Cubic Bezier Curves Under the Hood
Random trivia: Acorn uses three different implementations of bezier curves for various bits. One is NSBezierCurve, which is provided by Apple’s frameworks, as well as two I’ve written myself (for the bezier shape, as well as smooth brush strokes).
If you watch that video, and think “hey, this is awesome I’d love to know more”, make sure to check out A Primer on Bézier Curves by Mike Pomax.
