gsap/src/ScrollTrigger.js

GSAP is a robust JavaScript toolset that turns developers into animation superheroes. Build high-performance animations that work in **every** major browser. Animate CSS, SVG, canvas, React, Vue, WebGL, colors, strings, motion paths, generic objects...any

/*!
 * ScrollTrigger 3.8.0
 * https://greensock.com
 *
 * @license Copyright 2008-2021, GreenSock. All rights reserved.
 * Subject to the terms at https://greensock.com/standard-license or for
 * Club GreenSock members, the agreement issued with that membership.
 * @author: Jack Doyle, jack@greensock.com
*/
/* eslint-disable */

let gsap, _coreInitted, _win, _doc, _docEl, _body, _root, _resizeDelay, _raf, _request, _toArray, _clamp, _time2, _syncInterval, _refreshing, _pointerIsDown, _transformProp, _i, _prevWidth, _prevHeight, _autoRefresh, _sort, _suppressOverwrites, _ignoreResize,
	_limitCallbacks, // if true, we'll only trigger callbacks if the active state toggles, so if you scroll immediately past both the start and end positions of a ScrollTrigger (thus inactive to inactive), neither its onEnter nor onLeave will be called. This is useful during startup.
	_startup = 1,
	_proxies = [],
	_scrollers = [],
	_getTime = Date.now,
	_time1 = _getTime(),
	_lastScrollTime = 0,
	_enabled = 1,
	_passThrough = v => v,
	_getTarget = t => _toArray(t)[0] || (_isString(t) ? console.warn("Element not found:", t) : null),
	_round = value => Math.round(value * 100000) / 100000 || 0,
	_windowExists = () => typeof(window) !== "undefined",
	_getGSAP = () => gsap || (_windowExists() && (gsap = window.gsap) && gsap.registerPlugin && gsap),
	_isViewport = e => !!~_root.indexOf(e),
	_getProxyProp = (element, property) => ~_proxies.indexOf(element) && _proxies[_proxies.indexOf(element) + 1][property],
	_getScrollFunc = (element, {s, sc}) => { // we store the scroller functions in a alternating sequenced Array like [element, verticalScrollFunc, horizontalScrollFunc, ...] so that we can minimize memory, maximize performance, and we also record the last position as a ".rec" property in order to revert to that after refreshing to ensure things don't shift around.
		let i = _scrollers.indexOf(element),
			offset = sc === _vertical.sc ? 1 : 2;
		!~i && (i = _scrollers.push(element) - 1);
		return _scrollers[i + offset] || (_scrollers[i + offset] = _getProxyProp(element, s) || (_isViewport(element) ? sc : function(value) { return arguments.length ? (element[s] = value) : element[s]; }));
	},
	_getBoundsFunc = element => _getProxyProp(element, "getBoundingClientRect") || (_isViewport(element) ? () => {_winOffsets.width = _win.innerWidth; _winOffsets.height = _win.innerHeight; return _winOffsets;} : () => _getBounds(element)),
	_getSizeFunc = (scroller, isViewport, {d, d2, a}) => (a = _getProxyProp(scroller, "getBoundingClientRect")) ? () => a()[d] : () => (isViewport ? _win["inner" + d2] : scroller["client" + d2]) || 0,
	_getOffsetsFunc = (element, isViewport) => !isViewport || ~_proxies.indexOf(element) ? _getBoundsFunc(element) : () => _winOffsets,
	_maxScroll = (element, {s, d2, d, a}) => (s = "scroll" + d2) && (a = _getProxyProp(element, s)) ? a() - _getBoundsFunc(element)()[d] : _isViewport(element) ? (_body[s] || _docEl[s]) - (_win["inner" + d2] || _docEl["client" + d2] || _body["client" + d2]) : element[s] - element["offset" + d2],
	_iterateAutoRefresh = (func, events) => {
		for (let i = 0; i < _autoRefresh.length; i += 3) {
			(!events || ~events.indexOf(_autoRefresh[i+1])) && func(_autoRefresh[i], _autoRefresh[i+1], _autoRefresh[i+2]);
		}
	},
	_isString = value => typeof(value) === "string",
	_isFunction = value => typeof(value) === "function",
	_isNumber = value => typeof(value) === "number",
	_isObject = value => typeof(value) === "object",
	_callIfFunc = value => _isFunction(value) && value(),
	_combineFunc = (f1, f2) => () => {
		let result1 = _callIfFunc(f1),
			result2 = _callIfFunc(f2);
		return () => {
			_callIfFunc(result1);
			_callIfFunc(result2);
		}
	},
	_endAnimation = (animation, reversed, pause) => animation && animation.progress(reversed ? 0 : 1) && pause && animation.pause(),
	_callback = (self, func) => {
		let result = func(self);
		result && result.totalTime && (self.callbackAnimation = result);
	},
	_abs = Math.abs,
	_scrollLeft = "scrollLeft",
	_scrollTop = "scrollTop",
	_left = "left",
	_top = "top",
	_right = "right",
	_bottom = "bottom",
	_width = "width",
	_height = "height",
	_Right = "Right",
	_Left = "Left",
	_Top = "Top",
	_Bottom = "Bottom",
	_padding = "padding",
	_margin = "margin",
	_Width = "Width",
	_Height = "Height",
	_px = "px",
	_horizontal = {s: _scrollLeft, p: _left, p2: _Left, os: _right, os2: _Right, d: _width, d2: _Width, a: "x", sc: function(value) { return arguments.length ? _win.scrollTo(value, _vertical.sc()) : _win.pageXOffset || _doc[_scrollLeft] || _docEl[_scrollLeft] || _body[_scrollLeft] || 0}},
	_vertical = {s: _scrollTop, p: _top, p2: _Top, os: _bottom, os2: _Bottom, d: _height, d2: _Height, a: "y", op: _horizontal, sc: function(value) { return arguments.length ? _win.scrollTo(_horizontal.sc(), value) : _win.pageYOffset || _doc[_scrollTop] || _docEl[_scrollTop] || _body[_scrollTop] || 0}},
	_getComputedStyle = element => _win.getComputedStyle(element),
	_makePositionable = element => { // if the element already has position: absolute or fixed, leave that, otherwise make it position: relative
		let position = _getComputedStyle(element).position;
		element.style.position = (position === "absolute" || position === "fixed") ? position : "relative";
	},
	_setDefaults = (obj, defaults) => {
		for (let p in defaults) {
			(p in obj) || (obj[p] = defaults[p]);
		}
		return obj;
	},
	_getBounds = (element, withoutTransforms) => {
		let tween = withoutTransforms && _getComputedStyle(element)[_transformProp] !== "matrix(1, 0, 0, 1, 0, 0)" && gsap.to(element, {x: 0, y: 0, xPercent: 0, yPercent: 0, rotation: 0, rotationX: 0, rotationY: 0, scale: 1, skewX: 0, skewY: 0}).progress(1),
			bounds = element.getBoundingClientRect();
		tween && tween.progress(0).kill();
		return bounds;
	},
	_getSize = (element, {d2}) => element["offset" + d2] || element["client" + d2] || 0,
	_getLabelRatioArray = timeline => {
		let a = [],
			labels = timeline.labels,
			duration = timeline.duration(),
			p;
		for (p in labels) {
			a.push(labels[p] / duration);
		}
		return a;
	},
	_getClosestLabel = animation => value => gsap.utils.snap(_getLabelRatioArray(animation), value),
	_snapDirectional = snapIncrementOrArray => {
		let snap = gsap.utils.snap(snapIncrementOrArray),
			a = Array.isArray(snapIncrementOrArray) && snapIncrementOrArray.slice(0).sort((a, b) => a - b);
		return a ? (value, direction) => {
			let i;
			if (!direction) {
				return snap(value);
			}
			if (direction > 0) {
				value -= 1e-4; // to avoid rounding errors. If we're too strict, it might snap forward, then immediately again, and again.
				for (i = 0; i < a.length; i++) {
					if (a[i] >= value) {
						return a[i];
					}
				}
				return a[i-1];
			} else {
				i = a.length;
				value += 1e-4;
				while (i--) {
					if (a[i] <= value) {
						return a[i];
					}
				}
			}
			return a[0];
		} : (value, direction) => {
			let snapped = snap(value);
			return !direction || Math.abs(snapped - value) < 0.001 || ((snapped - value < 0) === direction < 0) ? snapped : snap(direction < 0 ? value - snapIncrementOrArray : value + snapIncrementOrArray);
		};
	},
	_getLabelAtDirection = timeline => (value, st) => _snapDirectional(_getLabelRatioArray(timeline))(value, st.direction),
	_multiListener = (func, element, types, callback) => types.split(",").forEach(type => func(element, type, callback)),
	_addListener = (element, type, func) => element.addEventListener(type, func, {passive: true}),
	_removeListener = (element, type, func) => element.removeEventListener(type, func),
	_markerDefaults = {startColor: "green", endColor: "red", indent: 0, fontSize: "16px", fontWeight:"normal"},
	_defaults = {toggleActions: "play", anticipatePin: 0},
	_keywords = {top: 0, left: 0, center: 0.5, bottom: 1, right: 1},
	_offsetToPx = (value, size) => {
		if (_isString(value)) {
			let eqIndex = value.indexOf("="),
				relative = ~eqIndex ? +(value.charAt(eqIndex-1) + 1) * parseFloat(value.substr(eqIndex + 1)) : 0;
			if (~eqIndex) {
				(value.indexOf("%") > eqIndex) && (relative *= size / 100);
				value = value.substr(0, eqIndex-1);
			}
			value = relative + ((value in _keywords) ? _keywords[value] * size : ~value.indexOf("%") ? parseFloat(value) * size / 100 : parseFloat(value) || 0);
		}
		return value;
	},
	_createMarker = (type, name, container, direction, {startColor, endColor, fontSize, indent, fontWeight}, offset, matchWidthEl, containerAnimation) => {
		let e = _doc.createElement("div"),
			useFixedPosition = _isViewport(container) || _getProxyProp(container, "pinType") === "fixed",
			isScroller = type.indexOf("scroller") !== -1,
			parent = useFixedPosition ? _body : container,
			isStart = type.indexOf("start") !== -1,
			color = isStart ? startColor : endColor,
			css = "border-color:" + color + ";font-size:" + fontSize + ";color:" + color + ";font-weight:" + fontWeight + ";pointer-events:none;white-space:nowrap;font-family:sans-serif,Arial;z-index:1000;padding:4px 8px;border-width:0;border-style:solid;";
		css += "position:" + ((isScroller || containerAnimation) && useFixedPosition ? "fixed;" : "absolute;");
		(isScroller || containerAnimation || !useFixedPosition) && (css += (direction === _vertical ? _right : _bottom) + ":" + (offset + parseFloat(indent)) + "px;");
		matchWidthEl && (css += "box-sizing:border-box;text-align:left;width:" + matchWidthEl.offsetWidth + "px;");
		e._isStart = isStart;
		e.setAttribute("class", "gsap-marker-" + type + (name ? " marker-" + name : ""));
		e.style.cssText = css;
		e.innerText = name || name === 0 ? type + "-" + name : type;
		parent.children[0] ? parent.insertBefore(e, parent.children[0]) : parent.appendChild(e);
		e._offset = e["offset" + direction.op.d2];
		_positionMarker(e, 0, direction, isStart);
		return e;
	},
	_positionMarker = (marker, start, direction, flipped) => {
		let vars = {display: "block"},
			side = direction[flipped ? "os2" : "p2"],
			oppositeSide = direction[flipped ? "p2" : "os2"];
		marker._isFlipped = flipped;
		vars[direction.a + "Percent"] = flipped ? -100 : 0;
		vars[direction.a] = flipped ? "1px" : 0;
		vars["border" + side + _Width] = 1;
		vars["border" + oppositeSide + _Width] = 0;
		vars[direction.p] = start + "px";
		gsap.set(marker, vars);
	},
	_triggers = [],
	_ids = {},
	_sync = () => _getTime() - _lastScrollTime > 20 && _updateAll(),
	_onScroll = () => {
		let time = _getTime();
		if (_lastScrollTime !== time) {
			_updateAll();
			_lastScrollTime || _dispatch("scrollStart");
			_lastScrollTime = time;
		} else if (!_request) {
			_request = _raf(_updateAll);
		}
	},
	_onResize = () => !_refreshing && !_ignoreResize && !_doc.fullscreenElement && _resizeDelay.restart(true), // ignore resizes triggered by refresh()
	_listeners = {},
	_emptyArray = [],
	_media = [],
	_creatingMedia, // when ScrollTrigger.matchMedia() is called, we record the current media key here (like "(min-width: 800px)") so that we can assign it to everything that's created during that call. Then we can revert just those when necessary. In the ScrollTrigger's init() call, the _creatingMedia is recorded as a "media" property on the instance.
	_lastMediaTick,
	_onMediaChange = e => {
		let tick = gsap.ticker.frame,
			matches = [],
			i = 0,
			index;
		if (_lastMediaTick !== tick || _startup) {
			_revertAll();
			for (; i < _media.length; i+=4) {
				index = _win.matchMedia(_media[i]).matches;
				if (index !== _media[i+3]) { // note: some browsers fire the matchMedia event multiple times, like when going full screen, so we shouldn't call the function multiple times. Check to see if it's already matched.
					_media[i+3] = index;
					index ? matches.push(i) : _revertAll(1, _media[i]) || (_isFunction(_media[i+2]) && _media[i+2]()); // Firefox doesn't update the "matches" property of the MediaQueryList object correctly - it only does so as it calls its change handler - so we must re-create a media query here to ensure it's accurate.
				}
			}
			_revertRecorded(); // in case killing/reverting any of the animations actually added inline styles back.
			for (i = 0; i < matches.length; i++) {
				index = matches[i];
				_creatingMedia = _media[index];
				_media[index+2] = _media[index+1](e);
			}
			_creatingMedia = 0;
			_coreInitted && _refreshAll(0, 1);
			_lastMediaTick = tick;
			_dispatch("matchMedia");
		}
	},
	_softRefresh = () => _removeListener(ScrollTrigger, "scrollEnd", _softRefresh) || _refreshAll(true),
	_dispatch = type => (_listeners[type] && _listeners[type].map(f => f())) || _emptyArray,
	_savedStyles = [], // when ScrollTrigger.saveStyles() is called, the inline styles are recorded in this Array in a sequential format like [element, cssText, gsCache, media]. This keeps it very memory-efficient and fast to iterate through.
	_revertRecorded = media => {
		for (let i = 0; i < _savedStyles.length; i+=5) {
			if (!media || _savedStyles[i+4] === media) {
				_savedStyles[i].style.cssText = _savedStyles[i+1];
				_savedStyles[i].getBBox && _savedStyles[i].setAttribute("transform", _savedStyles[i+2] || "");
				_savedStyles[i+3].uncache = 1;
			}
		}
	},
	_revertAll = (kill, media) => {
		let trigger;
		for (_i = 0; _i < _triggers.length; _i++) {
			trigger = _triggers[_i];
			if (!media || trigger.media === media) {
				if (kill) {
					trigger.kill(1);
				} else {
					trigger.revert();
				}
			}
		}
		media && _revertRecorded(media);
		media || _dispatch("revert");
	},
	_clearScrollMemory = () => _scrollers.forEach(obj => typeof(obj) === "function" && (obj.rec = 0)), // zero-out all the recorded scroll positions. Don't use _triggers because if, for example, .matchMedia() is used to create some ScrollTriggers and then the user resizes and it removes ALL ScrollTriggers, and then go back to a size where there are ScrollTriggers, it would have kept the position(s) saved from the initial state.
	_refreshingAll,
	_refreshAll = (force, skipRevert) => {
		if (_lastScrollTime && !force) {
			_addListener(ScrollTrigger, "scrollEnd", _softRefresh);
			return;
		}
		_refreshingAll = true;
		let refreshInits = _dispatch("refreshInit");
		_sort && ScrollTrigger.sort();
		skipRevert || _revertAll();
		_triggers.forEach(t => t.refresh()) // don't loop with _i because during a refresh() someone could call ScrollTrigger.update() which would iterate through _i resulting in a skip.
		refreshInits.forEach(result => result && result.render && result.render(-1)); // if the onRefreshInit() returns an animation (typically a gsap.set()), revert it. This makes it easy to put things in a certain spot before refreshing for measurement purposes, and then put things back.
		_clearScrollMemory();
		_resizeDelay.pause();
		_refreshingAll = false;
		_dispatch("refresh");
	},
	_lastScroll = 0,
	_direction = 1,
	_updateAll = () => {
		if (!_refreshingAll) {
			let l = _triggers.length,
				time = _getTime(),
				recordVelocity = time - _time1 >= 50,
				scroll = l && _triggers[0].scroll();
			_direction = _lastScroll > scroll ? -1 : 1;
			_lastScroll = scroll;
			if (recordVelocity) {
				if (_lastScrollTime && !_pointerIsDown && time - _lastScrollTime > 200) {
					_lastScrollTime = 0;
					_dispatch("scrollEnd");
				}
				_time2 = _time1;
				_time1 = time;
			}
			if (_direction < 0) {
				_i = l;
				while (_i-- > 0) {
					_triggers[_i] && _triggers[_i].update(0, recordVelocity);
				}
				_direction = 1;
			} else {
				for (_i = 0; _i < l; _i++) {
					_triggers[_i] && _triggers[_i].update(0, recordVelocity);
				}
			}
			_request = 0;
		}
	},
	_propNamesToCopy = [_left, _top, _bottom, _right, _margin + _Bottom, _margin + _Right, _margin + _Top, _margin + _Left, "display", "flexShrink", "float", "zIndex", "grid-column-start", "grid-column-end", "grid-row-start", "grid-row-end", "grid-area", "justify-self", "align-self", "place-self"],
	_stateProps = _propNamesToCopy.concat([_width, _height, "boxSizing", "max" + _Width, "max" + _Height, "position", _margin, _padding, _padding + _Top, _padding + _Right, _padding + _Bottom, _padding + _Left]),
	_swapPinOut = (pin, spacer, state) => {
		_setState(state);
		let cache = pin._gsap;
		if (cache.spacerIsNative) {
			_setState(cache.spacerState);
		} else if (pin.parentNode === spacer) {
			let parent = spacer.parentNode;
			if (parent) {
				parent.insertBefore(pin, spacer);
				parent.removeChild(spacer);
			}
		}
	},
	_swapPinIn = (pin, spacer, cs, spacerState) => {
		if (pin.parentNode !== spacer) {
			let i = _propNamesToCopy.length,
				spacerStyle = spacer.style,
				pinStyle = pin.style,
				p;
			while (i--) {
				p = _propNamesToCopy[i];
				spacerStyle[p] = cs[p];
			}
			spacerStyle.position = cs.position === "absolute" ? "absolute" : "relative";
			(cs.display === "inline") && (spacerStyle.display = "inline-block");
			pinStyle[_bottom] = pinStyle[_right] = "auto";
			spacerStyle.overflow = "visible";
			spacerStyle.boxSizing = "border-box";
			spacerStyle[_width] = _getSize(pin, _horizontal) + _px;
			spacerStyle[_height] = _getSize(pin, _vertical) + _px;
			spacerStyle[_padding] = pinStyle[_margin] = pinStyle[_top] = pinStyle[_left] = "0";
			_setState(spacerState);
			pinStyle[_width] = pinStyle["max" + _Width] = cs[_width];
			pinStyle[_height] = pinStyle["max" + _Height] = cs[_height];
			pinStyle[_padding] = cs[_padding];
			pin.parentNode.insertBefore(spacer, pin);
			spacer.appendChild(pin);
		}
	},
	_capsExp = /([A-Z])/g,
	_setState = state => {
		if (state) {
			let style = state.t.style,
				l = state.length,
				i = 0,
				p, value;
			(state.t._gsap || gsap.core.getCache(state.t)).uncache = 1; // otherwise transforms may be off
			for (; i < l; i +=2) {
				value = state[i+1];
				p = state[i];
				if (value) {
					style[p] = value;
				} else if (style[p]) {
					style.removeProperty(p.replace(_capsExp, "-$1").toLowerCase());
				}
			}
		}
	},
	_getState = element => { // returns an Array with alternating values like [property, value, property, value] and a "t" property pointing to the target (element). Makes it fast and cheap.
		let l = _stateProps.length,
			style = element.style,
			state = [],
			i = 0;
		for (; i < l; i++) {
			state.push(_stateProps[i], style[_stateProps[i]]);
		}
		state.t = element;
		return state;
	},
	_copyState = (state, override, omitOffsets) => {
		let result = [],
			l = state.length,
			i = omitOffsets ? 8 : 0, // skip top, left, right, bottom if omitOffsets is true
			p;
		for (; i < l; i += 2) {
			p = state[i];
			result.push(p, (p in override) ? override[p] : state[i+1]);
		}
		result.t = state.t;
		return result;
	},
	_winOffsets = {left:0, top:0},
	// // potential future feature (?) Allow users to calculate where a trigger hits (scroll position) like getScrollPosition("#id", "top bottom")
	// _getScrollPosition = (trigger, position, {scroller, containerAnimation, horizontal}) => {
	// 	scroller = _getTarget(scroller || _win);
	// 	let direction = horizontal ? _horizontal : _vertical,
	// 		isViewport = _isViewport(scroller);
	// 	_getSizeFunc(scroller, isViewport, direction);
	// 	return _parsePosition(position, _getTarget(trigger), _getSizeFunc(scroller, isViewport, direction)(), direction, _getScrollFunc(scroller, direction)(), 0, 0, 0, _getOffsetsFunc(scroller, isViewport)(), isViewport ? 0 : parseFloat(_getComputedStyle(scroller)["border" + direction.p2 + _Width]) || 0, 0, containerAnimation ? containerAnimation.duration() : _maxScroll(scroller), containerAnimation);
	// },
	_parsePosition = (value, trigger, scrollerSize, direction, scroll, marker, markerScroller, self, scrollerBounds, borderWidth, useFixedPosition, scrollerMax, containerAnimation) => {
		_isFunction(value) && (value = value(self));
		if (_isString(value) && value.substr(0,3) === "max") {
			value = scrollerMax + (value.charAt(4) === "=" ? _offsetToPx("0" + value.substr(3), scrollerSize) : 0);
		}
		let time = containerAnimation ? containerAnimation.time() : 0,
			p1, p2, element;
		containerAnimation && containerAnimation.seek(0);
		if (!_isNumber(value)) {
			_isFunction(trigger) && (trigger = trigger(self));
			let offsets = value.split(" "),
				bounds, localOffset, globalOffset, display;
			element = _getTarget(trigger) || _body;
			bounds = _getBounds(element) || {};
			if ((!bounds || (!bounds.left && !bounds.top)) && _getComputedStyle(element).display === "none") { // if display is "none", it won't report getBoundingClientRect() properly
				display = element.style.display;
				element.style.display = "block";
				bounds = _getBounds(element);
				display ? (element.style.display = display) : element.style.removeProperty("display");
			}
			localOffset = _offsetToPx(offsets[0], bounds[direction.d]);
			globalOffset = _offsetToPx(offsets[1] || "0", scrollerSize);
			value = bounds[direction.p] - scrollerBounds[direction.p] - borderWidth + localOffset + scroll - globalOffset;
			markerScroller && _positionMarker(markerScroller, globalOffset, direction, (scrollerSize - globalOffset < 20 || (markerScroller._isStart && globalOffset > 20)));
			scrollerSize -= scrollerSize - globalOffset; // adjust for the marker
		} else if (markerScroller) {
			_positionMarker(markerScroller, scrollerSize, direction, true);
		}
		if (marker) {
			let position = value + scrollerSize,
				isStart = marker._isStart;
			p1 = "scroll" + direction.d2;
			_positionMarker(marker, position, direction, (isStart && position > 20) || (!isStart && (useFixedPosition ? Math.max(_body[p1], _docEl[p1]) : marker.parentNode[p1]) <= position + 1));
			if (useFixedPosition) {
				scrollerBounds = _getBounds(markerScroller);
				useFixedPosition && (marker.style[direction.op.p] = (scrollerBounds[direction.op.p] - direction.op.m - marker._offset) + _px);
			}
		}
		if (containerAnimation && element) {
			p1 = _getBounds(element);
			containerAnimation.seek(scrollerMax);
			p2 = _getBounds(element);
			containerAnimation._caScrollDist = p1[direction.p] - p2[direction.p];
			value = value / (containerAnimation._caScrollDist) * scrollerMax;
		}
		containerAnimation && containerAnimation.seek(time);
		return containerAnimation ? value : Math.round(value);
	},
	_prefixExp = /(?:webkit|moz|length|cssText|inset)/i,
	_reparent = (element, parent, top, left) => {
		if (element.parentNode !== parent) {
			let style = element.style,
				p, cs;
			if (parent === _body) {
				element._stOrig = style.cssText; // record original inline styles so we can revert them later
				cs = _getComputedStyle(element);
				for (p in cs) { // must copy all relevant styles to ensure that nothing changes visually when we reparent to the <body>. Skip the vendor prefixed ones.
					if (!+p && !_prefixExp.test(p) && cs[p] && typeof style[p] === "string" && p !== "0") {
						style[p] = cs[p];
					}
				}
				style.top = top;
				style.left = left;
			} else {
				style.cssText = element._stOrig;
			}
			gsap.core.getCache(element).uncache = 1;
			parent.appendChild(element);
		}
	},
	// _mergeAnimations = animations => {
	// 	let tl = gsap.timeline({smoothChildTiming: true}).startTime(Math.min(...animations.map(a => a.globalTime(0))));
	// 	animations.forEach(a => {let time = a.totalTime(); tl.add(a); a.totalTime(time); });
	// 	tl.smoothChildTiming = false;
	// 	return tl;
	// },

	// returns a function that can be used to tween the scroll position in the direction provided, and when doing so it'll add a .tween property to the FUNCTION itself, and remove it when the tween completes or gets killed. This gives us a way to have multiple ScrollTriggers use a central function for any given scroller and see if there's a scroll tween running (which would affect if/how things get updated)
	_getTweenCreator = (scroller, direction) => {
		let getScroll = _getScrollFunc(scroller, direction),
			prop = "_scroll" + direction.p2, // add a tweenable property to the scroller that's a getter/setter function, like _scrollTop or _scrollLeft. This way, if someone does gsap.killTweensOf(scroller) it'll kill the scroll tween.
			lastScroll1, lastScroll2,
			getTween = (scrollTo, vars, initialValue, change1, change2) => {
				let tween = getTween.tween,
					onComplete = vars.onComplete,
					modifiers = {};
				tween && tween.kill();
				lastScroll1 = Math.round(initialValue);
				vars[prop] = scrollTo;
				vars.modifiers = modifiers;
				modifiers[prop] = value => {
					value = _round(getScroll()); // round because in some [very uncommon] Windows environments, it can get reported with decimals even though it was set without.
					if (value !== lastScroll1 && value !== lastScroll2 && Math.abs(value - lastScroll1) > 2) { // if the user scrolls, kill the tween. iOS Safari intermittently misreports the scroll position, it may be the most recently-set one or the one before that! When Safari is zoomed (CMD-+), it often misreports as 1 pixel off too! So if we set the scroll position to 125, for example, it'll actually report it as 124.
						tween.kill();
						getTween.tween = 0;
					} else {
						value = initialValue + change1 * tween.ratio + change2 * tween.ratio * tween.ratio;
					}
					lastScroll2 = lastScroll1;
					return (lastScroll1 = _round(value));
				};
				vars.onComplete = () => {
					getTween.tween = 0;
					onComplete && onComplete.call(tween);
				};
				tween = getTween.tween = gsap.to(scroller, vars);
				return tween;
			};
		scroller[prop] = getScroll;
		scroller.addEventListener("wheel", () => getTween.tween && getTween.tween.kill() && (getTween.tween = 0), {passive: true}); // Windows machines handle mousewheel scrolling in chunks (like "3 lines per scroll") meaning the typical strategy for cancelling the scroll isn't as sensitive. It's much more likely to match one of the previous 2 scroll event positions. So we kill any snapping as soon as there's a wheel event.
		return getTween;
	};

_horizontal.op = _vertical;



export class ScrollTrigger {

	constructor(vars, animation) {
		_coreInitted || ScrollTrigger.register(gsap) || console.warn("Please gsap.registerPlugin(ScrollTrigger)");
		this.init(vars, animation);
	}

	init(vars, animation) {
		this.progress = this.start = 0;
		this.vars && this.kill(1); // in case it's being initted again
		if (!_enabled) {
			this.update = this.refresh = this.kill = _passThrough;
			return;
		}
		vars = _setDefaults((_isString(vars) || _isNumber(vars) || vars.nodeType) ? {trigger: vars} : vars, _defaults);
		let {onUpdate, toggleClass, id, onToggle, onRefresh, scrub, trigger, pin, pinSpacing, invalidateOnRefresh, anticipatePin, onScrubComplete, onSnapComplete, once, snap, pinReparent, pinSpacer, containerAnimation, fastScrollEnd, preventOverlaps} = vars,
			direction = vars.horizontal || (vars.containerAnimation && vars.horizontal !== false) ? _horizontal : _vertical,
			isToggle = !scrub && scrub !== 0,
			scroller = _getTarget(vars.scroller || _win),
			scrollerCache = gsap.core.getCache(scroller),
			isViewport = _isViewport(scroller),
			useFixedPosition = ("pinType" in vars ? vars.pinType : _getProxyProp(scroller, "pinType") || (isViewport && "fixed")) === "fixed",
			callbacks = [vars.onEnter, vars.onLeave, vars.onEnterBack, vars.onLeaveBack],
			toggleActions = isToggle && vars.toggleActions.split(" "),
			markers = "markers" in vars ? vars.markers : _defaults.markers,
			borderWidth = isViewport ? 0 : parseFloat(_getComputedStyle(scroller)["border" + direction.p2 + _Width]) || 0,
			self = this,
			onRefreshInit = vars.onRefreshInit && (() => vars.onRefreshInit(self)),
			getScrollerSize = _getSizeFunc(scroller, isViewport, direction),
			getScrollerOffsets = _getOffsetsFunc(scroller, isViewport),
			lastSnap = 0,
			scrollFunc = _getScrollFunc(scroller, direction),
			tweenTo, pinCache, snapFunc, scroll1, scroll2, start, end, markerStart, markerEnd, markerStartTrigger, markerEndTrigger, markerVars,
			change, pinOriginalState, pinActiveState, pinState, spacer, offset, pinGetter, pinSetter, pinStart, pinChange, spacingStart, spacerState, markerStartSetter,
			markerEndSetter, cs, snap1, snap2, scrubTween, scrubSmooth, snapDurClamp, snapDelayedCall, prevProgress, prevScroll, prevAnimProgress, caMarkerSetter;

		self.media = _creatingMedia;
		anticipatePin *= 45;
		self.scroller = scroller;
		self.scroll = containerAnimation ? containerAnimation.time.bind(containerAnimation) : scrollFunc;
		scroll1 = scrollFunc();
		self.vars = vars;
		animation = animation || vars.animation;
		("refreshPriority" in vars) && (_sort = 1);
		scrollerCache.tweenScroll = scrollerCache.tweenScroll || {
			top: _getTweenCreator(scroller, _vertical),
			left: _getTweenCreator(scroller, _horizontal)
		};
		self.tweenTo = tweenTo = scrollerCache.tweenScroll[direction.p];
		if (animation) {
			animation.vars.lazy = false;
			animation._initted || (animation.vars.immediateRender !== false && vars.immediateRender !== false && animation.render(0, true, true));
			self.animation = animation.pause();
			animation.scrollTrigger = self;
			scrubSmooth = _isNumber(scrub) && scrub;
			scrubSmooth && (scrubTween = gsap.to(animation, {ease: "power3", duration: scrubSmooth, onComplete: () => onScrubComplete && onScrubComplete(self)}));
			snap1 = 0;
			id || (id = animation.vars.id);
		}
		_triggers.push(self);
		if (snap) {
			if (!_isObject(snap) || snap.push) {
				snap = {snapTo: snap};
			}
			("scrollBehavior" in _body.style) && gsap.set(isViewport ? [_body, _docEl] : scroller, {scrollBehavior: "auto"}); // smooth scrolling doesn't work with snap.
			snapFunc = _isFunction(snap.snapTo) ? snap.snapTo : snap.snapTo === "labels" ? _getClosestLabel(animation) : snap.snapTo === "labelsDirectional" ? _getLabelAtDirection(animation) : snap.directional !== false ? (value, st) => _snapDirectional(snap.snapTo)(value, st.direction) : gsap.utils.snap(snap.snapTo);
			snapDurClamp = snap.duration || {min: 0.1, max: 2};
			snapDurClamp = _isObject(snapDurClamp) ? _clamp(snapDurClamp.min, snapDurClamp.max) : _clamp(snapDurClamp, snapDurClamp);
			snapDelayedCall = gsap.delayedCall(snap.delay || (scrubSmooth / 2) || 0.1, () => {
				if (Math.abs(self.getVelocity()) < 10 && !_pointerIsDown && lastSnap !== scrollFunc()) {
					let totalProgress = animation && !isToggle ? animation.totalProgress() : self.progress,
						velocity = ((totalProgress - snap2) / (_getTime() - _time2) * 1000) || 0,
						change1 = gsap.utils.clamp(-self.progress, 1 - self.progress, _abs(velocity / 2) * velocity / 0.185),
						naturalEnd = self.progress + (snap.inertia === false ? 0 : change1),
						endValue = _clamp(0, 1, snapFunc(naturalEnd, self)),
						scroll = scrollFunc(),
						endScroll = Math.round(start + endValue * change),
						{ onStart, onInterrupt, onComplete } = snap,
						tween = tweenTo.tween;
					if (scroll <= end && scroll >= start && endScroll !== scroll) {
						if (tween && !tween._initted && tween.data <= _abs(endScroll - scroll)) { // there's an overlapping snap! So we must figure out which one is closer and let that tween live.
							return;
						}
						if (snap.inertia === false) {
							change1 = endValue - self.progress;
						}
						tweenTo(endScroll, {
							duration: snapDurClamp(_abs( (Math.max(_abs(naturalEnd - totalProgress), _abs(endValue - totalProgress)) * 0.185 / velocity / 0.05) || 0)),
							ease: snap.ease || "power3",
							data: _abs(endScroll - scroll), // record the distance so that if another snap tween occurs (conflict) we can prioritize the closest snap.
							onInterrupt: () => snapDelayedCall.restart(true) && onInterrupt && onInterrupt(self),
							onComplete: () => {
								lastSnap = scrollFunc();
								snap1 = snap2 = animation && !isToggle ? animation.totalProgress() : self.progress;
								onSnapComplete && onSnapComplete(self);
								onComplete && onComplete(self);
							}
						}, scroll, change1 * change, endScroll - scroll - change1 * change);
						onStart && onStart(self, tweenTo.tween);
					}
				} else if (self.isActive) {
					snapDelayedCall.restart(true);
				}
			}).pause();
		}
		id && (_ids[id] = self);
		trigger = self.trigger = _getTarget(trigger || pin);
		pin = pin === true ? trigger : _getTarget(pin);
		_isString(toggleClass) && (toggleClass = {targets: trigger, className: toggleClass});
		if (pin) {
			(pinSpacing === false || pinSpacing === _margin) || (pinSpacing = !pinSpacing && _getComputedStyle(pin.parentNode).display === "flex" ? false : _padding); // if the parent is display: flex, don't apply pinSpacing by default.
			self.pin = pin;
			vars.force3D !== false && gsap.set(pin, {force3D: true});
			pinCache = gsap.core.getCache(pin);
			if (!pinCache.spacer) { // record the spacer and pinOriginalState on the cache in case someone tries pinning the same element with MULTIPLE ScrollTriggers - we don't want to have multiple spacers or record the "original" pin state after it has already been affected by another ScrollTrigger.
				if (pinSpacer) {
					pinSpacer = _getTarget(pinSpacer);
					pinSpacer && !pinSpacer.nodeType && (pinSpacer = pinSpacer.current || pinSpacer.nativeElement); // for React & Angular
					pinCache.spacerIsNative = !!pinSpacer;
					pinSpacer && (pinCache.spacerState = _getState(pinSpacer));
				}
				pinCache.spacer = spacer = pinSpacer || _doc.createElement("div");
				spacer.classList.add("pin-spacer");
				id && spacer.classList.add("pin-spacer-" + id);
				pinCache.pinState = pinOriginalState = _getState(pin);
			} else {
				pinOriginalState = pinCache.pinState;
			}
			self.spacer = spacer = pinCache.spacer;
			cs = _getComputedStyle(pin);
			spacingStart = cs[pinSpacing + direction.os2];
			pinGetter = gsap.getProperty(pin);
			pinSetter = gsap.quickSetter(pin, direction.a, _px);
			// pin.firstChild && !_maxScroll(pin, direction) && (pin.style.overflow = "hidden"); // protects from collapsing margins, but can have unintended consequences as demonstrated here: https://codepen.io/GreenSock/pen/1e42c7a73bfa409d2cf1e184e7a4248d so it was removed in favor of just telling people to set up their CSS to avoid the collapsing margins (overflow: hidden | auto is just one option. Another is border-top: 1px solid transparent).
			_swapPinIn(pin, spacer, cs);
			pinState = _getState(pin);
		}
		if (markers) {
			markerVars = _isObject(markers) ? _setDefaults(markers, _markerDefaults) : _markerDefaults;
			markerStartTrigger = _createMarker("scroller-start", id, scroller, direction, markerVars, 0);
			markerEndTrigger = _createMarker("scroller-end", id, scroller, direction, markerVars, 0, markerStartTrigger);
			offset = markerStartTrigger["offset" + direction.op.d2];
			markerStart = _createMarker("start", id, scroller, direction, markerVars, offset, 0, containerAnimation);
			markerEnd =_createMarker("end", id, scroller, direction, markerVars, offset, 0, containerAnimation);
			containerAnimation && (caMarkerSetter = gsap.quickSetter([markerStart, markerEnd], direction.a, _px));
			if ((!useFixedPosition && !(_proxies.length && _getProxyProp(scroller, "fixedMarkers") === true))) {
				_makePositionable(isViewport ? _body : scroller);
				gsap.set([markerStartTrigger, markerEndTrigger], {force3D: true});
				markerStartSetter = gsap.quickSetter(markerStartTrigger, direction.a, _px);
				markerEndSetter = gsap.quickSetter(markerEndTrigger, direction.a, _px);
			}
		}

		if (containerAnimation) {
			let oldOnUpdate = containerAnimation.vars.onUpdate,
				oldParams = containerAnimation.vars.onUpdateParams;
			containerAnimation.eventCallback("onUpdate", () => {
				self.update(0, 0, 1);
				oldOnUpdate && oldOnUpdate.apply(oldParams || []);
			});
		}

		self.previous = () => _triggers[_triggers.indexOf(self) - 1];
		self.next = () => _triggers[_triggers.indexOf(self) + 1];

		self.revert = revert => {
			let r = revert !== false || !self.enabled,
				prevRefreshing = _refreshing;
			if (r !== self.isReverted) {
				if (r) {
					self.scroll.rec || (self.scroll.rec = scrollFunc());
					prevScroll = Math.max(scrollFunc(), self.scroll.rec || 0); // record the scroll so we can revert later (repositioning/pinning things can affect scroll position). In the static refresh() method, we first record all the scroll positions as a reference.
					prevProgress = self.progress;
					prevAnimProgress = animation && animation.progress();
				}
				markerStart && [markerStart, markerEnd, markerStartTrigger, markerEndTrigger].forEach(m => m.style.display = r ? "none" : "block");
				r && (_refreshing = 1);
				self.update(r); // make sure the pin is back in its original position so that all the measurements are correct.
				_refreshing = prevRefreshing;
				pin && (r ? _swapPinOut(pin, spacer, pinOriginalState) : (!pinReparent || !self.isActive) && _swapPinIn(pin, spacer, _getComputedStyle(pin), spacerState));
				self.isReverted = r;
			}
		}


		self.refresh = (soft, force) => {
			if ((_refreshing || !self.enabled) && !force) {
				return;
			}
			if (pin && soft && _lastScrollTime) {
				_addListener(ScrollTrigger, "scrollEnd", _softRefresh);
				return;
			}

			_refreshing = 1;
			scrubTween && scrubTween.pause();
			invalidateOnRefresh && animation && animation.progress(0).invalidate();
			self.isReverted || self.revert();
			let size = getScrollerSize(),
				scrollerBounds = getScrollerOffsets(),
				max = containerAnimation ? containerAnimation.duration() : _maxScroll(scroller, direction),
				offset = 0,
				otherPinOffset = 0,
				parsedEnd = vars.end,
				parsedEndTrigger = vars.endTrigger || trigger,
				parsedStart = vars.start || (vars.start === 0 || !trigger ? 0 : (pin ? "0 0" : "0 100%")),
				pinnedContainer = vars.pinnedContainer && _getTarget(vars.pinnedContainer),
				triggerIndex = (trigger && Math.max(0, _triggers.indexOf(self))) || 0,
				i = triggerIndex,
				cs, bounds, scroll, isVertical, override, curTrigger, curPin, oppositeScroll, initted, revertedPins;
			while (i--) { // user might try to pin the same element more than once, so we must find any prior triggers with the same pin, revert them, and determine how long they're pinning so that we can offset things appropriately. Make sure we revert from last to first so that things "rewind" properly.
				curTrigger = _triggers[i];
				curTrigger.end || curTrigger.refresh(0, 1) || (_refreshing = 1); // if it's a timeline-based trigger that hasn't been fully initialized yet because it's waiting for 1 tick, just force the refresh() here, otherwise if it contains a pin that's supposed to affect other ScrollTriggers further down the page, they won't be adjusted properly.
				curPin = curTrigger.pin;
				if (curPin && (curPin === trigger || curPin === pin) && !curTrigger.isReverted) {
					revertedPins || (revertedPins = []);
					revertedPins.unshift(curTrigger); // we'll revert from first to last to make sure things reach their end state properly
					curTrigger.revert();
				}
			}
			_isFunction(parsedStart) && (parsedStart = parsedStart(self));
			start = _parsePosition(parsedStart, trigger, size, direction, scrollFunc(), markerStart, markerStartTrigger, self, scrollerBounds, borderWidth, useFixedPosition, max, containerAnimation) || (pin ? -0.001 : 0);
			_isFunction(parsedEnd) && (parsedEnd = parsedEnd(self));
			if (_isString(parsedEnd) && !parsedEnd.indexOf("+=")) {
				if (~parsedEnd.indexOf(" ")) {
					parsedEnd = (_isString(parsedStart) ? parsedStart.split(" ")[0] : "") + parsedEnd;
				} else {
					offset = _offsetToPx(parsedEnd.substr(2), size);
					parsedEnd = _isString(parsedStart) ? parsedStart : start + offset; // _parsePosition won't factor in the offset if the start is a number, so do it here.
					parsedEndTrigger = trigger;
				}
			}
			end = Math.max(start, _parsePosition(parsedEnd || (parsedEndTrigger ? "100% 0" : max), parsedEndTrigger, size, direction, scrollFunc() + offset, markerEnd, markerEndTrigger, self, scrollerBounds, borderWidth, useFixedPosition, max, containerAnimation)) || -0.001;
			change = (end - start) || ((start -= 0.01) && 0.001);

			offset = 0;
			i = triggerIndex;
			while (i--) {
				curTrigger = _triggers[i];
				curPin = curTrigger.pin;
				if (curPin && curTrigger.start - curTrigger._pinPush < start && !containerAnimation) {
					cs = curTrigger.end - curTrigger.start;
					(curPin === trigger || curPin === pinnedContainer) && !_isNumber(parsedStart) && (offset += cs); // numeric start values shouldn't be offset at all - treat them as absolute
					curPin === pin && (otherPinOffset += cs);
				}
			}
			start += offset;
			end += offset;
			self._pinPush = otherPinOffset;
			if (markerStart && offset) { // offset the markers if necessary
				cs = {};
				cs[direction.a] = "+=" + offset;
				pinnedContainer && (cs[direction.p] = "-=" + scrollFunc());
				gsap.set([markerStart, markerEnd], cs);
			}

			if (pin) {
				cs = _getComputedStyle(pin);
				isVertical = direction === _vertical;
				scroll = scrollFunc(); // recalculate because the triggers can affect the scroll
				pinStart = parseFloat(pinGetter(direction.a)) + otherPinOffset;
				!max && end > 1 && ((isViewport ? _body : scroller).style["overflow-" + direction.a] = "scroll"); // makes sure the scroller has a scrollbar, otherwise if something has width: 100%, for example, it would be too big (exclude the scrollbar). See https://greensock.com/forums/topic/25182-scrolltrigger-width-of-page-increase-where-markers-are-set-to-false/
				_swapPinIn(pin, spacer, cs);
				pinState = _getState(pin);
				// transforms will interfere with the top/left/right/bottom placement, so remove them temporarily. getBoundingClientRect() factors in transforms.
				bounds = _getBounds(pin, true);
				oppositeScroll = useFixedPosition && _getScrollFunc(scroller, isVertical ? _horizontal : _vertical)();
				if (pinSpacing) {
					spacerState = [pinSpacing + direction.os2, change + otherPinOffset + _px];
					spacerState.t = spacer;
					i = (pinSpacing === _padding) ? _getSize(pin, direction) + change + otherPinOffset : 0;
					i && spacerState.push(direction.d, i + _px); // for box-sizing: border-box (must include padding).
					_setState(spacerState);
					useFixedPosition && scrollFunc(prevScroll);
				}
				if (useFixedPosition) {
					override = {
						top: (bounds.top + (isVertical ? scroll - start : oppositeScroll)) + _px,
						left: (bounds.left + (isVertical ? oppositeScroll : scroll - start)) + _px,
						boxSizing: "border-box",
						position: "fixed"
					};
					override[_width] = override["max" + _Width] = Math.ceil(bounds.width) + _px;
					override[_height] = override["max" + _Height] = Math.ceil(bounds.height) + _px;
					override[_margin] = override[_margin + _Top] = override[_margin + _Right] = override[_margin + _Bottom] = override[_margin + _Left] = "0";
					override[_padding] = cs[_padding];
					override[_padding + _Top] = cs[_padding + _Top];
					override[_padding + _Right] = cs[_padding + _Right];
					override[_padding + _Bottom] = cs[_padding + _Bottom];
					override[_padding + _Left] = cs[_padding + _Left];
					pinActiveState = _copyState(pinOriginalState, override, pinReparent);
				}
				if (animation) { // the animation might be affecting the transform, so we must jump to the end, check the value, and compensate accordingly. Otherwise, when it becomes unpinned, the pinSetter() will get set to a value that doesn't include whatever the animation did.
					initted = animation._initted; // if not, we must invalidate() after this step, otherwise it could lock in starting values prematurely.
					_suppressOverwrites(1);
					animation.render(animation.duration(), true, true);
					pinChange = pinGetter(direction.a) - pinStart + change + otherPinOffset;
					change !== pinChange && pinActiveState.splice(pinActiveState.length - 2, 2); // transform is the last property/value set in the state Array. Since the animation is controlling that, we should omit it.
					animation.render(0, true, true);
					initted || animation.invalidate();
					_suppressOverwrites(0);
				} else {
					pinChange = change
				}
			} else if (trigger && scrollFunc() && !containerAnimation) { // it may be INSIDE a pinned element, so walk up the tree and look for any elements with _pinOffset to compensate because anything with pinSpacing that's already scrolled would throw off the measurements in getBoundingClientRect()
				bounds = trigger.parentNode;
				while (bounds && bounds !== _body) {
					if (bounds._pinOffset) {
						start -= bounds._pinOffset;
						end -= bounds._pinOffset;
					}
					bounds = bounds.parentNode;
				}
			}
			revertedPins && revertedPins.forEach(t => t.revert(false));
			self.start = start;
			self.end = end;
			scroll1 = scroll2 = scrollFunc(); // reset velocity
			if (!containerAnimation) {
				scroll1 < prevScroll && scrollFunc(prevScroll);
				self.scroll.rec = 0;
			}
			self.revert(false);
			_refreshing = 0;
			animation && isToggle && animation._initted && animation.progress() !== prevAnimProgress && animation.progress(prevAnimProgress, true).render(animation.time(), true, true); // must force a re-render because if saveStyles() was used on the target(s), the styles could have been wiped out during the refresh().
			if (prevProgress !== self.progress) { // ensures that the direction is set properly (when refreshing, progress is set back to 0 initially, then back again to wherever it needs to be) and that callbacks are triggered.
				animation && !isToggle && animation.totalProgress(prevProgress, true); // to avoid issues where animation callbacks like onStart aren't triggered.
				self.progress = prevProgress;
				self.update(0, 0, 1);
			}
			pin && pinSpacing && (spacer._pinOffset = Math.round(self.progress * pinChange));
			onRefresh && onRefresh(self);
		};

		self.getVelocity = () => ((scrollFunc() - scroll2) / (_getTime() - _time2) * 1000) || 0;

		self.endAnimation = () => {
			_endAnimation(self.callbackAnimation);
			if (animation) {
				scrubTween ? scrubTween.progress(1) : (!animation.paused() ? _endAnimation(animation, animation.reversed()) : isToggle || _endAnimation(animation, self.direction < 0, 1));
			}
		};

		self.getTrailing = name => {
			let i = _triggers.indexOf(self),
				a = self.direction > 0 ? _triggers.slice(0, i).reverse() : _triggers.slice(i+1);
			return _isString(name) ? a.filter(t => t.vars.preventOverlaps === name) : a;
		};


		self.update = (reset, recordVelocity, forceFake) => {
			if (containerAnimation && !forceFake && !reset) {
				return;
			}
			let scroll = self.scroll(),
				p = reset ? 0 : (scroll - start) / change,
				clipped = p < 0 ? 0 : p > 1 ? 1 : p || 0,
				prevProgress = self.progress,
				isActive, wasActive, toggleState, action, stateChanged, toggled, isAtMax, isTakingAction;
			if (recordVelocity) {
				scroll2 = scroll1;
				scroll1 = containerAnimation ? scrollFunc() : scroll;
				if (snap) {
					snap2 = snap1;
					snap1 = animation && !isToggle ? animation.totalProgress() : clipped;
				}
			}
			// anticipate the pinning a few ticks ahead of time based on velocity to avoid a visual glitch due to the fact that most browsers do scrolling on a separate thread (not synced with requestAnimationFrame).
			(anticipatePin && !clipped && pin && !_refreshing && !_startup && _lastScrollTime && start < scroll + ((scroll - scroll2) / (_getTime() - _time2)) * anticipatePin) && (clipped = 0.0001);
			if (clipped !== prevProgress && self.enabled) {
				isActive = self.isActive = !!clipped && clipped < 1;
				wasActive = !!prevProgress && prevProgress < 1;
				toggled = isActive !== wasActive;
				stateChanged = toggled || !!clipped !== !!prevProgress; // could go from start all the way to end, thus it didn't toggle but it did change state in a sense (may need to fire a callback)
				self.direction = clipped > prevProgress ? 1 : -1;
				self.progress = clipped;

				if (stateChanged && !_refreshing) {
					toggleState = clipped && !prevProgress ? 0 : clipped === 1 ? 1 : prevProgress === 1 ? 2 : 3; // 0 = enter, 1 = leave, 2 = enterBack, 3 = leaveBack (we prioritize the FIRST encounter, thus if you scroll really fast past the onEnter and onLeave in one tick, it'd prioritize onEnter.
					if (isToggle) {
						action = (!toggled && toggleActions[toggleState + 1] !== "none" && toggleActions[toggleState + 1]) || toggleActions[toggleState]; // if it didn't toggle, that means it shot right past and since we prioritize the "enter" action, we should switch to the "leave" in this case (but only if one is defined)
						isTakingAction = animation && (action === "complete" || action === "reset" || action in animation);
					}
				}

				preventOverlaps && toggled && (isTakingAction || scrub || !animation) && (_isFunction(preventOverlaps) ? preventOverlaps(self) : self.getTrailing(preventOverlaps).forEach(t => t.endAnimation()));

				if (!isToggle) {
					if (scrubTween && !_refreshing && !_startup) {
						scrubTween.vars.totalProgress = clipped;
						scrubTween.invalidate().restart();
					} else if (animation) {
						animation.totalProgress(clipped, !!_refreshing);
					}
				}
				if (pin) {
					reset && pinSpacing && (spacer.style[pinSpacing + direction.os2] = spacingStart);
					if (!useFixedPosition) {
						pinSetter(pinStart + pinChange * clipped);
					} else if (stateChanged) {
						isAtMax = !reset && clipped > prevProgress && end + 1 > scroll && scroll + 1 >= _maxScroll(scroller, direction); // if it's at the VERY end of the page, don't switch away from position: fixed because it's pointless and it could cause a brief flash when the user scrolls back up (when it gets pinned again)
						if (pinReparent) {
							if (!reset && (isActive || isAtMax)) {
								let bounds = _getBounds(pin, true),
									offset = scroll - start;
								_reparent(pin, _body, (bounds.top + (direction === _vertical ? offset : 0)) + _px, (bounds.left + (direction === _vertical ? 0 : offset)) + _px);
							} else {
								_reparent(pin, spacer);
							}
						}
						_setState(isActive || isAtMax ? pinActiveState : pinState);
						(pinChange !== change && clipped < 1 && isActive) || pinSetter(pinStart + (clipped