cairo/test/shape-sierpinski.c

/*
 * 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 <chris@chris-wilson.co.uk>
 */

/* I thought I spied a bug... */

#include "cairo-test.h"

#define WIDTH		(1024)
#define HEIGHT		(600)

static const double m_1_sqrt_3 = 0.577359269;

static void
T (cairo_t *cr, int size)
{
    cairo_move_to (cr, 0, 0);
    cairo_line_to (cr, size, 0);
    cairo_line_to (cr, size/2, size*m_1_sqrt_3);

    size /= 2;
    if (size >= 4) {
	T (cr, size);
	cairo_save (cr); {
	    cairo_translate (cr, size, 0);
	    T (cr, size);
	} cairo_restore (cr);
	cairo_save (cr); {
	    cairo_translate (cr, size/2, size*m_1_sqrt_3);
	    T (cr, size);
	} cairo_restore (cr);
    }
}

static cairo_test_status_t
draw (cairo_t *cr, int width, int height)
{
    cairo_set_source_rgb (cr, 1, 1, 1);
    cairo_paint (cr);

    cairo_translate (cr, 0, 8);

    cairo_set_source_rgb (cr, 0, 0, 0);
    cairo_set_line_width (cr, 1.);

    T (cr, WIDTH);

    cairo_translate (cr, 0, 2*HEIGHT-16);
    cairo_scale (cr, 1, -1);

    T (cr, WIDTH);

    cairo_stroke (cr);

    return CAIRO_TEST_SUCCESS;
}

CAIRO_TEST (shape_sierpinski,
	    "A fractal triangle",
	    "stroke", /* keywords */
	    NULL, /* requirements */
	    WIDTH, 2*HEIGHT,
	    NULL, draw)