Fixed infinite loop on large displays

This commit is contained in:
Chuck Dries 2017-02-14 04:22:22 -07:00
parent 377d8ae7d3
commit 9f82dd214c

View File

@ -4,6 +4,7 @@ var speed = .0005; //speed multiplier
//setup necissary stuff
var target = null;
var targetHeight = null;
var prevHeight = null;
var currentHeight = null;
var startTime = null;
var count = 0;
@ -12,6 +13,7 @@ function smoothScroll(targetId){
target = document.getElementById(targetId);//grab the element
targetHeight = target.offsetTop; //get its height
currentHeight = getScrollY(); //grab the current scroll position
prevHeight = null;
startTime = null; //we have to reset the start time every time the animation runs
if(currentHeight != targetHeight){
count = 0;
@ -22,12 +24,12 @@ function animateScroll(timeStamp){
if (startTime == null) startTime = timeStamp; //record the time the animation started if we're just starting
var deltaStep = (timeStamp - startTime) * speed; //timeStamp - startTime gives us miliseconds since the animation started, we scale this down because its usually in the hundreds.
currentHeight = getScrollY(); //record the current scroll position of the window
prevHeight = currentHeight;//store height before scroll action so we can compare it to the height after we try to scroll
var offsetScroll = targetHeight - currentHeight; //calculate how far we still need to go
var deltaScroll = deltaStep * offsetScroll; //decide how far to scroll this tick
window.scroll(0, currentHeight + deltaScroll); //scroll!
currentHeight = getScrollY();//re-record the current height after scrolling for comparison
count++;
if((currentHeight != targetHeight) || ((currentHeight + offsetScroll < window.innerHeight)&& count < 50)){ //schedule another tick until we get where we're going or we get as far as we can
if((currentHeight != targetHeight) && (currentHeight != prevHeight)){ //schedule another tick until we get where we're going or we get as far as we can
window.requestAnimationFrame(animateScroll);
}