The code is simple: a square is drawn by drawing two concentric circles and then applying a distortion to make them into looser spirals until they are complete circles and all the way through to the center point, at which point you stop drawing. The distortion distance controls how far you have to travel before reaching the center of your spiral, essentially making it wider or narrower. Interesting effects can be achieved by flipping this distortion, by adding another new distortion onto a drawn one (often called ""delayed feedback""), or by overlaying them both at once.