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Re: Request for clearer specification regarding relative curved paths

From: Chris Lilley <chris@w3.org>
Date: Tue, 19 Aug 2003 16:15:04 +0200
Message-ID: <5854312250.20030819161504@w3.org>
To: George Williams <gww@silcom.com>
Cc: www-svg@w3.org

On Tuesday, August 19, 2003, 2:08:08 AM, George wrote:

GW> The SVG 1.1 specification does not say exactly how "relative" should be
GW> interpreted in specifying curved splines.
GW>    M x0 y0 c x1 y1 x2 y2 x3 y3

GW> I have been used to reading PostScript Type1 fonts and I mistakenly
GW> assumed this corresponded to
GW>    M x0 y0 C x1+x0 y1+y0 x2+x1+x0 y2+y1+y0 x3+x2+x1+x0 y3+y2+y1+y0
GW> (the type1 rrcurveto operator where each point is relative to the
GW> previous point rather than having them all relative to the initial
GW> point.

GW> If you could add a statement to the effect that all points are relative
GW> to the initial point it would make the lives of people like me easier
GW> :-)

Yes, we can certainly add that clarification. It seemed obvious at the
time but as you correctly point out, there are other possible
interpretations that are equally obvious to different communities.

All path command can have a 'current point' and end up by creating a
new 'current point' for the next command in the path, which is why our
formulation of elliptical arcs is so weird.

GW> Thanks,
GW> George Williams

GW> PfaEdit  http://pfaedit.sf.net/

Might PFA Edit grow intoa tool for directly creating SVG fonts?

 Chris                            mailto:chris@w3.org
Received on Friday, 22 August 2003 15:54:58 UTC

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