W3C home > Mailing lists > Public > www-svg@w3.org > December 2004

Re: SVG 1.1 Spec Rec - 7.6 The Transform Attribute

From: Chris Lilley <chris@w3.org>
Date: Thu, 23 Dec 2004 11:42:40 +0100
Message-ID: <1736288516.20041223114240@w3.org>
To: pegan@gresham-forms.co.uk
Cc: www-svg@w3.org

On Thursday, December 16, 2004, 6:16:48 PM, pegan wrote:

pgfcu> Hi SVG  WG,
pgfcu>  
pgfcu> According to 1.1  spec :-
pgfcu> "The value of the transform attribute is a
pgfcu> <transform-list>,  which is defined as a list of transform
pgfcu> definitions, which are applied in the  order provided".
pgfcu>  
pgfcu> The transform definitions seem to be applied in the
pgfcu> reverse order to the provided order (ie. right to left) in ASV6 
pgfcu> and Batik. 

Yes, they are. To understand why that is correct, you need to look into
matrix math a little, in particular to understand the terms premultiply
and postmultiply. I suggest having a look at a computer graphics primer
on geometry, (just the first chapter), which I wrote a while ago:

http://www.ii.uib.no/undervisning/kurs/v01/i291/i291/geom_sn.pdf

-- 
 Chris Lilley                    mailto:chris@w3.org
 Chair, W3C SVG Working Group
 Member, W3C Technical Architecture Group
Received on Thursday, 23 December 2004 10:42:41 GMT

This archive was generated by hypermail 2.3.1 : Friday, 8 March 2013 15:54:29 GMT