Function _parsePosition

src/ScrollTrigger.js:454–507

(value, trigger, scrollerSize, direction, scroll, marker, markerScroller, self, scrollerBounds, borderWidth, useFixedPosition, scrollerMax, containerAnimation, clampZeroProp)

	// 	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, clampZeroProp) => {
		_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);
		isNaN(value) || (value = +value); // convert a string number like "45" to an actual number
		if (!_isNumber(value)) {
			_isFunction(trigger) && (trigger = trigger(self));
			let offsets = (value || "0").split(" "),
				bounds, localOffset, globalOffset, display;
			element = _getTarget(trigger, self) || _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 {
			containerAnimation && (value = gsap.utils.mapRange(containerAnimation.scrollTrigger.start, containerAnimation.scrollTrigger.end, 0, scrollerMax, value));
			markerScroller && _positionMarker(markerScroller, scrollerSize, direction, true);
		}
		if (clampZeroProp) {
			self[clampZeroProp] = value || -0.001;
			value < 0 && (value = 0);
		}
		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) {