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Diffstat (limited to 'test/round-join-bug-520.c')
-rw-r--r-- | test/round-join-bug-520.c | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/test/round-join-bug-520.c b/test/round-join-bug-520.c new file mode 100644 index 000000000..be2b5aa0d --- /dev/null +++ b/test/round-join-bug-520.c @@ -0,0 +1,109 @@ +/* + * Author: Christian Rohlfs, 2022 + * + * 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. + */ + +#include "cairo-test.h" + +#define WIDTH 100 +#define HEIGHT WIDTH + +static cairo_test_status_t +draw_round(cairo_t *cr, int width, int height) +{ + /* Fail condition: + 0 >= 2 * ( 1 - tolerance / (line_width / 2) )^2 - 1, + with the default tolerance of 0.1, `failing_line_width` is in + [0.117157287525381; 0.682842712474619] + range. + */ + + double failing_line_width = 0.3; + + cairo_set_tolerance(cr, 0.1); + cairo_scale(cr, width, height); + + cairo_set_source_rgb(cr, 1, 1, 1); + cairo_paint(cr); + + cairo_move_to(cr, 0.2, 0.2); + cairo_line_to(cr, 0.8, 0.2); + cairo_line_to(cr, 0.8, 0.8); + cairo_line_to(cr, 0.2, 0.8); + cairo_close_path(cr); + + cairo_set_line_join(cr, CAIRO_LINE_JOIN_ROUND); + cairo_set_source_rgb(cr, 0, 0, 0); + cairo_set_line_width(cr, failing_line_width); + cairo_stroke(cr); + + return CAIRO_TEST_SUCCESS; +} + +static cairo_test_status_t +draw_bevel(cairo_t *cr, int width, int height) +{ + /* Fail condition: + arc_height < tolerance + For 90° join `arc_height` is equal to + line_width / 2 * (1 - sqrt(1/2)) + which is 0.1464466094067262 of a `line_width`. + */ + + double line_width = 0.3; + double failing_tolerance = 0.3 * line_width; + + cairo_set_tolerance(cr, width * failing_tolerance); + cairo_scale(cr, width, height); + + cairo_set_source_rgb(cr, 1, 1, 1); + cairo_paint(cr); + + cairo_move_to(cr, 0.2, 0.2); + cairo_line_to(cr, 0.8, 0.2); + cairo_line_to(cr, 0.8, 0.8); + cairo_line_to(cr, 0.2, 0.8); + cairo_close_path(cr); + + cairo_set_line_join(cr, CAIRO_LINE_JOIN_ROUND); + cairo_set_source_rgb(cr, 0, 0, 0); + cairo_set_line_width(cr, line_width); + cairo_stroke(cr); + + return CAIRO_TEST_SUCCESS; +} + + +CAIRO_TEST (round_join_bug_520_round, + "Tests round joins within tolerance", + "stroke, cap, join", /* keywords */ + NULL, /* requirements */ + WIDTH, HEIGHT, + NULL, draw_round) + +CAIRO_TEST (round_join_bug_520_bevel, + "Tests round joins omission when `arc_height < tolerance`", + "stroke, cap, join", /* keywords */ + NULL, /* requirements */ + WIDTH, HEIGHT, + NULL, draw_bevel) + |