catmullRom(pt1: Vec2, m1: Vec2, m2: Vec2, pt2: Vec2): Vec2
A second order function returning an evaluator for the given 2D Catmull-Rom curve
parampt1- Previous point
paramm1- First point
paramm2- Second point
parampt2- Next point
returnsA function which gives the value on the 2D Catmull-Rom curve at t