notes/Resources/dev/snippets/javascript.md

Lerp

function lerp(a, b, v){
	return a*v+b*(1-v);
}

Easing Functions

// accelerating from zero velocitieee
function easeInQuad(t) { return t*t }

// decelerating to zero velocity
function easeOutQuad(t) { return t*(2-t) }

// acceleration until halfway, then deceleration
function easeInOutQuad(t) { return t<.5 ? 2*t*t : -1+(4-2*t)*t }

// accelerating from zero velocity 
function easeInCubic(t) { return t*t*t }

// decelerating to zero velocity 
function easeOutCubic(t) { return (--t)*t*t+1 }

// acceleration until halfway, then deceleration 
function easeInOutCubic(t) { return t<.5 ? 4*t*t*t : (t-1)*(2*t-2)*(2*t-2)+1 }

// accelerating from zero velocity 
function easeInQuart(t) { return t*t*t*t }

// decelerating to zero velocity 
function easeOutQuart(t) { return 1-(--t)*t*t*t }

// acceleration until halfway, then deceleration
function easeInOutQuart(t) { return t<.5 ? 8*t*t*t*t : 1-8*(--t)*t*t*t }

// accelerating from zero velocity
function easeInQuint(t) { return t*t*t*t*t }

// decelerating to zero velocity
function easeOutQuint(t) { return 1+(--t)*t*t*t*t }

// acceleration until halfway, then deceleration 
function easeInOutQuint(t) { return t<.5 ? 16*t*t*t*t*t : 1+16*(--t)*t*t*t*t }

Chunk Array

function chunk(arr, chunkSize) {
  const R = [];
  for (let i=0,len=arr.length; i<len; i+=chunkSize)
    R.push(arr.slice(i,i+chunkSize));
  return R;
}

Size of String

function byteCount(s) {
    return encodeURI(s).split(/%..|./).length - 1;
}

Debounce

function debounce(func, wait, immediate) {
	var timeout;
	return function () {
		var context = this, args = arguments;
		var later = function () {
			timeout = null;
			if (!immediate) func.apply(context, args);
		};
		var callNow = immediate && !timeout;
		clearTimeout(timeout);
		timeout = setTimeout(later, wait);
		if (callNow) func.apply(context, args);
	};
};