W3C home > Mailing lists > Public > www-svg@w3.org > January 2011

Why the positiveness constraint in width and height parameters of the viewBox attribute?

From: <giampaolo@tomassoni.biz>
Date: Thu, 20 Jan 2011 22:08:49 +0100
Message-ID: <22769b6826357bc9681b4697d3503b24.squirrel@webmail.tomassoni.biz>
To: www-svg@w3.org
Hi,

I can't get why the 22 June 2010's SVG Working Draft do states the following:

"A negative value for <width> or <height> is an error (see Error
processing)."

(see http://www.w3.org/TR/SVG11/coords.html#ViewBoxAttribute, third
pharagraph).

Having a negative <height> value may be an invaluably simple way to map a
classic cartesian coordinate system into the SVG standard one.

I can't see any reason why forbid this. Besides, the resulting
transformation matrix is generally invertible. The only way one can get a
singular matrix is setting <width> and/or <height> to 0, which is covered
anyway by the SVG draft (no rendering of the drawing).

Regards,

Giampaolo
Received on Thursday, 20 January 2011 21:41:27 GMT

This archive was generated by hypermail 2.3.1 : Friday, 8 March 2013 15:54:47 GMT