Re: Margins for filters?

On Sun, Apr 18, 2010 at 10:43 PM, Dirk Schulze <vbs85@gmx.de> wrote:

> > I think it's entirely possible that changing the spec would fix more
> > content than it breaks :-).
> Indeed. But we can't talk about downward compatibility of SVG 2.0, SVG
> Fitler 1.2 and change the complete concept of drawing and calculating a
> filter.
>

Yes. I think we should change SVG 1.1.

Specifically, I suggest we change the definition of the filter effects
region so that we no longer clip to it. The filter effects region becomes
completely irrelevant and we can remove it. I suggest we continue to allow
filter primitive subregions to clip filter primitives, but that we make the
default filter primitive subregion (for all filter primitives) be infinite
so no clipping is performed. Remove all mention of "intermediate
offscreens".

We could redefine 'filterRes' to specify the maximum size of the
implementation's temporary buffers, but it's probably better to drop it from
the spec entirely. I don't think authors can pick a specific filterRes that
will be optimal across a wide variety of devices and implementations.

I think these changes are more likely to help than hurt existing content,
would make life much easier for authors going forward, and would eventually
even make implementation easier.

To the current margin concept in the draft: It's my opinion, that just
> adding an extra unit system and more attributes (mx, my ...) will be
> much more confusing for the user. It's a bad choice to rescue the
> current filterRegion concept.
>

I agree.

Rob
-- 
"He was pierced for our transgressions, he was crushed for our iniquities;
the punishment that brought us peace was upon him, and by his wounds we are
healed. We all, like sheep, have gone astray, each of us has turned to his
own way; and the LORD has laid on him the iniquity of us all." [Isaiah
53:5-6]