RE: CSS3 Text: Multi-Directional Scripts in Vertical Inline Progression

Fantasai, overall I think your conclusions are correct, even if I don't
agree with all your arguments. Some of my issues:

The'direction' property today (ie in horizontal flow as supported by
CSS2) sets inline progression for block element (CSS2 says 'specifies
the base writing direction of blocks') and MAY set directionality.
However, typically it does not set character directionality (this is
done through the bidi algorithm and the usage of the 'unicode-bidi'

I read the determination of the inline progression as setting the
starting edge of the line box.

We could possibly say that 'direction' doesn't set inline-progression
for vertical layout, but that would be terribly ackward.

Your proposal (text-orientation-vertical/horizontal +
glyph-orientation-vertical/horizontal) is comprehensive but fairly
complex. I am still not convinced that these 2 concepts should not be
merged. And I am not convinced that we need to support all possible

I think we agree more or less on the behavior expressed by
'text-orientation-xxx: natural' and 'glyph-orientation-xx:auto' which
are their initial values. It is interesting to note that for these
values, the 'direction' property is w/o any doubt tightly correlated
with the inline-progression.

I would propose for the time being to remove glyph-orientation-xxx
properties from the CSS3 text WD and not add the 'text-orientation-xxx'
properties. And just have 'block-progression', 'direction' and
'writing-mode' (as a shorthand for the 2 other properties). I could
myself have 'lived' with the current definition of
'glyph-orientation-xxx' even if there are some values that don't make
much sense for some bidi situations (because of reordering or lackof).
But I also agree that text-orientation is more elegant in that respect.

We could always spend more time in refining the details of vertical
layout but make progress on the bulk of the text module.


Received on Friday, 18 April 2003 21:46:17 UTC