I think we are talking at cross purposes here. You are talking about the direction of successive lines. I was thinking of the direction of characters. That is what I thought the original question was about, and it is certainly what most of the ongoing discussion has been about.It seems strangely inconsistent to me that Unicode has detailed controls
for horizontal layout direction and the complex bidi algorithm, but has
nothing for vertical layout. I can force Latin text to be rendered right
to left or Hebrew left to right (although such overrides are hardly
plain text issues), but there is no way I can select vertical layout
even for languages in which that is a normal way of writing. We already
have U+202A LEFT-TO-RIGHT EMBEDDING and U+202B RIGHT-TO-LEFT EMBEDDING.
It would be easy to define new characters TOP-TO-BOTTOM EMBEDDING and
BOTTOM-TO-TOP EMBEDDING, with similar scope until the next PDF
character.
Which scripts are written bottom to top in vertical layout?
If I remember well then both latin and hebrew script are written top to bottom.
.
I don't know of any scripts in which the ordering of lines is bottom to top. But in scripts in which the character direction is top to bottom the column direction may be right to left (e.g. Chinese) or left to right (e.g. Mongolian).
-- Peter Kirk [EMAIL PROTECTED] (personal) [EMAIL PROTECTED] (work) http://www.qaya.org/
