Use new pixman extended blend operators

It also adds extended-blend tests.

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

1 files changed, 117 insertions, 0 deletions

diff --git a/test/extended-blend.c b/test/extended-blend.c
new file mode 100644
index 00000000..cd2b06b9
--- /dev/null
+++ b/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)
+