2 * Copyright © 2005 Red Hat, Inc.
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 * Red Hat, Inc. not be used in advertising or publicity pertaining to
10 * distribution of the software without specific, written prior
11 * permission. Red Hat, Inc. makes no representations about the
12 * suitability of this software for any purpose. It is provided "as
13 * is" without express or implied warranty.
15 * RED HAT, INC. DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
16 * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
17 * FITNESS, IN NO EVENT SHALL RED HAT, INC. 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.
23 * Author: Carl D. Worth <cworth@cworth.org>
26 #include "cairo-test.h"
30 /* At one point, an optimization was proposed for cairo in which a
31 * curve_to would be optimized as a line_to. The initial (buggy)
32 * implementation verified that the slopes of several segments of the
33 * spline's control polygon were identical, but left open the
34 * possibility of an anti-parallel slope for one segment.
36 * For example, given a spline with collinear control points (A,B,C,D)
37 * positioned as follows:
41 * The code verified identical slopes for AB, CD, and AD. The missing
42 * check for the BC segment allowed it to be anti-parallel to the
43 * others as above, and hence invalid to replace this spline with the
46 static cairo_test_status_t
47 draw (cairo_t *cr, int width, int height)
49 cairo_set_source_rgb (cr, 1.0, 1.0, 1.0); /* white */
52 cairo_set_line_width (cr, 1.0);
53 cairo_set_line_cap (cr, CAIRO_LINE_CAP_BUTT);
54 cairo_set_line_join (cr, CAIRO_LINE_JOIN_BEVEL);
55 cairo_set_source_rgb (cr, 0.0, 0.0, 0.0); /* black */
57 cairo_translate (cr, 0, 1.0);
59 /* The CABD spline as described above. We ensure that the spline
60 * folds over on itself outside the bounds of the image to avoid
61 * the reference image having the curved portion of that fold,
62 * (which would just be harder to match in all the backends than
73 cairo_translate (cr, 0, 2.0);
75 /* A reflected version: DBAC */
86 return CAIRO_TEST_SUCCESS;
89 CAIRO_TEST (curve_to_as_line_to,
90 "Test optimization treating curve_to as line_to",
91 "path", /* keywords */
92 NULL, /* requirements */