From: fantasai (fantasai.lists@inkedblade.net)
Date: Wed May 18 2011 - 01:37:03 CDT
On 05/17/2011 03:10 PM, Ken Whistler wrote:
> On 5/17/2011 1:04 PM, fantasai wrote:
>> I'm looking for this information in order to complete this appendix:
>> http://dev.w3.org/csswg/css3-writing-modes/#script-orientations
>>
> Well, that is part of the conceptual problem we are having here, then.
> That draft appendix refers to the concept of "vertical scripts in Unicode 6.0"
> as if that concept were actually defined normatively in Unicode 6.0,
> and the problem is merely acquiring the precise listing somehow.
> But Unicode 6.0 (or any earlier version) does *not* define "vertical scripts".
I've removed "Unicode 6.0" from the table and just left it in the prose.
My intention was to make it clear that the appendix would be incomplete
wrt future versions of Unicode.
> This is handled better in the css3 text by the beginning of Section 5,
> which divides scripts into three types, defined right there:
>
> horizontal-only
> Scripts that have horizontal, but not vertical, native orientation. Includes: Latin, Arabic, Hebrew, Devanagari
> vertical-only
> Scripts that have vertical, but not horizontal, native orientation. Includes: Mongolian, Manchu
> bi-orientational
> Scripts that have both vertical and horizontal native orientation. Includes: Han, Hangul, Japanese Kana
Yes. The intention of the appendix is to add more definitive information
to the definitions, though, not to repeat them. :)
> The vertical-only definition is also o.k., but the exemplars are not. "Manchu" is
> represented (in Unicode) with the Mongolian script -- it is not a separate script,
> but rather a separate language, written with the Mongolian script with some extensions
> not needed for the Mongolian language. Instead, add Phags-Pa, which is
> the other script in Unicode with "vertical-only" orientation as defined here.
Done.
> Appendix B should then have *two* tables. The vertical-only table would
> include only Mongolian and Phags-Pa, both of which would have a rotate
> transform. The bi-orientational table would include Han and all the CJK-influenced
> scripts, all of which would have a translate transform.
Sure, I can split the table. The distinction wouldn't be relevant
for CSS, however, as we're not distinguishing bi-orientational
scripts from vertical-only ones behavior-wise. (UTN22 makes the
distinction, but it handles cases that we're considering to be
out-of-scope for this version.)
> The script value "Hrkt" should be omitted. There are no characters
> with that Script property value in Unicode 6.0 (nor have there ever been,
> in any prior version of the standard).
Ok. I wasn't sure, because Hrkt was listed in the scripts data list:
http://www.unicode.org/Public/UNIDATA/PropertyValueAliases.txt
(Jpan, which is also a combination of scripts, wasn't listed in the Unicode
datafile, so I assumed there was something in Unicode that belonged to Hrkt.)
Anyway, removed.
> And I don't see what the point of including Egyptian hieroglyphics in
> this table is. Yes, Egyptian hieroglyphics are laid out both in horizontal
> (right-to-left or left-to-right) and in vertical directions. But in either case,
> Unicode plain text is not enough.
True that a major component of Egyptian hieroglyphic layout is not defined
by the combination of Unicode and CSS, but I don't see the point of excluding
it from this table. As you say, it's equally underdefined for both horizontal
and vertical text. At the very least, by including them in this table the
individual hieroglyphs can be set upright rather than sideways, which would be,
if I understand correctly, less correct.
tate-chu-yoko, btw, is handled by the 'text-combine' property:
http://dev.w3.org/csswg/css3-writing-modes/#text-combine
On this topic, I've been wondering, how come the ideographic description
characters aren't used to set Egyptian hieroglyphic? They seem at least
as powerful as the MdC notation described in Unicode section 14.18.
> But if it is included in this table, note that Cuneiform also has numerous
> instances of vertical layout.
So, the entry would be
Xsux ; Cuneiform ; rotate
?
~fantasai
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