Re: [css-animations] How animation-timing-function in keyframe rule interacts with direction

On Oct 16, 2014, at 2:47 PM, Sylvain Galineau <galineau@adobe.com> wrote:

> We should resolve the issue raised by dbaron [1] (Bug 14805 [2])
> 
> If we have:
> 
> 	@keyframes timings {
> 		25% { animation-timing-function: linear; }
> 		40% { animation-timing-function: ease-out; }	
> 	}
> 
> ..then when the animation moves forward we expect linear to apply between 25% and 40%. But if the animation is moving backward e.g. due to an animation-direction: alternate then we also want linear to apply between 40% and 25%. 
> 
> Objections?
> 
> 
> [1] http://lists.w3.org/Archives/Public/www-style/2011Mar/0744.html
> [2] https://www.w3.org/Bugs/Public/show_bug.cgi?id=14805


I don’t think that’s right. The reverse animation should be a mirror-image of the forward animation, so the reverse animation should be linear for the last 25% of its travel.

I just noticed that the spec needs some editorial cleanup here. The Note under animation-timing-function says "See for more detail on this.”. I presume it means to link to “http://dev.w3.org/csswg/css-animations/#timing-functions”.

Simon

Received on Saturday, 18 October 2014 02:09:32 UTC