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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 12:11:11 +0100
Message-ID: <3DDCBF4F.7070900@pinkjuice.com>
To: www-svg@w3.org
CC: vincent.hardy@sun.com

P.S.

In short:
If the issue with the jagged lines is caused by smoothing done by 
ASV/CSV, and if there is nothing else involved, then a solution might be 
to add something like "Smoothing of paths or curves is not allowed." to 
the spec. Then I could forward to same bug report to Corel and Adobe :)

Then we get more consistent rendering; and if we want smooth paths, we 
can make them as smooth as we want, and have these changes reflected 
cosistently across viewers.

But I'm sure therse are other points of views, and other aspects or 
facts that I'm missing.

Tobi

Tobias Reif wrote:

> 
> 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 
> relevant.
> 
> 
>>> 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.
> 
> 
> Tobi
> 


-- 
http://www.pinkjuice.com/
Received on Thursday, 21 November 2002 06:11:11 GMT

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