Use new pixman extended blend operators

It also adds extended-blend tests.

Based on a previous patch by Emmanuel Pacaud <emmanuel.pacaud@free.fr>

src/cairo-image-surface.c

@@ -936,6 +936,37 @@ _pixman_operator (cairo_operator_t op)
 	return PIXMAN_OP_ADD;
     case CAIRO_OPERATOR_SATURATE:
 	return PIXMAN_OP_SATURATE;
+
+    case CAIRO_OPERATOR_MULTIPLY:
+	return PIXMAN_OP_MULTIPLY;
+    case CAIRO_OPERATOR_SCREEN:
+	return PIXMAN_OP_SCREEN;
+    case CAIRO_OPERATOR_OVERLAY:
+	return PIXMAN_OP_OVERLAY;
+    case CAIRO_OPERATOR_DARKEN:
+	return PIXMAN_OP_DARKEN;
+    case CAIRO_OPERATOR_LIGHTEN:
+ 	return PIXMAN_OP_LIGHTEN;
+    case CAIRO_OPERATOR_COLOR_DODGE:
+ 	return PIXMAN_OP_COLOR_DODGE;
+    case CAIRO_OPERATOR_COLOR_BURN:
+ 	return PIXMAN_OP_COLOR_BURN;
+    case CAIRO_OPERATOR_HARD_LIGHT:
+ 	return PIXMAN_OP_HARD_LIGHT;
+    case CAIRO_OPERATOR_SOFT_LIGHT:
+	return PIXMAN_OP_SOFT_LIGHT;
+    case CAIRO_OPERATOR_DIFFERENCE:
+	return PIXMAN_OP_DIFFERENCE;
+    case CAIRO_OPERATOR_EXCLUSION:
+	return PIXMAN_OP_EXCLUSION;
+    case CAIRO_OPERATOR_HSL_HUE:
+	return PIXMAN_OP_HSL_HUE;
+    case CAIRO_OPERATOR_HSL_SATURATION:
+	return PIXMAN_OP_HSL_SATURATION;
+    case CAIRO_OPERATOR_HSL_COLOR:
+	return PIXMAN_OP_HSL_COLOR;
+    case CAIRO_OPERATOR_HSL_LUMINOSITY:
+	return PIXMAN_OP_HSL_LUMINOSITY;
     default:
 	return PIXMAN_OP_OVER;
     }

src/cairo-misc.c

@@ -334,6 +334,21 @@ _cairo_operator_bounded_by_mask (cairo_operator_t op)
     case CAIRO_OPERATOR_XOR:
     case CAIRO_OPERATOR_ADD:
     case CAIRO_OPERATOR_SATURATE:
+    case CAIRO_OPERATOR_MULTIPLY:
+    case CAIRO_OPERATOR_SCREEN:
+    case CAIRO_OPERATOR_OVERLAY:
+    case CAIRO_OPERATOR_DARKEN:
+    case CAIRO_OPERATOR_LIGHTEN:
+    case CAIRO_OPERATOR_COLOR_DODGE:
+    case CAIRO_OPERATOR_COLOR_BURN:
+    case CAIRO_OPERATOR_HARD_LIGHT:
+    case CAIRO_OPERATOR_SOFT_LIGHT:
+    case CAIRO_OPERATOR_DIFFERENCE:
+    case CAIRO_OPERATOR_EXCLUSION:
+    case CAIRO_OPERATOR_HSL_HUE:
+    case CAIRO_OPERATOR_HSL_SATURATION:
+    case CAIRO_OPERATOR_HSL_COLOR:
+    case CAIRO_OPERATOR_HSL_LUMINOSITY:
 	return TRUE;
     case CAIRO_OPERATOR_OUT:
     case CAIRO_OPERATOR_IN:
@@ -372,6 +387,21 @@ _cairo_operator_bounded_by_source (cairo_operator_t op)
     case CAIRO_OPERATOR_XOR:
     case CAIRO_OPERATOR_ADD:
     case CAIRO_OPERATOR_SATURATE:
+    case CAIRO_OPERATOR_MULTIPLY:
+    case CAIRO_OPERATOR_SCREEN:
+    case CAIRO_OPERATOR_OVERLAY:
+    case CAIRO_OPERATOR_DARKEN:
+    case CAIRO_OPERATOR_LIGHTEN:
+    case CAIRO_OPERATOR_COLOR_DODGE:
+    case CAIRO_OPERATOR_COLOR_BURN:
+    case CAIRO_OPERATOR_HARD_LIGHT:
+    case CAIRO_OPERATOR_SOFT_LIGHT:
+    case CAIRO_OPERATOR_DIFFERENCE:
+    case CAIRO_OPERATOR_EXCLUSION:
+    case CAIRO_OPERATOR_HSL_HUE:
+    case CAIRO_OPERATOR_HSL_SATURATION:
+    case CAIRO_OPERATOR_HSL_COLOR:
+    case CAIRO_OPERATOR_HSL_LUMINOSITY:
 	return TRUE;
     case CAIRO_OPERATOR_CLEAR:
     case CAIRO_OPERATOR_SOURCE:

src/cairo.h

@@ -422,6 +422,41 @@ cairo_pop_group_to_source (cairo_t *cr);
  * @CAIRO_OPERATOR_ADD: source and destination layers are accumulated
  * @CAIRO_OPERATOR_SATURATE: like over, but assuming source and dest are
  * disjoint geometries
+ * @CAIRO_OPERATOR_MULTIPLY: source and destination layers are multiplied.
+ * This causes the result to be at least as dark as the darker inputs.
+ * @CAIRO_OPERATOR_SCREEN: source and destination are complemented and
+ * multiplied. This causes the result to be at least as light as the lighter
+ * inputs.
+ * @CAIRO_OPERATOR_OVERLAY: multiplies or screens, depending on the 
+ * lightness of the destination color.
+ * @CAIRO_OPERATOR_DARKEN: replaces the destination with the source if it
+ * is darker, otherwise keeps the source.
+ * @CAIRO_OPERATOR_LIGHTEN: replaces the destination with the source if it
+ * is lighter, otherwise keeps the source.
+ * @CAIRO_OPERATOR_COLOR_DODGE: brightens the destination color to reflect 
+ * the source color.
+ * @CAIRO_OPERATOR_COLOR_BURN: darkens the destination color to reflect
+ * the source color.
+ * @CAIRO_OPERATOR_HARD_LIGHT: Multiplies or screens, dependant on source 
+ * color.
+ * @CAIRO_OPERATOR_SOFT_LIGHT: Darkens or lightens, dependant on source 
+ * color.
+ * @CAIRO_OPERATOR_DIFFERENCE: Takes the difference of the source and 
+ * destination color.
+ * @CAIRO_OPERATOR_EXCLUSION: Produces an effect similar to difference, but
+ * with lower contrast.
+ * @CAIRO_OPERATOR_HSL_HUE: Creates a color with the hue of the source 
+ * and the saturation and luminosity of the target.
+ * @CAIRO_OPERATOR_HSL_SATURATION: Creates a color with the saturation
+ * of the source and the hue and luminosity of the target. Painting with 
+ * this mode onto a gray area prduces no change.
+ * @CAIRO_OPERATOR_HSL_COLOR: Creates a color with the hue and saturation 
+ * of the source and the luminosity of the target. This preserves the gray 
+ * levels of the target and is useful for coloring monochrome images or
+ * tinting color images.
+ * @CAIRO_OPERATOR_HSL_LUMINOSITY: Creates a color with the luminosity of 
+ * the source and the hue and saturation of the target. This produces an 
+ * inverse effect to @CAIRO_OPERATOR_HSL_COLOR.
  *
  * #cairo_operator_t is used to set the compositing operator for all cairo
  * drawing operations.
@@ -458,7 +493,23 @@ typedef enum _cairo_operator {
 
     CAIRO_OPERATOR_XOR,
     CAIRO_OPERATOR_ADD,
-    CAIRO_OPERATOR_SATURATE
+    CAIRO_OPERATOR_SATURATE,
+
+    CAIRO_OPERATOR_MULTIPLY,
+    CAIRO_OPERATOR_SCREEN,
+    CAIRO_OPERATOR_OVERLAY,
+    CAIRO_OPERATOR_DARKEN,
+    CAIRO_OPERATOR_LIGHTEN,
+    CAIRO_OPERATOR_COLOR_DODGE,
+    CAIRO_OPERATOR_COLOR_BURN,
+    CAIRO_OPERATOR_HARD_LIGHT,
+    CAIRO_OPERATOR_SOFT_LIGHT,
+    CAIRO_OPERATOR_DIFFERENCE,
+    CAIRO_OPERATOR_EXCLUSION,
+    CAIRO_OPERATOR_HSL_HUE,
+    CAIRO_OPERATOR_HSL_SATURATION,
+    CAIRO_OPERATOR_HSL_COLOR,
+    CAIRO_OPERATOR_HSL_LUMINOSITY
 } cairo_operator_t;
 
 cairo_public void

test/Makefile.am

@@ -308,6 +308,10 @@ REFERENCE_IMAGES = \
 	device-offset.ref.png \
 	device-offset.rgb24.ref.png \
 	device-offset-scale.ref.png \
+	extended-blend.argb32.ref.png \
+	extended-blend.rgb24.ref.png \
+	extended-blend-alpha.argb32.ref.png \
+	extended-blend-alpha.rgb24.ref.png \
 	extend-pad-border.ref.png \
 	extend-pad.ref.png \
 	extend-pad.ps.ref.png \

test/Makefile.sources

@@ -55,6 +55,8 @@ test_sources = \
 	extend-reflect-similar.c			\
 	extend-repeat.c					\
 	extend-repeat-similar.c				\
+	extended-blend.c				\
+	extended-blend-alpha.c				\
 	fill-alpha.c					\
 	fill-alpha-pattern.c				\
 	fill-and-stroke.c				\

test/extended-blend-alpha.c

@@ -0,0 +1,115 @@
+/*
+ * Copyright © 2005 Red Hat, Inc.
+ * Copyright © 2007 Emmanuel Pacaud
+ * Copyright © 2008 Benjamin Otte
+ *
+ * Permission to use, copy, modify, distribute, and sell this software
+ * and its documentation for any purpose is hereby granted without
+ * fee, provided that the above copyright notice appear in all copies
+ * and that both that copyright notice and this permission notice
+ * appear in supporting documentation, and that the name of
+ * Red Hat, Inc. not be used in advertising or publicity pertaining to
+ * distribution of the software without specific, written prior
+ * permission. Red Hat, Inc. makes no representations about the
+ * suitability of this software for any purpose.  It is provided "as
+ * is" without express or implied warranty.
+ *
+ * RED HAT, INC. DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
+ * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS, IN NO EVENT SHALL RED HAT, INC. BE LIABLE FOR ANY SPECIAL,
+ * INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+ * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR
+ * IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ * Authors: Owen Taylor <otaylor@redhat.com>
+ *          Kristian Høgsberg <krh@redhat.com>
+ *          Emmanuel Pacaud <emmanuel.pacaud@lapp.in2p3.fr>
+ */
+
+#include <math.h>
+#include "cairo-test.h"
+#include <stdio.h>
+
+#define STEPS 16
+#define START_OPERATOR	CAIRO_OPERATOR_MULTIPLY
+#define STOP_OPERATOR	CAIRO_OPERATOR_HSL_LUMINOSITY
+
+static void
+create_patterns (cairo_t *bg, cairo_t *fg)
+{
+    int x;
+
+    for (x = 0; x < STEPS; x++) {
+	/* draw a yellow background fading in using discrete steps */
+	cairo_set_source_rgba (bg, 1, 1, 0, (double) x / (STEPS - 1));
+	cairo_rectangle (bg, x, 0, 1, STEPS);
+	cairo_fill (bg);
+
+	/* draw an orthogonal teal pattern fading in using discrete steps */
+	cairo_set_source_rgba (fg, 0, 1, 1, (double) x / (STEPS - 1));
+	cairo_rectangle (fg, 0, x, STEPS, 1);
+	cairo_fill (fg);
+    }
+}
+
+/* expects a STEP*STEP pixel rectangle */
+static void
+do_blend (cairo_t *cr, cairo_operator_t op, cairo_surface_t *bg, cairo_surface_t *fg)
+{
+    /* not using CAIRO_OPERATOR_SOURCE here, it triggers a librsvg bug */
+    cairo_set_operator (cr, CAIRO_OPERATOR_OVER);
+    cairo_set_source_surface (cr, bg, 0, 0);
+    cairo_paint (cr);
+
+    cairo_set_operator (cr, op);
+    cairo_set_source_surface (cr, fg, 0, 0);
+    cairo_paint (cr);
+}
+
+#define SIZE 5
+#define COUNT 4
+#define FULL_WIDTH  ((STEPS + 1) * COUNT - 1)
+#define FULL_HEIGHT ((COUNT + STOP_OPERATOR - START_OPERATOR) / COUNT) * (STEPS + 1)
+
+static cairo_test_status_t
+draw (cairo_t *cr, int width, int height)
+{
+    size_t i = 0;
+    cairo_operator_t op;
+    cairo_t *bgcr, *fgcr;
+    cairo_surface_t *bg, *fg;
+
+    bg = cairo_surface_create_similar (cairo_get_target (cr), 
+	    CAIRO_CONTENT_COLOR_ALPHA, SIZE * STEPS, SIZE * STEPS);
+    fg = cairo_surface_create_similar (cairo_get_target (cr), 
+	    CAIRO_CONTENT_COLOR_ALPHA, SIZE * STEPS, SIZE * STEPS);
+    bgcr = cairo_create (bg);
+    fgcr = cairo_create (fg);
+    cairo_scale (bgcr, SIZE, SIZE);
+    cairo_scale (fgcr, SIZE, SIZE);
+    create_patterns (bgcr, fgcr);
+    cairo_destroy (bgcr);
+    cairo_destroy (fgcr);
+
+    for (op = START_OPERATOR; op <= STOP_OPERATOR; op++, i++) {
+	cairo_save (cr);
+	cairo_translate (cr, 
+		SIZE * (STEPS + 1) * (i % COUNT),
+		SIZE * (STEPS + 1) * (i / COUNT));
+	do_blend (cr, op, bg, fg);
+	cairo_restore (cr);
+    }
+
+    cairo_surface_destroy (fg);
+    cairo_surface_destroy (bg);
+
+    return CAIRO_TEST_SUCCESS;
+}
+
+CAIRO_TEST (extended_blend_alpha,
+	    "Tests extended blend modes with alpha",
+	    "operator", /* keywords */
+	    NULL, /* requirements */
+	    FULL_WIDTH * SIZE, FULL_HEIGHT * SIZE,
+	    NULL, draw)

test/extended-blend.c

@@ -0,0 +1,117 @@
+/*
+ * Copyright © 2005 Red Hat, Inc.
+ * Copyright © 2007 Emmanuel Pacaud
+ * Copyright © 2008 Benjamin Otte
+ *
+ * Permission to use, copy, modify, distribute, and sell this software
+ * and its documentation for any purpose is hereby granted without
+ * fee, provided that the above copyright notice appear in all copies
+ * and that both that copyright notice and this permission notice
+ * appear in supporting documentation, and that the name of
+ * Red Hat, Inc. not be used in advertising or publicity pertaining to
+ * distribution of the software without specific, written prior
+ * permission. Red Hat, Inc. makes no representations about the
+ * suitability of this software for any purpose.  It is provided "as
+ * is" without express or implied warranty.
+ *
+ * RED HAT, INC. DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
+ * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS, IN NO EVENT SHALL RED HAT, INC. BE LIABLE FOR ANY SPECIAL,
+ * INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+ * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR
+ * IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ * Authors: Owen Taylor <otaylor@redhat.com>
+ *          Kristian Høgsberg <krh@redhat.com>
+ *          Emmanuel Pacaud <emmanuel.pacaud@lapp.in2p3.fr>
+ */
+
+#include <math.h>
+#include "cairo-test.h"
+#include <stdio.h>
+
+#define STEPS 16
+#define START_OPERATOR	CAIRO_OPERATOR_MULTIPLY
+#define STOP_OPERATOR	CAIRO_OPERATOR_HSL_LUMINOSITY
+
+static void
+create_patterns (cairo_t *bg, cairo_t *fg)
+{
+    int x;
+
+    for (x = 0; x < STEPS; x++) {
+	double i = (double) x / (STEPS - 1);
+	/* draw a yellow background fading in using discrete steps */
+	cairo_set_source_rgba (bg, i, i, 0, 1);
+	cairo_rectangle (bg, x, 0, 1, STEPS);
+	cairo_fill (bg);
+
+	/* draw an orthogonal teal pattern fading in using discrete steps */
+	cairo_set_source_rgba (fg, 0, i, i, 1);
+	cairo_rectangle (fg, 0, x, STEPS, 1);
+	cairo_fill (fg);
+    }
+}
+
+/* expects a STEP*STEP pixel rectangle */
+static void
+do_blend (cairo_t *cr, cairo_operator_t op, cairo_surface_t *bg, cairo_surface_t *fg)
+{
+    /* not using CAIRO_OPERATOR_SOURCE here, it triggers a librsvg bug */
+    cairo_set_operator (cr, CAIRO_OPERATOR_OVER);
+    cairo_set_source_surface (cr, bg, 0, 0);
+    cairo_paint (cr);
+
+    cairo_set_operator (cr, op);
+    cairo_set_source_surface (cr, fg, 0, 0);
+    cairo_paint (cr);
+}
+
+#define SIZE 5
+#define COUNT 4
+#define FULL_WIDTH  ((STEPS + 1) * COUNT - 1)
+#define FULL_HEIGHT ((COUNT + STOP_OPERATOR - START_OPERATOR) / COUNT) * (STEPS + 1)
+
+static cairo_test_status_t
+draw (cairo_t *cr, int width, int height)
+{
+    size_t i = 0;
+    cairo_operator_t op;
+    cairo_t *bgcr, *fgcr;
+    cairo_surface_t *bg, *fg;
+
+    bg = cairo_surface_create_similar (cairo_get_target (cr), 
+	    CAIRO_CONTENT_COLOR_ALPHA, SIZE * STEPS, SIZE * STEPS);
+    fg = cairo_surface_create_similar (cairo_get_target (cr), 
+	    CAIRO_CONTENT_COLOR_ALPHA, SIZE * STEPS, SIZE * STEPS);
+    bgcr = cairo_create (bg);
+    fgcr = cairo_create (fg);
+    cairo_scale (bgcr, SIZE, SIZE);
+    cairo_scale (fgcr, SIZE, SIZE);
+    create_patterns (bgcr, fgcr);
+    cairo_destroy (bgcr);
+    cairo_destroy (fgcr);
+
+    for (op = START_OPERATOR; op <= STOP_OPERATOR; op++, i++) {
+	cairo_save (cr);
+	cairo_translate (cr, 
+		SIZE * (STEPS + 1) * (i % COUNT),
+		SIZE * (STEPS + 1) * (i / COUNT));
+	do_blend (cr, op, bg, fg);
+	cairo_restore (cr);
+    }
+
+    cairo_surface_destroy (fg);
+    cairo_surface_destroy (bg);
+
+    return CAIRO_TEST_SUCCESS;
+}
+
+CAIRO_TEST (extended_blend,
+	    "Tests extended blend modes without alpha",
+	    "operator", /* keywords */
+	    NULL, /* requirements */
+	    FULL_WIDTH * SIZE, FULL_HEIGHT * SIZE,
+	    NULL, draw)
+