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beta-0.89.2
[luatex.git] / source / libs / pixman / pixman-src / pixman / pixman-combine-float.c
blobf5145bc9d78383f34ed2e0576b579c9598e196d9
1 /* -*- Mode: c; c-basic-offset: 4; tab-width: 8; indent-tabs-mode: t; -*- */
2 /*
3 * Copyright © 2010, 2012 Soren Sandmann Pedersen
4 * Copyright © 2010, 2012 Red Hat, Inc.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the "Software"),
8 * to deal in the Software without restriction, including without limitation
9 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10 * and/or sell copies of the Software, and to permit persons to whom the
11 * Software is furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice (including the next
14 * paragraph) shall be included in all copies or substantial portions of the
15 * Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
22 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
23 * DEALINGS IN THE SOFTWARE.
24 *
25 * Author: Soren Sandmann Pedersen (sandmann@cs.au.dk)
26 */
27
28 #ifdef HAVE_CONFIG_H
29 #include <config.h>
30 #endif
31
32 #include <math.h>
33 #include <string.h>
34 #include <float.h>
35
36 #include "pixman-private.h"
37
38 /* Workaround for http://gcc.gnu.org/PR54965 */
39 /* GCC 4.6 has problems with force_inline, so just use normal inline instead */
40 #if defined(__GNUC__) && (__GNUC__ == 4) && (__GNUC_MINOR__ == 6)
41 #undef force_inline
42 #define force_inline __inline__
43 #endif
44
45 typedef float (* combine_channel_t) (float sa, float s, float da, float d);
46
47 static force_inline void
48 combine_inner (pixman_bool_t component,
49 float *dest, const float *src, const float *mask, int n_pixels,
50 combine_channel_t combine_a, combine_channel_t combine_c)
51 {
52 int i;
53
54 if (!mask)
55 {
56 for (i = 0; i < 4 * n_pixels; i += 4)
57 {
58 float sa = src[i + 0];
59 float sr = src[i + 1];
60 float sg = src[i + 2];
61 float sb = src[i + 3];
62
63 float da = dest[i + 0];
64 float dr = dest[i + 1];
65 float dg = dest[i + 2];
66 float db = dest[i + 3];
67
68 dest[i + 0] = combine_a (sa, sa, da, da);
69 dest[i + 1] = combine_c (sa, sr, da, dr);
70 dest[i + 2] = combine_c (sa, sg, da, dg);
71 dest[i + 3] = combine_c (sa, sb, da, db);
72 }
73 }
74 else
75 {
76 for (i = 0; i < 4 * n_pixels; i += 4)
77 {
78 float sa, sr, sg, sb;
79 float ma, mr, mg, mb;
80 float da, dr, dg, db;
81
82 sa = src[i + 0];
83 sr = src[i + 1];
84 sg = src[i + 2];
85 sb = src[i + 3];
86
87 if (component)
88 {
89 ma = mask[i + 0];
90 mr = mask[i + 1];
91 mg = mask[i + 2];
92 mb = mask[i + 3];
93
94 sr *= mr;
95 sg *= mg;
96 sb *= mb;
97
98 ma *= sa;
99 mr *= sa;
100 mg *= sa;
101 mb *= sa;
102
103 sa = ma;
104 }
105 else
106 {
107 ma = mask[i + 0];
108
109 sa *= ma;
110 sr *= ma;
111 sg *= ma;
112 sb *= ma;
113
114 ma = mr = mg = mb = sa;
115 }
116
117 da = dest[i + 0];
118 dr = dest[i + 1];
119 dg = dest[i + 2];
120 db = dest[i + 3];
121
122 dest[i + 0] = combine_a (ma, sa, da, da);
123 dest[i + 1] = combine_c (mr, sr, da, dr);
124 dest[i + 2] = combine_c (mg, sg, da, dg);
125 dest[i + 3] = combine_c (mb, sb, da, db);
126 }
127 }
128 }
129
130 #define MAKE_COMBINER(name, component, combine_a, combine_c) \
131 static void \
132 combine_ ## name ## _float (pixman_implementation_t *imp, \
133 pixman_op_t op, \
134 float *dest, \
135 const float *src, \
136 const float *mask, \
137 int n_pixels) \
138 { \
139 combine_inner (component, dest, src, mask, n_pixels, \
140 combine_a, combine_c); \
141 }
142
143 #define MAKE_COMBINERS(name, combine_a, combine_c) \
144 MAKE_COMBINER(name ## _ca, TRUE, combine_a, combine_c) \
145 MAKE_COMBINER(name ## _u, FALSE, combine_a, combine_c)
146
147
148 /*
149 * Porter/Duff operators
150 */
151 typedef enum
152 {
153 ZERO,
154 ONE,
155 SRC_ALPHA,
156 DEST_ALPHA,
157 INV_SA,
158 INV_DA,
159 SA_OVER_DA,
160 DA_OVER_SA,
161 INV_SA_OVER_DA,
162 INV_DA_OVER_SA,
163 ONE_MINUS_SA_OVER_DA,
164 ONE_MINUS_DA_OVER_SA,
165 ONE_MINUS_INV_DA_OVER_SA,
166 ONE_MINUS_INV_SA_OVER_DA
167 } combine_factor_t;
168
169 #define CLAMP(f) \
170 (((f) < 0)? 0 : (((f) > 1.0) ? 1.0 : (f)))
171
172 static force_inline float
173 get_factor (combine_factor_t factor, float sa, float da)
174 {
175 float f = -1;
176
177 switch (factor)
178 {
179 case ZERO:
180 f = 0.0f;
181 break;
182
183 case ONE:
184 f = 1.0f;
185 break;
186
187 case SRC_ALPHA:
188 f = sa;
189 break;
190
191 case DEST_ALPHA:
192 f = da;
193 break;
194
195 case INV_SA:
196 f = 1 - sa;
197 break;
198
199 case INV_DA:
200 f = 1 - da;
201 break;
202
203 case SA_OVER_DA:
204 if (FLOAT_IS_ZERO (da))
205 f = 1.0f;
206 else
207 f = CLAMP (sa / da);
208 break;
209
210 case DA_OVER_SA:
211 if (FLOAT_IS_ZERO (sa))
212 f = 1.0f;
213 else
214 f = CLAMP (da / sa);
215 break;
216
217 case INV_SA_OVER_DA:
218 if (FLOAT_IS_ZERO (da))
219 f = 1.0f;
220 else
221 f = CLAMP ((1.0f - sa) / da);
222 break;
223
224 case INV_DA_OVER_SA:
225 if (FLOAT_IS_ZERO (sa))
226 f = 1.0f;
227 else
228 f = CLAMP ((1.0f - da) / sa);
229 break;
230
231 case ONE_MINUS_SA_OVER_DA:
232 if (FLOAT_IS_ZERO (da))
233 f = 0.0f;
234 else
235 f = CLAMP (1.0f - sa / da);
236 break;
237
238 case ONE_MINUS_DA_OVER_SA:
239 if (FLOAT_IS_ZERO (sa))
240 f = 0.0f;
241 else
242 f = CLAMP (1.0f - da / sa);
243 break;
244
245 case ONE_MINUS_INV_DA_OVER_SA:
246 if (FLOAT_IS_ZERO (sa))
247 f = 0.0f;
248 else
249 f = CLAMP (1.0f - (1.0f - da) / sa);
250 break;
251
252 case ONE_MINUS_INV_SA_OVER_DA:
253 if (FLOAT_IS_ZERO (da))
254 f = 0.0f;
255 else
256 f = CLAMP (1.0f - (1.0f - sa) / da);
257 break;
258 }
259
260 return f;
261 }
262
263 #define MAKE_PD_COMBINERS(name, a, b) \
264 static float force_inline \
265 pd_combine_ ## name (float sa, float s, float da, float d) \
266 { \
267 const float fa = get_factor (a, sa, da); \
268 const float fb = get_factor (b, sa, da); \
269 \
270 return MIN (1.0f, s * fa + d * fb); \
271 } \
272 \
273 MAKE_COMBINERS(name, pd_combine_ ## name, pd_combine_ ## name)
274
275 MAKE_PD_COMBINERS (clear, ZERO, ZERO)
276 MAKE_PD_COMBINERS (src, ONE, ZERO)
277 MAKE_PD_COMBINERS (dst, ZERO, ONE)
278 MAKE_PD_COMBINERS (over, ONE, INV_SA)
279 MAKE_PD_COMBINERS (over_reverse, INV_DA, ONE)
280 MAKE_PD_COMBINERS (in, DEST_ALPHA, ZERO)
281 MAKE_PD_COMBINERS (in_reverse, ZERO, SRC_ALPHA)
282 MAKE_PD_COMBINERS (out, INV_DA, ZERO)
283 MAKE_PD_COMBINERS (out_reverse, ZERO, INV_SA)
284 MAKE_PD_COMBINERS (atop, DEST_ALPHA, INV_SA)
285 MAKE_PD_COMBINERS (atop_reverse, INV_DA, SRC_ALPHA)
286 MAKE_PD_COMBINERS (xor, INV_DA, INV_SA)
287 MAKE_PD_COMBINERS (add, ONE, ONE)
288
289 MAKE_PD_COMBINERS (saturate, INV_DA_OVER_SA, ONE)
290
291 MAKE_PD_COMBINERS (disjoint_clear, ZERO, ZERO)
292 MAKE_PD_COMBINERS (disjoint_src, ONE, ZERO)
293 MAKE_PD_COMBINERS (disjoint_dst, ZERO, ONE)
294 MAKE_PD_COMBINERS (disjoint_over, ONE, INV_SA_OVER_DA)
295 MAKE_PD_COMBINERS (disjoint_over_reverse, INV_DA_OVER_SA, ONE)
296 MAKE_PD_COMBINERS (disjoint_in, ONE_MINUS_INV_DA_OVER_SA, ZERO)
297 MAKE_PD_COMBINERS (disjoint_in_reverse, ZERO, ONE_MINUS_INV_SA_OVER_DA)
298 MAKE_PD_COMBINERS (disjoint_out, INV_DA_OVER_SA, ZERO)
299 MAKE_PD_COMBINERS (disjoint_out_reverse, ZERO, INV_SA_OVER_DA)
300 MAKE_PD_COMBINERS (disjoint_atop, ONE_MINUS_INV_DA_OVER_SA, INV_SA_OVER_DA)
301 MAKE_PD_COMBINERS (disjoint_atop_reverse, INV_DA_OVER_SA, ONE_MINUS_INV_SA_OVER_DA)
302 MAKE_PD_COMBINERS (disjoint_xor, INV_DA_OVER_SA, INV_SA_OVER_DA)
303
304 MAKE_PD_COMBINERS (conjoint_clear, ZERO, ZERO)
305 MAKE_PD_COMBINERS (conjoint_src, ONE, ZERO)
306 MAKE_PD_COMBINERS (conjoint_dst, ZERO, ONE)
307 MAKE_PD_COMBINERS (conjoint_over, ONE, ONE_MINUS_SA_OVER_DA)
308 MAKE_PD_COMBINERS (conjoint_over_reverse, ONE_MINUS_DA_OVER_SA, ONE)
309 MAKE_PD_COMBINERS (conjoint_in, DA_OVER_SA, ZERO)
310 MAKE_PD_COMBINERS (conjoint_in_reverse, ZERO, SA_OVER_DA)
311 MAKE_PD_COMBINERS (conjoint_out, ONE_MINUS_DA_OVER_SA, ZERO)
312 MAKE_PD_COMBINERS (conjoint_out_reverse, ZERO, ONE_MINUS_SA_OVER_DA)
313 MAKE_PD_COMBINERS (conjoint_atop, DA_OVER_SA, ONE_MINUS_SA_OVER_DA)
314 MAKE_PD_COMBINERS (conjoint_atop_reverse, ONE_MINUS_DA_OVER_SA, SA_OVER_DA)
315 MAKE_PD_COMBINERS (conjoint_xor, ONE_MINUS_DA_OVER_SA, ONE_MINUS_SA_OVER_DA)
316
317 /*
318 * PDF blend modes:
319 *
320 * The following blend modes have been taken from the PDF ISO 32000
321 * specification, which at this point in time is available from
322 *
323 * http://www.adobe.com/devnet/pdf/pdf_reference.html
324 *
325 * The specific documents of interest are the PDF spec itself:
326 *
327 * http://wwwimages.adobe.com/www.adobe.com/content/dam/Adobe/en/devnet/pdf/pdfs/PDF32000_2008.pdf
328 *
329 * chapters 11.3.5 and 11.3.6 and a later supplement for Adobe Acrobat
330 * 9.1 and Reader 9.1:
331 *
332 * http://wwwimages.adobe.com/www.adobe.com/content/dam/Adobe/en/devnet/pdf/pdfs/adobe_supplement_iso32000_1.pdf
333 *
334 * that clarifies the specifications for blend modes ColorDodge and
335 * ColorBurn.
336 *
337 * The formula for computing the final pixel color given in 11.3.6 is:
338 *
339 * αr × Cr = (1 – αs) × αb × Cb + (1 – αb) × αs × Cs + αb × αs × B(Cb, Cs)
340 *
341 * with B() is the blend function. When B(Cb, Cs) = Cs, this formula
342 * reduces to the regular OVER operator.
343 *
344 * Cs and Cb are not premultiplied, so in our implementation we instead
345 * use:
346 *
347 * cr = (1 – αs) × cb + (1 – αb) × cs + αb × αs × B (cb/αb, cs/αs)
348 *
349 * where cr, cs, and cb are premultiplied colors, and where the
350 *
351 * αb × αs × B(cb/αb, cs/αs)
352 *
353 * part is first arithmetically simplified under the assumption that αb
354 * and αs are not 0, and then updated to produce a meaningful result when
355 * they are.
356 *
357 * For all the blend mode operators, the alpha channel is given by
358 *
359 * αr = αs + αb + αb × αs
360 */
361
362 #define MAKE_SEPARABLE_PDF_COMBINERS(name) \
363 static force_inline float \
364 combine_ ## name ## _a (float sa, float s, float da, float d) \
365 { \
366 return da + sa - da * sa; \
367 } \
368 \
369 static force_inline float \
370 combine_ ## name ## _c (float sa, float s, float da, float d) \
371 { \
372 float f = (1 - sa) * d + (1 - da) * s; \
373 \
374 return f + blend_ ## name (sa, s, da, d); \
375 } \
376 \
377 MAKE_COMBINERS (name, combine_ ## name ## _a, combine_ ## name ## _c)
378
379 /*
380 * Multiply
381 *
382 * ad * as * B(d / ad, s / as)
383 * = ad * as * d/ad * s/as
384 * = d * s
385 *
386 */
387 static force_inline float
388 blend_multiply (float sa, float s, float da, float d)
389 {
390 return d * s;
391 }
392
393 /*
394 * Screen
395 *
396 * ad * as * B(d/ad, s/as)
397 * = ad * as * (d/ad + s/as - s/as * d/ad)
398 * = ad * s + as * d - s * d
399 */
400 static force_inline float
401 blend_screen (float sa, float s, float da, float d)
402 {
403 return d * sa + s * da - s * d;
404 }
405
406 /*
407 * Overlay
408 *
409 * ad * as * B(d/ad, s/as)
410 * = ad * as * Hardlight (s, d)
411 * = if (d / ad < 0.5)
412 * as * ad * Multiply (s/as, 2 * d/ad)
413 * else
414 * as * ad * Screen (s/as, 2 * d / ad - 1)
415 * = if (d < 0.5 * ad)
416 * as * ad * s/as * 2 * d /ad
417 * else
418 * as * ad * (s/as + 2 * d / ad - 1 - s / as * (2 * d / ad - 1))
419 * = if (2 * d < ad)
420 * 2 * s * d
421 * else
422 * ad * s + 2 * as * d - as * ad - ad * s * (2 * d / ad - 1)
423 * = if (2 * d < ad)
424 * 2 * s * d
425 * else
426 * as * ad - 2 * (ad - d) * (as - s)
427 */
428 static force_inline float
429 blend_overlay (float sa, float s, float da, float d)
430 {
431 if (2 * d < da)
432 return 2 * s * d;
433 else
434 return sa * da - 2 * (da - d) * (sa - s);
435 }
436
437 /*
438 * Darken
439 *
440 * ad * as * B(d/ad, s/as)
441 * = ad * as * MIN(d/ad, s/as)
442 * = MIN (as * d, ad * s)
443 */
444 static force_inline float
445 blend_darken (float sa, float s, float da, float d)
446 {
447 s = s * da;
448 d = d * sa;
449
450 if (s > d)
451 return d;
452 else
453 return s;
454 }
455
456 /*
457 * Lighten
458 *
459 * ad * as * B(d/ad, s/as)
460 * = ad * as * MAX(d/ad, s/as)
461 * = MAX (as * d, ad * s)
462 */
463 static force_inline float
464 blend_lighten (float sa, float s, float da, float d)
465 {
466 s = s * da;
467 d = d * sa;
468
469 if (s > d)
470 return s;
471 else
472 return d;
473 }
474
475 /*
476 * Color dodge
477 *
478 * ad * as * B(d/ad, s/as)
479 * = if d/ad = 0
480 * ad * as * 0
481 * else if (d/ad >= (1 - s/as)
482 * ad * as * 1
483 * else
484 * ad * as * ((d/ad) / (1 - s/as))
485 * = if d = 0
486 * 0
487 * elif as * d >= ad * (as - s)
488 * ad * as
489 * else
490 * as * (as * d / (as - s))
491 *
492 */
493 static force_inline float
494 blend_color_dodge (float sa, float s, float da, float d)
495 {
496 if (FLOAT_IS_ZERO (d))
497 return 0.0f;
498 else if (d * sa >= sa * da - s * da)
499 return sa * da;
500 else if (FLOAT_IS_ZERO (sa - s))
501 return sa * da;
502 else
503 return sa * sa * d / (sa - s);
504 }
505
506 /*
507 * Color burn
508 *
509 * We modify the first clause "if d = 1" to "if d >= 1" since with
510 * premultiplied colors d > 1 can actually happen.
511 *
512 * ad * as * B(d/ad, s/as)
513 * = if d/ad >= 1
514 * ad * as * 1
515 * elif (1 - d/ad) >= s/as
516 * ad * as * 0
517 * else
518 * ad * as * (1 - ((1 - d/ad) / (s/as)))
519 * = if d >= ad
520 * ad * as
521 * elif as * ad - as * d >= ad * s
522 * 0
523 * else
524 * ad * as - as * as * (ad - d) / s
525 */
526 static force_inline float
527 blend_color_burn (float sa, float s, float da, float d)
528 {
529 if (d >= da)
530 return sa * da;
531 else if (sa * (da - d) >= s * da)
532 return 0.0f;
533 else if (FLOAT_IS_ZERO (s))
534 return 0.0f;
535 else
536 return sa * (da - sa * (da - d) / s);
537 }
538
539 /*
540 * Hard light
541 *
542 * ad * as * B(d/ad, s/as)
543 * = if (s/as <= 0.5)
544 * ad * as * Multiply (d/ad, 2 * s/as)
545 * else
546 * ad * as * Screen (d/ad, 2 * s/as - 1)
547 * = if 2 * s <= as
548 * ad * as * d/ad * 2 * s / as
549 * else
550 * ad * as * (d/ad + (2 * s/as - 1) + d/ad * (2 * s/as - 1))
551 * = if 2 * s <= as
552 * 2 * s * d
553 * else
554 * as * ad - 2 * (ad - d) * (as - s)
555 */
556 static force_inline float
557 blend_hard_light (float sa, float s, float da, float d)
558 {
559 if (2 * s < sa)
560 return 2 * s * d;
561 else
562 return sa * da - 2 * (da - d) * (sa - s);
563 }
564
565 /*
566 * Soft light
567 *
568 * ad * as * B(d/ad, s/as)
569 * = if (s/as <= 0.5)
570 * ad * as * (d/ad - (1 - 2 * s/as) * d/ad * (1 - d/ad))
571 * else if (d/ad <= 0.25)
572 * ad * as * (d/ad + (2 * s/as - 1) * ((((16 * d/ad - 12) * d/ad + 4) * d/ad) - d/ad))
573 * else
574 * ad * as * (d/ad + (2 * s/as - 1) * sqrt (d/ad))
575 * = if (2 * s <= as)
576 * d * as - d * (ad - d) * (as - 2 * s) / ad;
577 * else if (4 * d <= ad)
578 * (2 * s - as) * d * ((16 * d / ad - 12) * d / ad + 3);
579 * else
580 * d * as + (sqrt (d * ad) - d) * (2 * s - as);
581 */
582 static force_inline float
583 blend_soft_light (float sa, float s, float da, float d)
584 {
585 if (2 * s <= sa)
586 {
587 if (FLOAT_IS_ZERO (da))
588 return d * sa;
589 else
590 return d * sa - d * (da - d) * (sa - 2 * s) / da;
591 }
592 else
593 {
594 if (FLOAT_IS_ZERO (da))
595 {
596 return d * sa;
597 }
598 else
599 {
600 if (4 * d <= da)
601 return d * sa + (2 * s - sa) * d * ((16 * d / da - 12) * d / da + 3);
602 else
603 return d * sa + (sqrtf (d * da) - d) * (2 * s - sa);
604 }
605 }
606 }
607
608 /*
609 * Difference
610 *
611 * ad * as * B(s/as, d/ad)
612 * = ad * as * abs (s/as - d/ad)
613 * = if (s/as <= d/ad)
614 * ad * as * (d/ad - s/as)
615 * else
616 * ad * as * (s/as - d/ad)
617 * = if (ad * s <= as * d)
618 * as * d - ad * s
619 * else
620 * ad * s - as * d
621 */
622 static force_inline float
623 blend_difference (float sa, float s, float da, float d)
624 {
625 float dsa = d * sa;
626 float sda = s * da;
627
628 if (sda < dsa)
629 return dsa - sda;
630 else
631 return sda - dsa;
632 }
633
634 /*
635 * Exclusion
636 *
637 * ad * as * B(s/as, d/ad)
638 * = ad * as * (d/ad + s/as - 2 * d/ad * s/as)
639 * = as * d + ad * s - 2 * s * d
640 */
641 static force_inline float
642 blend_exclusion (float sa, float s, float da, float d)
643 {
644 return s * da + d * sa - 2 * d * s;
645 }
646
647 MAKE_SEPARABLE_PDF_COMBINERS (multiply)
648 MAKE_SEPARABLE_PDF_COMBINERS (screen)
649 MAKE_SEPARABLE_PDF_COMBINERS (overlay)
650 MAKE_SEPARABLE_PDF_COMBINERS (darken)
651 MAKE_SEPARABLE_PDF_COMBINERS (lighten)
652 MAKE_SEPARABLE_PDF_COMBINERS (color_dodge)
653 MAKE_SEPARABLE_PDF_COMBINERS (color_burn)
654 MAKE_SEPARABLE_PDF_COMBINERS (hard_light)
655 MAKE_SEPARABLE_PDF_COMBINERS (soft_light)
656 MAKE_SEPARABLE_PDF_COMBINERS (difference)
657 MAKE_SEPARABLE_PDF_COMBINERS (exclusion)
658
659 /*
660 * PDF nonseperable blend modes are implemented using the following functions
661 * to operate in Hsl space, with Cmax, Cmid, Cmin referring to the max, mid
662 * and min value of the red, green and blue components.
663 *
664 * LUM (C) = 0.3 × Cred + 0.59 × Cgreen + 0.11 × Cblue
665 *
666 * clip_color (C):
667 * l = LUM (C)
668 * min = Cmin
669 * max = Cmax
670 * if n < 0.0
671 * C = l + (((C – l) × l) ⁄ (l – min))
672 * if x > 1.0
673 * C = l + (((C – l) × (1 – l) ) ⁄ (max – l))
674 * return C
675 *
676 * set_lum (C, l):
677 * d = l – LUM (C)
678 * C += d
679 * return clip_color (C)
680 *
681 * SAT (C) = CH_MAX (C) - CH_MIN (C)
682 *
683 * set_sat (C, s):
684 * if Cmax > Cmin
685 * Cmid = ( ( ( Cmid – Cmin ) × s ) ⁄ ( Cmax – Cmin ) )
686 * Cmax = s
687 * else
688 * Cmid = Cmax = 0.0
689 * Cmin = 0.0
690 * return C
691 */
692
693 /* For premultiplied colors, we need to know what happens when C is
694 * multiplied by a real number. LUM and SAT are linear:
695 *
696 * LUM (r × C) = r × LUM (C) SAT (r * C) = r * SAT (C)
697 *
698 * If we extend clip_color with an extra argument a and change
699 *
700 * if x >= 1.0
701 *
702 * into
703 *
704 * if x >= a
705 *
706 * then clip_color is also linear:
707 *
708 * r * clip_color (C, a) = clip_color (r * C, r * a);
709 *
710 * for positive r.
711 *
712 * Similarly, we can extend set_lum with an extra argument that is just passed
713 * on to clip_color:
714 *
715 * r * set_lum (C, l, a)
716 *
717 * = r × clip_color (C + l - LUM (C), a)
718 *
719 * = clip_color (r * C + r × l - r * LUM (C), r * a)
720 *
721 * = set_lum (r * C, r * l, r * a)
722 *
723 * Finally, set_sat:
724 *
725 * r * set_sat (C, s) = set_sat (x * C, r * s)
726 *
727 * The above holds for all non-zero x, because the x'es in the fraction for
728 * C_mid cancel out. Specifically, it holds for x = r:
729 *
730 * r * set_sat (C, s) = set_sat (r * C, r * s)
731 *
732 */
733 typedef struct
734 {
735 float r;
736 float g;
737 float b;
738 } rgb_t;
739
740 static force_inline float
741 minf (float a, float b)
742 {
743 return a < b? a : b;
744 }
745
746 static force_inline float
747 maxf (float a, float b)
748 {
749 return a > b? a : b;
750 }
751
752 static force_inline float
753 channel_min (const rgb_t *c)
754 {
755 return minf (minf (c->r, c->g), c->b);
756 }
757
758 static force_inline float
759 channel_max (const rgb_t *c)
760 {
761 return maxf (maxf (c->r, c->g), c->b);
762 }
763
764 static force_inline float
765 get_lum (const rgb_t *c)
766 {
767 return c->r * 0.3f + c->g * 0.59f + c->b * 0.11f;
768 }
769
770 static force_inline float
771 get_sat (const rgb_t *c)
772 {
773 return channel_max (c) - channel_min (c);
774 }
775
776 static void
777 clip_color (rgb_t *color, float a)
778 {
779 float l = get_lum (color);
780 float n = channel_min (color);
781 float x = channel_max (color);
782 float t;
783
784 if (n < 0.0f)
785 {
786 t = l - n;
787 if (FLOAT_IS_ZERO (t))
788 {
789 color->r = 0.0f;
790 color->g = 0.0f;
791 color->b = 0.0f;
792 }
793 else
794 {
795 color->r = l + (((color->r - l) * l) / t);
796 color->g = l + (((color->g - l) * l) / t);
797 color->b = l + (((color->b - l) * l) / t);
798 }
799 }
800 if (x > a)
801 {
802 t = x - l;
803 if (FLOAT_IS_ZERO (t))
804 {
805 color->r = a;
806 color->g = a;
807 color->b = a;
808 }
809 else
810 {
811 color->r = l + (((color->r - l) * (a - l) / t));
812 color->g = l + (((color->g - l) * (a - l) / t));
813 color->b = l + (((color->b - l) * (a - l) / t));
814 }
815 }
816 }
817
818 static void
819 set_lum (rgb_t *color, float sa, float l)
820 {
821 float d = l - get_lum (color);
822
823 color->r = color->r + d;
824 color->g = color->g + d;
825 color->b = color->b + d;
826
827 clip_color (color, sa);
828 }
829
830 static void
831 set_sat (rgb_t *src, float sat)
832 {
833 float *max, *mid, *min;
834 float t;
835
836 if (src->r > src->g)
837 {
838 if (src->r > src->b)
839 {
840 max = &(src->r);
841
842 if (src->g > src->b)
843 {
844 mid = &(src->g);
845 min = &(src->b);
846 }
847 else
848 {
849 mid = &(src->b);
850 min = &(src->g);
851 }
852 }
853 else
854 {
855 max = &(src->b);
856 mid = &(src->r);
857 min = &(src->g);
858 }
859 }
860 else
861 {
862 if (src->r > src->b)
863 {
864 max = &(src->g);
865 mid = &(src->r);
866 min = &(src->b);
867 }
868 else
869 {
870 min = &(src->r);
871
872 if (src->g > src->b)
873 {
874 max = &(src->g);
875 mid = &(src->b);
876 }
877 else
878 {
879 max = &(src->b);
880 mid = &(src->g);
881 }
882 }
883 }
884
885 t = *max - *min;
886
887 if (FLOAT_IS_ZERO (t))
888 {
889 *mid = *max = 0.0f;
890 }
891 else
892 {
893 *mid = ((*mid - *min) * sat) / t;
894 *max = sat;
895 }
896
897 *min = 0.0f;
898 }
899
900 /* Hue:
901 *
902 * as * ad * B(s/as, d/as)
903 * = as * ad * set_lum (set_sat (s/as, SAT (d/ad)), LUM (d/ad), 1)
904 * = set_lum (set_sat (ad * s, as * SAT (d)), as * LUM (d), as * ad)
905 *
906 */
907 static force_inline void
908 blend_hsl_hue (rgb_t *res,
909 const rgb_t *dest, float da,
910 const rgb_t *src, float sa)
911 {
912 res->r = src->r * da;
913 res->g = src->g * da;
914 res->b = src->b * da;
915
916 set_sat (res, get_sat (dest) * sa);
917 set_lum (res, sa * da, get_lum (dest) * sa);
918 }
919
920 /*
921 * Saturation
922 *
923 * as * ad * B(s/as, d/ad)
924 * = as * ad * set_lum (set_sat (d/ad, SAT (s/as)), LUM (d/ad), 1)
925 * = set_lum (as * ad * set_sat (d/ad, SAT (s/as)),
926 * as * LUM (d), as * ad)
927 * = set_lum (set_sat (as * d, ad * SAT (s), as * LUM (d), as * ad))
928 */
929 static force_inline void
930 blend_hsl_saturation (rgb_t *res,
931 const rgb_t *dest, float da,
932 const rgb_t *src, float sa)
933 {
934 res->r = dest->r * sa;
935 res->g = dest->g * sa;
936 res->b = dest->b * sa;
937
938 set_sat (res, get_sat (src) * da);
939 set_lum (res, sa * da, get_lum (dest) * sa);
940 }
941
942 /*
943 * Color
944 *
945 * as * ad * B(s/as, d/as)
946 * = as * ad * set_lum (s/as, LUM (d/ad), 1)
947 * = set_lum (s * ad, as * LUM (d), as * ad)
948 */
949 static force_inline void
950 blend_hsl_color (rgb_t *res,
951 const rgb_t *dest, float da,
952 const rgb_t *src, float sa)
953 {
954 res->r = src->r * da;
955 res->g = src->g * da;
956 res->b = src->b * da;
957
958 set_lum (res, sa * da, get_lum (dest) * sa);
959 }
960
961 /*
962 * Luminosity
963 *
964 * as * ad * B(s/as, d/ad)
965 * = as * ad * set_lum (d/ad, LUM (s/as), 1)
966 * = set_lum (as * d, ad * LUM (s), as * ad)
967 */
968 static force_inline void
969 blend_hsl_luminosity (rgb_t *res,
970 const rgb_t *dest, float da,
971 const rgb_t *src, float sa)
972 {
973 res->r = dest->r * sa;
974 res->g = dest->g * sa;
975 res->b = dest->b * sa;
976
977 set_lum (res, sa * da, get_lum (src) * da);
978 }
979
980 #define MAKE_NON_SEPARABLE_PDF_COMBINERS(name) \
981 static void \
982 combine_ ## name ## _u_float (pixman_implementation_t *imp, \
983 pixman_op_t op, \
984 float *dest, \
985 const float *src, \
986 const float *mask, \
987 int n_pixels) \
988 { \
989 int i; \
990 \
991 for (i = 0; i < 4 * n_pixels; i += 4) \
992 { \
993 float sa, da; \
994 rgb_t sc, dc, rc; \
995 \
996 sa = src[i + 0]; \
997 sc.r = src[i + 1]; \
998 sc.g = src[i + 2]; \
999 sc.b = src[i + 3]; \
1000 \
1001 da = dest[i + 0]; \
1002 dc.r = dest[i + 1]; \
1003 dc.g = dest[i + 2]; \
1004 dc.b = dest[i + 3]; \
1005 \
1006 if (mask) \
1007 { \
1008 float ma = mask[i + 0]; \
1009 \
1010 /* Component alpha is not supported for HSL modes */ \
1011 sa *= ma; \
1012 sc.r *= ma; \
1013 sc.g *= ma; \
1014 sc.g *= ma; \
1015 } \
1016 \
1017 blend_ ## name (&rc, &dc, da, &sc, sa); \
1018 \
1019 dest[i + 0] = sa + da - sa * da; \
1020 dest[i + 1] = (1 - sa) * dc.r + (1 - da) * sc.r + rc.r; \
1021 dest[i + 2] = (1 - sa) * dc.g + (1 - da) * sc.g + rc.g; \
1022 dest[i + 3] = (1 - sa) * dc.b + (1 - da) * sc.b + rc.b; \
1023 } \
1024 }
1025
1026 MAKE_NON_SEPARABLE_PDF_COMBINERS(hsl_hue)
1027 MAKE_NON_SEPARABLE_PDF_COMBINERS(hsl_saturation)
1028 MAKE_NON_SEPARABLE_PDF_COMBINERS(hsl_color)
1029 MAKE_NON_SEPARABLE_PDF_COMBINERS(hsl_luminosity)
1030
1031 void
1032 _pixman_setup_combiner_functions_float (pixman_implementation_t *imp)
1033 {
1034 /* Unified alpha */
1035 imp->combine_float[PIXMAN_OP_CLEAR] = combine_clear_u_float;
1036 imp->combine_float[PIXMAN_OP_SRC] = combine_src_u_float;
1037 imp->combine_float[PIXMAN_OP_DST] = combine_dst_u_float;
1038 imp->combine_float[PIXMAN_OP_OVER] = combine_over_u_float;
1039 imp->combine_float[PIXMAN_OP_OVER_REVERSE] = combine_over_reverse_u_float;
1040 imp->combine_float[PIXMAN_OP_IN] = combine_in_u_float;
1041 imp->combine_float[PIXMAN_OP_IN_REVERSE] = combine_in_reverse_u_float;
1042 imp->combine_float[PIXMAN_OP_OUT] = combine_out_u_float;
1043 imp->combine_float[PIXMAN_OP_OUT_REVERSE] = combine_out_reverse_u_float;
1044 imp->combine_float[PIXMAN_OP_ATOP] = combine_atop_u_float;
1045 imp->combine_float[PIXMAN_OP_ATOP_REVERSE] = combine_atop_reverse_u_float;
1046 imp->combine_float[PIXMAN_OP_XOR] = combine_xor_u_float;
1047 imp->combine_float[PIXMAN_OP_ADD] = combine_add_u_float;
1048 imp->combine_float[PIXMAN_OP_SATURATE] = combine_saturate_u_float;
1049
1050 /* Disjoint, unified */
1051 imp->combine_float[PIXMAN_OP_DISJOINT_CLEAR] = combine_disjoint_clear_u_float;
1052 imp->combine_float[PIXMAN_OP_DISJOINT_SRC] = combine_disjoint_src_u_float;
1053 imp->combine_float[PIXMAN_OP_DISJOINT_DST] = combine_disjoint_dst_u_float;
1054 imp->combine_float[PIXMAN_OP_DISJOINT_OVER] = combine_disjoint_over_u_float;
1055 imp->combine_float[PIXMAN_OP_DISJOINT_OVER_REVERSE] = combine_disjoint_over_reverse_u_float;
1056 imp->combine_float[PIXMAN_OP_DISJOINT_IN] = combine_disjoint_in_u_float;
1057 imp->combine_float[PIXMAN_OP_DISJOINT_IN_REVERSE] = combine_disjoint_in_reverse_u_float;
1058 imp->combine_float[PIXMAN_OP_DISJOINT_OUT] = combine_disjoint_out_u_float;
1059 imp->combine_float[PIXMAN_OP_DISJOINT_OUT_REVERSE] = combine_disjoint_out_reverse_u_float;
1060 imp->combine_float[PIXMAN_OP_DISJOINT_ATOP] = combine_disjoint_atop_u_float;
1061 imp->combine_float[PIXMAN_OP_DISJOINT_ATOP_REVERSE] = combine_disjoint_atop_reverse_u_float;
1062 imp->combine_float[PIXMAN_OP_DISJOINT_XOR] = combine_disjoint_xor_u_float;
1063
1064 /* Conjoint, unified */
1065 imp->combine_float[PIXMAN_OP_CONJOINT_CLEAR] = combine_conjoint_clear_u_float;
1066 imp->combine_float[PIXMAN_OP_CONJOINT_SRC] = combine_conjoint_src_u_float;
1067 imp->combine_float[PIXMAN_OP_CONJOINT_DST] = combine_conjoint_dst_u_float;
1068 imp->combine_float[PIXMAN_OP_CONJOINT_OVER] = combine_conjoint_over_u_float;
1069 imp->combine_float[PIXMAN_OP_CONJOINT_OVER_REVERSE] = combine_conjoint_over_reverse_u_float;
1070 imp->combine_float[PIXMAN_OP_CONJOINT_IN] = combine_conjoint_in_u_float;
1071 imp->combine_float[PIXMAN_OP_CONJOINT_IN_REVERSE] = combine_conjoint_in_reverse_u_float;
1072 imp->combine_float[PIXMAN_OP_CONJOINT_OUT] = combine_conjoint_out_u_float;
1073 imp->combine_float[PIXMAN_OP_CONJOINT_OUT_REVERSE] = combine_conjoint_out_reverse_u_float;
1074 imp->combine_float[PIXMAN_OP_CONJOINT_ATOP] = combine_conjoint_atop_u_float;
1075 imp->combine_float[PIXMAN_OP_CONJOINT_ATOP_REVERSE] = combine_conjoint_atop_reverse_u_float;
1076 imp->combine_float[PIXMAN_OP_CONJOINT_XOR] = combine_conjoint_xor_u_float;
1077
1078 /* PDF operators, unified */
1079 imp->combine_float[PIXMAN_OP_MULTIPLY] = combine_multiply_u_float;
1080 imp->combine_float[PIXMAN_OP_SCREEN] = combine_screen_u_float;
1081 imp->combine_float[PIXMAN_OP_OVERLAY] = combine_overlay_u_float;
1082 imp->combine_float[PIXMAN_OP_DARKEN] = combine_darken_u_float;
1083 imp->combine_float[PIXMAN_OP_LIGHTEN] = combine_lighten_u_float;
1084 imp->combine_float[PIXMAN_OP_COLOR_DODGE] = combine_color_dodge_u_float;
1085 imp->combine_float[PIXMAN_OP_COLOR_BURN] = combine_color_burn_u_float;
1086 imp->combine_float[PIXMAN_OP_HARD_LIGHT] = combine_hard_light_u_float;
1087 imp->combine_float[PIXMAN_OP_SOFT_LIGHT] = combine_soft_light_u_float;
1088 imp->combine_float[PIXMAN_OP_DIFFERENCE] = combine_difference_u_float;
1089 imp->combine_float[PIXMAN_OP_EXCLUSION] = combine_exclusion_u_float;
1090
1091 imp->combine_float[PIXMAN_OP_HSL_HUE] = combine_hsl_hue_u_float;
1092 imp->combine_float[PIXMAN_OP_HSL_SATURATION] = combine_hsl_saturation_u_float;
1093 imp->combine_float[PIXMAN_OP_HSL_COLOR] = combine_hsl_color_u_float;
1094 imp->combine_float[PIXMAN_OP_HSL_LUMINOSITY] = combine_hsl_luminosity_u_float;
1095
1096 /* Component alpha combiners */
1097 imp->combine_float_ca[PIXMAN_OP_CLEAR] = combine_clear_ca_float;
1098 imp->combine_float_ca[PIXMAN_OP_SRC] = combine_src_ca_float;
1099 imp->combine_float_ca[PIXMAN_OP_DST] = combine_dst_ca_float;
1100 imp->combine_float_ca[PIXMAN_OP_OVER] = combine_over_ca_float;
1101 imp->combine_float_ca[PIXMAN_OP_OVER_REVERSE] = combine_over_reverse_ca_float;
1102 imp->combine_float_ca[PIXMAN_OP_IN] = combine_in_ca_float;
1103 imp->combine_float_ca[PIXMAN_OP_IN_REVERSE] = combine_in_reverse_ca_float;
1104 imp->combine_float_ca[PIXMAN_OP_OUT] = combine_out_ca_float;
1105 imp->combine_float_ca[PIXMAN_OP_OUT_REVERSE] = combine_out_reverse_ca_float;
1106 imp->combine_float_ca[PIXMAN_OP_ATOP] = combine_atop_ca_float;
1107 imp->combine_float_ca[PIXMAN_OP_ATOP_REVERSE] = combine_atop_reverse_ca_float;
1108 imp->combine_float_ca[PIXMAN_OP_XOR] = combine_xor_ca_float;
1109 imp->combine_float_ca[PIXMAN_OP_ADD] = combine_add_ca_float;
1110 imp->combine_float_ca[PIXMAN_OP_SATURATE] = combine_saturate_ca_float;
1111
1112 /* Disjoint CA */
1113 imp->combine_float_ca[PIXMAN_OP_DISJOINT_CLEAR] = combine_disjoint_clear_ca_float;
1114 imp->combine_float_ca[PIXMAN_OP_DISJOINT_SRC] = combine_disjoint_src_ca_float;
1115 imp->combine_float_ca[PIXMAN_OP_DISJOINT_DST] = combine_disjoint_dst_ca_float;
1116 imp->combine_float_ca[PIXMAN_OP_DISJOINT_OVER] = combine_disjoint_over_ca_float;
1117 imp->combine_float_ca[PIXMAN_OP_DISJOINT_OVER_REVERSE] = combine_disjoint_over_reverse_ca_float;
1118 imp->combine_float_ca[PIXMAN_OP_DISJOINT_IN] = combine_disjoint_in_ca_float;
1119 imp->combine_float_ca[PIXMAN_OP_DISJOINT_IN_REVERSE] = combine_disjoint_in_reverse_ca_float;
1120 imp->combine_float_ca[PIXMAN_OP_DISJOINT_OUT] = combine_disjoint_out_ca_float;
1121 imp->combine_float_ca[PIXMAN_OP_DISJOINT_OUT_REVERSE] = combine_disjoint_out_reverse_ca_float;
1122 imp->combine_float_ca[PIXMAN_OP_DISJOINT_ATOP] = combine_disjoint_atop_ca_float;
1123 imp->combine_float_ca[PIXMAN_OP_DISJOINT_ATOP_REVERSE] = combine_disjoint_atop_reverse_ca_float;
1124 imp->combine_float_ca[PIXMAN_OP_DISJOINT_XOR] = combine_disjoint_xor_ca_float;
1125
1126 /* Conjoint CA */
1127 imp->combine_float_ca[PIXMAN_OP_CONJOINT_CLEAR] = combine_conjoint_clear_ca_float;
1128 imp->combine_float_ca[PIXMAN_OP_CONJOINT_SRC] = combine_conjoint_src_ca_float;
1129 imp->combine_float_ca[PIXMAN_OP_CONJOINT_DST] = combine_conjoint_dst_ca_float;
1130 imp->combine_float_ca[PIXMAN_OP_CONJOINT_OVER] = combine_conjoint_over_ca_float;
1131 imp->combine_float_ca[PIXMAN_OP_CONJOINT_OVER_REVERSE] = combine_conjoint_over_reverse_ca_float;
1132 imp->combine_float_ca[PIXMAN_OP_CONJOINT_IN] = combine_conjoint_in_ca_float;
1133 imp->combine_float_ca[PIXMAN_OP_CONJOINT_IN_REVERSE] = combine_conjoint_in_reverse_ca_float;
1134 imp->combine_float_ca[PIXMAN_OP_CONJOINT_OUT] = combine_conjoint_out_ca_float;
1135 imp->combine_float_ca[PIXMAN_OP_CONJOINT_OUT_REVERSE] = combine_conjoint_out_reverse_ca_float;
1136 imp->combine_float_ca[PIXMAN_OP_CONJOINT_ATOP] = combine_conjoint_atop_ca_float;
1137 imp->combine_float_ca[PIXMAN_OP_CONJOINT_ATOP_REVERSE] = combine_conjoint_atop_reverse_ca_float;
1138 imp->combine_float_ca[PIXMAN_OP_CONJOINT_XOR] = combine_conjoint_xor_ca_float;
1139
1140 /* PDF operators CA */
1141 imp->combine_float_ca[PIXMAN_OP_MULTIPLY] = combine_multiply_ca_float;
1142 imp->combine_float_ca[PIXMAN_OP_SCREEN] = combine_screen_ca_float;
1143 imp->combine_float_ca[PIXMAN_OP_OVERLAY] = combine_overlay_ca_float;
1144 imp->combine_float_ca[PIXMAN_OP_DARKEN] = combine_darken_ca_float;
1145 imp->combine_float_ca[PIXMAN_OP_LIGHTEN] = combine_lighten_ca_float;
1146 imp->combine_float_ca[PIXMAN_OP_COLOR_DODGE] = combine_color_dodge_ca_float;
1147 imp->combine_float_ca[PIXMAN_OP_COLOR_BURN] = combine_color_burn_ca_float;
1148 imp->combine_float_ca[PIXMAN_OP_HARD_LIGHT] = combine_hard_light_ca_float;
1149 imp->combine_float_ca[PIXMAN_OP_SOFT_LIGHT] = combine_soft_light_ca_float;
1150 imp->combine_float_ca[PIXMAN_OP_DIFFERENCE] = combine_difference_ca_float;
1151 imp->combine_float_ca[PIXMAN_OP_EXCLUSION] = combine_exclusion_ca_float;
1152
1153 /* It is not clear that these make sense, so make them noops for now */
1154 imp->combine_float_ca[PIXMAN_OP_HSL_HUE] = combine_dst_u_float;
1155 imp->combine_float_ca[PIXMAN_OP_HSL_SATURATION] = combine_dst_u_float;
1156 imp->combine_float_ca[PIXMAN_OP_HSL_COLOR] = combine_dst_u_float;
1157 imp->combine_float_ca[PIXMAN_OP_HSL_LUMINOSITY] = combine_dst_u_float;
1158 }
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