This just reoccured to me for the nth time, but I really wish browsers would just pass along the layout engines own cached values with Scroll/Resize events, like: scrollPosition[x,y], document[w,h], window[w,h] /cc @ietf @w3c @csswg @webkit @mozilla @MicrosoftEdge ...heck, even just a delta[x,y] would be an improvement.

it would make things like parallaxers & scroll position based triggers so much smoother (like at least 2x instantly), since we wouldn't be causing thrashing when we attempt to re-measure these values every 16ms (or sooner)