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Re: SVG 2 rendering model

From: Leonard Rosenthol <lrosenth@adobe.com>
Date: Thu, 2 Aug 2012 13:08:36 -0700
To: Rik Cabanier <cabanier@adobe.com>, Nikos Andronikos <nikos.andronikos@cisra.canon.com.au>, "public-svg-wg@w3.org" <public-svg-wg@w3.org>
Message-ID: <CC4055AF.2915E%lrosenth@adobe.com>
On 8/2/12 3:34 PM, "Rik Cabanier" <cabanier@adobe.com> wrote:

>Hi Leonard,
>> The problem with making isolated the default is that it will impact
>> performance for all of the normal cases.
>Isolated is faster since you don't have to composite all the group to get
>the background.

But you DO have to create an "offscreen buffer", composite the entire
group into that, and then blit the entire "offscreen" back.   So you're
clearly using more memory and time than simply putting bits into the
existing buffer.

>The compositing spec specifies the order in which filters and compositing
>The filters spec should say if the stacking group it creates is isolated
>or not. I believe people don't want it to be isolated (and can post some
>examples if needed)

But how would you apply a filter to a group that has already been blended
into the background?  The result is certainly going to be different -
which may be good or bad.

I would think that given a group with a filter applied to it, you have to
make that specific group isolated, apply the filter, and only then blend
it to the background.

Received on Thursday, 2 August 2012 20:09:06 UTC

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