-- Smooth Interpolation Curve Generator
-- @author Validark
-- @original https://github.com/gre/bezier-easing
-- 		Copyright (c) 2014 Gaëtan Renaudeau, MIT License (see bottom for full license)
-- @testsite http://cubic-bezier.com/
-- @testsite http://greweb.me/bezier-easing-editor/example/