/* * Copyright © 2011 Intel Corporation * * 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: Chris Wilson */ /* Not strictly overlapping, but it does highlight the error in * an optimisation of fill-box handling that I frequently am * tempted to write. */ #include "cairo-test.h" #define WIDTH (20) #define HEIGHT (20) static void border (cairo_t *cr) { cairo_rectangle (cr, 1, 1, 8, 8); cairo_rectangle (cr, 1.25, 1.25, 7.5, 7.5); cairo_rectangle (cr, 1.75, 1.75, 6.5, 6.5); cairo_rectangle (cr, 2, 2, 6, 6); } static cairo_test_status_t draw (cairo_t *cr, int width, int height) { cairo_set_fill_rule (cr, CAIRO_FILL_RULE_EVEN_ODD); cairo_set_source_rgb (cr, 1, 1, 1); cairo_paint (cr); border (cr); cairo_set_source_rgb (cr, 1, 0, 0); cairo_set_operator (cr, CAIRO_OPERATOR_OVER); cairo_fill (cr); cairo_translate (cr, 10, 0); border (cr); cairo_set_source_rgb (cr, 0, 0, 1); cairo_set_operator (cr, CAIRO_OPERATOR_SOURCE); cairo_fill (cr); cairo_translate (cr, 0, 10); cairo_rectangle (cr, 0, 0, 10, 10); cairo_clip (cr); border (cr); cairo_set_source_rgb (cr, 0, 1, 0); cairo_set_operator (cr, CAIRO_OPERATOR_IN); cairo_fill (cr); cairo_reset_clip (cr); cairo_translate (cr, -10, 0); cairo_rectangle (cr, 0, 0, 10, 10); cairo_clip (cr); border (cr); cairo_set_source_rgb (cr, 0, 0, 1); cairo_set_operator (cr, CAIRO_OPERATOR_CLEAR); cairo_fill (cr); return CAIRO_TEST_SUCCESS; } CAIRO_TEST (overlapping_boxes, "A sub-pixel double border to highlight the danger in an easy optimisation", "fill", /* keywords */ NULL, /* requirements */ WIDTH, HEIGHT, NULL, draw)