Pomax's primer on bézier curves is the reference they used: https://pomax.github.io/bezierinfo/ https://pomax.github.io/bezierinfo/ They do a pretty good job i

Pomax's primer on bézier curves is the reference they used: https://pomax.github.io/bezierinfo/ https://pomax.github.io/bezierinfo/ They do a pretty good job introducing the mathematics gently I think. But maybe work backwards from whatever you don't understand?