test: Exercise stroking bugs with xlib/trapezoids

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=84115
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

4 files changed, 62 insertions, 0 deletions

diff --git a/test/Makefile.sources b/test/Makefile.sources
index 689645c50..7e80b90c1 100644
--- a/test/Makefile.sources
+++ b/test/Makefile.sources
@@ -26,6 +26,7 @@ test_sources = \
 	bilevel-image.c					\
 	bug-40410.c					\
 	bug-51910.c					\
+	bug-84115.c					\
 	bug-bo-rectangular.c				\
 	bug-bo-collins.c				\
 	bug-bo-ricotz.c					\
diff --git a/test/bug-84115.c b/test/bug-84115.c
new file mode 100644
index 000000000..4db113c5c
--- /dev/null
+++ b/test/bug-84115.c
@@ -0,0 +1,61 @@
+/*
+ * Copyright © 2011 Krzysztof Kosiński
+ *
+ * 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: Krzysztof Kosiński <tweenk.pl@gmail.com>
+ */
+
+#include "cairo-test.h"
+
+#define WIDTH	800
+#define HEIGHT	800
+
+static cairo_test_status_t
+draw (cairo_t *cr, int width, int height)
+{
+    double lw = 800;
+    int n = 0;
+
+    cairo_set_source_rgb (cr, 1,1,1);
+    cairo_paint (cr);
+
+    cairo_set_source_rgba (cr, 0, 0, 0, .4);
+    cairo_set_line_cap (cr, CAIRO_LINE_CAP_BUTT);
+    do {
+	cairo_set_line_width(cr, lw);
+	cairo_arc(cr, WIDTH/2, HEIGHT/2, lw/2,
+		  2*M_PI*(13*n + 1) / 130, 2*M_PI*(13*n + 12) / 130);
+	cairo_stroke(cr);
+
+	n++;
+	lw /= 1.1;
+    } while (lw > 0.5);
+
+    return CAIRO_TEST_SUCCESS;
+}
+
+CAIRO_TEST (bug_84115,
+	    "Exercises a bug found in stroke generation using trapezoids",
+	    "stroke", /* keywords */
+	    NULL, /* requirements */
+	    WIDTH, HEIGHT,
+	    NULL, draw)
diff --git a/test/reference/bug-84115.ref.png b/test/reference/bug-84115.ref.png
new file mode 100644
index 000000000..f249ba56f
--- /dev/null
+++ b/test/reference/bug-84115.ref.png
diff --git a/test/reference/bug-84115.xlib.ref.png b/test/reference/bug-84115.xlib.ref.png
new file mode 100644
index 000000000..2e17a6570
--- /dev/null
+++ b/test/reference/bug-84115.xlib.ref.png