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Diffstat (limited to 'libs/cairo-1.16.0/test/skew-extreme.c')
| -rw-r--r-- | libs/cairo-1.16.0/test/skew-extreme.c | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/libs/cairo-1.16.0/test/skew-extreme.c b/libs/cairo-1.16.0/test/skew-extreme.c new file mode 100644 index 0000000..e0ee1c4 --- /dev/null +++ b/libs/cairo-1.16.0/test/skew-extreme.c @@ -0,0 +1,118 @@ +/* + * 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) |