bezier(pt1: Vec2, pt2: Vec2, pt3: Vec2, pt4: Vec2): Vec2

A second order function returning an evaluator for the given 2D quadratic Bezier curve

parampt1- First point

parampt2- First control point

parampt3- Second control point

parampt4- Second point

returnsA function which gives the value on the 2D quadratic Bezier curve at t