Use a more interesting pattern than "blue" for canvas import/export tests.

1 files changed, 56 insertions, 0 deletions

diff --git a/libdimension/tests/test_canvas.c b/libdimension/tests/test_canvas.c
new file mode 100644
index 0000000..b5d02ad
--- /dev/null
+++ b/libdimension/tests/test_canvas.c
@@ -0,0 +1,56 @@
+/*************************************************************************
+ * Copyright (C) 2011 Tavian Barnes <tavianator@tavianator.com>          *
+ *                                                                       *
+ * This file is part of The Dimension Test Suite.                        *
+ *                                                                       *
+ * The Dimension Test Suite is free software; you can redistribute it    *
+ * and/or modify it under the terms of the GNU General Public License as *
+ * published by the Free Software Foundation; either version 3 of the    *
+ * License, or (at your option) any later version.                       *
+ *                                                                       *
+ * The Dimension Test Suite 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  *
+ * General Public License for more details.                              *
+ *                                                                       *
+ * You should have received a copy of the GNU General Public License     *
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>. *
+ *************************************************************************/
+
+#include "tests.h"
+
+void
+dmnsn_paint_test_canvas(dmnsn_canvas *canvas)
+{
+  static const size_t size = 8;
+
+  for (size_t y = 0; y < canvas->height; ++y) {
+    for (size_t x = 0; x < canvas->width; ++x) {
+      dmnsn_color a, b;
+      double n = 3.0*x/canvas->width;
+      if (x < canvas->width/3) {
+        a = dmnsn_red;
+        b = dmnsn_green;
+      } else if (x < 2*canvas->width/3) {
+        a = dmnsn_green;
+        b = dmnsn_blue;
+        n -= 1.0;
+      } else {
+        a = dmnsn_blue;
+        b = dmnsn_red;
+        n -= 2.0;
+      }
+
+      if ((x*y)%(2*size) < size) {
+        a = dmnsn_color_to_sRGB(a);
+        b = dmnsn_color_to_sRGB(b);
+      }
+      dmnsn_color color = dmnsn_color_gradient(a, b, n);
+      if ((x*y)%(2*size) < size) {
+        color = dmnsn_color_from_sRGB(color);
+      }
+
+      dmnsn_set_pixel(canvas, x, y, color);
+    }
+  }
+}