Re: [css-filters-2] Clarify 'backdrop-filter' in circular case

On Thu, Aug 13, 2015 at 2:46 PM, Tab Atkins Jr. <jackalmage@gmail.com>
wrote:

> On Thu, Aug 13, 2015 at 2:29 PM, Rik Cabanier <cabanier@gmail.com> wrote:
> > On Thu, Aug 13, 2015 at 2:20 PM, Rik Cabanier <cabanier@gmail.com>
> wrote:
> >> You execute an extra pass where you render everything upto your nearest
> >> sibling, but you ignore any opacity, filters and compositiing.
> >> Then you use this as input to the backdrop filter.
> >> http://www.w3.org/TR/SVG/filters.html#EnableBackgroundProperty
> describes
> >> the algorithm in more details.
> >>
> >> This is the same problem that we faced when we planning on introducing
> >> non-isolated blending. https://codereview.chromium.org/23455060/#msg33
> >> describes the notes from enne on how to implement this.
> >
> > The actual location of the solution is here:
> > https://codereview.chromium.org/23455060/#msg37
>
> Can this algorithm be ported into the actual spec?  There's currently
> no link from Filters or Compositing to that algorithm, and even if
> there was, you have to realize the need to translate between
> 'enable-background' and 'isolation'/all the other properties that
> cause a stacking context.
>

It used to be in the css compositing spec, but I was told to take it out
because there were no implementations at the time.
I can probably look in the history and add it to a level 2 spec.