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18 * INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
19 * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
20 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR
21 * IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
23 * Author: Carl D. Worth <cworth@cworth.org>
28 * 2005-01-07 Carl Worth <cworth@cworth.org>
32 * From: Chris <fltk@functionalfuture.com>
33 * Subject: [cairo] Render to image buffer artifacts
34 * To: cairo@cairographics.org
35 * Date: Fri, 07 Jan 2005 02:22:28 -0500
37 * I've attached the code and image that shows this off. Scaling at
38 * different levels seems to change the corruption.
40 * For some reason there are artifacts in the alpha channel. I don't know
41 * if that's the only place, but the alpha channel looks bad.
43 * If you run the code and parse the attached image, directing stdout to a
44 * file, you can see in the lower left corner there are alpha values where
45 * it should be transparent.
48 * 2005-01-11 Carl Worth <cworth@cworth.org>
50 * I trimmed the original test case down to the code that appears here.
54 #include "cairo-test.h"
59 static cairo_test_status_t
60 draw (cairo_t *cr, int width, int height)
62 /* We draw in the default black, so paint white first. */
64 cairo_set_source_rgb (cr, 1.0, 1.0, 1.0); /* white */
68 cairo_scale (cr, 1.0/(1<<16), 1.0/(1<<16));
70 cairo_move_to (cr, 131072,39321);
71 cairo_line_to (cr, 1103072,1288088);
72 cairo_line_to (cr, 1179648,1294990);
73 cairo_close_path (cr);
77 return CAIRO_TEST_SUCCESS;
80 CAIRO_TEST (leaky_polygon,
81 "Exercises a corner case in the trapezoid rasterization in which pixels outside the trapezoids received a non-zero alpha",
82 "fill, trap", /* keywords */
83 NULL, /* requirements */