X controls how far the radius is on y=0, and y controls how far the radius is on x=0. Size controls the pen size, and speed controls the speed at which the pen travels. Press F to activate filling, which fills your shape in. Press C to clear the board. Hold N to see the coordinates. Left/right arrow keys to browse the presets. I really suggest turbo mode and a high speed. Seems like filling doesn't work when you change the speed while it's filling. I'll try and fix that. Weird patterns are generated when you use fill, so if you want a solid color.
Well, I have no idea how sine and cosine work, but I managed to make this. Fixed filling by making it work differently. Doesn't work at higher speeds.
