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-rw-r--r--test/drunkard-tails.c135
1 files changed, 135 insertions, 0 deletions
diff --git a/test/drunkard-tails.c b/test/drunkard-tails.c
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+++ b/test/drunkard-tails.c
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+/*
+ * 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>
+ */
+
+#include "cairo-test.h"
+
+#define LINE_WIDTH 10.
+#define SIZE (5 * LINE_WIDTH)
+#define PAD (3 * LINE_WIDTH)
+
+static uint32_t state;
+
+static double
+uniform_random (double minval, double maxval)
+{
+ static uint32_t const poly = 0x9a795537U;
+ uint32_t n = 32;
+ while (n-->0)
+ state = 2*state < state ? (2*state ^ poly) : 2*state;
+ return minval + state * (maxval - minval) / 4294967296.0;
+}
+
+static void
+make_path (cairo_t *cr)
+{
+ int i;
+
+ state = 0xdeadbeef;
+
+ cairo_move_to (cr, SIZE/2, SIZE/2);
+ for (i = 0; i < 200; i++) {
+ double theta = uniform_random (-M_PI, M_PI);
+ cairo_rel_line_to (cr,
+ cos (theta) * LINE_WIDTH / 4,
+ sin (theta) * LINE_WIDTH / 4);
+ }
+}
+
+static void
+draw_caps_joins (cairo_t *cr)
+{
+ cairo_save (cr);
+
+ cairo_translate (cr, PAD, PAD);
+
+ cairo_reset_clip (cr);
+ cairo_rectangle (cr, 0, 0, SIZE, SIZE);
+ cairo_clip (cr);
+
+ make_path (cr);
+ cairo_set_line_cap (cr, CAIRO_LINE_CAP_BUTT);
+ cairo_set_line_join (cr, CAIRO_LINE_JOIN_BEVEL);
+ cairo_stroke (cr);
+
+ cairo_translate (cr, SIZE + PAD, 0.);
+
+ cairo_reset_clip (cr);
+ cairo_rectangle (cr, 0, 0, SIZE, SIZE);
+ cairo_clip (cr);
+
+ make_path (cr);
+ cairo_set_line_cap (cr, CAIRO_LINE_CAP_ROUND);
+ cairo_set_line_join (cr, CAIRO_LINE_JOIN_ROUND);
+ cairo_stroke (cr);
+
+ cairo_translate (cr, SIZE + PAD, 0.);
+
+ cairo_reset_clip (cr);
+ cairo_rectangle (cr, 0, 0, SIZE, SIZE);
+ cairo_clip (cr);
+
+ make_path (cr);
+ cairo_set_line_cap (cr, CAIRO_LINE_CAP_SQUARE);
+ cairo_set_line_join (cr, CAIRO_LINE_JOIN_MITER);
+ cairo_stroke (cr);
+
+ cairo_restore (cr);
+}
+
+static cairo_test_status_t
+draw (cairo_t *cr, int width, int height)
+{
+ /* We draw in the default black, so paint white first. */
+ cairo_save (cr);
+ cairo_set_source_rgb (cr, 1.0, 1.0, 1.0); /* white */
+ cairo_paint (cr);
+ cairo_restore (cr);
+
+ cairo_set_line_width (cr, LINE_WIDTH);
+
+ draw_caps_joins (cr);
+
+ cairo_save (cr);
+ /* and reflect to generate the opposite vertex ordering */
+ cairo_translate (cr, 0, height);
+ cairo_scale (cr, 1, -1);
+
+ draw_caps_joins (cr);
+ cairo_restore (cr);
+
+ cairo_translate (cr, 0, SIZE + PAD);
+
+ return CAIRO_TEST_SUCCESS;
+}
+
+CAIRO_TEST (drunkard_tails,
+ "Test caps and joins on short tail segments",
+ "stroke, cap, join", /* keywords */
+ NULL, /* requirements */
+ 3 * (PAD + SIZE) + PAD,
+ 2 * (PAD + SIZE) + PAD,
+ NULL, draw)
+