1. The thing being shaped "upright" should be a grapheme cluster. Note that this may not be a *default* grapheme cluster.
2. Upright should *mean* upright. It may not be a good idea to apply it to, for example, Arabic text, but what's the point of a style if it doesn't do what you ask it too? There may be cases in which, for example, one wants to render even shaping characters upright. For example, if I want a single Arabic character "upright" in an example.
> -----Original Message-----
> From: Koji Ishii [mailto:kojiishi@...]
> Sent: Monday, January 16, 2012 8:23 PM
> To: public-i18n-bidi@... > Cc: 'WWW International' (www-international@...); John Daggett
> Subject: Shaping characters in upright orientation in vertical text flow
> Hello, I've got an item that I need your help.
> CSS Writing Modes Level 3 has the "text-orientation" property. With that,
> you can set glyph orientation in vertical text flow.
> The issue is about how to render shaping characters when "text-orientation:
> upright" is applied. Please scroll down the spec a little bit to see "Figure 12.
> 'text-orientation' values"; "upright" is the one I'm talking about. You see all
> characters including Latin are upright in this style.
> How do you expect shaping characters look in this case?
> Currently, the spec states "Shaping characters from such scripts are shaped in
> their isolated forms." This is primarily from fantasai's investigations.
> Another source to support this behavior is how Excel renders its vertical text
> There're other options such as "always keep them sideways (i.e., rotated by
> 90 degrees.)" This is the behavior usually done by using "text-orientation:
> sideways-right" (see Figure 12 for examples,) but I understand there're
> some scripts that can never be written in upright and therefore renders the
> same way as "sideways-right" even when author applied "upright".
> I personally have no idea which one is the right behavior here.
> John Daggett in his recent mail pointed out that:
> > For 'upright' the spec currently states "Shaping characters from such
> > scripts are shaped in their isolated forms." This means that 'upright'
> > applied to Arabic in vertical text would break the shaping.
> > I'm really not sure that this is the right behavior, I think this
> > behavior is why Microsoft was talking about making an alternate
> > proposal for UTR50.
> Could anyone give us your opinions on this? Thank you for your support in
>  http://dev.w3.org/csswg/css3-writing-modes/#text-orientation >  http://lists.w3.org/Archives/Public/www-archive/2012Jan/att- > 0010/upright-excel.png
>  http://lists.w3.org/Archives/Public/www-style/2012Jan/0655.html >