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Re: Normalizing a 'z' or 'Z' command

From: Andreas Neumann <a.neumann@carto.net>
Date: Thu, 8 May 2008 08:38:11 +0200 (CEST)
Message-ID: <23466.193.246.86.39.1210228691.squirrel@webmail.customers.iirc.at>
To: "public-svg-wg@w3.org" <public-svg-wg@w3.org>

Hi,

I would also vote against normalizing the close (z|Z) case with a lineto
command.

In the spec it says "When a subpath ends in a 'closepath', it differs in
behavior from what happens when "manually" closing a subpath via a
'lineto' command in how 'stroke-linejoin' and 'stroke-linecap' are
implemented." [1]

If we normalize it with a lineto command there could be undesired visual
effects where the stroke-linecap interferes with the stroke-linejoin.
Would be visible with larger stroke-width values.

[1] http://www.w3.org/TR/SVGMobile12/paths.html#PathDataClosePathCommand

> The following two paths are not interpolable[4] if the lineto isn't added
> as a normalization step:
>
>    <path d="M0 0l10 10z"/>
>    <path d="M0 0l10 10l-10 -10z"/>

well - but interpolating two path geometries is already very restrictive
anyway. You'd have to have exactly the same number of vertices and the
same segment types for both paths. An authoring tool could relax this
restrictiveness (I think Dr. Olaf once demonstrated such a tool), or
alternatively, an upcoming SVG 1.2 module could improve the situation in
that it would define rules on how to interpolate two paths that are not
exactly the same.

> I would like the 1.2T spec to define how close commands should be
> normalized.

certainly, yes.

Andreas

-- 
Andreas Neumann
Böschacherstrasse 6, CH-8624 Grüt/Gossau, Switzerland
Email: a.neumann@carto.net, Web:
* http://www.carto.net/ (Carto and SVG resources)
* http://www.carto.net/neumann/ (personal page)
* http://www.svgopen.org/ (SVG Open Conference)
* http://www.geofoto.ch/ (Georeferenced Photos of Switzerland)
Received on Thursday, 8 May 2008 06:38:51 GMT

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