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Re: Identical rendering? [was Re: SVG 1.2 General feedback]

From: Tobias Reif <tobiasreif@pinkjuice.com>
Date: Thu, 21 Nov 2002 11:04:51 +0100
Message-ID: <3DDCAFC3.6060708@pinkjuice.com>
To: www-svg@w3.org
CC: Vincent Hardy <vincent.hardy@sun.com>

Hi Vincent,

>> [...]
>> Two issues I found with Squiggles rendering quality:
>> http://nagoya.apache.org/bugzilla/show_bug.cgi?id=14673
> This shows that Batik does not do as well with 
> text-rendering=optimizeGeometricPrecision. In Batik, that turns off 
> anti-aliasing and the text does not look as good becauce we do not do 
> hinting. This is a known limitiation.

... of "..."? If it's a limitation of Squiggle, then the bug report is 

>> http://nagoya.apache.org/bugzilla/show_bug.cgi?id=12013
> You point out to several differences between ASV and Batik, but it is 
> unclear to me what is 'right'. For example, the feather is jagged indeed 
> (i.e., the path has lots of control points that do not describe a smooth 
> curve).

I see.

> So I am not convinced Batik is not doing anything bad there.

Me neither; it just doesn't look as pretty, and what's more important, 
shows that different viewers render the SVG differently.

So the issues are not to be dismissed as irrelevant, but are to be 
solved; if not in Batik, then in the spec.
If both viewers conform to the 1.0 spec, then 1.2 needs to be clearer 
and more detailed, so that we get [subj], without the "?".

Perhaps the spec needs to go to go down to the level of anti-aliasing 
etc algorithms etc.

> We 
> do not smooth curves before rendering.

I'm much more interested in a solution than in an explanation :)

I don't know if ASV and CSV do "smoothing", but the text (bash etc) also 
doesn't look as pretty, as I describe.

The curves of the feather are so jagged in Batik, that if that is 
conformant rendering *and* if the rendering behaviour of ASV and CSV are 
also conformant, there is a grey area in the spec where too much 
difference in rendering behaviour is allowed, which results in very 
relevant rendering differences, which means lower quality, less 
predictability, thus less usefulness of SVG itself.

Sorry if I'm drastic this morning, but I want to express that it helps 
SVG if stuff like this gets resolved, in some way.


Received on Thursday, 21 November 2002 05:04:52 UTC

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