Re: Updated filters specification

On Wed, 27 Apr 2011 06:05:13 +0200, Vincent Hardy <vhardy@adobe.com> wrote:

>
> On Apr 26, 2011, at 8:55 PM, Robert O'Callahan wrote:
>
> On Tue, Apr 26, 2011 at 7:20 PM, Erik Dahlstrom  
> <ed@opera.com<mailto:ed@opera.com>> wrote:
> Deprecating (or dropping) 'enable-background' would essentially mean  
> that BackgroundImage and BackgroundAlpha would always generate a  
> transparent black result in the context of filters (I presume this is  
> what the browsers that don't support enable-background already do, and  
> it follows the error handling that is defined for when there was no  
> "enable-background:new" parent element). Typically that means that  
> things still render without errors but probably not as intended by the  
> author.
>
> Why can't we define BackgroundImage and BackgroundAlpha in a way that  
> continues to work in the absence of enable-background? I think we can,  
> even with GPU-accelerated rendering. In the worst case you can detect  
> use of BackgroundImage/BackgroundAlpha and automatically infer the  
> equivalent of enable-background for the ancestor elements.
>
> I think it would be difficult to get the exact equivalent of the current  
> behavior because currently, enable-background can be on the element's  
> parent, grand-parent, or any other ancestor.
>
> Vincent.

That's true, but in practice I think that most files with  
'enable-background' has had that attribute set only on the root svg  
element. That accounts for most of the Illustrator files I've seen anyway.  
Btw does Illustrator always add 'enable-background' there, even when it's  
not used by any filters?

-- 
Erik Dahlstrom, Core Technology Developer, Opera Software
Co-Chair, W3C SVG Working Group
Personal blog: http://my.opera.com/macdev_ed