Debounced Scroll for Ads

debounced-scroll.js

if ( !window.requestAnimationFrame ){
	window.requestAnimationFrame = (function(){
		return window.webkitRequestAnimationFrame ||
			window.mozRequestAnimationFrame ||
			window.oRequestAnimationFrame ||
			window.msRequestAnimationFrame ||
			function( callback ) {
				window.setTimeout( callback, 1000 / 60 );
			};
	})();
}

var eventName = 'scroll.bottom-ads',
    lastScrollY = 0,
    ticking = false;

$( window ).on( eventName, function( evt ) {

	lastScrollY = window.pageYOffset;

	if ( !ticking ) {
		requestAnimationFrame( handleScroll );
		ticking = true;
	}

});

function handleScroll() {

	var bottomOfWindow = lastScrollY + $( window ).height();
	var topOfDiv = $('#gpt_gallery_smarttout').offset().top;

	if ( bottomOfWindow > topOfDiv && bottomAdsFired === 0 ) {
		console.log('Load My Ads Now!');
		bottomAdsFired = true;
		$( window ).off( eventName );
	}

	ticking = false;
}