Re: [css-transitions] Some matrix-based rotation interpolations are "wrong"

On Fri, Mar 6, 2015 at 5:58 PM Boris Zbarsky <bzbarsky@mit.edu> wrote:

> On 3/6/15 1:29 AM, Rik Cabanier wrote:
> > Where are Benoit's proposals posted?
>
> https://lists.w3.org/Archives/Public/public-fx/2014JanMar/0078.html
>
> The same proposal was brought up independently by someone else at
> https://lists.w3.org/Archives/Public/public-fx/2014JanMar/0014.html
>
> Benoit had a testcase that demonstrated the sorts of problems the
> current spec algorithm can cause that can be avoided with his proposal,
> but that link seems to be 404 now.  I'll see if I can locate another copy
>

Very interesting.

If we are opening the door for alternative matrix interpolation behaviors,
then I'd also like us to consider falling back to a 50% flip when
attempting to interpolate matrices or mis-matched transform lists.

Just like the current matrix behavior, this won't match author
expectations. Unlike the current matrix behavior, the author has a
reasonably good chance of working out why.

Sincerely,
    -Shane Stephens


>
> > Also, it will be very hard for Apple to change their behavior as it is
> > implemented on top of the OS' Core Animation library.
>
> Noted.  Also noted that Apple controls that library.
>
> -Boris
>
>