Re: [css3-animations] Complex animations

On Tue, Mar 29, 2011 at 12:13 PM, Robert O'Callahan <robert@ocallahan.org>wrote:

> On Wed, Mar 30, 2011 at 6:30 AM, Rik Cabanier <cabanier@gmail.com> wrote:
>
>> The second part of your problem is a little different. In order to do
>> that, you need to have a precise timing event so you can determine if your
>> character is colliding with something else.
>> Mozilla's proposal could be part of the solution:
>> http://hacks.mozilla.org/2010/08/more-efficient-javascript-animations-with-mozrequestanimationframe/
>> This proposal lets you call a JS function at precise intervals much like
>> Flash's onEnterFrame function. If you combine this with my request to pause
>> all animations on the page, you would know the precise state of everything
>> in the DOM.
>>
>
> I think requestAnimationFrame is tremendously useful (I helped design it)
> but it can't be a complete solution since when animations are carried out
> off the HTML5 event loop thread (which you want for smoothness), JS may not
> be able to run at the moment the animation finishes.
>

This is why being able to pause all animations is important.
I don't think that this will give many issues with smoothness as long as you
use animations for the bulk of the motion and keep you JavaScript to a
minimum.
The Flash player pauses all rendering during its ActionScript phase and real
world performance of games and animations is fine.


> SMIL animations can easily express what you need to express here. Perhaps
> we don't need to make CSS animations cover this use case.
>

I have to admit that I'm not that familiar with SMIL. I just glanced at the
spec and it seems overly complicated. Maybe it's better to extend the CSS
animation spec to allow for true keyframe animation.

Rik