[ttml2] Handling non-kana text for rubyAlign with spaceAround or spaceBetween

r12a has just created a new issue for https://github.com/w3c/ttml2:

== Handling non-kana text for rubyAlign with spaceAround or 
spaceBetween ==
10.2.34 tts:rubyAlign
https://www.w3.org/TR/2016/WD-ttml2-20161117/#style-attribute-rubyAlign

> If the value is spaceBetween, then excess whitespace is equally 
distributed between each ruby annotation glyph area. If the value is 
spaceAround, then excess whitespace is equally distributed before and 
after each ruby annotation glyph area descendant.

Note that the [CSS Ruby 
spec](https://www.w3.org/TR/css-ruby-1/#valuedef-ruby-align-ruby-alignspace-between)
  recommends the use of justification rather than just distributing 
space equally.  Both approaches would have the same result for 
ideographic base characters annotated with kana, but not the same if 
they were annotated with say pinyin latin text.

JLReq and CLReq, afaict, expect Latin annotations to be centred, 
rather than to have the letters stretched out.  This isn't accounted 
for here, and i expect it needs to be.

Note, btw, that centred latin text is a justification for the use of 
justification in the CSS spec, however i'm not sure that is completely
 thought out, because if the annotation were two short latin words 
they may be separated rather than centred if justification is applied,
 and i think that the expectation is that they would be still centred.
  (I want to raise this question for CSS, too.)

Please view or discuss this issue at 
https://github.com/w3c/ttml2/issues/251 using your GitHub account

Received on Thursday, 16 February 2017 17:31:39 UTC