Add an illustration of pinyin for ruby align

[r12a]

10.2.34 tts:rubyAlign
http://w3c.github.io/ttml2/spec/ttml2.html#style-attribute-rubyAlign

Given the text about glyph area descendants it would be particularly useful to have an illustration of what would be expected in the case of Latin annotations of base text.

For example:
周杰伦(Jay Chou)

[skynavga]

I agree that the current text does not correctly deal with this case, and needs to be recast in terms of a somewhat different criteria that would treat this case as having 2 (not 7) ruby text boxes to be aligned with 3 base text boxes.

[dae-kim]

Can we recommend that Latin annotations should be "center"?

Is there a pinyin version of https://drafts.csswg.org/css-ruby-1/?
What are the rules around overhang, overlap, etc?

When we say "latin", do we mean specifically the standard/half-width variants like U+0041?
Or do we also mean the full-width variants like U+FF21?

[dae-kim]

@r12a @skynavga any opinions on recommending that Latin annotations should be "center"?
Or any insights into technical guidelines around pinyin?

[skynavga]

I think it is not needed, and makes the specification and implementation more complex. As it is, the algorithm works for all scripts; making it script dependent is too complex. If an author wants a different default, then all they need to do is change the default using the element; or if they want to make sure to use center on some ruby, they can merely specify tts:rubyAlign.

My suggestion is to close this issue marking it WORKS FOR ME.

[palemieux]

@skynavga How does this "WORKS FOR ME" in light of your comment #274 (comment)

[r12a]

Is there a pinyin version of https://drafts.csswg.org/css-ruby-1/?

No. The ruby spec is designed to cope with pinyin as well as japanese ruby (which may also involve Latin text annotations).

What are the rules around overhang, overlap, etc?

See https://w3c.github.io/clreq/#positioning_of_romanization. Note that centring is the expected default, but also that a certain amount of gap is needed between adjacent annotations.

The CSS ruby spec also suggests a default of centred text for pinyin (see https://drafts.csswg.org/css-ruby-1/#default-ua-ruby).

When we say "latin", do we mean specifically the standard/half-width variants like U+0041?
Or do we also mean the full-width variants like U+FF21?

I don't think i've ever seen a full width latin character used for ruby (though i wouldn't discount it). Clreq mentions half-width glyphs, but also says that normally (and this is what i usually see) the Latin text is proportionally spaced.

[dae-kim]

@skynavga @r12a
I can add an illustration of pinyin with rubyAlign explicitly set to "center".
Since it is reasonable to assume an author using pinyin has a specific display in mind, I don't see any need to alter the prose.

[r12a]

I see that the default alignment has now been changed in https://w3c.github.io/ttml2/#style-attribute-rubyAlign to center. That means that this example looks fine to me, since we don't need to worry about Nr and Nb counts, and this is what i would have expected to see. Thanks for adding.

However... Since no distinction is made (unlike CSS) between fullwidth and not fullwidth characters in terms of default alignment, the other examples in 10.2.34 tts:ruby are now wrong. They are showing space-around alignment, rather than center alignment.

[cconcolato]

@r12a fixed. Can you approve the PR?

[r12a]

The i18n WG has closed its tracker for this issue. Thank you for your edits.