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[whatwg] [WebApps] canvas transform()/setTransform()

From: 黒澤剛志 <taken.spc@gmail.com>
Date: Thu, 28 Dec 2006 11:02:05 +0900
Message-ID: <646543300612271802g56908cc6m6b7ef39fdbca3666@mail.gmail.com>
Dear WHATWG,

Web Application 1.0 adds the transform() and the setTransform() to the
canvas 2d context.
The conversion of the arguments of these methods to the matrices is
described in the section 3.14.6.1.2.

> The transform(m11, m12, m21, m22, dx, dy) method must multiply the current transformation matrix with the matrix described by:
> m11  m12  dx
> m21  m22  dy
> 0     0     1
>
> The setTransform(m11, m12, m21, m22, dx, dy) method...
- http://www.whatwg.org/specs/web-apps/current-work/#transform

However, this is repugnant. And it isn't compatible with many graphics
systems. So the matrix should be

m11  m21  dx
m12  m22  dy ... (b)
0     0     1

In addtion, the rhino-canvas implements both methods. It uses the matrix (b).
http://rhino-canvas.sourceforge.net/

regards.
-- 
KUROSAWA, Takeshi - http://taken.s101.xrea.com/
Received on Wednesday, 27 December 2006 18:02:05 UTC

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