At 04:37 PM 8/18/2005, Stephen Deach wrote:
>Mongolian was originally written as RL-TB in an Aramaic-derivative script.
>
>Then the whole page was rotated 90-deg CCW (glyphs and layout are simply
>rotated from the original form). This is essentially its current vertical
>writing form TB-LR.
>
>-- Now comes the wierd part. Small snippets of horizontal text are now
>written LTR with glyphs inverted 180-degrees from the original form.
>
>So yes, it is currently laid out LTR, but it is really written as if it
>was RTL-inverted.
To be more precise, the Sogdian script from which Mongolian is derived has
been rotated 180 degrees so that that script is now upside down. Since most
of the historical use of the Mongolian script seems to be in its vertical
form, the LTR form of Mongolian is only a 90 degree rotation from the
historical usage.
The following is pure conjecture, but I suspect the LTR use of the
Mongolian script came about when Traditional Mongolian Script was included
in Cyrillac Mongolian texts. I certainly have examples of Mongolian texts
that combine both Cyrillac Mongolian and traditional Mongolian in the LTR
from. These texts also show that the Sogdian script has been rotated 180
degrees in the LTR form as noted above.
It is the 180 degree rotation of the script that converted what is a RTL
script to and LTR script just as one would expect from the embeddings of
rotated Roman and Arabic scripts in vertical documents. For example, Arabic
rotated 90 degrees counter clock-wise becomes top to bottom (and when it is
rotated 90 degree clockwise it becomes a bottom to top script).
>At 2005.08.16-04:35(-0400), fantasai wrote:
>>Stephen Deach wrote:
>>>I would like to see your list of languages using RTL scripts.
>>>The only scripts identified as RTL in Unicode are Arabic and Hebrew.
>>>(Then there is the strange case of Mongolian which is marked as LTR but
>>>I think should be treated as "RTL rotated to read top-down".)
>>
>>Mongolian is LTR because when it goes horizontal for brief spans, it is
>>usually LTR. (Probably because most scripts out there are LTR.) Longer
>>texts are always laid out vertically, in which case Mongolian has the
>>same directionality behavior as CJK.
>>
>>~fantasai
>
>
>---Steve Deach
> sdeach@adobe.com
Steve
=====================================
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steve@zilles.org
Received on Friday, 19 August 2005 20:14:57 UTC