Re: [web-animations] Web Animations minutes, 2 Oct 2014

----- Original Message -----
> From: "Tab Atkins Jr." <>
> On Thu, Oct 2, 2014 at 8:21 PM, Brian Birtles <> wrote:
> > =============================================================
> > (Brian)
> >
> >
> >
> > Shane: seems reasonable to be able to define an animation that runs forever
> > and has always been running. So long as it takes into account
> > iterationStart
> > so that at currentTime 0 it lines up with iterationStart.
> >
> > Brian: we'd have to change delay and startTime to be unrestricted doubles?
> >
> > Shane: Probably ok.
> This doesn't work, since you can't tell what your .currentIteration
> value is (it's Infinity, since we don't implement transfinites), nor
> how far through that iteration you are.

Right, the current iteration is always positive infinity (that's the proposal in the bug anyway). We already have infinite currentIteration values for zero-duration animations that repeat forever so that's not out of the question--but it does break accumulating behavior and would mean special handling is needed for alternating behavior.

With regards to working out your position in an iteration, I think it depends if you allow the start time or the delay to be negative infinity. I think it's probably better to only allow the delay (since that applies to the animation which is also where you'd set the infinitely repeating behavior; and it means we don't end up with infinite current times in the player).

For delay we discussed calculating the time fraction by lining up the iterations so that animation local time zero corresponds to iterationStart.

I think there's a fair bit of extra spec work involved to make that happen, but I think it's possible?


Received on Friday, 3 October 2014 15:27:18 UTC