[gtk/wip/baedert/nodeeditor: 13/14] testsuite: Add cross-fade-in-opacity test

[Timm Bäder <baedert src gnome org>]

commit 5bb4d7e7cbc776eee72d6e8ea0d855955067f772
Author: Timm Bäder <mail baedert org>
Date:   Wed Apr 24 12:48:59 2019 +0200

    testsuite: Add cross-fade-in-opacity test
    
    Making sure that an opacity node doesn't end up reviving a node that's
    hidden because the cross-fade has progress 0 or 1.

 testsuite/gsk/gl/cross-fade-in-opacity.gl.png | Bin 0 -> 618 bytes
 testsuite/gsk/gl/cross-fade-in-opacity.node   |  23 +++++++++++++++++++++++
 2 files changed, 23 insertions(+)
---
diff --git a/testsuite/gsk/gl/cross-fade-in-opacity.gl.png b/testsuite/gsk/gl/cross-fade-in-opacity.gl.png
new file mode 100644
index 0000000000..d9e47b7bd3
Binary files /dev/null and b/testsuite/gsk/gl/cross-fade-in-opacity.gl.png differ
diff --git a/testsuite/gsk/gl/cross-fade-in-opacity.node b/testsuite/gsk/gl/cross-fade-in-opacity.node
new file mode 100644
index 0000000000..ff65e3a8cb
--- /dev/null
+++ b/testsuite/gsk/gl/cross-fade-in-opacity.node
@@ -0,0 +1,23 @@
+/* Background */
+color {
+  bounds: 0 0 200 200;
+  color: white;
+}
+
+/* It is important that the following node structure leaves the
+ * start child of the cross-fade node invisible. */
+opacity {
+  opacity: 0.4;
+
+  child: cross-fade {
+    start: color {
+      color: blue;
+      bounds: 0 0 100 100;
+    }
+    end: color {
+      color: red;
+      bounds: 100 100 100 100;
+    }
+    progress: 1.0;
+  }
+}