I found this little blob engine code, and converted it run in WPF under C#. The GUI drawing code is verified with ApprovalTests.Net. See the Android Kotlin version.
From the website: Blob Sallad
Original version by: Björn Lindberg
See his writeup at Blob Sallad — Canvas Tag and JavaScript Physics Simulation Experiment
Here's a test that verifies the OohFace. It creates a canvas, sets up the translate tranformation, executes the test code, and verifies the results. If this code produces the same image, as the one approved, the test will pass.
[Test]
public void DrawOohFaceTest()
{
var canvas = new Canvas {Width = 100, Height = 100};
var translateTransform = new TranslateTransform(50.0, 50.0);
var transformGroup = new TransformGroup();
transformGroup.Children.Add(translateTransform);
var blob = new Blob(50.0, 50.0, 25.0, 5);
blob.DrawOohFace(canvas, 3.0, transformGroup);
var wpf = new ContentControl {Content = canvas};
WpfApprovals.Verify(wpf);
}