Re: [css-ruby] What does it mean for "ruby-position: inter-character" to force writing-mode to be vertical?

On 14/12/14 15:29, Koji Ishii wrote:

> On Thu, Dec 11, 2014 at 7:55 AM, Jonathan Kew <jfkthame@gmail.com> wrote:
>> On 10/12/14 22:36, Daniel Holbert wrote:
>>
>>>    (3) Which 'writing-mode' value should we actually use?  There are two
>>> distinct vertical values for the "writing-mode" property: "vertical-rl"
>>> and "vertical-lr" -- which of those should we use here?  (In practice,
>>> maybe it doesn't matter, because elsewhere the spec says "There are no
>>> line breaking opportunities within inter-character annotations", and I
>>> think the "rl" vs. "lr" distinction would only matter if there are
>>> linebreaks. ...
>>
>> IIRC, the distinction is significant even without linebreaks if the
>> 'text-orientation' property is 'sideways': in this case, glyphs are rotated
>> 90° CW in 'vertical-rl' mode, but 90° CCW in 'vertical-lr'.
>
> 'sideways' always rotates CW regardless of 'vertical-rl' or
> 'vertical-lr', because 'over' direction of baseline is on the right
> side, so it doesn't matter either. I can't imagine any cases where it
> matters.

That's not what Writing Modes[1] says:

# sideways
#
#    This value is equivalent to sideways-right in vertical-rl writing
#    mode and equivalent to sideways-left in vertical-lr writing mode.

Given that:

# sideways-left
#
#    In vertical writing modes, this causes text to be set as if in a
#    horizontal layout, but rotated 90° counter-clockwise.

this means that "writing-mode:vertical-lr; text-orientation:sideways" 
results in text that is rotated counter-clockwise.

And then the 'over' direction of sideways-left text (and therefore of 
'text-orientation:sideways' text in 'writing-mode:vertical-lr') is on 
the left.[2]

JK


[1] http://www.w3.org/TR/css3-writing-modes/#text-orientation
[2] http://www.w3.org/TR/css3-writing-modes/#logical-to-physical

Received on Sunday, 14 December 2014 17:56:03 UTC