[test] Stress the intersection handling by feeding spans/traps random curves

Another stress test for the fill/stroke and intersection finders.

1 files changed, 81 insertions, 0 deletions

diff --git a/test/random-intersections-curves-eo.c b/test/random-intersections-curves-eo.c
new file mode 100644
index 00000000..3fa12b2b
--- /dev/null
+++ b/test/random-intersections-curves-eo.c
@@ -0,0 +1,81 @@
+/*
+ * Copyright © 2006 M Joonas Pihlaja
+ *
+ * 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: M Joonas Pihlaja <jpihlaja@cc.helsinki.fi>
+ */
+#include "cairo-test.h"
+
+#define SIZE 512
+#define NUM_SEGMENTS 128
+
+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 cairo_test_status_t
+draw (cairo_t *cr, int width, int height)
+{
+    int i;
+
+    cairo_set_source_rgb (cr, 0, 0, 0);
+    cairo_paint (cr);
+
+    state = 0x12345678;
+    cairo_translate (cr, 1, 1);
+    cairo_set_fill_rule (cr, CAIRO_FILL_RULE_EVEN_ODD);
+
+    cairo_move_to (cr, 0, 0);
+    for (i = 0; i < NUM_SEGMENTS; i++) {
+	cairo_curve_to (cr,
+			uniform_random (-SIZE, SIZE),
+			uniform_random (-SIZE, SIZE),
+			uniform_random (-SIZE, SIZE),
+			uniform_random (-SIZE, SIZE),
+			uniform_random (0, SIZE),
+			uniform_random (0, SIZE));
+    }
+    cairo_close_path (cr);
+
+    cairo_set_source_rgb (cr, 1, 0, 0);
+    cairo_fill_preserve (cr);
+    cairo_set_source_rgb (cr, 0, 1, 0);
+    cairo_set_line_width (cr, 0.5);
+    cairo_stroke (cr);
+
+    return CAIRO_TEST_SUCCESS;
+}
+
+CAIRO_TEST (random_intersections_curves_eo,
+	    "Tests the tessellator trapezoid generation and intersection computation",
+	    "trap", /* keywords */
+	    NULL, /* requirements */
+	    SIZE+3, SIZE+3,
+	    NULL, draw)