[cairo-commit] test/horizontal-clip.c test/horizontal-clip.ref.png test/Makefile.sources

[Chris Wilson]

 test/Makefile.sources        |    1 
 test/horizontal-clip.c       |   76 +++++++++++++++++++++++++++++++++++++++++++
 test/horizontal-clip.ref.png |binary
 3 files changed, 77 insertions(+)

New commits:
commit 1b888c4c3a3f7002dc092fd48088cd0b5031e12c
Author: Chris Wilson <chris at chris-wilson.co.uk>
Date:   Wed Jul 27 19:48:36 2011 +0100

    test: Add horizontal clip test
    
    Doesn't actually hit the code path but it should...
    
    Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>

diff --git a/test/Makefile.sources b/test/Makefile.sources
index 783897d..d2f66d5 100644
--- a/test/Makefile.sources
+++ b/test/Makefile.sources
@@ -132,6 +132,7 @@ test_sources = \
 	half-coverage.c					\
 	halo.c						\
 	hatchings.c					\
+	horizontal-clip.c				\
 	huge-linear.c					\
 	huge-radial.c					\
 	image-surface-source.c				\
diff --git a/test/horizontal-clip.c b/test/horizontal-clip.c
new file mode 100644
index 0000000..2a5025c
--- /dev/null
+++ b/test/horizontal-clip.c
@@ -0,0 +1,76 @@
+/*
+ * Copyright 2011 Intel Corporation
+ *
+ * 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
+ * Chris Wilson not be used in advertising or publicity pertaining to
+ * distribution of the software without specific, written prior
+ * permission. Chris Wilson makes no representations about the
+ * suitability of this software for any purpose.  It is provided "as
+ * is" without express or implied warranty.
+ *
+ * CHRIS WILSON DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
+ * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS, IN NO EVENT SHALL CHRIS WILSON 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: Chris Wilson <chris at chris-wilson.co.uk>
+ */
+
+/* Exercises a bug spotted by Andrea Canciani where the polygon clipping
+ * code was hopeless broken with horizontal edges.
+ */
+
+#include "cairo-test.h"
+
+#define WIDTH 20
+#define HEIGHT 20
+
+#define BUG 1
+
+static cairo_test_status_t
+draw (cairo_t *cr, int width, int height)
+{
+    cairo_set_source_rgb (cr, 1, 1, 1);
+    cairo_paint (cr);
+    cairo_set_source_rgb (cr, 0, 0, 0);
+
+    cairo_move_to (cr, 0-256, 4 - BUG);
+    cairo_line_to (cr, WIDTH + 256, 4 + BUG);
+    cairo_line_to (cr, WIDTH + 256, 2 - BUG);
+    cairo_line_to (cr, 0-256, 2 + BUG);
+    cairo_fill (cr);
+
+    cairo_move_to (cr, 0-256, 6 - BUG);
+    cairo_line_to (cr, WIDTH + 256, 6 + BUG);
+    cairo_line_to (cr, WIDTH + 256, 8 - BUG);
+    cairo_line_to (cr, 0-256, 8 + BUG);
+    cairo_fill (cr);
+
+    cairo_move_to (cr, WIDTH+256, 12 - BUG);
+    cairo_line_to (cr, 0-256, 12 + BUG);
+    cairo_line_to (cr, 0-256, 14 - BUG);
+    cairo_line_to (cr, WIDTH+256, 14 + BUG);
+    cairo_fill (cr);
+
+    cairo_move_to (cr, WIDTH+256, 18 - BUG);
+    cairo_line_to (cr, 0-256, 18 + BUG);
+    cairo_line_to (cr, 0-256, 16 - BUG);
+    cairo_line_to (cr, WIDTH+256, 16 + BUG);
+    cairo_fill (cr);
+
+    return CAIRO_TEST_SUCCESS;
+}
+
+CAIRO_TEST (horizontal_clip,
+	    "Tests intersection of a nearly horizontal lines with a clipped polygon",
+	    "clip, fill", /* keywords */
+	    NULL, /* requirements */
+	    WIDTH, HEIGHT,
+	    NULL, draw)
diff --git a/test/horizontal-clip.ref.png b/test/horizontal-clip.ref.png
new file mode 100644
index 0000000..51d9445
Binary files /dev/null and b/test/horizontal-clip.ref.png differ