testsuite: Add tests for rounded rect code

... including the bug that was fixed in the parent commit.

testsuite/gsk/meson.build

@@ -184,6 +184,7 @@ foreach test : node_parser_tests
 endforeach
 
 tests = [
+  ['rounded-rect'],
   ['transform'],
 ]
 

testsuite/gsk/rounded-rect.c

@@ -0,0 +1,100 @@
+/*
+ * Copyright © 2020 Benjamin Otte
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Benjamin Otte <otte@gnome.org>
+ */
+
+#include "config.h"
+
+#include <gtk/gtk.h>
+
+static void
+test_contains_rect (void)
+{
+  static double points[] = { -5, 0, 5, 10, 15, 85, 90, 95, 100, 105 };
+#define LAST (G_N_ELEMENTS(points) - 1)
+  GskRoundedRect rounded;
+  guint x1, x2, y1, y2;
+
+  gsk_rounded_rect_init_from_rect (&rounded, &GRAPHENE_RECT_INIT (0, 0, 100, 100), 10);
+
+  for (x1 = 0; x1 < G_N_ELEMENTS (points); x1++)
+    for (x2 = x1 + 1; x2 < G_N_ELEMENTS (points); x2++)
+      for (y1 = 0; y1 < G_N_ELEMENTS (points); y1++)
+        for (y2 = y1 + 1; y2 < G_N_ELEMENTS (points); y2++)
+          {
+            graphene_rect_t rect;
+            gboolean inside;
+
+            /* check all points are in the bounding box */
+            inside = x1 > 0 && y1 > 0 && x2 < LAST && y2 < LAST;
+            /* now check all the corners */
+            inside &= x1 > 2 || y1 > 2 || (x1 == 2 && y1 == 2);
+            inside &= x2 < LAST - 2 || y1 > 2 || (x2 == LAST - 2 && y1 == 2);
+            inside &= x2 < LAST - 2 || y2 < LAST - 2 || (x2 == LAST - 2 && y2 == LAST - 2);
+            inside &= x1 > 2 || y2 < LAST - 2 || (x1 == 2 && y2 == LAST - 2);
+
+            graphene_rect_init (&rect, points[x1], points[y1], points[x2] - points[x1], points[y2] - points[y1]);
+            if (inside)
+              g_assert_true (gsk_rounded_rect_contains_rect (&rounded, &rect));
+            else
+              g_assert_false (gsk_rounded_rect_contains_rect (&rounded, &rect));
+          }
+#undef LAST
+}
+
+static void
+test_intersects_rect (void)
+{
+  static double points[] = { -1, 0, 1, 99, 100, 101 };
+#define ALL_THE_POINTS (G_N_ELEMENTS(points))
+#define HALF_THE_POINTS (ALL_THE_POINTS / 2)
+  GskRoundedRect rounded;
+  guint x1, x2, y1, y2;
+
+  gsk_rounded_rect_init_from_rect (&rounded, &GRAPHENE_RECT_INIT (0, 0, 100, 100), 10);
+
+  for (x1 = 0; x1 < ALL_THE_POINTS; x1++)
+    for (x2 = x1 + 1; x2 < ALL_THE_POINTS; x2++)
+      for (y1 = 0; y1 < ALL_THE_POINTS; y1++)
+        for (y2 = y1 + 1; y2 < ALL_THE_POINTS; y2++)
+          {
+            graphene_rect_t rect;
+            gboolean should_contain_x, should_contain_y;
+
+            graphene_rect_init (&rect, points[x1], points[y1], points[x2] - points[x1], points[y2] - points[y1]);
+            should_contain_x = x1 < HALF_THE_POINTS && x2 >= HALF_THE_POINTS && y2 > 1 && y1 < ALL_THE_POINTS - 2;
+            should_contain_y = y1 < HALF_THE_POINTS && y2 >= HALF_THE_POINTS && x2 > 1 && x1 < ALL_THE_POINTS - 2;
+            if (should_contain_x || should_contain_y)
+              g_assert_true (gsk_rounded_rect_intersects_rect (&rounded, &rect));
+            else
+              g_assert_false (gsk_rounded_rect_intersects_rect (&rounded, &rect));
+          }
+#undef ALL_THE_POINTS
+#undef HALF_THE_POINTS
+}
+
+int
+main (int   argc,
+      char *argv[])
+{
+  gtk_test_init (&argc, &argv, NULL);
+
+  g_test_add_func ("/rounded-rect/contains-rect", test_contains_rect);
+  g_test_add_func ("/rounded-rect/intersects-rect", test_intersects_rect);
+
+  return g_test_run ();
+}