a ts/js library of standard easing functions, copied from easings.net, all credit to them.

if importing into a typescript project, add the following type declarations to your custom.d.ts

type tEaseOption = 'noEase' | 'easeInSine' | 'easeOutSine' | 'easeInOutSine' | 'easeInQuad' | 'easeOutQuad' | 'easeInOutQuad' | 'easeInCubic' | 'easeOutCubic' | 'easeInOutCubic' | 'easeInQuart' | 'easeOutQuart' | 'easeInOutQuart' | 'easeInQuint' | 'easeOutQuint' | 'easeInOutQuint' | 'easeInExpo' | 'easeOutExpo' | 'easeInOutExpo' | 'easeInCirc' | 'easeOutCirc' | 'easeInOutCirc' | 'easeInBack' | 'easeOutBack' | 'easeInOutBack' | 'easeInElastic' | 'easeOutElastic' | 'easeInOutElastic' | 'easeInBounce' | 'easeOutBounce' | 'easeInOutBounce';
type tEaseFunction = (x: number) => number;