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Re: Margins for filters?

From: Robert O'Callahan <robert@ocallahan.org>
Date: Mon, 19 Apr 2010 09:39:33 +1200
Message-ID: <t2r11e306601004181439nab70b54bxd0486b8be7ce4b7a@mail.gmail.com>
To: Dirk Schulze <vbs85@gmx.de>
Cc: Jasper van de Gronde <th.v.d.gronde@hccnet.nl>, Erik Dahlstrom <ed@opera.com>, www-svg@w3.org
On Mon, Apr 19, 2010 at 8:03 AM, Dirk Schulze <vbs85@gmx.de> wrote:

> I would like to keep filter effect regions to be consistent with masking
> or pattern. The most users know that they clip the results.
>

There aren't many users now, so maybe that's true. However, I'm skeptical
about the long term. Because the default filter region includes 10% margin
on each side, most users using small blurs --- or primitives that don't
extend the image --- will find things just work most of the time. Then
suddenly they'll use a larger blur, find it's getting clipped, and have no
idea what is going on. I've seen this, and it sounds like Jasper has too.
Remember, most users don't read specs, they just copy and paste content or
use tools.

> 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 agree. It's difficult to specify 'filterRes', if you don't know how
> the viewer optimize the effects. This may also depend on the platform
> (smart phone <> desktop).
>

Absolutely. And when some browsers implement SVG filters using the GPU, the
performance differences across browsers and devices will grow by another
order of magnitude.

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]
Received on Sunday, 18 April 2010 21:40:07 GMT

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