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Re: Circular paths

From: Dirk Schulze <vbs85@gmx.de>
Date: Tue, 4 Jan 2011 21:53:13 +0100
Cc: www-svg@w3.org
Message-Id: <2AD863D0-B948-416C-9616-DB163355B4F2@gmx.de>
To: Cameron McCormack <cam@mcc.id.au>

> Dirk Schulze:
>> That reminds me, that it would be great to have rules how to normalize
>> an arc :-)
> 
> What kind of rules do you want to see?  Just that arcs are normalized to,
> say, 1 or more cubic Béziers?  Or a specific number of them?
If you want to have consistent behavior between viewers a minimum should be the number ob cubic Béziers (I think we all agree that cubic Béziers are the best solution for normalization, but even that is not specified). Depending on the arc, one to three cubic Béziers are necessary to normalize an arc (see older comments on the list). How many degree of the ellipse should be covered by every curve?

We need some kind of algorithm in the specification. We already have an algorithm on WebKit that normalizes an arc for drawing it to a surface. While the behavior matches the behavior of Opera most of the time, we have examples where is doesn't (number of segements are different). And this will cause different normalized pathSegLists between viewers.

Dirk
Received on Tuesday, 4 January 2011 20:54:08 GMT

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