Martin> Mark - What you are assuming is that either the
Martin> line-wrapping is known beforehand (fixed formatting), or
Martin> when formatting for viewing, you have separate linebreaking
Martin> and one-line bidi machinery, and you are interested in how
Martin> to tell the one-line bidi machinery where to change
Martin> directions. Then your proposal works nicely, and may be a
Martin> good solution to implement bustrophedon.
Martin> But what I and John were speaking about is whether there is
Martin> a way to put directional controls into a plain text so that
Martin> it displays bustrophedon on all possible linebreaks (there
Martin> obviously isn't), and whether this is needed for plain text.
Assuming that you mean line wrapping when you say line breaking, the
implementation I was obliquely referring to does indeed work for all
possible line breaking points without the need for any explicit
directional controls except the user's choice of primary direction for
that script.
If your reordering/presentation algorithms are done right, there is no
need for explicit directional controls to implement boustrophedon
support. Special directionality effects within the usual boustrophedon
ordering can of course be done using the existing complement of explicit
directionality controls. If your algorithms are done right, that is :-)
------------------------------------------------------------------------
UAT (Unicode Aptitude Test) 2.?
1111. For plain text, you need at least one of the following to handle
boustrophedon. Which one presents the fewest potential problems?
A. Higher-level language markup.
B. Depend on the character code ranges of scripts known to use
boustrophedon.
C. Implement boustrophedon using existing directionality codes.
D. Add special formatting characters to signal boustrophedon.
------------------------------------------------------------------------
mleisher@crl.nmsu.edu
Mark Leisher "A designer knows he has achieved perfection
Computing Research Lab not when there is nothing left to add, but
New Mexico State University when there is nothing left to take away."
Box 30001, Dept. 3CRL -- Antoine de Saint-Exupéry
Las Cruces, NM 88003
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