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/*
* Copyright © 2007 Red Hat, Inc.
*
* 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: Carl Worth <cworth@cworth.org>
*/
#include "cairo-test.h"
/* This test case is designed to exercise the following bug:
*
* Skew transforms were broken by the cairo update in December
* https://bugzilla.mozilla.org/show_bug.cgi?id=373632
*
* What's happening is that the rectangle is being skewed into the
* following shape:
*
* a__b
* \ \
* \ \
* \ \
* \ \
* \ \
* d\_\c
*
* and the bug is that _cairo_traps_tessellate_convex_quad is
* comparing b.x as less then d.x and therefore determining that the bc
* edge is left of the ad edge. The fix is simply to compare c.x to
* d.x instead of b.x to d.x .
*/
#define PAD 2
#define LINE_WIDTH 10
#define LINE_LENGTH (2 * LINE_WIDTH)
#define SKEW_FACTOR 5.0
#define WIDTH (PAD + (LINE_LENGTH * SKEW_FACTOR) + LINE_WIDTH + PAD)
#define HEIGHT (PAD + LINE_WIDTH + (LINE_LENGTH * SKEW_FACTOR) + LINE_WIDTH + PAD)
static cairo_test_status_t
draw (cairo_t *cr, int width, int height)
{
/* We draw in the default black, so paint white first. */
cairo_save (cr);
cairo_set_source_rgb (cr, 1.0, 1.0, 1.0); /* white */
cairo_paint (cr);
cairo_restore (cr);
cairo_translate (cr, PAD, PAD);
cairo_set_line_width (cr, LINE_WIDTH);
cairo_set_line_cap (cr, CAIRO_LINE_CAP_BUTT);
cairo_save (cr);
{
cairo_matrix_t skew_x = {
1.0, 0.0,
SKEW_FACTOR, 1.0,
0.0, 0.0
};
cairo_translate (cr, LINE_WIDTH / 2.0, 0.0);
cairo_transform (cr, &skew_x);
cairo_move_to (cr, 0.0, 0.0);
cairo_line_to (cr, 0.0, LINE_LENGTH);
cairo_stroke (cr);
}
cairo_restore (cr);
cairo_translate (cr, 0.0, LINE_WIDTH);
cairo_save (cr);
{
cairo_matrix_t skew_y = {
1.0, SKEW_FACTOR,
0.0, 1.0,
0.0, 0.0
};
cairo_translate (cr, 0.0, LINE_WIDTH / 2.0);
cairo_transform (cr, &skew_y);
cairo_move_to (cr, 0.0, 0.0);
cairo_line_to (cr, LINE_LENGTH, 0.0);
cairo_stroke (cr);
}
cairo_restore (cr);
return CAIRO_TEST_SUCCESS;
}
CAIRO_TEST (skew_extreme,
"Test cases of extreme skew.",
"transform, stroke", /* keywords */
NULL, /* requirements */
WIDTH, HEIGHT,
NULL, draw)
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