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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
combine_inner(pixman_bool_t component,float * dest,const float * src,const float * mask,int n_pixels,combine_channel_t combine_a,combine_channel_t combine_c)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
get_factor(combine_factor_t factor,float sa,float da)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 
MAKE_PD_COMBINERS(clear,ZERO,ZERO)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  * http://www.adobe.com/devnet/acrobat/pdfs/PDF32000_2008.pdf
323  * The relevant chapters are 11.3.5 and 11.3.6.
324  * The formula for computing the final pixel color given in 11.3.6 is:
325  * αr × Cr = (1 – αs) × αb × Cb + (1 – αb) × αs × Cs + αb × αs × B(Cb, Cs)
326  * with B() being the blend function.
327  * Note that OVER is a special case of this operation, using B(Cb, Cs) = Cs
328  *
329  * These blend modes should match the SVG filter draft specification, as
330  * it has been designed to mirror ISO 32000. Note that at the current point
331  * no released draft exists that shows this, as the formulas have not been
332  * updated yet after the release of ISO 32000.
333  *
334  * The default implementation here uses the PDF_SEPARABLE_BLEND_MODE and
335  * PDF_NON_SEPARABLE_BLEND_MODE macros, which take the blend function as an
336  * argument. Note that this implementation operates on premultiplied colors,
337  * while the PDF specification does not. Therefore the code uses the formula
338  * ar.Cra = (1 – as) . Dca + (1 – ad) . Sca + B(Dca, ad, Sca, as)
339  */
340 
341 #define MAKE_SEPARABLE_PDF_COMBINERS(name)				\
342     static force_inline float						\
343     combine_ ## name ## _a (float sa, float s, float da, float d)	\
344     {									\
345 	return da + sa - da * sa;					\
346     }									\
347     									\
348     static force_inline float						\
349     combine_ ## name ## _c (float sa, float s, float da, float d)	\
350     {									\
351 	float f = (1 - sa) * d + (1 - da) * s;				\
352 									\
353 	return f + blend_ ## name (sa, s, da, d);			\
354     }									\
355     									\
356     MAKE_COMBINERS (name, combine_ ## name ## _a, combine_ ## name ## _c)
357 
358 static force_inline float
359 blend_multiply (float sa, float s, float da, float d)
360 {
361     return d * s;
362 }
363 
364 static force_inline float
blend_screen(float sa,float s,float da,float d)365 blend_screen (float sa, float s, float da, float d)
366 {
367     return d * sa + s * da - s * d;
368 }
369 
370 static force_inline float
blend_overlay(float sa,float s,float da,float d)371 blend_overlay (float sa, float s, float da, float d)
372 {
373     if (2 * d < da)
374 	return 2 * s * d;
375     else
376 	return sa * da - 2 * (da - d) * (sa - s);
377 }
378 
379 static force_inline float
blend_darken(float sa,float s,float da,float d)380 blend_darken (float sa, float s, float da, float d)
381 {
382     s = s * da;
383     d = d * sa;
384 
385     if (s > d)
386 	return d;
387     else
388 	return s;
389 }
390 
391 static force_inline float
blend_lighten(float sa,float s,float da,float d)392 blend_lighten (float sa, float s, float da, float d)
393 {
394     s = s * da;
395     d = d * sa;
396 
397     if (s > d)
398 	return s;
399     else
400 	return d;
401 }
402 
403 static force_inline float
blend_color_dodge(float sa,float s,float da,float d)404 blend_color_dodge (float sa, float s, float da, float d)
405 {
406     if (FLOAT_IS_ZERO (d))
407 	return 0.0f;
408     else if (d * sa >= sa * da - s * da)
409 	return sa * da;
410     else if (FLOAT_IS_ZERO (sa - s))
411 	return sa * da;
412     else
413 	return sa * sa * d / (sa - s);
414 }
415 
416 static force_inline float
blend_color_burn(float sa,float s,float da,float d)417 blend_color_burn (float sa, float s, float da, float d)
418 {
419     if (d >= da)
420 	return sa * da;
421     else if (sa * (da - d) >= s * da)
422 	return 0.0f;
423     else if (FLOAT_IS_ZERO (s))
424 	return 0.0f;
425     else
426 	return sa * (da - sa * (da - d) / s);
427 }
428 
429 static force_inline float
blend_hard_light(float sa,float s,float da,float d)430 blend_hard_light (float sa, float s, float da, float d)
431 {
432     if (2 * s < sa)
433 	return 2 * s * d;
434     else
435 	return sa * da - 2 * (da - d) * (sa - s);
436 }
437 
438 static force_inline float
blend_soft_light(float sa,float s,float da,float d)439 blend_soft_light (float sa, float s, float da, float d)
440 {
441     if (2 * s < sa)
442     {
443 	if (FLOAT_IS_ZERO (da))
444 	    return d * sa;
445 	else
446 	    return d * sa - d * (da - d) * (sa - 2 * s) / da;
447     }
448     else
449     {
450 	if (FLOAT_IS_ZERO (da))
451 	{
452 	    return 0.0f;
453 	}
454 	else
455 	{
456 	    if (4 * d <= da)
457 		return d * sa + (2 * s - sa) * d * ((16 * d / da - 12) * d / da + 3);
458 	    else
459 		return d * sa + (sqrtf (d * da) - d) * (2 * s - sa);
460 	}
461     }
462 }
463 
464 static force_inline float
blend_difference(float sa,float s,float da,float d)465 blend_difference (float sa, float s, float da, float d)
466 {
467     float dsa = d * sa;
468     float sda = s * da;
469 
470     if (sda < dsa)
471 	return dsa - sda;
472     else
473 	return sda - dsa;
474 }
475 
476 static force_inline float
blend_exclusion(float sa,float s,float da,float d)477 blend_exclusion (float sa, float s, float da, float d)
478 {
479     return s * da + d * sa - 2 * d * s;
480 }
481 
482 MAKE_SEPARABLE_PDF_COMBINERS (multiply)
483 MAKE_SEPARABLE_PDF_COMBINERS (screen)
484 MAKE_SEPARABLE_PDF_COMBINERS (overlay)
485 MAKE_SEPARABLE_PDF_COMBINERS (darken)
486 MAKE_SEPARABLE_PDF_COMBINERS (lighten)
487 MAKE_SEPARABLE_PDF_COMBINERS (color_dodge)
488 MAKE_SEPARABLE_PDF_COMBINERS (color_burn)
489 MAKE_SEPARABLE_PDF_COMBINERS (hard_light)
490 MAKE_SEPARABLE_PDF_COMBINERS (soft_light)
491 MAKE_SEPARABLE_PDF_COMBINERS (difference)
492 MAKE_SEPARABLE_PDF_COMBINERS (exclusion)
493 
494 /*
495  * PDF nonseperable blend modes.
496  *
497  * These are implemented using the following functions to operate in Hsl
498  * space, with Cmax, Cmid, Cmin referring to the max, mid and min value
499  * of the red, green and blue components.
500  *
501  * LUM (C) = 0.3 × Cred + 0.59 × Cgreen + 0.11 × Cblue
502  *
503  * clip_color (C):
504  *   l = LUM (C)
505  *   min = Cmin
506  *   max = Cmax
507  *   if n < 0.0
508  *     C = l + (((C – l) × l) ⁄     (l – min))
509  *   if x > 1.0
510  *     C = l + (((C – l) × (1 – l)) (max – l))
511  *   return C
512  *
513  * set_lum (C, l):
514  *   d = l – LUM (C)
515  *   C += d
516  *   return clip_color (C)
517  *
518  * SAT (C) = CH_MAX (C) - CH_MIN (C)
519  *
520  * set_sat (C, s):
521  *  if Cmax > Cmin
522  *    Cmid = ( ( ( Cmid – Cmin ) × s ) ⁄ ( Cmax – Cmin ) )
523  *    Cmax = s
524  *  else
525  *    Cmid = Cmax = 0.0
526  *  Cmin = 0.0
527  *  return C
528  */
529 
530 /* For premultiplied colors, we need to know what happens when C is
531  * multiplied by a real number. LUM and SAT are linear:
532  *
533  *    LUM (r × C) = r × LUM (C)		SAT (r × C) = r × SAT (C)
534  *
535  * If we extend clip_color with an extra argument a and change
536  *
537  *        if x >= 1.0
538  *
539  * into
540  *
541  *        if x >= a
542  *
543  * then clip_color is also linear:
544  *
545  *     r * clip_color (C, a) = clip_color (r_c, ra);
546  *
547  * for positive r.
548  *
549  * Similarly, we can extend set_lum with an extra argument that is just passed
550  * on to clip_color:
551  *
552  *     r × set_lum ( C, l, a)
553  *
554  *   = r × clip_color ( C + l - LUM (C), a)
555  *
556  *   = clip_color ( r * C + r × l - LUM (r × C), r * a)
557  *
558  *   = set_lum ( r * C, r * l, r * a)
559  *
560  * Finally, set_sat:
561  *
562  *     r * set_sat (C, s) = set_sat (x * C, r * s)
563  *
564  * The above holds for all non-zero x because they x'es in the fraction for
565  * C_mid cancel out. Specifically, it holds for x = r:
566  *
567  *     r * set_sat (C, s) = set_sat (r_c, rs)
568  *
569  *
570  *
571  *
572  * So, for the non-separable PDF blend modes, we have (using s, d for
573  * non-premultiplied colors, and S, D for premultiplied:
574  *
575  *   Color:
576  *
577  *     a_s * a_d * B(s, d)
578  *   = a_s * a_d * set_lum (S/a_s, LUM (D/a_d), 1)
579  *   = set_lum (S * a_d, a_s * LUM (D), a_s * a_d)
580  *
581  *
582  *   Luminosity:
583  *
584  *     a_s * a_d * B(s, d)
585  *   = a_s * a_d * set_lum (D/a_d, LUM(S/a_s), 1)
586  *   = set_lum (a_s * D, a_d * LUM(S), a_s * a_d)
587  *
588  *
589  *   Saturation:
590  *
591  *     a_s * a_d * B(s, d)
592  *   = a_s * a_d * set_lum (set_sat (D/a_d, SAT (S/a_s)), LUM (D/a_d), 1)
593  *   = set_lum (a_s * a_d * set_sat (D/a_d, SAT (S/a_s)),
594  *                                        a_s * LUM (D), a_s * a_d)
595  *   = set_lum (set_sat (a_s * D, a_d * SAT (S), a_s * LUM (D), a_s * a_d))
596  *
597  *   Hue:
598  *
599  *     a_s * a_d * B(s, d)
600  *   = a_s * a_d * set_lum (set_sat (S/a_s, SAT (D/a_d)), LUM (D/a_d), 1)
601  *   = set_lum (set_sat (a_d * S, a_s * SAT (D)), a_s * LUM (D), a_s * a_d)
602  *
603  */
604 
605 typedef struct
606 {
607     float	r;
608     float	g;
609     float	b;
610 } rgb_t;
611 
612 static force_inline float
minf(float a,float b)613 minf (float a, float b)
614 {
615     return a < b? a : b;
616 }
617 
618 static force_inline float
maxf(float a,float b)619 maxf (float a, float b)
620 {
621     return a > b? a : b;
622 }
623 
624 static force_inline float
channel_min(const rgb_t * c)625 channel_min (const rgb_t *c)
626 {
627     return minf (minf (c->r, c->g), c->b);
628 }
629 
630 static force_inline float
channel_max(const rgb_t * c)631 channel_max (const rgb_t *c)
632 {
633     return maxf (maxf (c->r, c->g), c->b);
634 }
635 
636 static force_inline float
get_lum(const rgb_t * c)637 get_lum (const rgb_t *c)
638 {
639     return c->r * 0.3f + c->g * 0.59f + c->b * 0.11f;
640 }
641 
642 static force_inline float
get_sat(const rgb_t * c)643 get_sat (const rgb_t *c)
644 {
645     return channel_max (c) - channel_min (c);
646 }
647 
648 static void
clip_color(rgb_t * color,float a)649 clip_color (rgb_t *color, float a)
650 {
651     float l = get_lum (color);
652     float n = channel_min (color);
653     float x = channel_max (color);
654     float t;
655 
656     if (n < 0.0f)
657     {
658 	t = l - n;
659 	if (FLOAT_IS_ZERO (t))
660 	{
661 	    color->r = 0.0f;
662 	    color->g = 0.0f;
663 	    color->b = 0.0f;
664 	}
665 	else
666 	{
667 	    color->r = l + (((color->r - l) * l) / t);
668 	    color->g = l + (((color->g - l) * l) / t);
669 	    color->b = l + (((color->b - l) * l) / t);
670 	}
671     }
672     if (x > a)
673     {
674 	t = x - l;
675 	if (FLOAT_IS_ZERO (t))
676 	{
677 	    color->r = a;
678 	    color->g = a;
679 	    color->b = a;
680 	}
681 	else
682 	{
683 	    color->r = l + (((color->r - l) * (a - l) / t));
684 	    color->g = l + (((color->g - l) * (a - l) / t));
685 	    color->b = l + (((color->b - l) * (a - l) / t));
686 	}
687     }
688 }
689 
690 static void
set_lum(rgb_t * color,float sa,float l)691 set_lum (rgb_t *color, float sa, float l)
692 {
693     float d = l - get_lum (color);
694 
695     color->r = color->r + d;
696     color->g = color->g + d;
697     color->b = color->b + d;
698 
699     clip_color (color, sa);
700 }
701 
702 static void
set_sat(rgb_t * src,float sat)703 set_sat (rgb_t *src, float sat)
704 {
705     float *max, *mid, *min;
706     float t;
707 
708     if (src->r > src->g)
709     {
710 	if (src->r > src->b)
711 	{
712 	    max = &(src->r);
713 
714 	    if (src->g > src->b)
715 	    {
716 		mid = &(src->g);
717 		min = &(src->b);
718 	    }
719 	    else
720 	    {
721 		mid = &(src->b);
722 		min = &(src->g);
723 	    }
724 	}
725 	else
726 	{
727 	    max = &(src->b);
728 	    mid = &(src->r);
729 	    min = &(src->g);
730 	}
731     }
732     else
733     {
734 	if (src->r > src->b)
735 	{
736 	    max = &(src->g);
737 	    mid = &(src->r);
738 	    min = &(src->b);
739 	}
740 	else
741 	{
742 	    min = &(src->r);
743 
744 	    if (src->g > src->b)
745 	    {
746 		max = &(src->g);
747 		mid = &(src->b);
748 	    }
749 	    else
750 	    {
751 		max = &(src->b);
752 		mid = &(src->g);
753 	    }
754 	}
755     }
756 
757     t = *max - *min;
758 
759     if (FLOAT_IS_ZERO (t))
760     {
761 	*mid = *max = 0.0f;
762     }
763     else
764     {
765 	*mid = ((*mid - *min) * sat) / t;
766 	*max = sat;
767     }
768 
769     *min = 0.0f;
770 }
771 
772 /*
773  * Hue:
774  * B(Cb, Cs) = set_lum (set_sat (Cs, SAT (Cb)), LUM (Cb))
775  */
776 static force_inline void
blend_hsl_hue(rgb_t * res,const rgb_t * dest,float da,const rgb_t * src,float sa)777 blend_hsl_hue (rgb_t *res,
778 	       const rgb_t *dest, float da,
779 	       const rgb_t *src, float sa)
780 {
781     res->r = src->r * da;
782     res->g = src->g * da;
783     res->b = src->b * da;
784 
785     set_sat (res, get_sat (dest) * sa);
786     set_lum (res, sa * da, get_lum (dest) * sa);
787 }
788 
789 /*
790  * Saturation:
791  * B(Cb, Cs) = set_lum (set_sat (Cb, SAT (Cs)), LUM (Cb))
792  */
793 static force_inline void
blend_hsl_saturation(rgb_t * res,const rgb_t * dest,float da,const rgb_t * src,float sa)794 blend_hsl_saturation (rgb_t *res,
795 		      const rgb_t *dest, float da,
796 		      const rgb_t *src, float sa)
797 {
798     res->r = dest->r * sa;
799     res->g = dest->g * sa;
800     res->b = dest->b * sa;
801 
802     set_sat (res, get_sat (src) * da);
803     set_lum (res, sa * da, get_lum (dest) * sa);
804 }
805 
806 /*
807  * Color:
808  * B(Cb, Cs) = set_lum (Cs, LUM (Cb))
809  */
810 static force_inline void
blend_hsl_color(rgb_t * res,const rgb_t * dest,float da,const rgb_t * src,float sa)811 blend_hsl_color (rgb_t *res,
812 		 const rgb_t *dest, float da,
813 		 const rgb_t *src, float sa)
814 {
815     res->r = src->r * da;
816     res->g = src->g * da;
817     res->b = src->b * da;
818 
819     set_lum (res, sa * da, get_lum (dest) * sa);
820 }
821 
822 /*
823  * Luminosity:
824  * B(Cb, Cs) = set_lum (Cb, LUM (Cs))
825  */
826 static force_inline void
blend_hsl_luminosity(rgb_t * res,const rgb_t * dest,float da,const rgb_t * src,float sa)827 blend_hsl_luminosity (rgb_t *res,
828 		      const rgb_t *dest, float da,
829 		      const rgb_t *src, float sa)
830 {
831     res->r = dest->r * sa;
832     res->g = dest->g * sa;
833     res->b = dest->b * sa;
834 
835     set_lum (res, sa * da, get_lum (src) * da);
836 }
837 
838 #define MAKE_NON_SEPARABLE_PDF_COMBINERS(name)				\
839     static void								\
840     combine_ ## name ## _u_float (pixman_implementation_t *imp,		\
841 				  pixman_op_t              op,		\
842 				  float                   *dest,	\
843 				  const float             *src,		\
844 				  const float             *mask,	\
845 				  int		           n_pixels)	\
846     {									\
847     	int i;								\
848 									\
849 	for (i = 0; i < 4 * n_pixels; i += 4)				\
850 	{								\
851 	    float sa, da;						\
852 	    rgb_t sc, dc, rc;						\
853 									\
854 	    sa = src[i + 0];						\
855 	    sc.r = src[i + 1];						\
856 	    sc.g = src[i + 2];						\
857 	    sc.b = src[i + 3];						\
858 									\
859 	    da = dest[i + 0];						\
860 	    dc.r = dest[i + 1];						\
861 	    dc.g = dest[i + 2];						\
862 	    dc.b = dest[i + 3];						\
863 									\
864 	    if (mask)							\
865 	    {								\
866 		float ma = mask[i + 0];					\
867 									\
868 		/* Component alpha is not supported for HSL modes */	\
869 		sa *= ma;						\
870 		sc.r *= ma;						\
871 		sc.g *= ma;						\
872 		sc.g *= ma;						\
873 	    }								\
874 									\
875 	    blend_ ## name (&rc, &dc, da, &sc, sa);			\
876 									\
877 	    dest[i + 0] = sa + da - sa * da;				\
878 	    dest[i + 1] = (1 - sa) * dc.r + (1 - da) * sc.r + rc.r;	\
879 	    dest[i + 2] = (1 - sa) * dc.g + (1 - da) * sc.g + rc.g;	\
880 	    dest[i + 3] = (1 - sa) * dc.b + (1 - da) * sc.b + rc.b;	\
881 	}								\
882     }
883 
884 MAKE_NON_SEPARABLE_PDF_COMBINERS(hsl_hue)
MAKE_NON_SEPARABLE_PDF_COMBINERS(hsl_saturation)885 MAKE_NON_SEPARABLE_PDF_COMBINERS(hsl_saturation)
886 MAKE_NON_SEPARABLE_PDF_COMBINERS(hsl_color)
887 MAKE_NON_SEPARABLE_PDF_COMBINERS(hsl_luminosity)
888 
889 void
890 _pixman_setup_combiner_functions_float (pixman_implementation_t *imp)
891 {
892     /* Unified alpha */
893     imp->combine_float[PIXMAN_OP_CLEAR] = combine_clear_u_float;
894     imp->combine_float[PIXMAN_OP_SRC] = combine_src_u_float;
895     imp->combine_float[PIXMAN_OP_DST] = combine_dst_u_float;
896     imp->combine_float[PIXMAN_OP_OVER] = combine_over_u_float;
897     imp->combine_float[PIXMAN_OP_OVER_REVERSE] = combine_over_reverse_u_float;
898     imp->combine_float[PIXMAN_OP_IN] = combine_in_u_float;
899     imp->combine_float[PIXMAN_OP_IN_REVERSE] = combine_in_reverse_u_float;
900     imp->combine_float[PIXMAN_OP_OUT] = combine_out_u_float;
901     imp->combine_float[PIXMAN_OP_OUT_REVERSE] = combine_out_reverse_u_float;
902     imp->combine_float[PIXMAN_OP_ATOP] = combine_atop_u_float;
903     imp->combine_float[PIXMAN_OP_ATOP_REVERSE] = combine_atop_reverse_u_float;
904     imp->combine_float[PIXMAN_OP_XOR] = combine_xor_u_float;
905     imp->combine_float[PIXMAN_OP_ADD] = combine_add_u_float;
906     imp->combine_float[PIXMAN_OP_SATURATE] = combine_saturate_u_float;
907 
908     /* Disjoint, unified */
909     imp->combine_float[PIXMAN_OP_DISJOINT_CLEAR] = combine_disjoint_clear_u_float;
910     imp->combine_float[PIXMAN_OP_DISJOINT_SRC] = combine_disjoint_src_u_float;
911     imp->combine_float[PIXMAN_OP_DISJOINT_DST] = combine_disjoint_dst_u_float;
912     imp->combine_float[PIXMAN_OP_DISJOINT_OVER] = combine_disjoint_over_u_float;
913     imp->combine_float[PIXMAN_OP_DISJOINT_OVER_REVERSE] = combine_disjoint_over_reverse_u_float;
914     imp->combine_float[PIXMAN_OP_DISJOINT_IN] = combine_disjoint_in_u_float;
915     imp->combine_float[PIXMAN_OP_DISJOINT_IN_REVERSE] = combine_disjoint_in_reverse_u_float;
916     imp->combine_float[PIXMAN_OP_DISJOINT_OUT] = combine_disjoint_out_u_float;
917     imp->combine_float[PIXMAN_OP_DISJOINT_OUT_REVERSE] = combine_disjoint_out_reverse_u_float;
918     imp->combine_float[PIXMAN_OP_DISJOINT_ATOP] = combine_disjoint_atop_u_float;
919     imp->combine_float[PIXMAN_OP_DISJOINT_ATOP_REVERSE] = combine_disjoint_atop_reverse_u_float;
920     imp->combine_float[PIXMAN_OP_DISJOINT_XOR] = combine_disjoint_xor_u_float;
921 
922     /* Conjoint, unified */
923     imp->combine_float[PIXMAN_OP_CONJOINT_CLEAR] = combine_conjoint_clear_u_float;
924     imp->combine_float[PIXMAN_OP_CONJOINT_SRC] = combine_conjoint_src_u_float;
925     imp->combine_float[PIXMAN_OP_CONJOINT_DST] = combine_conjoint_dst_u_float;
926     imp->combine_float[PIXMAN_OP_CONJOINT_OVER] = combine_conjoint_over_u_float;
927     imp->combine_float[PIXMAN_OP_CONJOINT_OVER_REVERSE] = combine_conjoint_over_reverse_u_float;
928     imp->combine_float[PIXMAN_OP_CONJOINT_IN] = combine_conjoint_in_u_float;
929     imp->combine_float[PIXMAN_OP_CONJOINT_IN_REVERSE] = combine_conjoint_in_reverse_u_float;
930     imp->combine_float[PIXMAN_OP_CONJOINT_OUT] = combine_conjoint_out_u_float;
931     imp->combine_float[PIXMAN_OP_CONJOINT_OUT_REVERSE] = combine_conjoint_out_reverse_u_float;
932     imp->combine_float[PIXMAN_OP_CONJOINT_ATOP] = combine_conjoint_atop_u_float;
933     imp->combine_float[PIXMAN_OP_CONJOINT_ATOP_REVERSE] = combine_conjoint_atop_reverse_u_float;
934     imp->combine_float[PIXMAN_OP_CONJOINT_XOR] = combine_conjoint_xor_u_float;
935 
936     /* PDF operators, unified */
937     imp->combine_float[PIXMAN_OP_MULTIPLY] = combine_multiply_u_float;
938     imp->combine_float[PIXMAN_OP_SCREEN] = combine_screen_u_float;
939     imp->combine_float[PIXMAN_OP_OVERLAY] = combine_overlay_u_float;
940     imp->combine_float[PIXMAN_OP_DARKEN] = combine_darken_u_float;
941     imp->combine_float[PIXMAN_OP_LIGHTEN] = combine_lighten_u_float;
942     imp->combine_float[PIXMAN_OP_COLOR_DODGE] = combine_color_dodge_u_float;
943     imp->combine_float[PIXMAN_OP_COLOR_BURN] = combine_color_burn_u_float;
944     imp->combine_float[PIXMAN_OP_HARD_LIGHT] = combine_hard_light_u_float;
945     imp->combine_float[PIXMAN_OP_SOFT_LIGHT] = combine_soft_light_u_float;
946     imp->combine_float[PIXMAN_OP_DIFFERENCE] = combine_difference_u_float;
947     imp->combine_float[PIXMAN_OP_EXCLUSION] = combine_exclusion_u_float;
948 
949     imp->combine_float[PIXMAN_OP_HSL_HUE] = combine_hsl_hue_u_float;
950     imp->combine_float[PIXMAN_OP_HSL_SATURATION] = combine_hsl_saturation_u_float;
951     imp->combine_float[PIXMAN_OP_HSL_COLOR] = combine_hsl_color_u_float;
952     imp->combine_float[PIXMAN_OP_HSL_LUMINOSITY] = combine_hsl_luminosity_u_float;
953 
954     /* Component alpha combiners */
955     imp->combine_float_ca[PIXMAN_OP_CLEAR] = combine_clear_ca_float;
956     imp->combine_float_ca[PIXMAN_OP_SRC] = combine_src_ca_float;
957     imp->combine_float_ca[PIXMAN_OP_DST] = combine_dst_ca_float;
958     imp->combine_float_ca[PIXMAN_OP_OVER] = combine_over_ca_float;
959     imp->combine_float_ca[PIXMAN_OP_OVER_REVERSE] = combine_over_reverse_ca_float;
960     imp->combine_float_ca[PIXMAN_OP_IN] = combine_in_ca_float;
961     imp->combine_float_ca[PIXMAN_OP_IN_REVERSE] = combine_in_reverse_ca_float;
962     imp->combine_float_ca[PIXMAN_OP_OUT] = combine_out_ca_float;
963     imp->combine_float_ca[PIXMAN_OP_OUT_REVERSE] = combine_out_reverse_ca_float;
964     imp->combine_float_ca[PIXMAN_OP_ATOP] = combine_atop_ca_float;
965     imp->combine_float_ca[PIXMAN_OP_ATOP_REVERSE] = combine_atop_reverse_ca_float;
966     imp->combine_float_ca[PIXMAN_OP_XOR] = combine_xor_ca_float;
967     imp->combine_float_ca[PIXMAN_OP_ADD] = combine_add_ca_float;
968     imp->combine_float_ca[PIXMAN_OP_SATURATE] = combine_saturate_ca_float;
969 
970     /* Disjoint CA */
971     imp->combine_float_ca[PIXMAN_OP_DISJOINT_CLEAR] = combine_disjoint_clear_ca_float;
972     imp->combine_float_ca[PIXMAN_OP_DISJOINT_SRC] = combine_disjoint_src_ca_float;
973     imp->combine_float_ca[PIXMAN_OP_DISJOINT_DST] = combine_disjoint_dst_ca_float;
974     imp->combine_float_ca[PIXMAN_OP_DISJOINT_OVER] = combine_disjoint_over_ca_float;
975     imp->combine_float_ca[PIXMAN_OP_DISJOINT_OVER_REVERSE] = combine_disjoint_over_reverse_ca_float;
976     imp->combine_float_ca[PIXMAN_OP_DISJOINT_IN] = combine_disjoint_in_ca_float;
977     imp->combine_float_ca[PIXMAN_OP_DISJOINT_IN_REVERSE] = combine_disjoint_in_reverse_ca_float;
978     imp->combine_float_ca[PIXMAN_OP_DISJOINT_OUT] = combine_disjoint_out_ca_float;
979     imp->combine_float_ca[PIXMAN_OP_DISJOINT_OUT_REVERSE] = combine_disjoint_out_reverse_ca_float;
980     imp->combine_float_ca[PIXMAN_OP_DISJOINT_ATOP] = combine_disjoint_atop_ca_float;
981     imp->combine_float_ca[PIXMAN_OP_DISJOINT_ATOP_REVERSE] = combine_disjoint_atop_reverse_ca_float;
982     imp->combine_float_ca[PIXMAN_OP_DISJOINT_XOR] = combine_disjoint_xor_ca_float;
983 
984     /* Conjoint CA */
985     imp->combine_float_ca[PIXMAN_OP_CONJOINT_CLEAR] = combine_conjoint_clear_ca_float;
986     imp->combine_float_ca[PIXMAN_OP_CONJOINT_SRC] = combine_conjoint_src_ca_float;
987     imp->combine_float_ca[PIXMAN_OP_CONJOINT_DST] = combine_conjoint_dst_ca_float;
988     imp->combine_float_ca[PIXMAN_OP_CONJOINT_OVER] = combine_conjoint_over_ca_float;
989     imp->combine_float_ca[PIXMAN_OP_CONJOINT_OVER_REVERSE] = combine_conjoint_over_reverse_ca_float;
990     imp->combine_float_ca[PIXMAN_OP_CONJOINT_IN] = combine_conjoint_in_ca_float;
991     imp->combine_float_ca[PIXMAN_OP_CONJOINT_IN_REVERSE] = combine_conjoint_in_reverse_ca_float;
992     imp->combine_float_ca[PIXMAN_OP_CONJOINT_OUT] = combine_conjoint_out_ca_float;
993     imp->combine_float_ca[PIXMAN_OP_CONJOINT_OUT_REVERSE] = combine_conjoint_out_reverse_ca_float;
994     imp->combine_float_ca[PIXMAN_OP_CONJOINT_ATOP] = combine_conjoint_atop_ca_float;
995     imp->combine_float_ca[PIXMAN_OP_CONJOINT_ATOP_REVERSE] = combine_conjoint_atop_reverse_ca_float;
996     imp->combine_float_ca[PIXMAN_OP_CONJOINT_XOR] = combine_conjoint_xor_ca_float;
997 
998     /* PDF operators CA */
999     imp->combine_float_ca[PIXMAN_OP_MULTIPLY] = combine_multiply_ca_float;
1000     imp->combine_float_ca[PIXMAN_OP_SCREEN] = combine_screen_ca_float;
1001     imp->combine_float_ca[PIXMAN_OP_OVERLAY] = combine_overlay_ca_float;
1002     imp->combine_float_ca[PIXMAN_OP_DARKEN] = combine_darken_ca_float;
1003     imp->combine_float_ca[PIXMAN_OP_LIGHTEN] = combine_lighten_ca_float;
1004     imp->combine_float_ca[PIXMAN_OP_COLOR_DODGE] = combine_color_dodge_ca_float;
1005     imp->combine_float_ca[PIXMAN_OP_COLOR_BURN] = combine_color_burn_ca_float;
1006     imp->combine_float_ca[PIXMAN_OP_HARD_LIGHT] = combine_hard_light_ca_float;
1007     imp->combine_float_ca[PIXMAN_OP_SOFT_LIGHT] = combine_soft_light_ca_float;
1008     imp->combine_float_ca[PIXMAN_OP_DIFFERENCE] = combine_difference_ca_float;
1009     imp->combine_float_ca[PIXMAN_OP_EXCLUSION] = combine_exclusion_ca_float;
1010 
1011     /* It is not clear that these make sense, so make them noops for now */
1012     imp->combine_float_ca[PIXMAN_OP_HSL_HUE] = combine_dst_u_float;
1013     imp->combine_float_ca[PIXMAN_OP_HSL_SATURATION] = combine_dst_u_float;
1014     imp->combine_float_ca[PIXMAN_OP_HSL_COLOR] = combine_dst_u_float;
1015     imp->combine_float_ca[PIXMAN_OP_HSL_LUMINOSITY] = combine_dst_u_float;
1016 }
1017