Day 15, "Growth". I had this theme seeded before I knew how I wanted to express it and then I stumbled on the phrase "differential line growth" - seemed relevant. As I explored the algorithm I detected a lot of overlap with the force directed graph layout I played with in graph and the flocking beaviour in emerge.
Typical implementations initiialize with a simple line or circle but I used the polyline from shape. I also reused the fill logic - when you are satisfied with the shape of the curve you can pause the growth and have it paint the interior.
Click the frame once to freeze and paint and again to restart. Click here to open full screen.