At 02:47 -0500 2001-12-29, [EMAIL PROTECTED] wrote:
>Actually, there is a more serious problem involved with vertical directional
>overrides: They would force the Unicode plain-text mechanism to become aware
>of both vertical directionality and directional priority. This sounds
>obvious, but in fact there are not two, but THREE issues involved with text
>directionality:
>
>1. Horizontal, that is, left-to-right (LTR) versus right-to-left (RTL).
>2. Vertical, that is, top-to-bottom (TTB) versus bottom-to-top (BTT).
>3. Priority of direction (e.g. (LTR, TTB) versus (TTB, LTR)).
There are more complex aspects of layout that might apply to Egyptian
and Mayan.
> Ogham is either (LTR, TTB) or (BTT, ???).
When written in manuscripts and on computers, Ogham is written as
Latin is. When inscribed on stone, it is written bottom-to-top, along
the top of the stone, and then down to the bottom on the other side.
I don't believe that there are any examples of multiple-line Ogham
lapidary text. By analogy with the manuscript tradition, I would
recommend (BTT, LTR) for Ogham vertical columnar display.
>Unicode characters have a default directionality, but both this and the
>override mechanism cover only the horizontal aspect, not the vertical aspect
>or the priority of one over the other. Thus, Mongolian characters are
>assigned the same directionality code as Latin ("L") even though the TTB
>directionality takes precedence over the LTR, the opposite of Latin.
Not in mixed Latin/Mongolian text. Mongolians do interesting things
too with Latin words in predominantly Mongolan text. But it seems
that the whole thing is done by rotating the whole text field.
>And there is no plain-text way to indicate the alternative directionality of
>Ogham or Han.
I think it is a question of DTP layout for Ogham, at least.
--
Michael Everson *** Everson Typography *** http://www.evertype.com
