My best friend’s girlfriend studies design. As part of her studies, they learned some programming using Processing.  As a designer (and not a programmer) she had a hard time getting things to work. Even though I don’t know processing at all I figured my experience in programming might come in handy.

And here is the result (I think it turned out quite well):

The next day she sent me this result (Notice what happens when you click, hold and release):

 

Credit: She told me that for the center circle she adapted a code snippet by "aa_debdeb" shown here.