(function($) {
	"use strict";
	(function() {
		var defaultoptions = {
			framerate: 150,
			animationtime: 1800,
			stepsize: 85,
			pulsealgorithm: true,
			pulsescale: 8,
			pulsenormalize: 1,
			accelerationdelta: 20,
			accelerationmax: 1,
			keyboardsupport: true,
			arrowscroll: 50,
			touchpadsupport: true,
			fixedbackground: true,
			excluded: ""
		};
		var options = defaultoptions;
		var isexcluded = false;
		var isframe = false;
		var direction = {
			x: 0,
			y: 0
		};
		var initdone = false;
		var root = document.documentelement;
		var activeelement;
		var observer;
		var deltabuffer = [120, 120, 120];
		var key = {
			left: 37,
			up: 38,
			right: 39,
			down: 40,
			spacebar: 32,
			pageup: 33,
			pagedown: 34,
			end: 35,
			home: 36
		};
		var options = defaultoptions;

		function inittest() {
			var disablekeyboard = false;
			if (disablekeyboard) {
				removeevent("keydown", keydown)
			}
			if (options.keyboardsupport && !disablekeyboard) {
				addevent("keydown", keydown)
			}
		}
		function init() {
			if (!document.body) return;
			var body = document.body;
			var html = document.documentelement;
			var windowheight = window.innerheight;
			var scrollheight = body.scrollheight;
			root = (document.compatmode.indexof('css') >= 0) ? html : body;
			activeelement = body;
			inittest();
			initdone = true;
			if (top != self) {
				isframe = true
			} else if (scrollheight > windowheight && (body.offsetheight <= windowheight || html.offsetheight <= windowheight)) {
				html.style.height = 'auto';
				if (root.offsetheight <= windowheight) {
					var underlay = document.createelement("div");
					underlay.style.clear = "both";
					body.appendchild(underlay)
				}
			}
			if (!options.fixedbackground && !isexcluded) {
				body.style.backgroundattachment = "scroll";
				html.style.backgroundattachment = "scroll"
			}
		}
		var que = [];
		var pending = false;
		var lastscroll = +new date;

		function scrollarray(elem, left, top, delay) {
			delay || (delay = 1000);
			directioncheck(left, top);
			if (options.accelerationmax != 1) {
				var now = +new date;
				var elapsed = now - lastscroll;
				if (elapsed < options.accelerationdelta) {
					var factor = (1 + (30 / elapsed)) / 2;
					if (factor > 1) {
						factor = math.min(factor, options.accelerationmax);
						left *= factor;
						top *= factor
					}
				}
				lastscroll = +new date
			}
			que.push({
				x: left,
				y: top,
				lastx: (left < 0) ? 0.99 : -0.99,
				lasty: (top < 0) ? 0.99 : -0.99,
				start: +new date
			});
			if (pending) {
				return
			}
			var scrollwindow = (elem === document.body);
			var step = function(time) {
					var now = +new date;
					var scrollx = 0;
					var scrolly = 0;
					for (var i = 0; i < que.length; i++) {
						var item = que[i];
						var elapsed = now - item.start;
						var finished = (elapsed >= options.animationtime);
						var position = (finished) ? 1 : elapsed / options.animationtime;
						if (options.pulsealgorithm) {
							position = pulse(position)
						}
						var x = (item.x * position - item.lastx) >> 0;
						var y = (item.y * position - item.lasty) >> 0;
						scrollx += x;
						scrolly += y;
						item.lastx += x;
						item.lasty += y;
						if (finished) {
							que.splice(i, 1);
							i--
						}
					}
					if (scrollwindow) {
						window.scrollby(scrollx, scrolly)
					} else {
						if (scrollx) elem.scrollleft += scrollx;
						if (scrolly) elem.scrolltop += scrolly
					}
					if (!left && !top) {
						que = []
					}
					if (que.length) {
						requestframe(step, elem, (delay / options.framerate + 1))
					} else {
						pending = false
					}
				};
			requestframe(step, elem, 0);
			pending = true
		}
		function wheel(event) {
			if (!initdone) {
				init()
			}
			var target = event.target;
			var overflowing = overflowingancestor(target);
			if (!overflowing || event.defaultprevented || isnodename(activeelement, "embed") || (isnodename(target, "embed") && /\.pdf/i.test(target.src))) {
				return true
			}
			var deltax = event.wheeldeltax || 0;
			var deltay = event.wheeldeltay || 0;
			if (!deltax && !deltay) {
				deltay = event.wheeldelta || 0
			}
			if (!options.touchpadsupport && istouchpad(deltay)) {
				return true
			}
			if (math.abs(deltax) > 1.2) {
				deltax *= options.stepsize / 120
			}
			if (math.abs(deltay) > 1.2) {
				deltay *= options.stepsize / 120
			}
			scrollarray(overflowing, -deltax, -deltay);
			event.preventdefault()
		}
		function keydown(event) {
			var target = event.target;
			var modifier = event.ctrlkey || event.altkey || event.metakey || (event.shiftkey && event.keycode !== key.spacebar);
			if (/input|textarea|select|embed/i.test(target.nodename) || target.iscontenteditable || event.defaultprevented || modifier) {
				return true
			}
			if (isnodename(target, "button") && event.keycode === key.spacebar) {
				return true
			}
			var shift, x = 0,
				y = 0;
			var elem = overflowingancestor(activeelement);
			var clientheight = elem.clientheight;
			if (elem == document.body) {
				clientheight = window.innerheight
			}
			switch (event.keycode) {
			case key.up:
				y = -options.arrowscroll;
				break;
			case key.down:
				y = options.arrowscroll;
				break;
			case key.spacebar:
				shift = event.shiftkey ? 1 : -1;
				y = -shift * clientheight * 0.9;
				break;
			case key.pageup:
				y = -clientheight * 0.9;
				break;
			case key.pagedown:
				y = clientheight * 0.9;
				break;
			case key.home:
				y = -elem.scrolltop;
				break;
			case key.end:
				var damt = elem.scrollheight - elem.scrolltop - clientheight;
				y = (damt > 0) ? damt + 10 : 0;
				break;
			case key.left:
				x = -options.arrowscroll;
				break;
			case key.right:
				x = options.arrowscroll;
				break;
			default:
				return true
			}
			scrollarray(elem, x, y);
			event.preventdefault()
		}
		function mousedown(event) {
			activeelement = event.target
		}
		var cache = {};
		setinterval(function() {
			cache = {}
		}, 10 * 1000);
		var uniqueid = (function() {
			var i = 0;
			return function(el) {
				return el.uniqueid || (el.uniqueid = i++)
			}
		})();

		function setcache(elems, overflowing) {
			for (var i = elems.length; i--;) cache[uniqueid(elems[i])] = overflowing;
			return overflowing
		}
		function overflowingancestor(el) {
			var elems = [],
				overflow = null;
			var rootscrollheight = root.scrollheight;
			do {
				var cached = cache[uniqueid(el)];
				if (cached) {
					return setcache(elems, cached)
				}
				elems.push(el);
				if (rootscrollheight === el.scrollheight) {
					if (!isframe || root.clientheight + 10 < rootscrollheight) {
						return setcache(elems, document.body)
					}
				} else if (el.clientheight + 10 < el.scrollheight) {
					if (getcomputedstyle(el, "").getpropertyvalue("overflow-y")) {
						overflow = getcomputedstyle(el, "").getpropertyvalue("overflow-y");
						if (overflow === "scroll" || overflow === "auto") {
							return setcache(elems, el)
						}
					}
				}
			} while (el = el.parentnode)
		}
		function addevent(type, fn, bubble) {
			window.addeventlistener(type, fn, (bubble || false))
		}
		function removeevent(type, fn, bubble) {
			window.removeeventlistener(type, fn, (bubble || false))
		}
		function isnodename(el, tag) {
			return (el.nodename || "").tolowercase() === tag.tolowercase()
		}
		function directioncheck(x, y) {
			x = (x > 0) ? 1 : -1;
			y = (y > 0) ? 1 : -1;
			if (direction.x !== x || direction.y !== y) {
				direction.x = x;
				direction.y = y;
				que = [];
				lastscroll = 0
			}
		}
		var deltabuffertimer;

		function istouchpad(deltay) {
			if (!deltay) return;
			deltay = math.abs(deltay);
			deltabuffer.push(deltay);
			deltabuffer.shift();
			cleartimeout(deltabuffertimer);
			var allequals = (deltabuffer[0] == deltabuffer[1] && deltabuffer[1] == deltabuffer[2]);
			var alldivisable = (isdivisible(deltabuffer[0], 120) && isdivisible(deltabuffer[1], 120) && isdivisible(deltabuffer[2], 120));
			return !(allequals || alldivisable)
		}
		function isdivisible(n, divisor) {
			return (math.floor(n / divisor) == n / divisor)
		}
		var requestframe = (function() {
			return window.requestanimationframe || window.webkitrequestanimationframe ||
			function(callback, element, delay) {
				window.settimeout(callback, delay || (1000 / 60))
			}
		})();

		function pulse_(x) {
			var val, start, expx;
			x = x * options.pulsescale;
			if (x < 1) {
				val = x - (1 - math.exp(-x))
			} else {
				start = math.exp(-1);
				x -= 1;
				expx = 1 - math.exp(-x);
				val = start + (expx * (1 - start))
			}
			return val * options.pulsenormalize
		}
		function pulse(x) {
			if (x >= 1) return 1;
			if (x <= 0) return 0;
			if (options.pulsenormalize == 1) {
				options.pulsenormalize /= pulse_(1)
			}
			return pulse_(x)
		}
		var ischrome = /chrome/i.test(window.navigator.useragent);
		var ismousewheelsupported = 'onmousewheel' in document;
		if (ismousewheelsupported && ischrome) {
			addevent("mousedown", mousedown);
			addevent("mousewheel", wheel);
			addevent("load", init)
		}
	})()
})(jquery);