I'm running a scroll event that triggers TweenMax animations, and I'm noticing that, while it looks good on Chrome, there is a considerable amount of lag on Firefox. Does anyone have a suggestion about how to handle this scroll event as efficiently as possible? Also, is there something about Firefox's rendering that I'm not aware of that might be causing this? Any leads would be appreciated!
The gist is that I'm looking for containers on my page called "customers", which each contain three individual "customer" elements. When a div that matches "customers" scrolls into view, trigger a TweenMax animation, and add a class called "animated", which prevents the element from re-animating subsequently.
Here is a fiddle with the basic demonstration: http://jsfiddle.net/epp37jsq/
EDIT
To clarify, the fiddle only demonstrates the behavior of my animation function. The lag does not occur there because the file size is quite small. On the actual site, I have 11 groups of 3 "customers." The image is the same, but pulled in 33 times. In the future, the images will be unique. In essence, the animation is being called for each of these 11 groups. I'm looking for suggestions on how to improve the speed of my page.
And my code:
var scrollTimer = null;
$(window).scroll(function () {
if (scrollTimer) {
clearTimeout(scrollTimer); // clear any previous pending timer
}
scrollTimer = setTimeout(handleScroll, 500); // set new timer
console.log("fired!");
});
function handleScroll() {
scrollTimer = null;
$('.customers').each(function() {
if (!$(this).hasClass('animated')) {
if ($(this).isOnScreen(0.45, 0.45)) {
TweenMax.staggerFromTo($(this).find('.customer'), 0.3, {
y: 50,
opacity: 0
}, {
y: 0,
opacity: 1,
ease: Power2.easeOut
}, 0.15);
$(this).addClass('animated');
}
}
});
}
Usually with Firefox, translating on the x or y axis can cause some jank. Sometimes adding a slight rotation:0.001 to your tween can help make your tween more smooth in Firefox.
Also using the GSAP special property autoAlpha instead of opacity can help increase performance
TweenMax.staggerFromTo($(this).find('.customer'), 0.3, {
y: 200,
rotation:0.01, /* add a slight rotation */
autoAlpha: 0 /* use instead of opacity */
}, {
y: 0,
rotation:0.01, /* add a slight rotation */
autoAlpha: 1, /* use instead of opacity */
ease: Power2.easeOut
}, 0.15);
autoAlpha is part of the GSAP CSSPlugin:
http://greensock.com/docs/#/HTML5/GSAP/Plugins/CSSPlugin/
autoAlpha - Identical to opacity except that when the value hits 0 the visibility property will be set to "hidden" in order to improve browser rendering performance and prevent clicks/interactivity on the target. When the value is anything other than 0, visibility will be set to "inherit". It is not set to "visible" in order to honor inheritance (imagine the parent element is hidden - setting the child to visible explicitly would cause it to appear when that's probably not what was intended). And for convenience, if the element's visibility is initially set to "hidden" and opacity is 1, it will assume opacity should also start at 0. This makes it simple to start things out on your page as invisible (set your css visibility:hidden) and then fade them in whenever you want.