Hacker News new | ask | show | jobs
by malandrew 4510 days ago
Yes, yes, a million times yes.

The biggest problem with this weak type system is obvious with CSS3 Matrix Transforms. CSS3 matrix transforms are the biggest bottleneck preventing fast updates to many DOM elements. Without fast updates of many elements across an entire page (window), pulling off the awesome smoothly animated effects found in modern desktop and mobile operating systems is pretty much impossible, especially in a system that implements immediate mode graphics over retain mode (DOM).

Marshalling matrix3d updates from numbers in an array of length 16 to a stringified array to apply it to an element, only to have the browser have to convert that stringified array back into an array of 16 numbers is insanity.

If you want performance, you need a more robust type system than just strings and children. I'm an engineer at Famo.us and we would absolutely love it if we could do something in javascript like element.set3DTransform(someLength16Array); We could simultaneously update thousands of DOM elements if arrays and typed arrays were supported instead of stringified.
1 comments
randallu 4510 days ago
Yeah, the CSS OM is really horrible too. CSS Animations is another area where you end up feeding huge generated strings into the DOM -- in theory Web Animations is meant to improve this, though personally I feel like the API too high level and ends up being really large because of this :(.

In your example, I think it'd only be a small patch (for WebKit, where my experience is) to optimize "elem.style.transform = new WebKitCSSMatrix(a,b,c,d)" without intermediate stringification. Mozilla doesn't expose a CSSMatrix type unfortunately. I've done some similar things for other CSS properties in WebKit -- have you considered submitting a patch? I've found the WK guys super receptive to small optimizations which don't change observable behavior (i.e.: you can't tell if the WebKitCSSMatrix was stringified or not currently) like that.

link
malandrew 4509 days ago
We're not über familiar with the internals of the browser or how to go about submitting a patch that fixes this. We did talk to people at Mozilla about this, but we still have to follow up on that.

Do you contribute to this area of Webkit? I'd love to chat more about this with you. Email is in my profile. Use the famo.us one.

link