Original article from https://www.a1k0n.net/2011/07/20/donut-math.html by Andy Sloane.
Youtube animation videos in C by Lex Fridman: https://www.youtube.com/watch?v=DEqXNfs_HhY
My blog link: https://tealtadpole.me/index.php/2021/11/23/javascript-donut-animation/