I learned simple harmonic motion in physics and I thought this would look cool so I made it. It's quite simple, there are 2 harmonic motions, 1 on the x axis and 1 on the y axis, and they are happening at the same time. This is called superposition if I'm not mistaken. The Tx and Ty variables are the time peroids of the 2 motions in seconds. When the flag is clicked they are randomized but they can be set manually by pressing the "n" key. Press shift+flag to speed up drawing. Also press the green flag a few times to see what kind of different shapes it can draw.