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/*
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 * Copyright © 2005 Red Hat, Inc.
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 *
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 * Permission to use, copy, modify, distribute, and sell this software
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 * and its documentation for any purpose is hereby granted without
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 * fee, provided that the above copyright notice appear in all copies
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 * and that both that copyright notice and this permission notice
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 * appear in supporting documentation, and that the name of
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 * Red Hat, Inc. not be used in advertising or publicity pertaining to
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 * distribution of the software without specific, written prior
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 * permission. Red Hat, Inc. makes no representations about the
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 * suitability of this software for any purpose.  It is provided "as
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 * is" without express or implied warranty.
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 *
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 * RED HAT, INC. DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
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 * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
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 * FITNESS, IN NO EVENT SHALL RED HAT, INC. BE LIABLE FOR ANY SPECIAL,
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 * INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
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 * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
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 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR
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 * IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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 *
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 * Author: Carl D. Worth <cworth@cworth.org>
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 */
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/* Bug history

            

        

            

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 *

            

        

            

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 * 2005-01-07 Carl Worth <cworth@cworth.org>

            

        

            

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 *

            

        

            

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 *   Bug reported:

            

        

            

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 *

            

        

            

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 *     From: Chris <fltk@functionalfuture.com>

            

        

            

                33
            

            

                
            

            

                
 *     Subject: [cairo] Render to image buffer artifacts

            

        

            

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 *     To: cairo@cairographics.org

            

        

            

                35
            

            

                
            

            

                
 *     Date: Fri, 07 Jan 2005 02:22:28 -0500

            

        

            

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 *

            

        

            

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 *     I've attached the code and image that shows this off.  Scaling at

            

        

            

                38
            

            

                
            

            

                
 *     different levels seems to change the corruption.

            

        

            

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 *

            

        

            

                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.

            

        

            

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 *

            

        

            

                43
            

            

                
            

            

                
 *     If you run the code and parse the attached image, directing stdout to a

            

        

            

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 *     file, you can see in the lower left corner there are alpha values where

            

        

            

                45
            

            

                
            

            

                
 *     it should be transparent.

            

        

            

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 *     [...]

            

        

            

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 *

            

        

            

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 * 2005-01-11 Carl Worth <cworth@cworth.org>

            

        

            

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 *

            

        

            

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 *   I trimmed the original test case down to the code that appears here.

            

        

            

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 *

            

        

            

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 */

            

        

            

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#include "cairo-test.h"

            

        

            

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#define WIDTH 21

            

        

            

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#define HEIGHT 21

            

        

            

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static cairo_test_status_t

            

        

            

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                3
            

            

                
draw (cairo_t *cr, int width, int height)

            

        

            

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{

            

        

            

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    /* We draw in the default black, so paint white first. */

            

        

            

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                3
            

            

                
    cairo_save (cr);

            

        

            

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                3
            

            

                
    cairo_set_source_rgb (cr, 1.0, 1.0, 1.0); /* white */

            

        

            

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                3
            

            

                
    cairo_paint (cr);

            

        

            

                66
            

            

                3
            

            

                
    cairo_restore (cr);

            

        

            

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                3
            

            

                
    cairo_scale (cr, 1.0/(1<<16), 1.0/(1<<16));

            

        

            

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                3
            

            

                
    cairo_move_to (cr, 131072,39321);

            

        

            

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                3
            

            

                
    cairo_line_to (cr, 1103072,1288088);

            

        

            

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                3
            

            

                
    cairo_line_to (cr, 1179648,1294990);

            

        

            

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                3
            

            

                
    cairo_close_path (cr);

            

        

            

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                3
            

            

                
    cairo_fill (cr);

            

        

            

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                3
            

            

                
    return CAIRO_TEST_SUCCESS;

            

        

            

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}

            

        

            

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                1
            

            

                
CAIRO_TEST (leaky_polygon,

            

        

            

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	    "Exercises a corner case in the trapezoid rasterization in which pixels outside the trapezoids received a non-zero alpha",

            

        

            

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	    "fill, trap", /* keywords */

            

        

            

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	    NULL, /* requirements */

            

        

            

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	    WIDTH, HEIGHT,

            

        

            

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	    NULL, draw)