test: Add arc-direction

A simple example of how to draw arcs.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

test/Makefile.sources

@@ -12,6 +12,7 @@ test_sources = \
 	a8-mask.c					\
 	aliasing.c					\
 	alpha-similar.c					\
+	arc-direction.c					\
 	arc-infinite-loop.c				\
 	arc-looping-dash.c				\
 	api-special-cases.c				\

test/arc-direction.c

@@ -0,0 +1,105 @@
+/*
+ * Copyright © 2012 Intel Corporation
+ *
+ * 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 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: Chris Wilson <chris@chris-wilson.co.uk>
+ */
+
+#include "cairo-test.h"
+
+#define SIZE		(2 * 20)
+#define PAD		(2)
+
+static cairo_test_status_t
+draw_arcs (cairo_t *cr)
+{
+    double start = M_PI/12, stop = 2*start;
+
+    cairo_move_to (cr, SIZE/2, SIZE/2);
+    cairo_arc (cr, SIZE/2, SIZE/2, SIZE/2, start, stop);
+    cairo_fill (cr);
+
+    cairo_translate (cr, SIZE+PAD, 0);
+    cairo_move_to (cr, SIZE/2, SIZE/2);
+    cairo_arc (cr, SIZE/2, SIZE/2, SIZE/2, 2*M_PI-stop, 2*M_PI-start);
+    cairo_fill (cr);
+
+    cairo_translate (cr, 0, SIZE+PAD);
+    cairo_move_to (cr, SIZE/2, SIZE/2);
+    cairo_arc_negative (cr, SIZE/2, SIZE/2, SIZE/2, 2*M_PI-stop, 2*M_PI-start);
+    cairo_fill (cr);
+
+    cairo_translate (cr, -SIZE-PAD, 0);
+    cairo_move_to (cr, SIZE/2, SIZE/2);
+    cairo_arc_negative (cr, SIZE/2, SIZE/2, SIZE/2, start, stop);
+    cairo_fill (cr);
+
+    return CAIRO_TEST_SUCCESS;
+}
+
+static cairo_test_status_t
+draw (cairo_t *cr, int width, int height)
+{
+    cairo_save (cr);
+    cairo_set_source_rgb (cr, 1.0, 1.0, 1.0); /* white */
+    cairo_paint (cr);
+    cairo_restore (cr);
+
+    cairo_save (cr);
+    cairo_translate (cr, PAD, PAD);
+    draw_arcs(cr);
+    cairo_restore (cr);
+
+    cairo_set_source_rgb (cr, 1, 0, 0);
+    cairo_translate (cr, 2*SIZE+3*PAD, 0);
+    cairo_save (cr);
+    cairo_translate (cr, 2*SIZE+2*PAD, PAD);
+    cairo_scale (cr, -1, 1);
+    draw_arcs(cr);
+    cairo_restore (cr);
+
+    cairo_set_source_rgb (cr, 1, 0, 1);
+    cairo_translate (cr, 0, 2*SIZE+3*PAD);
+    cairo_save (cr);
+    cairo_translate (cr, 2*SIZE+2*PAD, 2*SIZE+2*PAD);
+    cairo_scale (cr, -1, -1);
+    draw_arcs(cr);
+    cairo_restore (cr);
+
+    cairo_set_source_rgb (cr, 0, 0, 1);
+    cairo_translate (cr, -(2*SIZE+3*PAD), 0);
+    cairo_save (cr);
+    cairo_translate (cr, PAD, 2*SIZE+2*PAD);
+    cairo_scale (cr, 1, -1);
+    draw_arcs(cr);
+    cairo_restore (cr);
+
+    return CAIRO_TEST_SUCCESS;
+}
+
+CAIRO_TEST (arc_direction,
+	    "Test drawing positive/negative arcs",
+	    "arc fill", /* keywords */
+	    NULL, /* requirements */
+	    2*(3*PAD + 2*SIZE), 2*(3*PAD + 2*SIZE),
+	    NULL, draw)
+