test/Makefile.am

Add leaky_polygon test for trapezoid rasterization corner case.

7 files changed, 173 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index e28f29c7..4b853d29 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -5,6 +5,11 @@
 
 2005-01-13  Carl Worth  <cworth@cworth.org>
 
+	* test/leaky_polygon.c: 
+	* test/Makefile.am
+	* test/.cvsignore: Add leaky_polygon test for trapezoid
+	rasterization corner case.
+
 	* src/cairo_xlib_surface.c: 
 	* src/cairo_glitz_surface.c: 
 	* src/cairo_ft_font.c: 
diff --git a/test/.cvsignore b/test/.cvsignore
index ca4c6e56..27e57c1d 100644
--- a/test/.cvsignore
+++ b/test/.cvsignore
@@ -3,6 +3,7 @@
 Makefile
 Makefile.in
 fill_rule
+leaky_polygon
 line_width
 move_to_show_surface
 text_cache_crash
diff --git a/test/Makefile.am b/test/Makefile.am
index e0e5b078..7ade7591 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -1,6 +1,7 @@
 # All new test cases go here
 TESTS = 		\
 fill_rule		\
+leaky_polygon		\
 line_width		\
 move_to_show_surface	\
 text_cache_crash	\
@@ -11,6 +12,7 @@ text_rotate
 # here?
 EXTRA_DIST = \
 fill_rule-ref.png \
+leaky_polygon.png \
 line_width-ref.png \
 move_to_show_surface-ref.png \
 text_rotate-ref.png
@@ -52,6 +54,7 @@ xmalloc.h
 # time to break down and auto-generate the Makefile.am or something
 # from autogen.sh. My, but this is painful...
 fill_rule_SOURCES = fill_rule.c $(cairo_test_lib)
+leaky_polygon_SOURCES = leaky_polygon.c $(cairo_test_lib)
 line_width_SOURCES = line_width.c $(cairo_test_lib)
 move_to_show_surface_SOURCES = move_to_show_surface.c $(cairo_test_lib)
 text_cache_crash_SOURCES = text_cache_crash.c $(cairo_test_lib)
diff --git a/test/leaky-polygon-ref.png b/test/leaky-polygon-ref.png
new file mode 100644
index 00000000..b3362266
--- /dev/null
+++ b/test/leaky-polygon-ref.png
diff --git a/test/leaky-polygon.c b/test/leaky-polygon.c
new file mode 100644
index 00000000..39daf4ca
--- /dev/null
+++ b/test/leaky-polygon.c
@@ -0,0 +1,82 @@
+/*
+ * Copyright © 2005 Red Hat, Inc.
+ *
+ * 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.
+ *
+ * Author: Carl D. Worth <cworth@cworth.org>
+ */
+
+/* Bug history
+ *
+ * 2005-01-07 Carl Worth <cworth@cworth.org>
+ *
+ *   Bug reported:
+ *
+ *     From: Chris <fltk@functionalfuture.com>
+ *     Subject: [cairo] Render to image buffer artifacts
+ *     To: cairo@cairographics.org
+ *     Date: Fri, 07 Jan 2005 02:22:28 -0500
+ *
+ *     I've attached the code and image that shows this off.  Scaling at
+ *     different levels seems to change the corruption.
+ *
+ *     For some reason there are artifacts in the alpha channel.  I don't know
+ *     if that's the only place, but the alpha channel looks bad.
+ *
+ *     If you run the code and parse the attached image, directing stdout to a
+ *     file, you can see in the lower left corner there are alpha values where
+ *     it should be transparent.
+ *     [...]
+ *
+ * 2005-01-11 Carl Worth <cworth@cworth.org>
+ *
+ *   I trimmed the original test case down to the code that appears here.
+ *
+ */
+
+#include "cairo_test.h"
+
+#define WIDTH 21
+#define HEIGHT 21
+
+cairo_test_t test = {
+    "leaky_polygon",
+    "Exercises a corner case in the trapezoid rasterization in which pixels outside the trapezoids received a non-zero alpha",
+    WIDTH, HEIGHT
+};
+
+static void
+draw (cairo_t *cr, int width, int height)
+{
+    cairo_scale (cr, 1.0/(1<<16), 1.0/(1<<16));
+
+    cairo_move_to (cr, 131072,39321);
+    cairo_line_to (cr, 1103072,1288088);
+    cairo_line_to (cr, 1179648,1294990);
+    cairo_close_path (cr);
+
+    cairo_fill (cr);
+}
+
+int
+main (void)
+{
+    return cairo_test (&test, draw);
+}
diff --git a/test/leaky_polygon-ref.png b/test/leaky_polygon-ref.png
new file mode 100644
index 00000000..b3362266
--- /dev/null
+++ b/test/leaky_polygon-ref.png
diff --git a/test/leaky_polygon.c b/test/leaky_polygon.c
new file mode 100644
index 00000000..39daf4ca
--- /dev/null
+++ b/test/leaky_polygon.c
@@ -0,0 +1,82 @@
+/*
+ * Copyright © 2005 Red Hat, Inc.
+ *
+ * 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.
+ *
+ * Author: Carl D. Worth <cworth@cworth.org>
+ */
+
+/* Bug history
+ *
+ * 2005-01-07 Carl Worth <cworth@cworth.org>
+ *
+ *   Bug reported:
+ *
+ *     From: Chris <fltk@functionalfuture.com>
+ *     Subject: [cairo] Render to image buffer artifacts
+ *     To: cairo@cairographics.org
+ *     Date: Fri, 07 Jan 2005 02:22:28 -0500
+ *
+ *     I've attached the code and image that shows this off.  Scaling at
+ *     different levels seems to change the corruption.
+ *
+ *     For some reason there are artifacts in the alpha channel.  I don't know
+ *     if that's the only place, but the alpha channel looks bad.
+ *
+ *     If you run the code and parse the attached image, directing stdout to a
+ *     file, you can see in the lower left corner there are alpha values where
+ *     it should be transparent.
+ *     [...]
+ *
+ * 2005-01-11 Carl Worth <cworth@cworth.org>
+ *
+ *   I trimmed the original test case down to the code that appears here.
+ *
+ */
+
+#include "cairo_test.h"
+
+#define WIDTH 21
+#define HEIGHT 21
+
+cairo_test_t test = {
+    "leaky_polygon",
+    "Exercises a corner case in the trapezoid rasterization in which pixels outside the trapezoids received a non-zero alpha",
+    WIDTH, HEIGHT
+};
+
+static void
+draw (cairo_t *cr, int width, int height)
+{
+    cairo_scale (cr, 1.0/(1<<16), 1.0/(1<<16));
+
+    cairo_move_to (cr, 131072,39321);
+    cairo_line_to (cr, 1103072,1288088);
+    cairo_line_to (cr, 1179648,1294990);
+    cairo_close_path (cr);
+
+    cairo_fill (cr);
+}
+
+int
+main (void)
+{
+    return cairo_test (&test, draw);
+}