cairo/test/rectangle-rounding-error.c

   1 /*
   2  * Copyright © 2005 Bertram Felgenhauer
   3  *
   4  * Permission to use, copy, modify, distribute, and sell this software
   5  * and its documentation for any purpose is hereby granted without
   6  * fee, provided that the above copyright notice appear in all copies
   7  * and that both that copyright notice and this permission notice
   8  * appear in supporting documentation, and that the name of
   9  * the author not be used in advertising or publicity pertaining to
  10  * distribution of the software without specific, written prior
  11  * permission. The author makes no representations about the
  12  * suitability of this software for any purpose.  It is provided "as
  13  * is" without express or implied warranty.
  14  *
  15  * THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
  16  * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
  17  * FITNESS, IN NO EVENT SHALL THE AUTHOR. BE LIABLE FOR ANY SPECIAL,
  18  * INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
  19  * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
  20  * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR
  21  * IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  22  *
  23  * Author: Bertram Felgenhauer <int-e@gmx.de>
  24  */
  25
  26 #include "cairo-test.h"
  27
  28 /* Test case for:
  29  *
  30  *      https://bugs.freedesktop.org/show_bug.cgi?id=4137
  31  */
  32
  33 static cairo_test_draw_function_t draw;
  34
  35 static const cairo_test_t test = {
  36     "rectangle-rounding-error",
  37     "This demonstrates (or not) a rounding error that causes a gap between "
  38     "two neighbouring rectangles.",
  39     76, 76,
  40     draw
  41 };
  42
  43 static cairo_test_status_t
  44 draw (cairo_t *cr, int width, int height)
  45 {
  46     cairo_set_source_rgb (cr, 1, 1, 1);
  47     cairo_paint (cr);
  48
  49     cairo_set_antialias (cr, CAIRO_ANTIALIAS_NONE);
  50     cairo_set_source_rgb (cr, 0, 0, 0);
  51
  52     cairo_translate(cr, -300, -300);
  53     cairo_scale(cr, 677.0/26, 677.0/26);
  54     cairo_translate(cr, 1, 1);
  55
  56     /* this should draw a seamless 2x2 rectangle */
  57     cairo_rectangle(cr, 11, 11, 1, 1);
  58     cairo_rectangle(cr, 11, 12, 1, 1);
  59     cairo_rectangle(cr, 12, 11, 1, 1);
  60     cairo_rectangle(cr, 12, 12, 1, 1);
  61
  62     cairo_set_source_rgb(cr, 0, 0, 0);
  63     cairo_fill(cr);
  64
  65     return CAIRO_TEST_SUCCESS;
  66 }
  67
  68 int
  69 main (void)
  70 {
  71     return cairo_test (&test);
  72 }