/*

 * Copyright 2010 Soeren Sandmann Pedersen

 *

 * 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: Soeren Sandmann <sandmann@daimi.au.dk>

 */

/* Exercises a case of seam appearing between two polygons in the image

 * backend but not in xlib [using pixman].

 *

 * The test case draws two abutting quads both individually on the

 * leftm combining them with operator ADD, and in one go on the right.

 * Both methods should show no signs of seaming at the common edge

 * between the two quads, but the individually drawn ones have a

 * slight seam.

 *

 * The cause of the seam is that there are slight differences in the

 * output of the analytical coverage rasterization and the

 * supersampling rasterization methods, both employed by

 * cairo-tor-scan-converter.  When drawn individually, the scan

 * converter gets a partial view of the geometry at a time, so it ends

 * up making different decisions about which scanlines it rasterizes

 * with which method, compared to when the geometry is draw all at

 * once.  Though both methods produce seamless results individually

 * (where applicable), they don't produce bit-exact identical results,

 * and hence we get seaming where they meet.

 */

#include "cairo-test.h"

static void

	   double x1, double y1, double x2, double y2,

	   double x3, double y3, double x4, double y4)

{

static cairo_test_status_t

{

    /* On the left side, we have two quads drawn one at a time and

     * combined with OPERATOR_ADD.  This should be seamless, but

     * isn't. */

	       1.50, 1.50,

	       2.64, 1.63,

	       1.75, 2.75,

	       0.55, 2.63);

	       0.55, 2.63,

	       1.75, 2.75,

	       0.98, 4.11,

	       -0.35, 4.05);

    /* On the right side, we have the same two quads drawn both at the

     * same time.  This is seamless. */

	       1.50, 1.50,

	       2.64, 1.63,

	       1.75, 2.75,

	       0.55, 2.63);

	       0.55, 2.63,

	       1.75, 2.75,

	       0.98, 4.11,

	       -0.35, 4.05);

}

	    "Check the fidelity of the rasterisation.",

	    "raster", /* keywords */

	    "target=raster", /* requirements */

	    500, 300,

	    NULL, draw)