/* * 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 therfore 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)