 | else | ||
3339 | { | ||
3340 | png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) | ||
3341 | >> png_ptr->gamma_shift][red>>8]; | ||
3342 | png_uint_16 green_1 = | ||
3343 | png_ptr->gamma_16_to_1[(green&0xff) >> | ||
3344 | png_ptr->gamma_shift][green>>8]; | ||
3345 | png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) | ||
3346 | >> png_ptr->gamma_shift][blue>>8]; | ||
3347 | png_uint_16 gray16 = (png_uint_16)((rc*red_1 + gc*green_1 | ||
3348 | + bc*blue_1 + 16384)>>15); | ||
3349 | w = png_ptr->gamma_16_from_1[(gray16&0xff) >> | ||
3350 | png_ptr->gamma_shift][gray16 >> 8]; | ||
3351 | rgb_error |= 1; | ||
3352 | } | ||
3353 | |||
3354 | *(dp++) = (png_byte)((w>>8) & 0xff); | ||
3355 | *(dp++) = (png_byte)(w & 0xff); | ||
3356 | |||
3357 | if (have_alpha) | ||
3358 | { | ||
3359 | *(dp++) = *(sp++); | ||
3360 | *(dp++) = *(sp++); | ||
3361 | } | ||
3362 | } | ||
3363 | } | ||
3364 | else | ||
3365 | #endif | ||
3366 | { | ||
3367 | png_bytep sp = row; | ||
3368 | png_bytep dp = row; | ||
3369 | png_uint_32 i; | ||
3370 | |||
3371 | for (i = 0; i < row_width; i++) | ||
3372 | { | ||
3373 | png_uint_16 red, green, blue, gray16; | ||
3374 | |||
3375 | red = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; | ||
3376 | green = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; | ||
3377 | blue = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; | ||
3378 | |||
3379 | if (red != green || red != blue) | ||
3380 | rgb_error |= 1; | ||
3381 | |||
3382 | /* From 1.5.5 in the 16 bit case do the accurate conversion even | ||
3383 | * in the 'fast' case - this is because this is where the code | ||
3384 | * ends up when handling linear 16 bit data. | ||
3385 | */ | ||
3386 | gray16 = (png_uint_16)((rc*red + gc*green + bc*blue + 16384) >> | ||
3387 | 15); | ||
3388 | *(dp++) = (png_byte)((gray16>>8) & 0xff); | ||
3389 | *(dp++) = (png_byte)(gray16 & 0xff); | ||
3390 | |||
3391 | if (have_alpha) | ||
3392 | { | ||
3393 | *(dp++) = *(sp++); | ||
3394 | *(dp++) = *(sp++); | ||
3395 | } | ||
3396 | } | ||
3397 | } | ||
3398 | } | ||
3399 | |||
3400 | row_info->channels = (png_byte)(row_info->channels - 2); | ||
3401 | row_info->color_type = (png_byte)(row_info->color_type & | ||
3402 | ~PNG_COLOR_MASK_COLOR); | ||
3403 | row_info->pixel_depth = (png_byte)(row_info->channels * | ||
3404 | row_info->bit_depth); | ||
3405 | row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); | ||
3406 | } | ||
3407 | return rgb_error; | ||
3408 | } | ||
3409 | #endif | ||
3410 | #endif /* PNG_READ_TRANSFORMS_SUPPORTED */ | ||
3411 | |||
3412 | #ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED | ||
3413 | /* Build a grayscale palette. Palette is assumed to be 1 << bit_depth | ||
3414 | * large of png_color. This lets grayscale images be treated as | ||
3415 | * paletted. Most useful for gamma correction and simplification | ||
3416 | * of code. This API is not used internally. | ||
3417 | */ | ||
3418 | void PNGAPI | ||
3419 | png_build_grayscale_palette(int bit_depth, png_colorp palette) | ||
3420 | { | ||
3421 | int num_palette; | ||
3422 | int color_inc; | ||
3423 | int i; | ||
3424 | int v; | ||
3425 | |||
3426 | png_debug(1, "in png_do_build_grayscale_palette"); | ||
3427 | |||
3428 | if (palette == NULL) | ||
3429 | return; | ||
3430 | |||
3431 | switch (bit_depth) | ||
3432 | { | ||
3433 | case 1: | ||
3434 | num_palette = 2; | ||
3435 | color_inc = 0xff; | ||
3436 | break; | ||
3437 | |||
3438 | case 2: | ||
3439 | num_palette = 4; | ||
3440 | color_inc = 0x55; | ||
3441 | break; | ||
3442 | |||
3443 | case 4: | ||
3444 | num_palette = 16; | ||
3445 | color_inc = 0x11; | ||
3446 | break; | ||
3447 | |||
3448 | case 8: | ||
3449 | num_palette = 256; | ||
3450 | color_inc = 1; | ||
3451 | break; | ||
3452 | |||
3453 | default: | ||
3454 | num_palette = 0; | ||
3455 | color_inc = 0; | ||
3456 | break; | ||
3457 | } | ||
3458 | |||
3459 | for (i = 0, v = 0; i < num_palette; i++, v += color_inc) | ||
3460 | { | ||
3461 | palette[i].red = (png_byte)v; | ||
3462 | palette[i].green = (png_byte)v; | ||
3463 | palette[i].blue = (png_byte)v; | ||
3464 | } | ||
3465 | } | ||
3466 | #endif | ||
3467 | |||
3468 | |||
3469 | #ifdef PNG_READ_TRANSFORMS_SUPPORTED | ||
3470 | #if (defined PNG_READ_BACKGROUND_SUPPORTED) ||\ | ||
3471 | (defined PNG_READ_ALPHA_MODE_SUPPORTED) | ||
3472 | /* Replace any alpha or transparency with the supplied background color. | ||
3473 | * "background" is already in the screen gamma, while "background_1" is | ||
3474 | * at a gamma of 1.0. Paletted files have already been taken care of. | ||
3475 | */ | ||
3476 | void /* PRIVATE */ | ||
3477 | png_do_compose(png_row_infop row_info, png_bytep row, png_structp png_ptr) | ||
3478 | { | ||
3479 | #ifdef PNG_READ_GAMMA_SUPPORTED | ||
3480 | png_const_bytep gamma_table = png_ptr->gamma_table; | ||
3481 | png_const_bytep gamma_from_1 = png_ptr->gamma_from_1; | ||
3482 | png_const_bytep gamma_to_1 = png_ptr->gamma_to_1; | ||
3483 | png_const_uint_16pp gamma_16 = png_ptr->gamma_16_table; | ||
3484 | png_const_uint_16pp gamma_16_from_1 = png_ptr->gamma_16_from_1; | ||
3485 | png_const_uint_16pp gamma_16_to_1 = png_ptr->gamma_16_to_1; | ||
3486 | int gamma_shift = png_ptr->gamma_shift; | ||
3487 | #endif | ||
3488 | |||
3489 | png_bytep sp; | ||
3490 | png_uint_32 i; | ||
3491 | png_uint_32 row_width = row_info->width; | ||
3492 | int optimize = (png_ptr->flags & PNG_FLAG_OPTIMIZE_ALPHA) != 0; | ||
3493 | int shift; | ||
3494 | |||
3495 | png_debug(1, "in png_do_compose"); | ||
3496 | |||
3497 | { | ||
3498 | switch (row_info->color_type) | ||
3499 | { | ||
3500 | case PNG_COLOR_TYPE_GRAY: | ||
3501 | { | ||
3502 | switch (row_info->bit_depth) | ||
3503 | { | ||
3504 | case 1: | ||
3505 | { | ||
3506 | sp = row; | ||
3507 | shift = 7; | ||
3508 | for (i = 0; i < row_width; i++) | ||
3509 | { | ||
3510 | if ((png_uint_16)((*sp >> shift) & 0x01) | ||
3511 | == png_ptr->trans_color.gray) | ||
3512 | { | ||
3513 | *sp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff); | ||
3514 | *sp |= (png_byte)(png_ptr->background.gray << shift); | ||
3515 | } | ||
3516 | |||
3517 | if (!shift) | ||
3518 | { | ||
3519 | shift = 7; | ||
3520 | sp++; | ||
3521 | } | ||
3522 | |||
3523 | else | ||
3524 | shift--; | ||
3525 | } | ||
3526 | break; | ||
3527 | } | ||
3528 | |||
3529 | case 2: | ||
3530 | { | ||
3531 | #ifdef PNG_READ_GAMMA_SUPPORTED | ||
3532 | if (gamma_table != NULL) | ||
3533 | { | ||
3534 | sp = row; | ||
3535 | shift = 6; | ||
3536 | for (i = 0; i < row_width; i++) | ||
3537 | { | ||
3538 | if ((png_uint_16)((*sp >> shift) & 0x03) | ||
3539 | == png_ptr->trans_color.gray) | ||
3540 | { | ||
3541 | *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff); | ||
3542 | *sp |= (png_byte)(png_ptr->background.gray << shift); | ||
3543 | } | ||
3544 | |||
3545 | else | ||
3546 | { | ||
3547 | png_byte p = (png_byte)((*sp >> shift) & 0x03); | ||
3548 | png_byte g = (png_byte)((gamma_table [p | (p << 2) | | ||
3549 | (p << 4) | (p << 6)] >> 6) & 0x03); | ||
3550 | *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff); | ||
3551 | *sp |= (png_byte)(g << shift); | ||
3552 | } | ||
3553 | |||
3554 | if (!shift) | ||
3555 | { | ||
3556 | shift = 6; | ||
3557 | sp++; | ||
3558 | } | ||
3559 | |||
3560 | else | ||
3561 | shift -= 2; | ||
3562 | } | ||
3563 | } | ||
3564 | |||
3565 | else | ||
3566 | #endif | ||
3567 | { | ||
3568 | sp = row; | ||
3569 | shift = 6; | ||
3570 | for (i = 0; i < row_width; i++) | ||
3571 | { | ||
3572 | if ((png_uint_16)((*sp >> shift) & 0x03) | ||
3573 | == png_ptr->trans_color.gray) | ||
3574 | { | ||
3575 | *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff); | ||
3576 | *sp |= (png_byte)(png_ptr->background.gray << shift); | ||
3577 | } | ||
3578 | |||
3579 | if (!shift) | ||
3580 | { | ||
3581 | shift = 6; | ||
3582 | sp++; | ||
3583 | } | ||
3584 | |||
3585 | else | ||
3586 | shift -= 2; | ||
3587 | } | ||
3588 | } | ||
3589 | break; | ||
3590 | } | ||
3591 | |||
3592 | case 4: | ||
3593 | { | ||
3594 | #ifdef PNG_READ_GAMMA_SUPPORTED | ||
3595 | if (gamma_table != NULL) | ||
3596 | { | ||
3597 | sp = row; | ||
3598 | shift = 4; | ||
3599 | for (i = 0; i < row_width; i++) | ||
3600 | { | ||
3601 | if ((png_uint_16)((*sp >> shift) & 0x0f) | ||
3602 | == png_ptr->trans_color.gray) | ||
3603 | { | ||
3604 | *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff); | ||
3605 | *sp |= (png_byte)(png_ptr->background.gray << shift); | ||
3606 | } | ||
3607 | |||
3608 | else | ||
3609 | { | ||
3610 | png_byte p = (png_byte)((*sp >> shift) & 0x0f); | ||
3611 | png_byte g = (png_byte)((gamma_table[p | | ||
3612 | (p << 4)] >> 4) & 0x0f); | ||
3613 | *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff); | ||
3614 | *sp |= (png_byte)(g << shift); | ||
3615 | } | ||
3616 | |||
3617 | if (!shift) | ||
3618 | { | ||
3619 | shift = 4; | ||
3620 | sp++; | ||
3621 | } | ||
3622 | |||
3623 | else | ||
3624 | shift -= 4; | ||
3625 | } | ||
3626 | } | ||
3627 | |||
3628 | else | ||
3629 | #endif | ||
3630 | { | ||
3631 | sp = row; | ||
3632 | shift = 4; | ||
3633 | for (i = 0; i < row_width; i++) | ||
3634 | { | ||
3635 | if ((png_uint_16)((*sp >> shift) & 0x0f) | ||
3636 | == png_ptr->trans_color.gray) | ||
3637 | { | ||
3638 | *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff); | ||
3639 | *sp |= (png_byte)(png_ptr->background.gray << shift); | ||
3640 | } | ||
3641 | |||
3642 | if (!shift) | ||
3643 | { | ||
3644 | shift = 4; | ||
3645 | sp++; | ||
3646 | } | ||
3647 | |||
3648 | else | ||
3649 | shift -= 4; | ||
3650 | } | ||
3651 | } | ||
3652 | break; | ||
3653 | } | ||
3654 | |||
3655 | case 8: | ||
3656 | { | ||
3657 | #ifdef PNG_READ_GAMMA_SUPPORTED | ||
3658 | if (gamma_table != NULL) | ||
3659 | { | ||
3660 | sp = row; | ||
3661 | for (i = 0; i < row_width; i++, sp++) | ||
3662 | { | ||
3663 | if (*sp == png_ptr->trans_color.gray) | ||
3664 | *sp = (png_byte)png_ptr->background.gray; | ||
3665 | |||
3666 | else | ||
3667 | *sp = gamma_table[*sp]; | ||
3668 | } | ||
3669 | } | ||
3670 | else | ||
3671 | #endif | ||
3672 | { | ||
3673 | sp = row; | ||
3674 | for (i = 0; i < row_width; i++, sp++) | ||
3675 | { | ||
3676 | if (*sp == png_ptr->trans_color.gray) | ||
3677 | *sp = (png_byte)png_ptr->background.gray; | ||
3678 | } | ||
3679 | } | ||
3680 | break; | ||
3681 | } | ||
3682 | |||
3683 | case 16: | ||
3684 | { | ||
3685 | #ifdef PNG_READ_GAMMA_SUPPORTED | ||
3686 | if (gamma_16 != NULL) | ||
3687 | { | ||
3688 | sp = row; | ||
3689 | for (i = 0; i < row_width; i++, sp += 2) | ||
3690 | { | ||
3691 | png_uint_16 v; | ||
3692 | |||
3693 | v = (png_uint_16)(((*sp) << 8) + *(sp + 1)); | ||
3694 | |||
3695 | if (v == png_ptr->trans_color.gray) | ||
3696 | { | ||
3697 | /* Background is already in screen gamma */ | ||
3698 | *sp = (png_byte)((png_ptr->background.gray >> 8) & 0xff); | ||
3699 | *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff); | ||
3700 | } | ||
3701 | |||
3702 | else | ||
3703 | { | ||
3704 | v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; | ||
3705 | *sp = (png_byte)((v >> 8) & 0xff); | ||
3706 | *(sp + 1) = (png_byte)(v & 0xff); | ||
3707 | } | ||
3708 | } | ||
3709 | } | ||
3710 | else | ||
3711 | #endif | ||
3712 | { | ||
3713 | sp = row; | ||
3714 | for (i = 0; i < row_width; i++, sp += 2) | ||
3715 | { | ||
3716 | png_uint_16 v; | ||
3717 | |||
3718 | v = (png_uint_16)(((*sp) << 8) + *(sp + 1)); | ||
3719 | |||
3720 | if (v == png_ptr->trans_color.gray) | ||
3721 | { | ||
3722 | *sp = (png_byte)((png_ptr->background.gray >> 8) & 0xff); | ||
3723 | *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff); | ||
3724 | } | ||
3725 | } | ||
3726 | } | ||
3727 | break; | ||
3728 | } | ||
3729 | |||
3730 | default: | ||
3731 | break; | ||
3732 | } | ||
3733 | break; | ||
3734 | } | ||
3735 | |||
3736 | case PNG_COLOR_TYPE_RGB: | ||
3737 | { | ||
3738 | if (row_info->bit_depth == 8) | ||
3739 | { | ||
3740 | #ifdef PNG_READ_GAMMA_SUPPORTED | ||
3741 | if (gamma_table != NULL) | ||
3742 | { | ||
3743 | sp = row; | ||
3744 | for (i = 0; i < row_width; i++, sp += 3) | ||
3745 | { | ||
3746 | if (*sp == png_ptr->trans_color.red && | ||
3747 | *(sp + 1) == png_ptr->trans_color.green && | ||
3748 | *(sp + 2) == png_ptr->trans_color.blue) | ||
3749 | { | ||
3750 | *sp = (png_byte)png_ptr->background.red; | ||
3751 | *(sp + 1) = (png_byte)png_ptr->background.green; | ||
3752 | *(sp + 2) = (png_byte)png_ptr->background.blue; | ||
3753 | } | ||
3754 | |||
3755 | else | ||
3756 | { | ||
3757 | *sp = gamma_table[*sp]; | ||
3758 | *(sp + 1) = gamma_table[*(sp + 1)]; | ||
3759 | *(sp + 2) = gamma_table[*(sp + 2)]; | ||
3760 | } | ||
3761 | } | ||
3762 | } | ||
3763 | else | ||
3764 | #endif | ||
3765 | { | ||
3766 | sp = row; | ||
3767 | for (i = 0; i < row_width; i++, sp += 3) | ||
3768 | { | ||
3769 | if (*sp == png_ptr->trans_color.red && | ||
3770 | *(sp + 1) == png_ptr->trans_color.green && | ||
3771 | *(sp + 2) == png_ptr->trans_color.blue) | ||
3772 | { | ||
3773 | *sp = (png_byte)png_ptr->background.red; | ||
3774 | *(sp + 1) = (png_byte)png_ptr->background.green; | ||
3775 | *(sp + 2) = (png_byte)png_ptr->background.blue; | ||
3776 | } | ||
3777 | } | ||
3778 | } | ||
3779 | } | ||
3780 | else /* if (row_info->bit_depth == 16) */ | ||
3781 | { | ||
3782 | #ifdef PNG_READ_GAMMA_SUPPORTED | ||
3783 | if (gamma_16 != NULL) | ||
3784 | { | ||
3785 | sp = row; | ||
3786 | for (i = 0; i < row_width; i++, sp += 6) | ||
3787 | { | ||
3788 | png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1)); | ||
3789 | |||
3790 | png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8) | ||
3791 | + *(sp + 3)); | ||
3792 | |||
3793 | png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8) | ||
3794 | + *(sp + 5)); | ||
3795 | |||
3796 | if (r == png_ptr->trans_color.red && | ||
3797 | g == png_ptr->trans_color.green && | ||
3798 | b == png_ptr->trans_color.blue) | ||
3799 | { | ||
3800 | /* Background is already in screen gamma */ | ||
3801 | *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff); | ||
3802 | *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff); | ||
3803 | *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) & 0xff); | ||
3804 | *(sp + 3) = (png_byte)(png_ptr->background.green & 0xff); | ||
3805 | *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) & 0xff); | ||
3806 | *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff); | ||
3807 | } | ||
3808 | |||
3809 | else | ||
3810 | { | ||
3811 | png_uint_16 v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; | ||
3812 | *sp = (png_byte)((v >> 8) & 0xff); | ||
3813 | *(sp + 1) = (png_byte)(v & 0xff); | ||
3814 | |||
3815 | v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)]; | ||
3816 | *(sp + 2) = (png_byte)((v >> 8) & 0xff); | ||
3817 | *(sp + 3) = (png_byte)(v & 0xff); | ||
3818 | |||
3819 | v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)]; | ||
3820 | *(sp + 4) = (png_byte)((v >> 8) & 0xff); | ||
3821 | *(sp + 5) = (png_byte)(v & 0xff); | ||
3822 | } | ||
3823 | } | ||
3824 | } | ||
3825 | |||
3826 | else | ||
3827 | #endif | ||
3828 | { | ||
3829 | sp = row; | ||
3830 | for (i = 0; i < row_width; i++, sp += 6) | ||
3831 | { | ||
3832 | png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1)); | ||
3833 | |||
3834 | png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8) | ||
3835 | + *(sp + 3)); | ||
3836 | |||
3837 | png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8) | ||
3838 | + *(sp + 5)); | ||
3839 | |||
3840 | if (r == png_ptr->trans_color.red && | ||
3841 | g == png_ptr->trans_color.green && | ||
3842 | b == png_ptr->trans_color.blue) | ||
3843 | { | ||
3844 | *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff); | ||
3845 | *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff); | ||
3846 | *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) & 0xff); | ||
3847 | *(sp + 3) = (png_byte)(png_ptr->background.green & 0xff); | ||
3848 | *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) & 0xff); | ||
3849 | *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff); | ||
3850 | } | ||
3851 | } | ||
3852 | } | ||
3853 | } | ||
3854 | break; | ||
3855 | } | ||
3856 | |||
3857 | case PNG_COLOR_TYPE_GRAY_ALPHA: | ||
3858 | { | ||
3859 | if (row_info->bit_depth == 8) | ||
3860 | { | ||
3861 | #ifdef PNG_READ_GAMMA_SUPPORTED | ||
3862 | if (gamma_to_1 != NULL && gamma_from_1 != NULL && | ||
3863 | gamma_table != NULL) | ||
3864 | { | ||
3865 | sp = row; | ||
3866 | for (i = 0; i < row_width; i++, sp += 2) | ||
3867 | { | ||
3868 | png_uint_16 a = *(sp + 1); | ||
3869 | |||
3870 | if (a == 0xff) | ||
3871 | *sp = gamma_table[*sp]; | ||
3872 | |||
3873 | else if (a == 0) | ||
3874 | { | ||
3875 | /* Background is already in screen gamma */ | ||
3876 | *sp = (png_byte)png_ptr->background.gray; | ||
3877 | } | ||
3878 | |||
3879 | else | ||
3880 | { | ||
3881 | png_byte v, w; | ||
3882 | |||
3883 | v = gamma_to_1[*sp]; | ||
3884 | png_composite(w, v, a, png_ptr->background_1.gray); | ||
3885 | if (!optimize) | ||
3886 | w = gamma_from_1[w]; | ||
3887 | *sp = w; | ||
3888 | } | ||
3889 | } | ||
3890 | } | ||
3891 | else | ||
3892 | #endif | ||
3893 | { | ||
3894 | sp = row; | ||
3895 | for (i = 0; i < row_width; i++, sp += 2) | ||
3896 | { | ||
3897 | png_byte a = *(sp + 1); | ||
3898 | |||
3899 | if (a == 0) | ||
3900 | *sp = (png_byte)png_ptr->background.gray; | ||
3901 | |||
3902 | else if (a < 0xff) | ||
3903 | png_composite(*sp, *sp, a, png_ptr->background_1.gray); | ||
3904 | } | ||
3905 | } | ||
3906 | } | ||
3907 | else /* if (png_ptr->bit_depth == 16) */ | ||
3908 | { | ||
3909 | #ifdef PNG_READ_GAMMA_SUPPORTED | ||
3910 | if (gamma_16 != NULL && gamma_16_from_1 != NULL && | ||
3911 | gamma_16_to_1 != NULL) | ||
3912 | { | ||
3913 | sp = row; | ||
3914 | for (i = 0; i < row_width; i++, sp += 4) | ||
3915 | { | ||
3916 | png_uint_16 a = (png_uint_16)(((*(sp + 2)) << 8) | ||
3917 | + *(sp + 3)); | ||
3918 | |||
3919 | if (a == (png_uint_16)0xffff) | ||
3920 | { | ||
3921 | png_uint_16 v; | ||
3922 | |||
3923 | v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; | ||
3924 | *sp = (png_byte)((v >> 8) & 0xff); | ||
3925 | *(sp + 1) = (png_byte)(v & 0xff); | ||
3926 | } | ||
3927 | |||
3928 | else if (a == 0) | ||
3929 | { | ||
3930 | /* Background is already in screen gamma */ | ||
3931 | *sp = (png_byte)((png_ptr->background.gray >> 8) & 0xff); | ||
3932 | *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff); | ||
3933 | } | ||
3934 | |||
3935 | else | ||
3936 | { | ||
3937 | png_uint_16 g, v, w; | ||
3938 | |||
3939 | g = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp]; | ||
3940 | png_composite_16(v, g, a, png_ptr->background_1.gray); | ||
3941 | if (optimize) | ||
3942 | w = v; | ||
3943 | else | ||
3944 | w = gamma_16_from_1[(v&0xff) >> gamma_shift][v >> 8]; | ||
3945 | *sp = (png_byte)((w >> 8) & 0xff); | ||
3946 | *(sp + 1) = (png_byte)(w & 0xff); | ||
3947 | } | ||
3948 | } | ||
3949 | } | ||
3950 | else | ||
3951 | #endif | ||
3952 | { | ||
3953 | sp = row; | ||
3954 | for (i = 0; i < row_width; i++, sp += 4) | ||
3955 | { | ||
3956 | png_uint_16 a = (png_uint_16)(((*(sp + 2)) << 8) | ||
3957 | + *(sp + 3)); | ||
3958 | |||
3959 | if (a == 0) | ||
3960 | { | ||
3961 | *sp = (png_byte)((png_ptr->background.gray >> 8) & 0xff); | ||
3962 | *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff); | ||
3963 | } | ||
3964 | |||
3965 | else if (a < 0xffff) | ||
3966 | { | ||
3967 | png_uint_16 g, v; | ||
3968 | |||
3969 | g = (png_uint_16)(((*sp) << 8) + *(sp + 1)); | ||
3970 | png_composite_16(v, g, a, png_ptr->background_1.gray); | ||
3971 | *sp = (png_byte)((v >> 8) & 0xff); | ||
3972 | *(sp + 1) = (png_byte)(v & 0xff); | ||
3973 | } | ||
3974 | } | ||
3975 | } | ||
3976 | } | ||
3977 | break; | ||
3978 | } | ||
3979 | |||
3980 | case PNG_COLOR_TYPE_RGB_ALPHA: | ||
3981 | { | ||
3982 | if (row_info->bit_depth == 8) | ||
3983 | { | ||
3984 | #ifdef PNG_READ_GAMMA_SUPPORTED | ||
3985 | if (gamma_to_1 != NULL && gamma_from_1 != NULL && | ||
3986 | gamma_table != NULL) | ||
3987 | { | ||
3988 | sp = row; | ||
3989 | for (i = 0; i < row_width; i++, sp += 4) | ||
3990 | { | ||
3991 | png_byte a = *(sp + 3); | ||
3992 | |||
3993 | if (a == 0xff) | ||
3994 | { | ||
3995 | *sp = gamma_table[*sp]; | ||
3996 | *(sp + 1) = gamma_table[*(sp + 1)]; | ||
3997 | *(sp + 2) = gamma_table[*(sp + 2)]; | ||
3998 | } | ||
3999 | |||
4000 | else if (a == 0) | ||
4001 | { | ||
4002 | /* Background is already in screen gamma */ | ||
4003 | *sp = (png_byte)png_ptr->background.red; | ||
4004 | *(sp + 1) = (png_byte)png_ptr->background.green; | ||
4005 | *(sp + 2) = (png_byte)png_ptr->background.blue; | ||
4006 | } | ||
4007 | |||
4008 | else | ||
4009 | { | ||
4010 | png_byte v, w; | ||
4011 | |||
4012 | v = gamma_to_1[*sp]; | ||
4013 | png_composite(w, v, a, png_ptr->background_1.red); | ||
4014 | if (!optimize) w = gamma_from_1[w]; | ||
4015 | *sp = w; | ||
4016 | |||
4017 | v = gamma_to_1[*(sp + 1)]; | ||
4018 | png_composite(w, v, a, png_ptr->background_1.green); | ||
4019 | if (!optimize) w = gamma_from_1[w]; | ||
4020 | *(sp + 1) = w; | ||
4021 | |||
4022 | v = gamma_to_1[*(sp + 2)]; | ||
4023 | png_composite(w, v, a, png_ptr->background_1.blue); | ||
4024 | if (!optimize) w = gamma_from_1[w]; | ||
4025 | *(sp + 2) = w; | ||
4026 | } | ||
4027 | } | ||
4028 | } | ||
4029 | else | ||
4030 | #endif | ||
4031 | { | ||
4032 | sp = row; | ||
4033 | for (i = 0; i < row_width; i++, sp += 4) | ||
4034 | { | ||
4035 | png_byte a = *(sp + 3); | ||
4036 | |||
4037 | if (a == 0) | ||
4038 | { | ||
4039 | *sp = (png_byte)png_ptr->background.red; | ||
4040 | *(sp + 1) = (png_byte)png_ptr->background.green; | ||
4041 | *(sp + 2) = (png_byte)png_ptr->background.blue; | ||
4042 | } | ||
4043 | |||
4044 | else if (a < 0xff) | ||
4045 | { | ||
4046 | png_composite(*sp, *sp, a, png_ptr->background.red); | ||
4047 | |||
4048 | png_composite(*(sp + 1), *(sp + 1), a, | ||
4049 | png_ptr->background.green); | ||
4050 | |||
4051 | png_composite(*(sp + 2), *(sp + 2), a, | ||
4052 | png_ptr->background.blue); | ||
4053 | } | ||
4054 | } | ||
4055 | } | ||
4056 | } | ||
4057 | else /* if (row_info->bit_depth == 16) */ | ||
4058 | { | ||
4059 | #ifdef PNG_READ_GAMMA_SUPPORTED | ||
4060 | if (gamma_16 != NULL && gamma_16_from_1 != NULL && | ||
4061 | gamma_16_to_1 != NULL) | ||
4062 | { | ||
4063 | sp = row; | ||
4064 | for (i = 0; i < row_width; i++, sp += 8) | ||
4065 | { | ||
4066 | png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6)) | ||
4067 | << 8) + (png_uint_16)(*(sp + 7))); | ||
4068 | |||
4069 | if (a == (png_uint_16)0xffff) | ||
4070 | { | ||
4071 | png_uint_16 v; | ||
4072 | |||
4073 | v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; | ||
4074 | *sp = (png_byte)((v >> 8) & 0xff); | ||
4075 | *(sp + 1) = (png_byte)(v & 0xff); | ||
4076 | |||
4077 | v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)]; | ||
4078 | *(sp + 2) = (png_byte)((v >> 8) & 0xff); | ||
4079 | *(sp + 3) = (png_byte)(v & 0xff); | ||
4080 | |||
4081 | v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)]; | ||
4082 | *(sp + 4) = (png_byte)((v >> 8) & 0xff); | ||
4083 | *(sp + 5) = (png_byte)(v & 0xff); | ||
4084 | } | ||
4085 | |||
4086 | else if (a == 0) | ||
4087 | { | ||
4088 | /* Background is already in screen gamma */ | ||
4089 | *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff); | ||
4090 | *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff); | ||
4091 | *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) & 0xff); | ||
4092 | *(sp + 3) = (png_byte)(png_ptr->background.green & 0xff); | ||
4093 | *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) & 0xff); | ||
4094 | *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff); | ||
4095 | } | ||
4096 | |||
4097 | else | ||
4098 | { | ||
4099 | png_uint_16 v, w; | ||
4100 | |||
4101 | v = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp]; | ||
4102 | png_composite_16(w, v, a, png_ptr->background_1.red); | ||
4103 | if (!optimize) | ||
4104 | w = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8]; | ||
4105 | *sp = (png_byte)((w >> 8) & 0xff); | ||
4106 | *(sp + 1) = (png_byte)(w & 0xff); | ||
4107 | |||
4108 | v = gamma_16_to_1[*(sp + 3) >> gamma_shift][*(sp + 2)]; | ||
4109 | png_composite_16(w, v, a, png_ptr->background_1.green); | ||
4110 | if (!optimize) | ||
4111 | w = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8]; | ||
4112 | |||
4113 | *(sp + 2) = (png_byte)((w >> 8) & 0xff); | ||
4114 | *(sp + 3) = (png_byte)(w & 0xff); | ||
4115 | |||
4116 | v = gamma_16_to_1[*(sp + 5) >> gamma_shift][*(sp + 4)]; | ||
4117 | png_composite_16(w, v, a, png_ptr->background_1.blue); | ||
4118 | if (!optimize) | ||
4119 | w = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8]; | ||
4120 | |||
4121 | *(sp + 4) = (png_byte)((w >> 8) & 0xff); | ||
4122 | *(sp + 5) = (png_byte)(w & 0xff); | ||
4123 | } | ||
4124 | } | ||
4125 | } | ||
4126 | |||
4127 | else | ||
4128 | #endif | ||
4129 | { | ||
4130 | sp = row; | ||
4131 | for (i = 0; i < row_width; i++, sp += 8) | ||
4132 | { | ||
4133 | png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6)) | ||
4134 | << 8) + (png_uint_16)(*(sp + 7))); | ||
4135 | |||
4136 | if (a == 0) | ||
4137 | { | ||
4138 | *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff); | ||
4139 | *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff); | ||
4140 | *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) & 0xff); | ||
4141 | *(sp + 3) = (png_byte)(png_ptr->background.green & 0xff); | ||
4142 | *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) & 0xff); | ||
4143 | *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff); | ||
4144 | } | ||
4145 | |||
4146 | else if (a < 0xffff) | ||
4147 | { | ||
4148 | png_uint_16 v; | ||
4149 | |||
4150 | png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1)); | ||
4151 | png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8) | ||
4152 | + *(sp + 3)); | ||
4153 | png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8) | ||
4154 | + *(sp + 5)); | ||
4155 | |||
4156 | png_composite_16(v, r, a, png_ptr->background.red); | ||
4157 | *sp = (png_byte)((v >> 8) & 0xff); | ||
4158 | *(sp + 1) = (png_byte)(v & 0xff); | ||
4159 | |||
4160 | png_composite_16(v, g, a, png_ptr->background.green); | ||
4161 | *(sp + 2) = (png_byte)((v >> 8) & 0xff); | ||
4162 | *(sp + 3) = (png_byte)(v & 0xff); | ||
4163 | |||
4164 | png_composite_16(v, b, a, png_ptr->background.blue); | ||
4165 | *(sp + 4) = (png_byte)((v >> 8) & 0xff); | ||
4166 | *(sp + 5) = (png_byte)(v & 0xff); | ||
4167 | } | ||
4168 | } | ||
4169 | } | ||
4170 | } | ||
4171 | break; | ||
4172 | } | ||
4173 | |||
4174 | default: | ||
4175 | break; | ||
4176 | } | ||
4177 | } | ||
4178 | } | ||
4179 | #endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_READ_ALPHA_MODE_SUPPORTED */ | ||
4180 | |||
4181 | #ifdef PNG_READ_GAMMA_SUPPORTED | ||
4182 | /* Gamma correct the image, avoiding the alpha channel. Make sure | ||
4183 | * you do this after you deal with the transparency issue on grayscale | ||
4184 | * or RGB images. If your bit depth is 8, use gamma_table, if it | ||
4185 | * is 16, use gamma_16_table and gamma_shift. Build these with | ||
4186 | * build_gamma_table(). | ||
4187 | */ | ||
4188 | void /* PRIVATE */ | ||
4189 | png_do_gamma(png_row_infop row_info, png_bytep row, png_structp png_ptr) | ||
4190 | { | ||
4191 | png_const_bytep gamma_table = png_ptr->gamma_table; | ||
4192 | png_const_uint_16pp gamma_16_table = png_ptr->gamma_16_table; | ||
4193 | int gamma_shift = png_ptr->gamma_shift; | ||
4194 | |||
4195 | png_bytep sp; | ||
4196 | png_uint_32 i; | ||
4197 | png_uint_32 row_width=row_info->width; | ||
4198 | |||
4199 | png_debug(1, "in png_do_gamma"); | ||
4200 | |||
4201 | if (((row_info->bit_depth <= 8 && gamma_table != NULL) || | ||
4202 | (row_info->bit_depth == 16 && gamma_16_table != NULL))) | ||
4203 | { | ||
4204 | switch (row_info->color_type) | ||
4205 | { | ||
4206 | case PNG_COLOR_TYPE_RGB: | ||
4207 | { | ||
4208 | if (row_info->bit_depth == 8) | ||
4209 | { | ||
4210 | sp = row; | ||
4211 | for (i = 0; i < row_width; i++) | ||
4212 | { | ||
4213 | *sp = gamma_table[*sp]; | ||
4214 | sp++; | ||
4215 | *sp = gamma_table[*sp]; | ||
4216 | sp++; | ||
4217 | *sp = gamma_table[*sp]; | ||
4218 | sp++; | ||
4219 | } | ||
4220 | } | ||
4221 | |||
4222 | else /* if (row_info->bit_depth == 16) */ | ||
4223 | { | ||
4224 | sp = row; | ||
4225 | for (i = 0; i < row_width; i++) | ||
4226 | { | ||
4227 | png_uint_16 v; | ||
4228 | |||
4229 | v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; | ||
4230 | *sp = (png_byte)((v >> 8) & 0xff); | ||
4231 | *(sp + 1) = (png_byte)(v & 0xff); | ||
4232 | sp += 2; | ||
4233 | |||
4234 | v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; | ||
4235 | *sp = (png_byte)((v >> 8) & 0xff); | ||
4236 | *(sp + 1) = (png_byte)(v & 0xff); | ||
4237 | sp += 2; | ||
4238 | |||
4239 | v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; | ||
4240 | *sp = (png_byte)((v >> 8) & 0xff); | ||
4241 | *(sp + 1) = (png_byte)(v & 0xff); | ||
4242 | sp += 2; | ||
4243 | } | ||
4244 | } | ||
4245 | break; | ||
4246 | } | ||
4247 | |||
4248 | case PNG_COLOR_TYPE_RGB_ALPHA: | ||
4249 | { | ||
4250 | if (row_info->bit_depth == 8) | ||
4251 | { | ||
4252 | sp = row; | ||
4253 | for (i = 0; i < row_width; i++) | ||
4254 | { | ||
4255 | *sp = gamma_table[*sp]; | ||
4256 | sp++; | ||
4257 | |||
4258 | *sp = gamma_table[*sp]; | ||
4259 | sp++; | ||
4260 | |||
4261 | *sp = gamma_table[*sp]; | ||
4262 | sp++; | ||
4263 | |||
4264 | sp++; | ||
4265 | } | ||
4266 | } | ||
4267 | |||
4268 | else /* if (row_info->bit_depth == 16) */ | ||
4269 | { | ||
4270 | sp = row; | ||
4271 | for (i = 0; i < row_width; i++) | ||
4272 | { | ||
4273 | png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; | ||
4274 | *sp = (png_byte)((v >> 8) & 0xff); | ||
4275 | *(sp + 1) = (png_byte)(v & 0xff); | ||
4276 | sp += 2; | ||
4277 | |||
4278 | v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; | ||
4279 | *sp = (png_byte)((v >> 8) & 0xff); | ||
4280 | *(sp + 1) = (png_byte)(v & 0xff); | ||
4281 | sp += 2; | ||
4282 | |||
4283 | v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; | ||
4284 | *sp = (png_byte)((v >> 8) & 0xff); | ||
4285 | *(sp + 1) = (png_byte)(v & 0xff); | ||
4286 | sp += 4; | ||
4287 | } | ||
4288 | } | ||
4289 | break; | ||
4290 | } | ||
4291 | |||
4292 | case PNG_COLOR_TYPE_GRAY_ALPHA: | ||
4293 | { | ||
4294 | if (row_info->bit_depth == 8) | ||
4295 | { | ||
4296 | sp = row; | ||
4297 | for (i = 0; i < row_width; i++) | ||
4298 | { | ||
4299 | *sp = gamma_table[*sp]; | ||
4300 | sp += 2; | ||
4301 | } | ||
4302 | } | ||
4303 | |||
4304 | else /* if (row_info->bit_depth == 16) */ | ||
4305 | { | ||
4306 | sp = row; | ||
4307 | for (i = 0; i < row_width; i++) | ||
4308 | { | ||
4309 | png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; | ||
4310 | *sp = (png_byte)((v >> 8) & 0xff); | ||
4311 | *(sp + 1) = (png_byte)(v & 0xff); | ||
4312 | sp += 4; | ||
4313 | } | ||
4314 | } | ||
4315 | break; | ||
4316 | } | ||
4317 | |||
4318 | case PNG_COLOR_TYPE_GRAY: | ||
4319 | { | ||
4320 | if (row_info->bit_depth == 2) | ||
4321 | { | ||
4322 | sp = row; | ||
4323 | for (i = 0; i < row_width; i += 4) | ||
4324 | { | ||
4325 | int a = *sp & 0xc0; | ||
4326 | int b = *sp & 0x30; | ||
4327 | int c = *sp & 0x0c; | ||
4328 | int d = *sp & 0x03; | ||
4329 | |||
4330 | *sp = (png_byte)( | ||
4331 | ((((int)gamma_table[a|(a>>2)|(a>>4)|(a>>6)]) ) & 0xc0)| | ||
4332 | ((((int)gamma_table[(b<<2)|b|(b>>2)|(b>>4)])>>2) & 0x30)| | ||
4333 | ((((int)gamma_table[(c<<4)|(c<<2)|c|(c>>2)])>>4) & 0x0c)| | ||
4334 | ((((int)gamma_table[(d<<6)|(d<<4)|(d<<2)|d])>>6) )); | ||
4335 | sp++; | ||
4336 | } | ||
4337 | } | ||
4338 | |||
4339 | if (row_info->bit_depth == 4) | ||
4340 | { | ||
4341 | sp = row; | ||
4342 | for (i = 0; i < row_width; i += 2) | ||
4343 | { | ||
4344 | int msb = *sp & 0xf0; | ||
4345 | int lsb = *sp & 0x0f; | ||
4346 | |||
4347 | *sp = (png_byte)((((int)gamma_table[msb | (msb >> 4)]) & 0xf0) | ||
4348 | | (((int)gamma_table[(lsb << 4) | lsb]) >> 4)); | ||
4349 | sp++; | ||
4350 | } | ||
4351 | } | ||
4352 | |||
4353 | else if (row_info->bit_depth == 8) | ||
4354 | { | ||
4355 | sp = row; | ||
4356 | for (i = 0; i < row_width; i++) | ||
4357 | { | ||
4358 | *sp = gamma_table[*sp]; | ||
4359 | sp++; | ||
4360 | } | ||
4361 | } | ||
4362 | |||
4363 | else if (row_info->bit_depth == 16) | ||
4364 | { | ||
4365 | sp = row; | ||
4366 | for (i = 0; i < row_width; i++) | ||
4367 | { | ||
4368 | png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; | ||
4369 | *sp = (png_byte)((v >> 8) & 0xff); | ||
4370 | *(sp + 1) = (png_byte)(v & 0xff); | ||
4371 | sp += 2; | ||
4372 | } | ||
4373 | } | ||
4374 | break; | ||
4375 | } | ||
4376 | |||
4377 | default: | ||
4378 | break; | ||
4379 | } | ||
4380 | } | ||
4381 | } | ||
4382 | #endif | ||
4383 | |||
4384 | #ifdef PNG_READ_ALPHA_MODE_SUPPORTED | ||
4385 | /* Encode the alpha channel to the output gamma (the input channel is always | ||
4386 | * linear.) Called only with color types that have an alpha channel. Needs the | ||
4387 | * from_1 tables. | ||
4388 | */ | ||
4389 | void /* PRIVATE */ | ||
4390 | png_do_encode_alpha(png_row_infop row_info, png_bytep row, png_structp png_ptr) | ||
4391 | { | ||
4392 | png_uint_32 row_width = row_info->width; | ||
4393 | |||
4394 | png_debug(1, "in png_do_encode_alpha"); | ||
4395 | |||
4396 | if (row_info->color_type & PNG_COLOR_MASK_ALPHA) | ||
4397 | { | ||
4398 | if (row_info->bit_depth == 8) | ||
4399 | { | ||
4400 | PNG_CONST png_bytep table = png_ptr->gamma_from_1; | ||
4401 | |||
4402 | if (table != NULL) | ||
4403 | { | ||
4404 | PNG_CONST int step = | ||
4405 | (row_info->color_type & PNG_COLOR_MASK_COLOR) ? 4 : 2; | ||
4406 | |||
4407 | /* The alpha channel is the last component: */ | ||
4408 | row += step - 1; | ||
4409 | |||
4410 | for (; row_width > 0; --row_width, row += step) | ||
4411 | *row = table[*row]; | ||
4412 | |||
4413 | return; | ||
4414 | } | ||
4415 | } | ||
4416 | |||
4417 | else if (row_info->bit_depth == 16) | ||
4418 | { | ||
4419 | PNG_CONST png_uint_16pp table = png_ptr->gamma_16_from_1; | ||
4420 | PNG_CONST int gamma_shift = png_ptr->gamma_shift; | ||
4421 | |||
4422 | if (table != NULL) | ||
4423 | { | ||
4424 | PNG_CONST int step = | ||
4425 | (row_info->color_type & PNG_COLOR_MASK_COLOR) ? 8 : 4; | ||
4426 | |||
4427 | /* The alpha channel is the last component: */ | ||
4428 | row += step - 2; | ||
4429 | |||
4430 | for (; row_width > 0; --row_width, row += step) | ||
4431 | { | ||
4432 | png_uint_16 v; | ||
4433 | |||
4434 | v = table[*(row + 1) >> gamma_shift][*row]; | ||
4435 | *row = (png_byte)((v >> 8) & 0xff); | ||
4436 | *(row + 1) = (png_byte)(v & 0xff); | ||
4437 | } | ||
4438 | |||
4439 | return; | ||
4440 | } | ||
4441 | } | ||
4442 | } | ||
4443 | |||
4444 | /* Only get to here if called with a weird row_info; no harm has been done, | ||
4445 | * so just issue a warning. | ||
4446 | */ | ||
4447 | png_warning(png_ptr, "png_do_encode_alpha: unexpected call"); | ||
4448 | } | ||
4449 | #endif | ||
4450 | |||
4451 | #ifdef PNG_READ_EXPAND_SUPPORTED | ||
4452 | /* Expands a palette row to an RGB or RGBA row depending | ||
4453 | * upon whether you supply trans and num_trans. | ||
4454 | */ | ||
4455 | void /* PRIVATE */ | ||
4456 | png_do_expand_palette(png_row_infop row_info, png_bytep row, | ||
4457 | png_const_colorp palette, png_const_bytep trans_alpha, int num_trans) | ||
4458 | { | ||
4459 | int shift, value; | ||
4460 | png_bytep sp, dp; | ||
4461 | png_uint_32 i; | ||
4462 | png_uint_32 row_width=row_info->width; | ||
4463 | |||
4464 | png_debug(1, "in png_do_expand_palette"); | ||
4465 | |||
4466 | if (row_info->color_type == PNG_COLOR_TYPE_PALETTE) | ||
4467 | { | ||
4468 | if (row_info->bit_depth < 8) | ||
4469 | { | ||
4470 | switch (row_info->bit_depth) | ||
4471 | { | ||
4472 | case 1: | ||
4473 | { | ||
4474 | sp = row + (png_size_t)((row_width - 1) >> 3); | ||
4475 | dp = row + (png_size_t)row_width - 1; | ||
4476 | shift = 7 - (int)((row_width + 7) & 0x07); | ||
4477 | for (i = 0; i < row_width; i++) | ||
4478 | { | ||
4479 | if ((*sp >> shift) & 0x01) | ||
4480 | *dp = 1; | ||
4481 | |||
4482 | else | ||
4483 | *dp = 0; | ||
4484 | |||
4485 | if (shift == 7) | ||
4486 | { | ||
4487 | shift = 0; | ||
4488 | sp--; | ||
4489 | } | ||
4490 | |||
4491 | else | ||
4492 | shift++; | ||
4493 | |||
4494 | dp--; | ||
4495 | } | ||
4496 | break; | ||
4497 | } | ||
4498 | |||
4499 | case 2: | ||
4500 | { | ||
4501 | sp = row + (png_size_t)((row_width - 1) >> 2); | ||
4502 | dp = row + (png_size_t)row_width - 1; | ||
4503 | shift = (int)((3 - ((row_width + 3) & 0x03)) << 1); | ||
4504 | for (i = 0; i < row_width; i++) | ||
4505 | { | ||
4506 | value = (*sp >> shift) & 0x03; | ||
4507 | *dp = (png_byte)value; | ||
4508 | if (shift == 6) | ||
4509 | { | ||
4510 | shift = 0; | ||
4511 | sp--; | ||
4512 | } | ||
4513 | |||
4514 | else | ||
4515 | shift += 2; | ||
4516 | |||
4517 | dp--; | ||
4518 | } | ||
4519 | break; | ||
4520 | } | ||
4521 | |||
4522 | case 4: | ||
4523 | { | ||
4524 | sp = row + (png_size_t)((row_width - 1) >> 1); | ||
4525 | dp = row + (png_size_t)row_width - 1; | ||
4526 | shift = (int)((row_width & 0x01) << 2); | ||
4527 | for (i = 0; i < row_width; i++) | ||
4528 | { | ||
4529 | value = (*sp >> shift) & 0x0f; | ||
4530 | *dp = (png_byte)value; | ||
4531 | if (shift == 4) | ||
4532 | { | ||
4533 | shift = 0; | ||
4534 | sp--; | ||
4535 | } | ||
4536 | |||
4537 | else | ||
4538 | shift += 4; | ||
4539 | |||
4540 | dp--; | ||
4541 | } | ||
4542 | break; | ||
4543 | } | ||
4544 | |||
4545 | default: | ||
4546 | break; | ||
4547 | } | ||
4548 | row_info->bit_depth = 8; | ||
4549 | row_info->pixel_depth = 8; | ||
4550 | row_info->rowbytes = row_width; | ||
4551 | } | ||
4552 | |||
4553 | if (row_info->bit_depth == 8) | ||
4554 | { | ||
4555 | { | ||
4556 | if (num_trans > 0) | ||
4557 | { | ||
4558 | sp = row + (png_size_t)row_width - 1; | ||
4559 | dp = row + (png_size_t)(row_width << 2) - 1; | ||
4560 | |||
4561 | for (i = 0; i < row_width; i++) | ||
4562 | { | ||
4563 | if ((int)(*sp) >= num_trans) | ||
4564 | *dp-- = 0xff; | ||
4565 | |||
4566 | else | ||
4567 | *dp-- = trans_alpha[*sp]; | ||
4568 | |||
4569 | *dp-- = palette[*sp].blue; | ||
4570 | *dp-- = palette[*sp].green; | ||
4571 | *dp-- = palette[*sp].red; | ||
4572 | sp--; | ||
4573 | } | ||
4574 | row_info->bit_depth = 8; | ||
4575 | row_info->pixel_depth = 32; | ||
4576 | row_info->rowbytes = row_width * 4; | ||
4577 | row_info->color_type = 6; | ||
4578 | row_info->channels = 4; | ||
4579 | } | ||
4580 | |||
4581 | else | ||
4582 | { | ||
4583 | sp = row + (png_size_t)row_width - 1; | ||
4584 | dp = row + (png_size_t)(row_width * 3) - 1; | ||
4585 | |||
4586 | for (i = 0; i < row_width; i++) | ||
4587 | { | ||
4588 | *dp-- = palette[*sp].blue; | ||
4589 | *dp-- = palette[*sp].green; | ||
4590 | *dp-- = palette[*sp].red; | ||
4591 | sp--; | ||
4592 | } | ||
4593 | |||
4594 | row_info->bit_depth = 8; | ||
4595 | row_info->pixel_depth = 24; | ||
4596 | row_info->rowbytes = row_width * 3; | ||
4597 | row_info->color_type = 2; | ||
4598 | row_info->channels = 3; | ||
4599 | } | ||
4600 | } | ||
4601 | } | ||
4602 | } | ||
4603 | } | ||
4604 | |||
4605 | /* If the bit depth < 8, it is expanded to 8. Also, if the already | ||
4606 | * expanded transparency value is supplied, an alpha channel is built. | ||
4607 | */ | ||
4608 | void /* PRIVATE */ | ||
4609 | png_do_expand(png_row_infop row_info, png_bytep row, | ||
4610 | png_const_color_16p trans_color) | ||
4611 | { | ||
4612 | int shift, value; | ||
4613 | png_bytep sp, dp; | ||
4614 | png_uint_32 i; | ||
4615 | png_uint_32 row_width=row_info->width; | ||
4616 | |||
4617 | png_debug(1, "in png_do_expand"); | ||
4618 | |||
4619 | { | ||
4620 | if (row_info->color_type == PNG_COLOR_TYPE_GRAY) | ||
4621 | { | ||
4622 | png_uint_16 gray = (png_uint_16)(trans_color ? trans_color->gray : 0); | ||
4623 | |||
4624 | if (row_info->bit_depth < 8) | ||
4625 | { | ||
4626 | switch (row_info->bit_depth) | ||
4627 | { | ||
4628 | case 1: | ||
4629 | { | ||
4630 | gray = (png_uint_16)((gray & 0x01) * 0xff); | ||
4631 | sp = row + (png_size_t)((row_width - 1) >> 3); | ||
4632 | dp = row + (png_size_t)row_width - 1; | ||
4633 | shift = 7 - (int)((row_width + 7) & 0x07); | ||
4634 | for (i = 0; i < row_width; i++) | ||
4635 | { | ||
4636 | if ((*sp >> shift) & 0x01) | ||
4637 | *dp = 0xff; | ||
4638 | |||
4639 | else | ||
4640 | *dp = 0; | ||
4641 | |||
4642 | if (shift == 7) | ||
4643 | { | ||
4644 | shift = 0; | ||
4645 | sp--; | ||
4646 | } | ||
4647 | |||
4648 | else | ||
4649 | shift++; | ||
4650 | |||
4651 | dp--; | ||
4652 | } | ||
4653 | break; | ||
4654 | } | ||
4655 | |||
4656 | case 2: | ||
4657 | { | ||
4658 | gray = (png_uint_16)((gray & 0x03) * 0x55); | ||
4659 | sp = row + (png_size_t)((row_width - 1) >> 2); | ||
4660 | dp = row + (png_size_t)row_width - 1; | ||
4661 | shift = (int)((3 - ((row_width + 3) & 0x03)) << 1); | ||
4662 | for (i = 0; i < row_width; i++) | ||
4663 | { | ||
4664 | value = (*sp >> shift) & 0x03; | ||
4665 | *dp = (png_byte)(value | (value << 2) | (value << 4) | | ||
4666 | (value << 6)); | ||
4667 | if (shift == 6) | ||
4668 | { | ||
4669 | shift = 0; | ||
4670 | sp--; | ||
4671 | } | ||
4672 | |||
4673 | else | ||
4674 | shift += 2; | ||
4675 | |||
4676 | dp--; | ||
4677 | } | ||
4678 | break; | ||
4679 | } | ||
4680 | |||
4681 | case 4: | ||
4682 | { | ||
4683 | gray = (png_uint_16)((gray & 0x0f) * 0x11); | ||
4684 | sp = row + (png_size_t)((row_width - 1) >> 1); | ||
4685 | dp = row + (png_size_t)row_width - 1; | ||
4686 | shift = (int)((1 - ((row_width + 1) & 0x01)) << 2); | ||
4687 | for (i = 0; i < row_width; i++) | ||
4688 | { | ||
4689 | value = (*sp >> shift) & 0x0f; | ||
4690 | *dp = (png_byte)(value | (value << 4)); | ||
4691 | if (shift == 4) | ||
4692 | { | ||
4693 | shift = 0; | ||
4694 | sp--; | ||
4695 | } | ||
4696 | |||
4697 | else | ||
4698 | shift = 4; | ||
4699 | |||
4700 | dp--; | ||
4701 | } | ||
4702 | break; | ||
4703 | } | ||
4704 | |||
4705 | default: | ||
4706 | break; | ||
4707 | } | ||
4708 | |||
4709 | row_info->bit_depth = 8; | ||
4710 | row_info->pixel_depth = 8; | ||
4711 | row_info->rowbytes = row_width; | ||
4712 | } | ||
4713 | |||
4714 | if (trans_color != NULL) | ||
4715 | { | ||
4716 | if (row_info->bit_depth == 8) | ||
4717 | { | ||
4718 | gray = gray & 0xff; | ||
4719 | sp = row + (png_size_t)row_width - 1; | ||
4720 | dp = row + (png_size_t)(row_width << 1) - 1; | ||
4721 | |||
4722 | for (i = 0; i < row_width; i++) | ||
4723 | { | ||
4724 | if (*sp == gray) | ||
4725 | *dp-- = 0; | ||
4726 | |||
4727 | else | ||
4728 | *dp-- = 0xff; | ||
4729 | |||
4730 | *dp-- = *sp--; | ||
4731 | } | ||
4732 | } | ||
4733 | |||
4734 | else if (row_info->bit_depth == 16) | ||
4735 | { | ||
4736 | png_byte gray_high = (png_byte)((gray >> 8) & 0xff); | ||
4737 | png_byte gray_low = (png_byte)(gray & 0xff); | ||
4738 | sp = row + row_info->rowbytes - 1; | ||
4739 | dp = row + (row_info->rowbytes << 1) - 1; | ||
4740 | for (i = 0; i < row_width; i++) | ||
4741 | { | ||
4742 | if (*(sp - 1) == gray_high && *(sp) == gray_low) | ||
4743 | { | ||
4744 | *dp-- = 0; | ||
4745 | *dp-- = 0; | ||
4746 | } | ||
4747 | |||
4748 | else | ||
4749 | { | ||
4750 | *dp-- = 0xff; | ||
4751 | *dp-- = 0xff; | ||
4752 | } | ||
4753 | |||
4754 | *dp-- = *sp--; | ||
4755 | *dp-- = *sp--; | ||
4756 | } | ||
4757 | } | ||
4758 | |||
4759 | row_info->color_type = PNG_COLOR_TYPE_GRAY_ALPHA; | ||
4760 | row_info->channels = 2; | ||
4761 | row_info->pixel_depth = (png_byte)(row_info->bit_depth << 1); | ||
4762 | row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, | ||
4763 | row_width); | ||
4764 | } | ||
4765 | } | ||
4766 | else if (row_info->color_type == PNG_COLOR_TYPE_RGB && trans_color) | ||
4767 | { | ||
4768 | if (row_info->bit_depth == 8) | ||
4769 | { | ||
4770 | png_byte red = (png_byte)(trans_color->red & 0xff); | ||
4771 | png_byte green = (png_byte)(trans_color->green & 0xff); | ||
4772 | png_byte blue = (png_byte)(trans_color->blue & 0xff); | ||
4773 | sp = row + (png_size_t)row_info->rowbytes - 1; | ||
4774 | dp = row + (png_size_t)(row_width << 2) - 1; | ||
4775 | for (i = 0; i < row_width; i++) | ||
4776 | { | ||
4777 | if (*(sp - 2) == red && *(sp - 1) == green && *(sp) == blue) | ||
4778 | *dp-- = 0; | ||
4779 | |||
4780 | else | ||
4781 | *dp-- = 0xff; | ||
4782 | |||
4783 | *dp-- = *sp--; | ||
4784 | *dp-- = *sp--; | ||
4785 | *dp-- = *sp--; | ||
4786 | } | ||
4787 | } | ||
4788 | else if (row_info->bit_depth == 16) | ||
4789 | { | ||
4790 | png_byte red_high = (png_byte)((trans_color->red >> 8) & 0xff); | ||
4791 | png_byte green_high = (png_byte)((trans_color->green >> 8) & 0xff); | ||
4792 | png_byte blue_high = (png_byte)((trans_color->blue >> 8) & 0xff); | ||
4793 | png_byte red_low = (png_byte)(trans_color->red & 0xff); | ||
4794 | png_byte green_low = (png_byte)(trans_color->green & 0xff); | ||
4795 | png_byte blue_low = (png_byte)(trans_color->blue & 0xff); | ||
4796 | sp = row + row_info->rowbytes - 1; | ||
4797 | dp = row + (png_size_t)(row_width << 3) - 1; | ||
4798 | for (i = 0; i < row_width; i++) | ||
4799 | { | ||
4800 | if (*(sp - 5) == red_high && | ||
4801 | *(sp - 4) == red_low && | ||
4802 | *(sp - 3) == green_high && | ||
4803 | *(sp - 2) == green_low && | ||
4804 | *(sp - 1) == blue_high && | ||
4805 | *(sp ) == blue_low) | ||
4806 | { | ||
4807 | *dp-- = 0; | ||
4808 | *dp-- = 0; | ||
4809 | } | ||
4810 | |||
4811 | else | ||
4812 | { | ||
4813 | *dp-- = 0xff; | ||
4814 | *dp-- = 0xff; | ||
4815 | } | ||
4816 | |||
4817 | *dp-- = *sp--; | ||
4818 | *dp-- = *sp--; | ||
4819 | *dp-- = *sp--; | ||
4820 | *dp-- = *sp--; | ||
4821 | *dp-- = *sp--; | ||
4822 | *dp-- = *sp--; | ||
4823 | } | ||
4824 | } | ||
4825 | row_info->color_type = PNG_COLOR_TYPE_RGB_ALPHA; | ||
4826 | row_info->channels = 4; | ||
4827 | row_info->pixel_depth = (png_byte)(row_info->bit_depth << 2); | ||
4828 | row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); | ||
4829 | } | ||
4830 | } | ||
4831 | } | ||
4832 | #endif | ||
4833 | |||
4834 | #ifdef PNG_READ_EXPAND_16_SUPPORTED | ||
4835 | /* If the bit depth is 8 and the color type is not a palette type expand the | ||
4836 | * whole row to 16 bits. Has no effect otherwise. | ||
4837 | */ | ||
4838 | void /* PRIVATE */ | ||
4839 | png_do_expand_16(png_row_infop row_info, png_bytep row) | ||
4840 | { | ||
4841 | if (row_info->bit_depth == 8 && | ||
4842 | row_info->color_type != PNG_COLOR_TYPE_PALETTE) | ||
4843 | { | ||
4844 | /* The row have a sequence of bytes containing [0..255] and we need | ||
4845 | * to turn it into another row containing [0..65535], to do this we | ||
4846 | * calculate: | ||
4847 | * | ||
4848 | * (input / 255) * 65535 | ||
4849 | * | ||
4850 | * Which happens to be exactly input * 257 and this can be achieved | ||
4851 | * simply by byte replication in place (copying backwards). | ||
4852 | */ | ||
4853 | png_byte *sp = row + row_info->rowbytes; /* source, last byte + 1 */ | ||
4854 | png_byte *dp = sp + row_info->rowbytes; /* destination, end + 1 */ | ||
4855 | while (dp > sp) | ||
4856 | dp[-2] = dp[-1] = *--sp, dp -= 2; | ||
4857 | |||
4858 | row_info->rowbytes *= 2; | ||
4859 | row_info->bit_depth = 16; | ||
4860 | row_info->pixel_depth = (png_byte)(row_info->channels * 16); | ||
4861 | } | ||
4862 | } | ||
4863 | #endif | ||
4864 | |||
4865 | #ifdef PNG_READ_QUANTIZE_SUPPORTED | ||
4866 | void /* PRIVATE */ | ||
4867 | png_do_quantize(png_row_infop row_info, png_bytep row, | ||
4868 | png_const_bytep palette_lookup, png_const_bytep quantize_lookup) | ||
4869 | { | ||
4870 | png_bytep sp, dp; | ||
4871 | png_uint_32 i; | ||
4872 | png_uint_32 row_width=row_info->width; | ||
4873 | |||
4874 | png_debug(1, "in png_do_quantize"); | ||
4875 | |||
4876 | if (row_info->bit_depth == 8) | ||
4877 | { | ||
4878 | if (row_info->color_type == PNG_COLOR_TYPE_RGB && palette_lookup) | ||
4879 | { | ||
4880 | int r, g, b, p; | ||
4881 | sp = row; | ||
4882 | dp = row; | ||
4883 | for (i = 0; i < row_width; i++) | ||
4884 | { | ||
4885 | r = *sp++; | ||
4886 | g = *sp++; | ||
4887 | b = *sp++; | ||
4888 | |||
4889 | /* This looks real messy, but the compiler will reduce | ||
4890 | * it down to a reasonable formula. For example, with | ||
4891 | * 5 bits per color, we get: | ||
4892 | * p = (((r >> 3) & 0x1f) << 10) | | ||
4893 | * (((g >> 3) & 0x1f) << 5) | | ||
4894 | * ((b >> 3) & 0x1f); | ||
4895 | */ | ||
4896 | p = (((r >> (8 - PNG_QUANTIZE_RED_BITS)) & | ||
4897 | ((1 << PNG_QUANTIZE_RED_BITS) - 1)) << | ||
4898 | (PNG_QUANTIZE_GREEN_BITS + PNG_QUANTIZE_BLUE_BITS)) | | ||
4899 | (((g >> (8 - PNG_QUANTIZE_GREEN_BITS)) & | ||
4900 | ((1 << PNG_QUANTIZE_GREEN_BITS) - 1)) << | ||
4901 | (PNG_QUANTIZE_BLUE_BITS)) | | ||
4902 | ((b >> (8 - PNG_QUANTIZE_BLUE_BITS)) & | ||
4903 | ((1 << PNG_QUANTIZE_BLUE_BITS) - 1)); | ||
4904 | |||
4905 | *dp++ = palette_lookup[p]; | ||
4906 | } | ||
4907 | |||
4908 | row_info->color_type = PNG_COLOR_TYPE_PALETTE; | ||
4909 | row_info->channels = 1; | ||
4910 | row_info->pixel_depth = row_info->bit_depth; | ||
4911 | row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); | ||
4912 | } | ||
4913 | |||
4914 | else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA && | ||
4915 | palette_lookup != NULL) | ||
4916 | { | ||
4917 | int r, g, b, p; | ||
4918 | sp = row; | ||
4919 | dp = row; | ||
4920 | for (i = 0; i < row_width; i++) | ||
4921 | { | ||
4922 | r = *sp++; | ||
4923 | g = *sp++; | ||
4924 | b = *sp++; | ||
4925 | sp++; | ||
4926 | |||
4927 | p = (((r >> (8 - PNG_QUANTIZE_RED_BITS)) & | ||
4928 | ((1 << PNG_QUANTIZE_RED_BITS) - 1)) << | ||
4929 | (PNG_QUANTIZE_GREEN_BITS + PNG_QUANTIZE_BLUE_BITS)) | | ||
4930 | (((g >> (8 - PNG_QUANTIZE_GREEN_BITS)) & | ||
4931 | ((1 << PNG_QUANTIZE_GREEN_BITS) - 1)) << | ||
4932 | (PNG_QUANTIZE_BLUE_BITS)) | | ||
4933 | ((b >> (8 - PNG_QUANTIZE_BLUE_BITS)) & | ||
4934 | ((1 << PNG_QUANTIZE_BLUE_BITS) - 1)); | ||
4935 | |||
4936 | *dp++ = palette_lookup[p]; | ||
4937 | } | ||
4938 | |||
4939 | row_info->color_type = PNG_COLOR_TYPE_PALETTE; | ||
4940 | row_info->channels = 1; | ||
4941 | row_info->pixel_depth = row_info->bit_depth; | ||
4942 | row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); | ||
4943 | } | ||
4944 | |||
4945 | else if (row_info->color_type == PNG_COLOR_TYPE_PALETTE && | ||
4946 | quantize_lookup) | ||
4947 | { | ||
4948 | sp = row; | ||
4949 | |||
4950 | for (i = 0; i < row_width; i++, sp++) | ||
4951 | { | ||
4952 | *sp = quantize_lookup[*sp]; | ||
4953 | } | ||
4954 | } | ||
4955 | } | ||
4956 | } | ||
4957 | #endif /* PNG_READ_QUANTIZE_SUPPORTED */ | ||
4958 | #endif /* PNG_READ_TRANSFORMS_SUPPORTED */ | ||
4959 | |||
4960 | #ifdef PNG_MNG_FEATURES_SUPPORTED | ||
4961 | /* Undoes intrapixel differencing */ | ||
4962 | void /* PRIVATE */ | ||
4963 | png_do_read_intrapixel(png_row_infop row_info, png_bytep row) | ||
4964 | { | ||
4965 | png_debug(1, "in png_do_read_intrapixel"); | ||
4966 | |||
4967 | if ( | ||
4968 | (row_info->color_type & PNG_COLOR_MASK_COLOR)) | ||
4969 | { | ||
4970 | int bytes_per_pixel; | ||
4971 | png_uint_32 row_width = row_info->width; | ||
4972 | |||
4973 | if (row_info->bit_depth == 8) | ||
4974 | { | ||
4975 | png_bytep rp; | ||
4976 | png_uint_32 i; | ||
4977 | |||
4978 | if (row_info->color_type == PNG_COLOR_TYPE_RGB) | ||
4979 | bytes_per_pixel = 3; | ||
4980 | |||
4981 | else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) | ||
4982 | bytes_per_pixel = 4; | ||
4983 | |||
4984 | else | ||
4985 | return; | ||
4986 | |||
4987 | for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) | ||
4988 | { | ||
4989 | *(rp) = (png_byte)((256 + *rp + *(rp + 1)) & 0xff); | ||
4990 | *(rp+2) = (png_byte)((256 + *(rp + 2) + *(rp + 1)) & 0xff); | ||
4991 | } | ||
4992 | } | ||
4993 | else if (row_info->bit_depth == 16) | ||
4994 | { | ||
4995 | png_bytep rp; | ||
4996 | png_uint_32 i; | ||
4997 | |||
4998 | if (row_info->color_type == PNG_COLOR_TYPE_RGB) | ||
4999 | bytes_per_pixel = 6; | ||
5000 | |||
5001 | else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) | ||
5002 | bytes_per_pixel = 8; | ||
5003 | |||
5004 | else | ||
5005 | return; | ||
5006 | |||
5007 | for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) | ||
5008 | { | ||
5009 | png_uint_32 s0 = (*(rp ) << 8) | *(rp + 1); | ||
5010 | png_uint_32 s1 = (*(rp + 2) << 8) | *(rp + 3); | ||
5011 | png_uint_32 s2 = (*(rp + 4) << 8) | *(rp + 5); | ||
5012 | png_uint_32 red = (s0 + s1 + 65536) & 0xffff; | ||
5013 | png_uint_32 blue = (s2 + s1 + 65536) & 0xffff; | ||
5014 | *(rp ) = (png_byte)((red >> 8) & 0xff); | ||
5015 | *(rp + 1) = (png_byte)(red & 0xff); | ||
5016 | *(rp + 4) = (png_byte)((blue >> 8) & 0xff); | ||
5017 | *(rp + 5) = (png_byte)(blue & 0xff); | ||
5018 | } | ||
5019 | } | ||
5020 | } | ||
5021 | } | ||
5022 | #endif /* PNG_MNG_FEATURES_SUPPORTED */ | ||
5023 | #endif /* PNG_READ_SUPPORTED */ | ||