On Sep 18, 2014, at 8:11 PM, Max Vujovic <mvujo...@adobe.com> wrote:

> Hi folks,
> 
> I’m wondering what work is left to ship -webkit-filter unprefixed?
> 
> I’m asking because Firefox is gearing up to ship filter unprefixed [1], and 
> it’d be great to see WebKit do it, too.

We ship both properties, prefixed filter and unprefixed filter. Both with two 
different functionalities.

* filter are just supported on SVG and just one reference to a <filter> element
* -webkit-filter work just on HTML elements. It has support for the shorthand 
properties (even though not following the spec by word yet) and allows 
references to multiple <filter> elements. However, the <filter> references are 
still buggy and especially filter regions are not handled correctly. There 
might be other potential performance regressions for SVG when it comes to 
references of local <filter> elements in the same document.

> 
> Some things that come to mind are:
> - Supporting the filter shorthand functions on SVG content.
> - Making sure the filter region and primitive subregion clipping calculations 
> match the spec.

Filters on SVG have an entirely different backend which is not compatible to 
the backend used for HTML elements. It basically is not designed for multiple 
filter instances. We would need to reimplement filters for SVG again, which 
doesn’t seem to be efficient. At the same time we need to make sure that SVG 
Filters are as reliable as they are today on SVG content since they are used a 
lot.

IMO the way forward is to correct the implementation of -webkit-filter where 
possible. Some parsing quirks might just be fixed for the unprefixed filter 
property. In a second step, -webkit-filter must be independent of the logic 
used by HTML as much as possible. We are already going these steps with using 
RenderElement and so on. In a last step we either set up -webkit-filters in 
another place then RenderLayer where we still mostly do it today, or transform 
SVG to use RenderLayer as well.

To answer you’re question: There is still some work left.

Greetings,
Dirk

PS: I saw that you sent the same message to blink-dev. Even thought a lot 
changed in the filter backend (HW accelerated SVG Filters and so on), most of 
the design principles still apply to Blink the same way as they do to WebKit.

> 
> Thanks,
> Max
> 
> [1]: 
> https://groups.google.com/d/msg/mozilla.dev.platform/ujWvBvtugGY/aS0oA44HuoUJ
> _______________________________________________
> webkit-dev mailing list
> webkit-dev@lists.webkit.org
> https://lists.webkit.org/mailman/listinfo/webkit-dev

_______________________________________________
webkit-dev mailing list
webkit-dev@lists.webkit.org
https://lists.webkit.org/mailman/listinfo/webkit-dev

Reply via email to