The Tor Browser: gfx/cairo/libpixman/src/pixman-combine-float.c@6474c204b198 (annotated)

gfx/cairo/libpixman/src/pixman-combine-float.c@6474c204b198 (annotated)

gfx/cairo/libpixman/src/pixman-combine-float.c

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /* -*- Mode: c; c-basic-offset: 4; tab-width: 8; indent-tabs-mode: t; -*- */
 /*
  * Copyright © 2010, 2012 Soren Sandmann Pedersen
  * Copyright © 2010, 2012 Red Hat, Inc.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
  * to deal in the Software without restriction, including without limitation
  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  * and/or sell copies of the Software, and to permit persons to whom the
  * Software is furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice (including the next
  * paragraph) shall be included in all copies or substantial portions of the
  * Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  * DEALINGS IN THE SOFTWARE.
  *
  * Author: Soren Sandmann Pedersen (sandmann@cs.au.dk)
  */
 #ifdef HAVE_CONFIG_H
 #include <config.h>
 #endif
 #include <math.h>
 #include <string.h>
 #include <float.h>
 #include "pixman-private.h"
 /* Workaround for http://gcc.gnu.org/PR54965 */
 /* GCC 4.6 has problems with force_inline, so just use normal inline instead */
 #if defined(__GNUC__) && (__GNUC__ == 4) && (__GNUC_MINOR__ == 6)
 #undef force_inline
 #define force_inline __inline__
 #endif
 #define IS_ZERO(f)     (-FLT_MIN < (f) && (f) < FLT_MIN)
 typedef float (* combine_channel_t) (float sa, float s, float da, float d);
 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)
 {
     int i;
     if (!mask)
     {
 	for (i = 0; i < 4 * n_pixels; i += 4)
 	{
 	    float sa = src[i + 0];
 	    float sr = src[i + 1];
 	    float sg = src[i + 2];
 	    float sb = src[i + 3];
 	    float da = dest[i + 0];
 	    float dr = dest[i + 1];
 	    float dg = dest[i + 2];
 	    float db = dest[i + 3];
 	    dest[i + 0] = combine_a (sa, sa, da, da);
 	    dest[i + 1] = combine_c (sa, sr, da, dr);
 	    dest[i + 2] = combine_c (sa, sg, da, dg);
 	    dest[i + 3] = combine_c (sa, sb, da, db);
 	}
     }
     else
     {
 	for (i = 0; i < 4 * n_pixels; i += 4)
 	{
 	    float sa, sr, sg, sb;
 	    float ma, mr, mg, mb;
 	    float da, dr, dg, db;
 	    sa = src[i + 0];
 	    sr = src[i + 1];
 	    sg = src[i + 2];
 	    sb = src[i + 3];
 	    if (component)
 	    {
 		ma = mask[i + 0];
 		mr = mask[i + 1];
 		mg = mask[i + 2];
 		mb = mask[i + 3];
 		sr *= mr;
 		sg *= mg;
 		sb *= mb;
 		ma *= sa;
 		mr *= sa;
 		mg *= sa;
 		mb *= sa;
 		sa = ma;
 	    }
 	    else
 	    {
 		ma = mask[i + 0];
 		sa *= ma;
 		sr *= ma;
 		sg *= ma;
 		sb *= ma;
 		ma = mr = mg = mb = sa;
 	    }
 	    da = dest[i + 0];
 	    dr = dest[i + 1];
 	    dg = dest[i + 2];
 	    db = dest[i + 3];
 	    dest[i + 0] = combine_a (ma, sa, da, da);
 	    dest[i + 1] = combine_c (mr, sr, da, dr);
 	    dest[i + 2] = combine_c (mg, sg, da, dg);
 	    dest[i + 3] = combine_c (mb, sb, da, db);
 	}
     }
 }
 #define MAKE_COMBINER(name, component, combine_a, combine_c)		\
     static void								\
     combine_ ## name ## _float (pixman_implementation_t *imp,		\
 				pixman_op_t              op,		\
 				float                   *dest,		\
 				const float             *src,		\
 				const float             *mask,		\
 				int		         n_pixels)	\
     {									\
 	combine_inner (component, dest, src, mask, n_pixels,		\
 		       combine_a, combine_c);				\
     }
 #define MAKE_COMBINERS(name, combine_a, combine_c)			\
     MAKE_COMBINER(name ## _ca, TRUE, combine_a, combine_c)		\
     MAKE_COMBINER(name ## _u, FALSE, combine_a, combine_c)
 /*
  * Porter/Duff operators
  */
 typedef enum
 {
     ZERO,
     ONE,
     SRC_ALPHA,
     DEST_ALPHA,
     INV_SA,
     INV_DA,
     SA_OVER_DA,
     DA_OVER_SA,
     INV_SA_OVER_DA,
     INV_DA_OVER_SA,
     ONE_MINUS_SA_OVER_DA,
     ONE_MINUS_DA_OVER_SA,
     ONE_MINUS_INV_DA_OVER_SA,
     ONE_MINUS_INV_SA_OVER_DA
 } combine_factor_t;
 #define CLAMP(f)					\
     (((f) < 0)? 0 : (((f) > 1.0) ? 1.0 : (f)))
 static force_inline float
 get_factor (combine_factor_t factor, float sa, float da)
 {
     float f = -1;
     switch (factor)
     {
     case ZERO:
 	f = 0.0f;
 	break;
     case ONE:
 	f = 1.0f;
 	break;
     case SRC_ALPHA:
 	f = sa;
 	break;
     case DEST_ALPHA:
 	f = da;
 	break;
     case INV_SA:
 	f = 1 - sa;
 	break;
     case INV_DA:
 	f = 1 - da;
 	break;
     case SA_OVER_DA:
 	if (IS_ZERO (da))
 	    f = 1.0f;
 	else
 	    f = CLAMP (sa / da);
 	break;
     case DA_OVER_SA:
 	if (IS_ZERO (sa))
 	    f = 1.0f;
 	else
 	    f = CLAMP (da / sa);
 	break;
     case INV_SA_OVER_DA:
 	if (IS_ZERO (da))
 	    f = 1.0f;
 	else
 	    f = CLAMP ((1.0f - sa) / da);
 	break;
     case INV_DA_OVER_SA:
 	if (IS_ZERO (sa))
 	    f = 1.0f;
 	else
 	    f = CLAMP ((1.0f - da) / sa);
 	break;
     case ONE_MINUS_SA_OVER_DA:
 	if (IS_ZERO (da))
 	    f = 0.0f;
 	else
 	    f = CLAMP (1.0f - sa / da);
 	break;
     case ONE_MINUS_DA_OVER_SA:
 	if (IS_ZERO (sa))
 	    f = 0.0f;
 	else
 	    f = CLAMP (1.0f - da / sa);
 	break;
     case ONE_MINUS_INV_DA_OVER_SA:
 	if (IS_ZERO (sa))
 	    f = 0.0f;
 	else
 	    f = CLAMP (1.0f - (1.0f - da) / sa);
 	break;
     case ONE_MINUS_INV_SA_OVER_DA:
 	if (IS_ZERO (da))
 	    f = 0.0f;
 	else
 	    f = CLAMP (1.0f - (1.0f - sa) / da);
 	break;
     }
     return f;
 }
 #define MAKE_PD_COMBINERS(name, a, b)					\
     static float force_inline						\
     pd_combine_ ## name (float sa, float s, float da, float d)		\
     {									\
 	const float fa = get_factor (a, sa, da);			\
 	const float fb = get_factor (b, sa, da);			\
 									\
 	return MIN (1.0f, s * fa + d * fb);				\
     }									\
     									\
     MAKE_COMBINERS(name, pd_combine_ ## name, pd_combine_ ## name)
 MAKE_PD_COMBINERS (clear,			ZERO,				ZERO)
 MAKE_PD_COMBINERS (src,				ONE,				ZERO)
 MAKE_PD_COMBINERS (dst,				ZERO,				ONE)
 MAKE_PD_COMBINERS (over,			ONE,				INV_SA)
 MAKE_PD_COMBINERS (over_reverse,		INV_DA,				ONE)
 MAKE_PD_COMBINERS (in,				DEST_ALPHA,			ZERO)
 MAKE_PD_COMBINERS (in_reverse,			ZERO,				SRC_ALPHA)
 MAKE_PD_COMBINERS (out,				INV_DA,				ZERO)
 MAKE_PD_COMBINERS (out_reverse,			ZERO,				INV_SA)
 MAKE_PD_COMBINERS (atop,			DEST_ALPHA,			INV_SA)
 MAKE_PD_COMBINERS (atop_reverse,		INV_DA,				SRC_ALPHA)
 MAKE_PD_COMBINERS (xor,				INV_DA,				INV_SA)
 MAKE_PD_COMBINERS (add,				ONE,				ONE)
 MAKE_PD_COMBINERS (saturate,			INV_DA_OVER_SA,			ONE)
 MAKE_PD_COMBINERS (disjoint_clear,		ZERO,				ZERO)
 MAKE_PD_COMBINERS (disjoint_src,		ONE,				ZERO)
 MAKE_PD_COMBINERS (disjoint_dst,		ZERO,				ONE)
 MAKE_PD_COMBINERS (disjoint_over,		ONE,				INV_SA_OVER_DA)
 MAKE_PD_COMBINERS (disjoint_over_reverse,	INV_DA_OVER_SA,			ONE)
 MAKE_PD_COMBINERS (disjoint_in,			ONE_MINUS_INV_DA_OVER_SA,	ZERO)
 MAKE_PD_COMBINERS (disjoint_in_reverse,		ZERO,				ONE_MINUS_INV_SA_OVER_DA)
 MAKE_PD_COMBINERS (disjoint_out,		INV_DA_OVER_SA,			ZERO)
 MAKE_PD_COMBINERS (disjoint_out_reverse,	ZERO,				INV_SA_OVER_DA)
 MAKE_PD_COMBINERS (disjoint_atop,		ONE_MINUS_INV_DA_OVER_SA,	INV_SA_OVER_DA)
 MAKE_PD_COMBINERS (disjoint_atop_reverse,	INV_DA_OVER_SA,			ONE_MINUS_INV_SA_OVER_DA)
 MAKE_PD_COMBINERS (disjoint_xor,		INV_DA_OVER_SA,			INV_SA_OVER_DA)
 MAKE_PD_COMBINERS (conjoint_clear,		ZERO,				ZERO)
 MAKE_PD_COMBINERS (conjoint_src,		ONE,				ZERO)
 MAKE_PD_COMBINERS (conjoint_dst,		ZERO,				ONE)
 MAKE_PD_COMBINERS (conjoint_over,		ONE,				ONE_MINUS_SA_OVER_DA)
 MAKE_PD_COMBINERS (conjoint_over_reverse,	ONE_MINUS_DA_OVER_SA,		ONE)
 MAKE_PD_COMBINERS (conjoint_in,			DA_OVER_SA,			ZERO)
 MAKE_PD_COMBINERS (conjoint_in_reverse,		ZERO,				SA_OVER_DA)
 MAKE_PD_COMBINERS (conjoint_out,		ONE_MINUS_DA_OVER_SA,		ZERO)
 MAKE_PD_COMBINERS (conjoint_out_reverse,	ZERO,				ONE_MINUS_SA_OVER_DA)
 MAKE_PD_COMBINERS (conjoint_atop,		DA_OVER_SA,			ONE_MINUS_SA_OVER_DA)
 MAKE_PD_COMBINERS (conjoint_atop_reverse,	ONE_MINUS_DA_OVER_SA,		SA_OVER_DA)
 MAKE_PD_COMBINERS (conjoint_xor,		ONE_MINUS_DA_OVER_SA,		ONE_MINUS_SA_OVER_DA)
 /*
  * PDF blend modes:
  *
  * The following blend modes have been taken from the PDF ISO 32000
  * specification, which at this point in time is available from
  * http://www.adobe.com/devnet/acrobat/pdfs/PDF32000_2008.pdf
  * The relevant chapters are 11.3.5 and 11.3.6.
  * The formula for computing the final pixel color given in 11.3.6 is:
  * αr × Cr = (1 – αs) × αb × Cb + (1 – αb) × αs × Cs + αb × αs × B(Cb, Cs)
  * with B() being the blend function.
  * Note that OVER is a special case of this operation, using B(Cb, Cs) = Cs
  *
  * These blend modes should match the SVG filter draft specification, as
  * it has been designed to mirror ISO 32000. Note that at the current point
  * no released draft exists that shows this, as the formulas have not been
  * updated yet after the release of ISO 32000.
  *
  * The default implementation here uses the PDF_SEPARABLE_BLEND_MODE and
  * PDF_NON_SEPARABLE_BLEND_MODE macros, which take the blend function as an
  * argument. Note that this implementation operates on premultiplied colors,
  * while the PDF specification does not. Therefore the code uses the formula
  * ar.Cra = (1 – as) . Dca + (1 – ad) . Sca + B(Dca, ad, Sca, as)
  */
 #define MAKE_SEPARABLE_PDF_COMBINERS(name)				\
     static force_inline float						\
     combine_ ## name ## _a (float sa, float s, float da, float d)	\
     {									\
 	return da + sa - da * sa;					\
     }									\
     									\
     static force_inline float						\
     combine_ ## name ## _c (float sa, float s, float da, float d)	\
     {									\
 	float f = (1 - sa) * d + (1 - da) * s;				\
 									\
 	return f + blend_ ## name (sa, s, da, d);			\
     }									\
     									\
     MAKE_COMBINERS (name, combine_ ## name ## _a, combine_ ## name ## _c)
 static force_inline float
 blend_multiply (float sa, float s, float da, float d)
 {
     return d * s;
 }
 static force_inline float
 blend_screen (float sa, float s, float da, float d)
 {
     return d * sa + s * da - s * d;
 }
 static force_inline float
 blend_overlay (float sa, float s, float da, float d)
 {
     if (2 * d < da)
 	return 2 * s * d;
     else
 	return sa * da - 2 * (da - d) * (sa - s);
 }
 static force_inline float
 blend_darken (float sa, float s, float da, float d)
 {
     s = s * da;
     d = d * sa;
     if (s > d)
 	return d;
     else
 	return s;
 }
 static force_inline float
 blend_lighten (float sa, float s, float da, float d)
 {
     s = s * da;
     d = d * sa;
     if (s > d)
 	return s;
     else
 	return d;
 }
 static force_inline float
 blend_color_dodge (float sa, float s, float da, float d)
 {
     if (IS_ZERO (d))
 	return 0.0f;
     else if (d * sa >= sa * da - s * da)
 	return sa * da;
     else if (IS_ZERO (sa - s))
 	return sa * da;
     else
 	return sa * sa * d / (sa - s);
 }
 static force_inline float
 blend_color_burn (float sa, float s, float da, float d)
 {
     if (d >= da)
 	return sa * da;
     else if (sa * (da - d) >= s * da)
 	return 0.0f;
     else if (IS_ZERO (s))
 	return 0.0f;
     else
 	return sa * (da - sa * (da - d) / s);
 }
 static force_inline float
 blend_hard_light (float sa, float s, float da, float d)
 {
     if (2 * s < sa)
 	return 2 * s * d;
     else
 	return sa * da - 2 * (da - d) * (sa - s);
 }
 static force_inline float
 blend_soft_light (float sa, float s, float da, float d)
 {
     if (2 * s < sa)
     {
 	if (IS_ZERO (da))
 	    return d * sa;
 	else
 	    return d * sa - d * (da - d) * (sa - 2 * s) / da;
     }
     else
     {
 	if (IS_ZERO (da))
 	{
 	    return 0.0f;
 	}
 	else
 	{
 	    if (4 * d <= da)
 		return d * sa + (2 * s - sa) * d * ((16 * d / da - 12) * d / da + 3);
 	    else
 		return d * sa + (sqrtf (d * da) - d) * (2 * s - sa);
 	}
     }
 }
 static force_inline float
 blend_difference (float sa, float s, float da, float d)
 {
     float dsa = d * sa;
     float sda = s * da;
     if (sda < dsa)
 	return dsa - sda;
     else
 	return sda - dsa;
 }
 static force_inline float
 blend_exclusion (float sa, float s, float da, float d)
 {
     return s * da + d * sa - 2 * d * s;
 }
 MAKE_SEPARABLE_PDF_COMBINERS (multiply)
 MAKE_SEPARABLE_PDF_COMBINERS (screen)
 MAKE_SEPARABLE_PDF_COMBINERS (overlay)
 MAKE_SEPARABLE_PDF_COMBINERS (darken)
 MAKE_SEPARABLE_PDF_COMBINERS (lighten)
 MAKE_SEPARABLE_PDF_COMBINERS (color_dodge)
 MAKE_SEPARABLE_PDF_COMBINERS (color_burn)
 MAKE_SEPARABLE_PDF_COMBINERS (hard_light)
 MAKE_SEPARABLE_PDF_COMBINERS (soft_light)
 MAKE_SEPARABLE_PDF_COMBINERS (difference)
 MAKE_SEPARABLE_PDF_COMBINERS (exclusion)
 /*
  * PDF nonseperable blend modes.
  *
  * These are implemented using the following functions to operate in Hsl
  * space, with Cmax, Cmid, Cmin referring to the max, mid and min value
  * of the red, green and blue components.
  *
  * LUM (C) = 0.3 × Cred + 0.59 × Cgreen + 0.11 × Cblue
  *
  * clip_color (C):
  *   l = LUM (C)
  *   min = Cmin
  *   max = Cmax
  *   if n < 0.0
  *     C = l + (((C – l) × l) ⁄     (l – min))
  *   if x > 1.0
  *     C = l + (((C – l) × (1 – l)) (max – l))
  *   return C
  *
  * set_lum (C, l):
  *   d = l – LUM (C)
  *   C += d
  *   return clip_color (C)
  *
  * SAT (C) = CH_MAX (C) - CH_MIN (C)
  *
  * set_sat (C, s):
  *  if Cmax > Cmin
  *    Cmid = ( ( ( Cmid – Cmin ) × s ) ⁄ ( Cmax – Cmin ) )
  *    Cmax = s
  *  else
  *    Cmid = Cmax = 0.0
  *  Cmin = 0.0
  *  return C
  */
 /* For premultiplied colors, we need to know what happens when C is
  * multiplied by a real number. LUM and SAT are linear:
  *
  *    LUM (r × C) = r × LUM (C)		SAT (r × C) = r × SAT (C)
  *
  * If we extend clip_color with an extra argument a and change
  *
  *        if x >= 1.0
  *
  * into
  *
  *        if x >= a
  *
  * then clip_color is also linear:
  *
  *     r * clip_color (C, a) = clip_color (r_c, ra);
  *
  * for positive r.
  *
  * Similarly, we can extend set_lum with an extra argument that is just passed
  * on to clip_color:
  *
  *     r × set_lum ( C, l, a)
  *
  *   = r × clip_color ( C + l - LUM (C), a)
  *
  *   = clip_color ( r * C + r × l - LUM (r × C), r * a)
  *
  *   = set_lum ( r * C, r * l, r * a)
  *
  * Finally, set_sat:
  *
  *     r * set_sat (C, s) = set_sat (x * C, r * s)
  *
  * The above holds for all non-zero x because they x'es in the fraction for
  * C_mid cancel out. Specifically, it holds for x = r:
  *
  *     r * set_sat (C, s) = set_sat (r_c, rs)
  *
  *
  *
  *
  * So, for the non-separable PDF blend modes, we have (using s, d for
  * non-premultiplied colors, and S, D for premultiplied:
  *
  *   Color:
  *
  *     a_s * a_d * B(s, d)
  *   = a_s * a_d * set_lum (S/a_s, LUM (D/a_d), 1)
  *   = set_lum (S * a_d, a_s * LUM (D), a_s * a_d)
  *
  *
  *   Luminosity:
  *
  *     a_s * a_d * B(s, d)
  *   = a_s * a_d * set_lum (D/a_d, LUM(S/a_s), 1)
  *   = set_lum (a_s * D, a_d * LUM(S), a_s * a_d)
  *
  *
  *   Saturation:
  *
  *     a_s * a_d * B(s, d)
  *   = a_s * a_d * set_lum (set_sat (D/a_d, SAT (S/a_s)), LUM (D/a_d), 1)
  *   = set_lum (a_s * a_d * set_sat (D/a_d, SAT (S/a_s)),
  *                                        a_s * LUM (D), a_s * a_d)
  *   = set_lum (set_sat (a_s * D, a_d * SAT (S), a_s * LUM (D), a_s * a_d))
  *
  *   Hue:
  *
  *     a_s * a_d * B(s, d)
  *   = a_s * a_d * set_lum (set_sat (S/a_s, SAT (D/a_d)), LUM (D/a_d), 1)
  *   = set_lum (set_sat (a_d * S, a_s * SAT (D)), a_s * LUM (D), a_s * a_d)
  *
  */
 typedef struct
 {
     float	r;
     float	g;
     float	b;
 } rgb_t;
 static force_inline float
 minf (float a, float b)
 {
     return a < b? a : b;
 }
 static force_inline float
 maxf (float a, float b)
 {
     return a > b? a : b;
 }
 static force_inline float
 channel_min (const rgb_t *c)
 {
     return minf (minf (c->r, c->g), c->b);
 }
 static force_inline float
 channel_max (const rgb_t *c)
 {
     return maxf (maxf (c->r, c->g), c->b);
 }
 static force_inline float
 get_lum (const rgb_t *c)
 {
     return c->r * 0.3f + c->g * 0.59f + c->b * 0.11f;
 }
 static force_inline float
 get_sat (const rgb_t *c)
 {
     return channel_max (c) - channel_min (c);
 }
 static void
 clip_color (rgb_t *color, float a)
 {
     float l = get_lum (color);
     float n = channel_min (color);
     float x = channel_max (color);
     float t;
     if (n < 0.0f)
     {
 	t = l - n;
 	if (IS_ZERO (t))
 	{
 	    color->r = 0.0f;
 	    color->g = 0.0f;
 	    color->b = 0.0f;
 	}
 	else
 	{
 	    color->r = l + (((color->r - l) * l) / t);
 	    color->g = l + (((color->g - l) * l) / t);
 	    color->b = l + (((color->b - l) * l) / t);
 	}
     }
     if (x > a)
     {
 	t = x - l;
 	if (IS_ZERO (t))
 	{
 	    color->r = a;
 	    color->g = a;
 	    color->b = a;
 	}
 	else
 	{
 	    color->r = l + (((color->r - l) * (a - l) / t));
 	    color->g = l + (((color->g - l) * (a - l) / t));
 	    color->b = l + (((color->b - l) * (a - l) / t));
 	}
     }
 }
 static void
 set_lum (rgb_t *color, float sa, float l)
 {
     float d = l - get_lum (color);
     color->r = color->r + d;
     color->g = color->g + d;
     color->b = color->b + d;
     clip_color (color, sa);
 }
 static void
 set_sat (rgb_t *src, float sat)
 {
     float *max, *mid, *min;
     float t;
     if (src->r > src->g)
     {
 	if (src->r > src->b)
 	{
 	    max = &(src->r);
 	    if (src->g > src->b)
 	    {
 		mid = &(src->g);
 		min = &(src->b);
 	    }
 	    else
 	    {
 		mid = &(src->b);
 		min = &(src->g);
 	    }
 	}
 	else
 	{
 	    max = &(src->b);
 	    mid = &(src->r);
 	    min = &(src->g);
 	}
     }
     else
     {
 	if (src->r > src->b)
 	{
 	    max = &(src->g);
 	    mid = &(src->r);
 	    min = &(src->b);
 	}
 	else
 	{
 	    min = &(src->r);
 	    if (src->g > src->b)
 	    {
 		max = &(src->g);
 		mid = &(src->b);
 	    }
 	    else
 	    {
 		max = &(src->b);
 		mid = &(src->g);
 	    }
 	}
     }
     t = *max - *min;
     if (IS_ZERO (t))
     {
 	*mid = *max = 0.0f;
     }
     else
     {
 	*mid = ((*mid - *min) * sat) / t;
 	*max = sat;
     }
     *min = 0.0f;
 }
 /*
  * Hue:
  * B(Cb, Cs) = set_lum (set_sat (Cs, SAT (Cb)), LUM (Cb))
  */
 static force_inline void
 blend_hsl_hue (rgb_t *res,
 	       const rgb_t *dest, float da,
 	       const rgb_t *src, float sa)
 {
     res->r = src->r * da;
     res->g = src->g * da;
     res->b = src->b * da;
     set_sat (res, get_sat (dest) * sa);
     set_lum (res, sa * da, get_lum (dest) * sa);
 }
 /*
  * Saturation:
  * B(Cb, Cs) = set_lum (set_sat (Cb, SAT (Cs)), LUM (Cb))
  */
 static force_inline void
 blend_hsl_saturation (rgb_t *res,
 		      const rgb_t *dest, float da,
 		      const rgb_t *src, float sa)
 {
     res->r = dest->r * sa;
     res->g = dest->g * sa;
     res->b = dest->b * sa;
     set_sat (res, get_sat (src) * da);
     set_lum (res, sa * da, get_lum (dest) * sa);
 }
 /*
  * Color:
  * B(Cb, Cs) = set_lum (Cs, LUM (Cb))
  */
 static force_inline void
 blend_hsl_color (rgb_t *res,
 		 const rgb_t *dest, float da,
 		 const rgb_t *src, float sa)
 {
     res->r = src->r * da;
     res->g = src->g * da;
     res->b = src->b * da;
     set_lum (res, sa * da, get_lum (dest) * sa);
 }
 /*
  * Luminosity:
  * B(Cb, Cs) = set_lum (Cb, LUM (Cs))
  */
 static force_inline void
 blend_hsl_luminosity (rgb_t *res,
 		      const rgb_t *dest, float da,
 		      const rgb_t *src, float sa)
 {
     res->r = dest->r * sa;
     res->g = dest->g * sa;
     res->b = dest->b * sa;
     set_lum (res, sa * da, get_lum (src) * da);
 }
 #define MAKE_NON_SEPARABLE_PDF_COMBINERS(name)				\
     static void								\
     combine_ ## name ## _u_float (pixman_implementation_t *imp,		\
 				  pixman_op_t              op,		\
 				  float                   *dest,	\
 				  const float             *src,		\
 				  const float             *mask,	\
 				  int		           n_pixels)	\
     {									\
     	int i;								\
 									\
 	for (i = 0; i < 4 * n_pixels; i += 4)				\
 	{								\
 	    float sa, da;						\
 	    rgb_t sc, dc, rc;						\
 									\
 	    sa = src[i + 0];						\
 	    sc.r = src[i + 1];						\
 	    sc.g = src[i + 2];						\
 	    sc.b = src[i + 3];						\
 									\
 	    da = dest[i + 0];						\
 	    dc.r = dest[i + 1];						\
 	    dc.g = dest[i + 2];						\
 	    dc.b = dest[i + 3];						\
 									\
 	    if (mask)							\
 	    {								\
 		float ma = mask[i + 0];					\
 									\
 		/* Component alpha is not supported for HSL modes */	\
 		sa *= ma;						\
 		sc.r *= ma;						\
 		sc.g *= ma;						\
 		sc.g *= ma;						\
 	    }								\
 									\
 	    blend_ ## name (&rc, &dc, da, &sc, sa);			\
 									\
 	    dest[i + 0] = sa + da - sa * da;				\
 	    dest[i + 1] = (1 - sa) * dc.r + (1 - da) * sc.r + rc.r;	\
 	    dest[i + 2] = (1 - sa) * dc.g + (1 - da) * sc.g + rc.g;	\
 	    dest[i + 3] = (1 - sa) * dc.b + (1 - da) * sc.b + rc.b;	\
 	}								\
     }
 MAKE_NON_SEPARABLE_PDF_COMBINERS(hsl_hue)
 MAKE_NON_SEPARABLE_PDF_COMBINERS(hsl_saturation)
 MAKE_NON_SEPARABLE_PDF_COMBINERS(hsl_color)
 MAKE_NON_SEPARABLE_PDF_COMBINERS(hsl_luminosity)
 void
 _pixman_setup_combiner_functions_float (pixman_implementation_t *imp)
 {
     /* Unified alpha */
     imp->combine_float[PIXMAN_OP_CLEAR] = combine_clear_u_float;
     imp->combine_float[PIXMAN_OP_SRC] = combine_src_u_float;
     imp->combine_float[PIXMAN_OP_DST] = combine_dst_u_float;
     imp->combine_float[PIXMAN_OP_OVER] = combine_over_u_float;
     imp->combine_float[PIXMAN_OP_OVER_REVERSE] = combine_over_reverse_u_float;
     imp->combine_float[PIXMAN_OP_IN] = combine_in_u_float;
     imp->combine_float[PIXMAN_OP_IN_REVERSE] = combine_in_reverse_u_float;
     imp->combine_float[PIXMAN_OP_OUT] = combine_out_u_float;
     imp->combine_float[PIXMAN_OP_OUT_REVERSE] = combine_out_reverse_u_float;
     imp->combine_float[PIXMAN_OP_ATOP] = combine_atop_u_float;
     imp->combine_float[PIXMAN_OP_ATOP_REVERSE] = combine_atop_reverse_u_float;
     imp->combine_float[PIXMAN_OP_XOR] = combine_xor_u_float;
     imp->combine_float[PIXMAN_OP_ADD] = combine_add_u_float;
     imp->combine_float[PIXMAN_OP_SATURATE] = combine_saturate_u_float;
     /* Disjoint, unified */
     imp->combine_float[PIXMAN_OP_DISJOINT_CLEAR] = combine_disjoint_clear_u_float;
     imp->combine_float[PIXMAN_OP_DISJOINT_SRC] = combine_disjoint_src_u_float;
     imp->combine_float[PIXMAN_OP_DISJOINT_DST] = combine_disjoint_dst_u_float;
     imp->combine_float[PIXMAN_OP_DISJOINT_OVER] = combine_disjoint_over_u_float;
     imp->combine_float[PIXMAN_OP_DISJOINT_OVER_REVERSE] = combine_disjoint_over_reverse_u_float;
     imp->combine_float[PIXMAN_OP_DISJOINT_IN] = combine_disjoint_in_u_float;
     imp->combine_float[PIXMAN_OP_DISJOINT_IN_REVERSE] = combine_disjoint_in_reverse_u_float;
     imp->combine_float[PIXMAN_OP_DISJOINT_OUT] = combine_disjoint_out_u_float;
     imp->combine_float[PIXMAN_OP_DISJOINT_OUT_REVERSE] = combine_disjoint_out_reverse_u_float;
     imp->combine_float[PIXMAN_OP_DISJOINT_ATOP] = combine_disjoint_atop_u_float;
     imp->combine_float[PIXMAN_OP_DISJOINT_ATOP_REVERSE] = combine_disjoint_atop_reverse_u_float;
     imp->combine_float[PIXMAN_OP_DISJOINT_XOR] = combine_disjoint_xor_u_float;
     /* Conjoint, unified */
     imp->combine_float[PIXMAN_OP_CONJOINT_CLEAR] = combine_conjoint_clear_u_float;
     imp->combine_float[PIXMAN_OP_CONJOINT_SRC] = combine_conjoint_src_u_float;
     imp->combine_float[PIXMAN_OP_CONJOINT_DST] = combine_conjoint_dst_u_float;
     imp->combine_float[PIXMAN_OP_CONJOINT_OVER] = combine_conjoint_over_u_float;
     imp->combine_float[PIXMAN_OP_CONJOINT_OVER_REVERSE] = combine_conjoint_over_reverse_u_float;
     imp->combine_float[PIXMAN_OP_CONJOINT_IN] = combine_conjoint_in_u_float;
     imp->combine_float[PIXMAN_OP_CONJOINT_IN_REVERSE] = combine_conjoint_in_reverse_u_float;
     imp->combine_float[PIXMAN_OP_CONJOINT_OUT] = combine_conjoint_out_u_float;
     imp->combine_float[PIXMAN_OP_CONJOINT_OUT_REVERSE] = combine_conjoint_out_reverse_u_float;
     imp->combine_float[PIXMAN_OP_CONJOINT_ATOP] = combine_conjoint_atop_u_float;
     imp->combine_float[PIXMAN_OP_CONJOINT_ATOP_REVERSE] = combine_conjoint_atop_reverse_u_float;
     imp->combine_float[PIXMAN_OP_CONJOINT_XOR] = combine_conjoint_xor_u_float;
     /* PDF operators, unified */
     imp->combine_float[PIXMAN_OP_MULTIPLY] = combine_multiply_u_float;
     imp->combine_float[PIXMAN_OP_SCREEN] = combine_screen_u_float;
     imp->combine_float[PIXMAN_OP_OVERLAY] = combine_overlay_u_float;
     imp->combine_float[PIXMAN_OP_DARKEN] = combine_darken_u_float;
     imp->combine_float[PIXMAN_OP_LIGHTEN] = combine_lighten_u_float;
     imp->combine_float[PIXMAN_OP_COLOR_DODGE] = combine_color_dodge_u_float;
     imp->combine_float[PIXMAN_OP_COLOR_BURN] = combine_color_burn_u_float;
     imp->combine_float[PIXMAN_OP_HARD_LIGHT] = combine_hard_light_u_float;
     imp->combine_float[PIXMAN_OP_SOFT_LIGHT] = combine_soft_light_u_float;
     imp->combine_float[PIXMAN_OP_DIFFERENCE] = combine_difference_u_float;
     imp->combine_float[PIXMAN_OP_EXCLUSION] = combine_exclusion_u_float;
     imp->combine_float[PIXMAN_OP_HSL_HUE] = combine_hsl_hue_u_float;
     imp->combine_float[PIXMAN_OP_HSL_SATURATION] = combine_hsl_saturation_u_float;
     imp->combine_float[PIXMAN_OP_HSL_COLOR] = combine_hsl_color_u_float;
     imp->combine_float[PIXMAN_OP_HSL_LUMINOSITY] = combine_hsl_luminosity_u_float;
     /* Component alpha combiners */
     imp->combine_float_ca[PIXMAN_OP_CLEAR] = combine_clear_ca_float;
     imp->combine_float_ca[PIXMAN_OP_SRC] = combine_src_ca_float;
     imp->combine_float_ca[PIXMAN_OP_DST] = combine_dst_ca_float;
     imp->combine_float_ca[PIXMAN_OP_OVER] = combine_over_ca_float;
     imp->combine_float_ca[PIXMAN_OP_OVER_REVERSE] = combine_over_reverse_ca_float;
     imp->combine_float_ca[PIXMAN_OP_IN] = combine_in_ca_float;
     imp->combine_float_ca[PIXMAN_OP_IN_REVERSE] = combine_in_reverse_ca_float;
     imp->combine_float_ca[PIXMAN_OP_OUT] = combine_out_ca_float;
     imp->combine_float_ca[PIXMAN_OP_OUT_REVERSE] = combine_out_reverse_ca_float;
     imp->combine_float_ca[PIXMAN_OP_ATOP] = combine_atop_ca_float;
     imp->combine_float_ca[PIXMAN_OP_ATOP_REVERSE] = combine_atop_reverse_ca_float;
     imp->combine_float_ca[PIXMAN_OP_XOR] = combine_xor_ca_float;
     imp->combine_float_ca[PIXMAN_OP_ADD] = combine_add_ca_float;
     imp->combine_float_ca[PIXMAN_OP_SATURATE] = combine_saturate_ca_float;
     /* Disjoint CA */
     imp->combine_float_ca[PIXMAN_OP_DISJOINT_CLEAR] = combine_disjoint_clear_ca_float;
     imp->combine_float_ca[PIXMAN_OP_DISJOINT_SRC] = combine_disjoint_src_ca_float;
     imp->combine_float_ca[PIXMAN_OP_DISJOINT_DST] = combine_disjoint_dst_ca_float;
     imp->combine_float_ca[PIXMAN_OP_DISJOINT_OVER] = combine_disjoint_over_ca_float;
     imp->combine_float_ca[PIXMAN_OP_DISJOINT_OVER_REVERSE] = combine_disjoint_over_reverse_ca_float;
     imp->combine_float_ca[PIXMAN_OP_DISJOINT_IN] = combine_disjoint_in_ca_float;
     imp->combine_float_ca[PIXMAN_OP_DISJOINT_IN_REVERSE] = combine_disjoint_in_reverse_ca_float;
     imp->combine_float_ca[PIXMAN_OP_DISJOINT_OUT] = combine_disjoint_out_ca_float;
     imp->combine_float_ca[PIXMAN_OP_DISJOINT_OUT_REVERSE] = combine_disjoint_out_reverse_ca_float;
     imp->combine_float_ca[PIXMAN_OP_DISJOINT_ATOP] = combine_disjoint_atop_ca_float;
     imp->combine_float_ca[PIXMAN_OP_DISJOINT_ATOP_REVERSE] = combine_disjoint_atop_reverse_ca_float;
     imp->combine_float_ca[PIXMAN_OP_DISJOINT_XOR] = combine_disjoint_xor_ca_float;
     /* Conjoint CA */
     imp->combine_float_ca[PIXMAN_OP_CONJOINT_CLEAR] = combine_conjoint_clear_ca_float;
     imp->combine_float_ca[PIXMAN_OP_CONJOINT_SRC] = combine_conjoint_src_ca_float;
     imp->combine_float_ca[PIXMAN_OP_CONJOINT_DST] = combine_conjoint_dst_ca_float;
     imp->combine_float_ca[PIXMAN_OP_CONJOINT_OVER] = combine_conjoint_over_ca_float;
     imp->combine_float_ca[PIXMAN_OP_CONJOINT_OVER_REVERSE] = combine_conjoint_over_reverse_ca_float;
     imp->combine_float_ca[PIXMAN_OP_CONJOINT_IN] = combine_conjoint_in_ca_float;
     imp->combine_float_ca[PIXMAN_OP_CONJOINT_IN_REVERSE] = combine_conjoint_in_reverse_ca_float;
     imp->combine_float_ca[PIXMAN_OP_CONJOINT_OUT] = combine_conjoint_out_ca_float;
     imp->combine_float_ca[PIXMAN_OP_CONJOINT_OUT_REVERSE] = combine_conjoint_out_reverse_ca_float;
     imp->combine_float_ca[PIXMAN_OP_CONJOINT_ATOP] = combine_conjoint_atop_ca_float;
     imp->combine_float_ca[PIXMAN_OP_CONJOINT_ATOP_REVERSE] = combine_conjoint_atop_reverse_ca_float;
     imp->combine_float_ca[PIXMAN_OP_CONJOINT_XOR] = combine_conjoint_xor_ca_float;
     /* PDF operators CA */
     imp->combine_float_ca[PIXMAN_OP_MULTIPLY] = combine_multiply_ca_float;
     imp->combine_float_ca[PIXMAN_OP_SCREEN] = combine_screen_ca_float;
     imp->combine_float_ca[PIXMAN_OP_OVERLAY] = combine_overlay_ca_float;
     imp->combine_float_ca[PIXMAN_OP_DARKEN] = combine_darken_ca_float;
     imp->combine_float_ca[PIXMAN_OP_LIGHTEN] = combine_lighten_ca_float;
     imp->combine_float_ca[PIXMAN_OP_COLOR_DODGE] = combine_color_dodge_ca_float;
     imp->combine_float_ca[PIXMAN_OP_COLOR_BURN] = combine_color_burn_ca_float;
     imp->combine_float_ca[PIXMAN_OP_HARD_LIGHT] = combine_hard_light_ca_float;
     imp->combine_float_ca[PIXMAN_OP_SOFT_LIGHT] = combine_soft_light_ca_float;
     imp->combine_float_ca[PIXMAN_OP_DIFFERENCE] = combine_difference_ca_float;
     imp->combine_float_ca[PIXMAN_OP_EXCLUSION] = combine_exclusion_ca_float;
     /* It is not clear that these make sense, so make them noops for now */
     imp->combine_float_ca[PIXMAN_OP_HSL_HUE] = combine_dst_u_float;
     imp->combine_float_ca[PIXMAN_OP_HSL_SATURATION] = combine_dst_u_float;
     imp->combine_float_ca[PIXMAN_OP_HSL_COLOR] = combine_dst_u_float;
     imp->combine_float_ca[PIXMAN_OP_HSL_LUMINOSITY] = combine_dst_u_float;
 }

The Tor Browser / annotate

gfx/cairo/libpixman/src/pixman-combine-float.c@6474c204b198 (annotated)

gfx/cairo/libpixman/src/pixman-combine-float.c