Re: [filters] notes to CSS filters

On Fri, Sep 23, 2011 at 6:20 PM, Dirk Schulze <vbs85@gmx.de> wrote:

> Am 23.09.2011 um 08:08 schrieb Robert O'Callahan:
>
> On Fri, Sep 23, 2011 at 5:02 PM, Dirk Schulze <vbs85@gmx.de> wrote:
>
>> But that is exactly the point. If we don't have a filter region, the
>> filter effect would be unbound! Right now just the filter region bounds
>> lightning effects. What else can clip the visible area?
>>
>
> The viewport? :-)
>
>
> I am sure you remember the ECMA-cloud [1]. On WebKit we did not have an
> intelligent auto clipping algorithm from the beginning. And blurring all
> elements on this site took more than a minute (1:30 to 2 IIRC). Imagine this
> page would use lightning effects instead of blur effects. We would need even
> more time.
>

Yeah, I fixed that bug in Gecko too :-).

If there really is nothing bounding the lighting effect, then it will cover
the viewport, and since that's probably not what the author wants, they'll
fix it by clipping the element somehow or combining the lighting image with
some kind of mask, presumably bounded. Hopefully whatever they use to
restrict the visibility of the lighting can be used by the browser to limit
how much of the lighting image needs to be computed.

Rob
-- 
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