$(function(){

	smoothscroll.init();

});


smoothscroll = {

	passive : function(){
		var supportsPassive = false;
		try {
		  document.addEventListener("test", null, { get passive() { supportsPassive = true }});
		} catch(e) {}

		return supportsPassive;
	},
	init : function(){


		var $window = $(window);
		var scrollTime = 1;
		var distance_offset = 2.8;
		var scrollDistance = $window.height() / distance_offset;

		if(this.passive()){
			window.addEventListener("wheel",this.scrolling,{passive: false});
		}else{
			$window.on("mousewheel DOMMouseScroll", this.scrolling);
		}

	},
	destroy : function(){

		if(this.passive()){
			window.removeEventListener("wheel",this.scrolling);
		}else{
		   $(window).off("mousewheel DOMMouseScroll", this.scrolling);
		}
		gsap.killTweensOf($(window),{scrollTo:true});

	},
	scrolling : function(event){

		event.preventDefault();

		var $window = $(window);
		var scrollTime = 1;
		var distance_offset = 2.8;
		var scrollDistance = $window.height() / distance_offset;
		var delta = 0;

		if(smoothscroll.passive()){
			delta = event.wheelDelta/120 || -event.deltaY/3;
		}else{
			if(typeof event.originalEvent.deltaY != "undefined"){
				delta = -event.originalEvent.deltaY/120;
			}else{
				delta = event.originalEvent.wheelDelta/120 || -event.originalEvent.detail/3;
			}
		}

		var scrollTop = $window.scrollTop();
		var finalScroll = scrollTop - parseInt(delta*scrollDistance);

		gsap.to($window, {
			duration: scrollTime,
			scrollTo : { y: finalScroll, autoKill:true },
			ease: 'power3.out',
			overwrite: 2
		});

		

	}

};