/* * Copyright © 2005 Red Hat, Inc. * Copyright © 2006 Red Hat, Inc. * * Permission to use, copy, modify, distribute, and sell this software * and its documentation for any purpose is hereby granted without * fee, provided that the above copyright notice appear in all copies * and that both that copyright notice and this permission notice * appear in supporting documentation, and that the name of * Red Hat, Inc. not be used in advertising or publicity pertaining to * distribution of the software without specific, written prior * permission. Red Hat, Inc. makes no representations about the * suitability of this software for any purpose. It is provided "as * is" without express or implied warranty. * * RED HAT, INC. DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND * FITNESS, IN NO EVENT SHALL RED HAT, INC. BE LIABLE FOR ANY SPECIAL, * INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR * IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. * * Author: Carl D. Worth */ #include "cairo-test.h" #define PAD 2 #define SIZE 10 cairo_test_t test = { "fill-and-stroke-alpha", "Use a group to fill/stroke a path then blend the result with alpha onto the destination", 2 * SIZE + 4 * PAD, SIZE + 2 * PAD, draw }; typedef void (*path_func_t) (cairo_t *cr); static void rectangle (cairo_t *cr) { cairo_rectangle (cr, PAD, PAD, SIZE, SIZE); } static void circle (cairo_t *cr) { cairo_arc (cr, PAD + SIZE / 2, PAD + SIZE / 2, SIZE / 2, 0, 2 * M_PI); } /* Given a path-generating function and two opaque patterns, fill and * stroke the path with the patterns (to an offscreen group), then * blend the result into the destination with the given alpha * value. */ static void fill_and_stroke_alpha (cairo_t *cr, path_func_t path_func, cairo_pattern_t *fill_pattern, cairo_pattern_t *stroke_pattern, double alpha) { cairo_push_group (cr); { (path_func) (cr); cairo_set_source (cr, fill_pattern); cairo_fill_preserve (cr); cairo_set_source (cr, stroke_pattern); cairo_stroke (cr); } cairo_pop_group_to_source (cr); cairo_paint_with_alpha (cr, alpha); } static cairo_test_status_t draw (cairo_t *cr, int width, int height) { cairo_pattern_t *blue; cairo_pattern_t *red; blue = cairo_pattern_create_rgb (0.0, 0.0, 1.0); red = cairo_pattern_create_rgb (1.0, 0.0, 0.0); cairo_test_paint_checkered (cr); fill_and_stroke_alpha (cr, rectangle, blue, red, 0.5); cairo_translate (cr, SIZE + 2 * PAD, 0); fill_and_stroke_alpha (cr, circle, red, blue, 0.5); cairo_pattern_destroy (blue); cairo_pattern_destroy (red); return CAIRO_TEST_SUCCESS; } int main (void) { return cairo_test (&test); }