[DEVENUM]
[reactos.git] / reactos / dll / 3rdparty / libpng / pngwtran.c
1
2 /* pngwtran.c - transforms the data in a row for PNG writers
3 *
4 * Last changed in libpng 1.5.13 [September 27, 2012]
5 * Copyright (c) 1998-2012 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
14 #include "pngpriv.h"
15
16 #ifdef PNG_WRITE_SUPPORTED
17
18 #ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
19 /* Transform the data according to the user's wishes. The order of
20 * transformations is significant.
21 */
22 void /* PRIVATE */
23 png_do_write_transformations(png_structp png_ptr, png_row_infop row_info)
24 {
25 png_debug(1, "in png_do_write_transformations");
26
27 if (png_ptr == NULL)
28 return;
29
30 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
31 if (png_ptr->transformations & PNG_USER_TRANSFORM)
32 if (png_ptr->write_user_transform_fn != NULL)
33 (*(png_ptr->write_user_transform_fn)) /* User write transform
34 function */
35 (png_ptr, /* png_ptr */
36 row_info, /* row_info: */
37 /* png_uint_32 width; width of row */
38 /* png_size_t rowbytes; number of bytes in row */
39 /* png_byte color_type; color type of pixels */
40 /* png_byte bit_depth; bit depth of samples */
41 /* png_byte channels; number of channels (1-4) */
42 /* png_byte pixel_depth; bits per pixel (depth*channels) */
43 png_ptr->row_buf + 1); /* start of pixel data for row */
44 #endif
45
46 #ifdef PNG_WRITE_FILLER_SUPPORTED
47 if (png_ptr->transformations & PNG_FILLER)
48 {
49 if (png_ptr->color_type & (PNG_COLOR_MASK_ALPHA|PNG_COLOR_MASK_PALETTE))
50 {
51 /* GA, RGBA or palette; in any of these cases libpng will not do the
52 * the correct thing (whatever that might be).
53 */
54 png_warning(png_ptr, "incorrect png_set_filler call ignored");
55 png_ptr->transformations &= ~PNG_FILLER;
56 }
57
58 else
59 png_do_strip_channel(row_info, png_ptr->row_buf + 1,
60 !(png_ptr->flags & PNG_FLAG_FILLER_AFTER));
61 }
62 #endif
63
64 #ifdef PNG_WRITE_PACKSWAP_SUPPORTED
65 if (png_ptr->transformations & PNG_PACKSWAP)
66 png_do_packswap(row_info, png_ptr->row_buf + 1);
67 #endif
68
69 #ifdef PNG_WRITE_PACK_SUPPORTED
70 if (png_ptr->transformations & PNG_PACK)
71 png_do_pack(row_info, png_ptr->row_buf + 1,
72 (png_uint_32)png_ptr->bit_depth);
73 #endif
74
75 #ifdef PNG_WRITE_SWAP_SUPPORTED
76 if (png_ptr->transformations & PNG_SWAP_BYTES)
77 png_do_swap(row_info, png_ptr->row_buf + 1);
78 #endif
79
80 #ifdef PNG_WRITE_SHIFT_SUPPORTED
81 if (png_ptr->transformations & PNG_SHIFT)
82 png_do_shift(row_info, png_ptr->row_buf + 1,
83 &(png_ptr->shift));
84 #endif
85
86 #ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
87 if (png_ptr->transformations & PNG_SWAP_ALPHA)
88 png_do_write_swap_alpha(row_info, png_ptr->row_buf + 1);
89 #endif
90
91 #ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
92 if (png_ptr->transformations & PNG_INVERT_ALPHA)
93 png_do_write_invert_alpha(row_info, png_ptr->row_buf + 1);
94 #endif
95
96 #ifdef PNG_WRITE_BGR_SUPPORTED
97 if (png_ptr->transformations & PNG_BGR)
98 png_do_bgr(row_info, png_ptr->row_buf + 1);
99 #endif
100
101 #ifdef PNG_WRITE_INVERT_SUPPORTED
102 if (png_ptr->transformations & PNG_INVERT_MONO)
103 png_do_invert(row_info, png_ptr->row_buf + 1);
104 #endif
105 }
106
107 #ifdef PNG_WRITE_PACK_SUPPORTED
108 /* Pack pixels into bytes. Pass the true bit depth in bit_depth. The
109 * row_info bit depth should be 8 (one pixel per byte). The channels
110 * should be 1 (this only happens on grayscale and paletted images).
111 */
112 void /* PRIVATE */
113 png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth)
114 {
115 png_debug(1, "in png_do_pack");
116
117 if (row_info->bit_depth == 8 &&
118 row_info->channels == 1)
119 {
120 switch ((int)bit_depth)
121 {
122 case 1:
123 {
124 png_bytep sp, dp;
125 int mask, v;
126 png_uint_32 i;
127 png_uint_32 row_width = row_info->width;
128
129 sp = row;
130 dp = row;
131 mask = 0x80;
132 v = 0;
133
134 for (i = 0; i < row_width; i++)
135 {
136 if (*sp != 0)
137 v |= mask;
138
139 sp++;
140
141 if (mask > 1)
142 mask >>= 1;
143
144 else
145 {
146 mask = 0x80;
147 *dp = (png_byte)v;
148 dp++;
149 v = 0;
150 }
151 }
152
153 if (mask != 0x80)
154 *dp = (png_byte)v;
155
156 break;
157 }
158
159 case 2:
160 {
161 png_bytep sp, dp;
162 int shift, v;
163 png_uint_32 i;
164 png_uint_32 row_width = row_info->width;
165
166 sp = row;
167 dp = row;
168 shift = 6;
169 v = 0;
170
171 for (i = 0; i < row_width; i++)
172 {
173 png_byte value;
174
175 value = (png_byte)(*sp & 0x03);
176 v |= (value << shift);
177
178 if (shift == 0)
179 {
180 shift = 6;
181 *dp = (png_byte)v;
182 dp++;
183 v = 0;
184 }
185
186 else
187 shift -= 2;
188
189 sp++;
190 }
191
192 if (shift != 6)
193 *dp = (png_byte)v;
194
195 break;
196 }
197
198 case 4:
199 {
200 png_bytep sp, dp;
201 int shift, v;
202 png_uint_32 i;
203 png_uint_32 row_width = row_info->width;
204
205 sp = row;
206 dp = row;
207 shift = 4;
208 v = 0;
209
210 for (i = 0; i < row_width; i++)
211 {
212 png_byte value;
213
214 value = (png_byte)(*sp & 0x0f);
215 v |= (value << shift);
216
217 if (shift == 0)
218 {
219 shift = 4;
220 *dp = (png_byte)v;
221 dp++;
222 v = 0;
223 }
224
225 else
226 shift -= 4;
227
228 sp++;
229 }
230
231 if (shift != 4)
232 *dp = (png_byte)v;
233
234 break;
235 }
236
237 default:
238 break;
239 }
240
241 row_info->bit_depth = (png_byte)bit_depth;
242 row_info->pixel_depth = (png_byte)(bit_depth * row_info->channels);
243 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
244 row_info->width);
245 }
246 }
247 #endif
248
249 #ifdef PNG_WRITE_SHIFT_SUPPORTED
250 /* Shift pixel values to take advantage of whole range. Pass the
251 * true number of bits in bit_depth. The row should be packed
252 * according to row_info->bit_depth. Thus, if you had a row of
253 * bit depth 4, but the pixels only had values from 0 to 7, you
254 * would pass 3 as bit_depth, and this routine would translate the
255 * data to 0 to 15.
256 */
257 void /* PRIVATE */
258 png_do_shift(png_row_infop row_info, png_bytep row,
259 png_const_color_8p bit_depth)
260 {
261 png_debug(1, "in png_do_shift");
262
263 if (row_info->color_type != PNG_COLOR_TYPE_PALETTE)
264 {
265 int shift_start[4], shift_dec[4];
266 int channels = 0;
267
268 if (row_info->color_type & PNG_COLOR_MASK_COLOR)
269 {
270 shift_start[channels] = row_info->bit_depth - bit_depth->red;
271 shift_dec[channels] = bit_depth->red;
272 channels++;
273
274 shift_start[channels] = row_info->bit_depth - bit_depth->green;
275 shift_dec[channels] = bit_depth->green;
276 channels++;
277
278 shift_start[channels] = row_info->bit_depth - bit_depth->blue;
279 shift_dec[channels] = bit_depth->blue;
280 channels++;
281 }
282
283 else
284 {
285 shift_start[channels] = row_info->bit_depth - bit_depth->gray;
286 shift_dec[channels] = bit_depth->gray;
287 channels++;
288 }
289
290 if (row_info->color_type & PNG_COLOR_MASK_ALPHA)
291 {
292 shift_start[channels] = row_info->bit_depth - bit_depth->alpha;
293 shift_dec[channels] = bit_depth->alpha;
294 channels++;
295 }
296
297 /* With low row depths, could only be grayscale, so one channel */
298 if (row_info->bit_depth < 8)
299 {
300 png_bytep bp = row;
301 png_size_t i;
302 png_byte mask;
303 png_size_t row_bytes = row_info->rowbytes;
304
305 if (bit_depth->gray == 1 && row_info->bit_depth == 2)
306 mask = 0x55;
307
308 else if (row_info->bit_depth == 4 && bit_depth->gray == 3)
309 mask = 0x11;
310
311 else
312 mask = 0xff;
313
314 for (i = 0; i < row_bytes; i++, bp++)
315 {
316 png_uint_16 v;
317 int j;
318
319 v = *bp;
320 *bp = 0;
321
322 for (j = shift_start[0]; j > -shift_dec[0]; j -= shift_dec[0])
323 {
324 if (j > 0)
325 *bp |= (png_byte)((v << j) & 0xff);
326
327 else
328 *bp |= (png_byte)((v >> (-j)) & mask);
329 }
330 }
331 }
332
333 else if (row_info->bit_depth == 8)
334 {
335 png_bytep bp = row;
336 png_uint_32 i;
337 png_uint_32 istop = channels * row_info->width;
338
339 for (i = 0; i < istop; i++, bp++)
340 {
341
342 png_uint_16 v;
343 int j;
344 int c = (int)(i%channels);
345
346 v = *bp;
347 *bp = 0;
348
349 for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
350 {
351 if (j > 0)
352 *bp |= (png_byte)((v << j) & 0xff);
353
354 else
355 *bp |= (png_byte)((v >> (-j)) & 0xff);
356 }
357 }
358 }
359
360 else
361 {
362 png_bytep bp;
363 png_uint_32 i;
364 png_uint_32 istop = channels * row_info->width;
365
366 for (bp = row, i = 0; i < istop; i++)
367 {
368 int c = (int)(i%channels);
369 png_uint_16 value, v;
370 int j;
371
372 v = (png_uint_16)(((png_uint_16)(*bp) << 8) + *(bp + 1));
373 value = 0;
374
375 for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
376 {
377 if (j > 0)
378 value |= (png_uint_16)((v << j) & (png_uint_16)0xffff);
379
380 else
381 value |= (png_uint_16)((v >> (-j)) & (png_uint_16)0xffff);
382 }
383 *bp++ = (png_byte)(value >> 8);
384 *bp++ = (png_byte)(value & 0xff);
385 }
386 }
387 }
388 }
389 #endif
390
391 #ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
392 void /* PRIVATE */
393 png_do_write_swap_alpha(png_row_infop row_info, png_bytep row)
394 {
395 png_debug(1, "in png_do_write_swap_alpha");
396
397 {
398 if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
399 {
400 if (row_info->bit_depth == 8)
401 {
402 /* This converts from ARGB to RGBA */
403 png_bytep sp, dp;
404 png_uint_32 i;
405 png_uint_32 row_width = row_info->width;
406
407 for (i = 0, sp = dp = row; i < row_width; i++)
408 {
409 png_byte save = *(sp++);
410 *(dp++) = *(sp++);
411 *(dp++) = *(sp++);
412 *(dp++) = *(sp++);
413 *(dp++) = save;
414 }
415 }
416
417 #ifdef PNG_WRITE_16BIT_SUPPORTED
418 else
419 {
420 /* This converts from AARRGGBB to RRGGBBAA */
421 png_bytep sp, dp;
422 png_uint_32 i;
423 png_uint_32 row_width = row_info->width;
424
425 for (i = 0, sp = dp = row; i < row_width; i++)
426 {
427 png_byte save[2];
428 save[0] = *(sp++);
429 save[1] = *(sp++);
430 *(dp++) = *(sp++);
431 *(dp++) = *(sp++);
432 *(dp++) = *(sp++);
433 *(dp++) = *(sp++);
434 *(dp++) = *(sp++);
435 *(dp++) = *(sp++);
436 *(dp++) = save[0];
437 *(dp++) = save[1];
438 }
439 }
440 #endif /* PNG_WRITE_16BIT_SUPPORTED */
441 }
442
443 else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
444 {
445 if (row_info->bit_depth == 8)
446 {
447 /* This converts from AG to GA */
448 png_bytep sp, dp;
449 png_uint_32 i;
450 png_uint_32 row_width = row_info->width;
451
452 for (i = 0, sp = dp = row; i < row_width; i++)
453 {
454 png_byte save = *(sp++);
455 *(dp++) = *(sp++);
456 *(dp++) = save;
457 }
458 }
459
460 #ifdef PNG_WRITE_16BIT_SUPPORTED
461 else
462 {
463 /* This converts from AAGG to GGAA */
464 png_bytep sp, dp;
465 png_uint_32 i;
466 png_uint_32 row_width = row_info->width;
467
468 for (i = 0, sp = dp = row; i < row_width; i++)
469 {
470 png_byte save[2];
471 save[0] = *(sp++);
472 save[1] = *(sp++);
473 *(dp++) = *(sp++);
474 *(dp++) = *(sp++);
475 *(dp++) = save[0];
476 *(dp++) = save[1];
477 }
478 }
479 #endif /* PNG_WRITE_16BIT_SUPPORTED */
480 }
481 }
482 }
483 #endif
484
485 #ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
486 void /* PRIVATE */
487 png_do_write_invert_alpha(png_row_infop row_info, png_bytep row)
488 {
489 png_debug(1, "in png_do_write_invert_alpha");
490
491 {
492 if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
493 {
494 if (row_info->bit_depth == 8)
495 {
496 /* This inverts the alpha channel in RGBA */
497 png_bytep sp, dp;
498 png_uint_32 i;
499 png_uint_32 row_width = row_info->width;
500
501 for (i = 0, sp = dp = row; i < row_width; i++)
502 {
503 /* Does nothing
504 *(dp++) = *(sp++);
505 *(dp++) = *(sp++);
506 *(dp++) = *(sp++);
507 */
508 sp+=3; dp = sp;
509 *(dp++) = (png_byte)(255 - *(sp++));
510 }
511 }
512
513 #ifdef PNG_WRITE_16BIT_SUPPORTED
514 else
515 {
516 /* This inverts the alpha channel in RRGGBBAA */
517 png_bytep sp, dp;
518 png_uint_32 i;
519 png_uint_32 row_width = row_info->width;
520
521 for (i = 0, sp = dp = row; i < row_width; i++)
522 {
523 /* Does nothing
524 *(dp++) = *(sp++);
525 *(dp++) = *(sp++);
526 *(dp++) = *(sp++);
527 *(dp++) = *(sp++);
528 *(dp++) = *(sp++);
529 *(dp++) = *(sp++);
530 */
531 sp+=6; dp = sp;
532 *(dp++) = (png_byte)(255 - *(sp++));
533 *(dp++) = (png_byte)(255 - *(sp++));
534 }
535 }
536 #endif /* PNG_WRITE_16BIT_SUPPORTED */
537 }
538
539 else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
540 {
541 if (row_info->bit_depth == 8)
542 {
543 /* This inverts the alpha channel in GA */
544 png_bytep sp, dp;
545 png_uint_32 i;
546 png_uint_32 row_width = row_info->width;
547
548 for (i = 0, sp = dp = row; i < row_width; i++)
549 {
550 *(dp++) = *(sp++);
551 *(dp++) = (png_byte)(255 - *(sp++));
552 }
553 }
554
555 #ifdef PNG_WRITE_16BIT_SUPPORTED
556 else
557 {
558 /* This inverts the alpha channel in GGAA */
559 png_bytep sp, dp;
560 png_uint_32 i;
561 png_uint_32 row_width = row_info->width;
562
563 for (i = 0, sp = dp = row; i < row_width; i++)
564 {
565 /* Does nothing
566 *(dp++) = *(sp++);
567 *(dp++) = *(sp++);
568 */
569 sp+=2; dp = sp;
570 *(dp++) = (png_byte)(255 - *(sp++));
571 *(dp++) = (png_byte)(255 - *(sp++));
572 }
573 }
574 #endif /* PNG_WRITE_16BIT_SUPPORTED */
575 }
576 }
577 }
578 #endif
579 #endif /* PNG_WRITE_TRANSFORMS_SUPPORTED */
580
581 #ifdef PNG_MNG_FEATURES_SUPPORTED
582 /* Undoes intrapixel differencing */
583 void /* PRIVATE */
584 png_do_write_intrapixel(png_row_infop row_info, png_bytep row)
585 {
586 png_debug(1, "in png_do_write_intrapixel");
587
588 if ((row_info->color_type & PNG_COLOR_MASK_COLOR))
589 {
590 int bytes_per_pixel;
591 png_uint_32 row_width = row_info->width;
592 if (row_info->bit_depth == 8)
593 {
594 png_bytep rp;
595 png_uint_32 i;
596
597 if (row_info->color_type == PNG_COLOR_TYPE_RGB)
598 bytes_per_pixel = 3;
599
600 else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
601 bytes_per_pixel = 4;
602
603 else
604 return;
605
606 for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
607 {
608 *(rp) = (png_byte)((*rp - *(rp + 1)) & 0xff);
609 *(rp + 2) = (png_byte)((*(rp + 2) - *(rp + 1)) & 0xff);
610 }
611 }
612
613 #ifdef PNG_WRITE_16BIT_SUPPORTED
614 else if (row_info->bit_depth == 16)
615 {
616 png_bytep rp;
617 png_uint_32 i;
618
619 if (row_info->color_type == PNG_COLOR_TYPE_RGB)
620 bytes_per_pixel = 6;
621
622 else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
623 bytes_per_pixel = 8;
624
625 else
626 return;
627
628 for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
629 {
630 png_uint_32 s0 = (*(rp ) << 8) | *(rp + 1);
631 png_uint_32 s1 = (*(rp + 2) << 8) | *(rp + 3);
632 png_uint_32 s2 = (*(rp + 4) << 8) | *(rp + 5);
633 png_uint_32 red = (png_uint_32)((s0 - s1) & 0xffffL);
634 png_uint_32 blue = (png_uint_32)((s2 - s1) & 0xffffL);
635 *(rp ) = (png_byte)((red >> 8) & 0xff);
636 *(rp + 1) = (png_byte)(red & 0xff);
637 *(rp + 4) = (png_byte)((blue >> 8) & 0xff);
638 *(rp + 5) = (png_byte)(blue & 0xff);
639 }
640 }
641 #endif /* PNG_WRITE_16BIT_SUPPORTED */
642 }
643 }
644 #endif /* PNG_MNG_FEATURES_SUPPORTED */
645 #endif /* PNG_WRITE_SUPPORTED */