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SVG text flip-invariance

From: R. Timothy Edwards <tim.edwards@multigig.com>
Date: Mon, 06 Jul 2009 17:08:03 -0400
Message-id: <4A5267B3.70903@multigig.com>
To: www-svg@w3.org
I have been looking at SVG as an alternate output format for xcircuit,
as there has been some interest in using xcircuit to generate output
that is more compatible with other systems (the primary output format
is PostScript).

I am presently attempting to determine if it is possible to generate
SVG output without flattening the hierarchy of objects in xcircuit.
I have been able to hack in the use of parameterized properties of
drawing elements using the scripts in the primer for the SVG 2.0
specification.  Which is not nearly as good as having parameters
defined natively, but it's a start.

I got stumped looking for a way to specify flip-invariant text.  This
appears to be an oversight in the SVG definition.  If I define a symbol
or other re-usable object containing text, and then use that object
with the transform "scale=(-1,1)", then the text will render backwards.
There should be a way to declare text to always read in the declared
orientation (e.g., left-to-right).  The correct way to do this is to
compute the bounding box of the text based on the text scale, rotation,
justification, etc., using the innermost transformation matrix, then
flip and rotate the text within that bounding box such that it is
rendered left-to-right and has an angle of -90 to 90 degrees.

Is such a thing possible?  Can it be hacked in with scripts?  Is it
being considered for future definitions of SVG?


| Dr. R. Timothy Edwards (Tim)   | email: tim.edwards@multigig.com     |
| MultiGiG, Inc.                 | web:   http://www.multigig.com      |
| 100 Enterprise Way, Suite A-3  | phone: (831) 621-3283               |
| Scotts Valley, CA 95066        | cell:  (240) 401-0616               |
Received on Tuesday, 7 July 2009 09:07:59 UTC

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