bezier(pt1: Vec2, pt2: Vec2, pt3: Vec2, pt4: Vec2): Vec2
A second order function returning an evaluator for the given 2D quadratic Bezier curveparampt1 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