RE: [opendocument-users] svg:d issues

["Jon Ferraiolo" <jonf@adobe.com>]

(SVG expert speaking up)

I don't understand "no mixtures of open and closed curves for one
shape". SVG path data is built on a notion of subpaths, where each
subpath begins with a "moveto" command (for pen plotter fans, lift the
pen up). Perhaps this wording means that ODF only supports a single
subpath within its path data.

Regardless of what the above quoted phrase was intended to convey, it
goes against interoperability goals to include optional features.

I agree that elliptical arcs can be approximated easily via cubic
beziers, but I also think it is reasonable to exclude them. One the Full
profile of SVG supports elliptical arcs; the Tiny and Basic profiles do
not. (http://www.w3.org/TR/SVGMobile/#sec-shapes)

Jon Ferraiolo
Adobe Systems, Inc.
Editor SVG 1.0

-----Original Message-----
From: Chris Nokleberg [mailto:chris@sixlegs.com] 
Sent: Friday, January 20, 2006 1:44 PM
To: opendocument-users@lists.oasis-open.org
Subject: [opendocument-users] svg:d issues

The OpenDocument spec for svg:d says:

  "Some implementations may only supports a subset of the SVG path
   specification, for instance no mixtures of open and closed curves for
   one shape, or no elliptical arc command."

From a document generator's perspective, the only possible takeaway from
this is "don't use svg:d if you want your document to be portable".

I realize that OpenOffice does not support the elliptical arc command,
but that should have been dealt with simply by opening a bug in
OpenOffice, rather than building a loophole into the specification. 
Given that elliptical arcs are easily approximated using cubic beziers,
it's not even clear why the bug would be hard to fix.

Alternatively, the spec could forbid the use of the elliptical arc
command.  Regardless, I don't think that the current situation is
tenable.

Thanks,
Chris


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