Re: [filters] notes to CSS filters

Am 23.09.2011 um 01:51 schrieb Robert O'Callahan:

> On Thu, Sep 22, 2011 at 10:15 PM, Dirk Schulze <vbs85@gmx.de> wrote:
> For the current CSS shorthand filter effects it is quite easy to omit filter regions. The implementations can calculate the boundaries
> themselves. What is the status on the SVG part? Do we find a way to limit the filter region size automatically?
> 
> Yes.
>  
> Right now one of the filter effects that can have unlimited size is lightning (same for feTurbulence IIRC).
> However, Firefox limits the size of a lighting effect automatically! You'll see that if you compare the example [3] between Firefox and Chrome/Opera. The size of the filter result on Firefox is smaller. Even if it is a bug in Firefox at the moment, we could add a rule to the filter specification that would specify this behavior. Once we've done that, we can omit filterRegions (or make it optional) and don't need to auto clip to (-10%, -10%, 120%, 120%) anymore.
> (Firefox takes the size of the previous filter effect and uses the same size for the lighting effect if no subregion was specified).
> 
> That's a bug. Maybe we don't need to do anything in the spec; if primitive regions are not specified the unbounded primitives can just fill the entire visible (clipped) area.
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?

Dirk