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[csswg-drafts] Error in prose describing order of multiple transform function

From: Simon Fraser via GitHub <sysbot+gh@w3.org>
Date: Fri, 13 Jan 2017 17:36:56 +0000
To: public-css-archive@w3.org
Message-ID: <issues.opened-200686064-1484329014-sysbot+gh@w3.org>
smfr has just created a new issue for 
https://github.com/w3c/csswg-drafts:

== Error in prose describing order of multiple transform function ==
https://www.w3.org/Bugs/Public/show_bug.cgi?id=29110:

http://www.w3.org/TR/2013/WD-css-transforms-1-20131126/#transform-rendering
states in Example 4:


|  transform: translate(80px, 80px) scale(1.5, 1.5) rotate(45deg);
| }
|
| This transform moves the element by 80 pixels in both the X and Y 
directions,
| then scales the element by 150%, then rotates it 45° clockwise about
 the Z axis. 

This is technically incorrect. It should read

"This transform rotates the element 45° clockwise about the Z axis, 
then scales the element by 150%, then moves it by 80 pixels in both 
the X and Y directions."

And further:

| Note that the scale and rotation operate about the center of the 
element,
| since the element has the default transform-origin of 50% 50%.

This is very misleading in this context, since it implies that the 
translation affects the transform-origin too, which it doesn't.

Similar issue in 
http://www.w3.org/TR/2013/WD-css-transforms-1-20131126/#transform-function-lists
 :
| [...] a nested set of transforms is equivalent to a single list of 
transform functions,
| applied from the outside in.

I'm not sure what that even means. Would "applied from the inside out"
 be more appropriate?
Mathematically, we're talking about the fact that for all x, we have 
(f o g)(x) == f(g(x)). Now, are we applying f and g "from the inside 
out" or "from the outside in"? Or is there a better way to put it? I 
feel like there should be.

Please view or discuss this issue at 
https://github.com/w3c/csswg-drafts/issues/909 using your GitHub 
account
Received on Friday, 13 January 2017 17:37:04 UTC

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