Re: [css3-images] processing model for transformations (image() vs. image-orientation)

On Wed, Nov 30, 2011 at 4:03 PM, L. David Baron <dbaron@dbaron.org> wrote:
> There are multiple features in css3-images that can transform an
> image.  For example:
>
> http://dev.w3.org/csswg/css3-images/#image-notation defines the
> 'ltr' and 'rtl' keywords which can cause an image to be flipped
> horizontally.
>
> http://dev.w3.org/csswg/css3-images/#image-orientation defines the
> image-orientation property which can cause an image to be rotated.
>
> It matters which one happens first, since doing them in a different
> order produces different results when image-orientation computes to
> 90deg or 270deg.  css3-images should define a processing model that
> says so.

These two features can't actually be used together.
'image-orientation' applies to "images", which is underdefined but
really means the <img> element. (It should also mean <video> and
<canvas>, I think.)  The image() function is an <image> type.

Though, I guess they could potentially interact once 'content' can
define replaced elements.  In that case, I think 'image-orientation'
should apply *after* the contents have resolved to an image.  I'll add
some text to that effect.

> (It may also be worth clarifying that all of this processing happens
> before CSS transformations.)

I don't think that image() needs this (the two transformations apply
to different things), but 'image-orientation' could use text like
this, yes.

~TJ

Received on Thursday, 1 December 2011 00:23:01 UTC