A list of easing functions for use with JavaScript and TypeScript

easings.ts

/**
 * A list of easing functions for use with JavaScript and TypeScript
 *
 * Usage:
 *
 * `Easings.linear(t)`
 * Where `t` in a value between 0 and 1
 */

const easeIn = (p: number) => (t: number) => Math.pow(t, p)
const easeOut = (p: number) => (t: number) => 1 - easeIn(p)(1 - t)
const easeInOut = (p: number) => (t: number) => t < .5 ? easeIn(p)(t * 2) / 2 : easeOut(p)(t * 2 - 1) / 2 + .5

const Easings = {
	linear: easeIn(1),
	easeInQuad: easeIn(2),
	easeOutQuad: easeOut(2),
	easeInOutQuad: easeInOut(2),
	easeInCubic: easeIn(3),
	easeOutCubic: easeOut(3),
	easeInOutCubic: easeInOut(3),
	easeInQuart: easeIn(4),
	easeOutQuart: easeOut(4),
	easeInOutQuart: easeInOut(4),
	easeInQuint: easeIn(5),
	easeOutQuint: easeOut(5),
	easeInOutQuint: easeInOut(5)
}