W3C home > Mailing lists > Public > www-international@w3.org > January to March 2012

Re: Shaping characters in upright orientation in vertical text flow

From: Martin J. Dürst <duerst@it.aoyama.ac.jp>
Date: Tue, 17 Jan 2012 14:16:38 +0900
Message-ID: <4F150436.7080106@it.aoyama.ac.jp>
To: Koji Ishii <kojiishi@gluesoft.co.jp>
CC: "public-i18n-bidi@w3.org" <public-i18n-bidi@w3.org>, "'WWW International' (www-international@w3.org)" <www-international@w3.org>, John Daggett <jdaggett@mozilla.com>
I think for Latin and similar scripts, it makes a lot of sense to have a 
setting where the characters are upright. There may be some character 
combinations (a possible example may be ij in Dutch) which would be 
written as one unit in this case. Similar rules may apply to Indic and 
South-East Asian grapheme clusters, and of course all combining 
characters go with the base character as a single unit.

The main question then is for fully cursive scripts such as Arabic. For 
this, I think that fantasai is in a much better position to judge what 
makes sense than others.

Regards,    Martin.

On 2012/01/17 13:22, Koji Ishii wrote:
> Hello, I've got an item that I need your help.
>
> CSS Writing Modes Level 3 has the "text-orientation" property[1]. 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 flow[2].
>
> 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"[1] (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[3]:
>> 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 advance.
>
> [1] http://dev.w3.org/csswg/css3-writing-modes/#text-orientation
> [2] http://lists.w3.org/Archives/Public/www-archive/2012Jan/att-0010/upright-excel.png
> [3] http://lists.w3.org/Archives/Public/www-style/2012Jan/0655.html
>
> Regards,
> Koji
>
>
Received on Tuesday, 17 January 2012 05:17:46 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Tuesday, 17 January 2012 05:17:46 GMT