On 12/05/2012 09:49 AM, Joseph Wright wrote:
On 04/12/2012 12:58, Taco Hoekwater wrote:
There is (of course) much more detail than this, but that is the overview.
Two follow-on questions :-)
First, I see that there are five primitives doing the work here:
\textdir, \mathdir, \pardir, \bodydir and \pagedir. The first two are
easy enough to understand, and I think I get \pardir (flips where the
\indent and so forth are). However, I'm not really clear on \bodydir and
\pagedir: anyone got a good explanation?
Quoting myself from an older message:
Taco wrote:
Roughly put, but I think fairly accurate, is that \bodydir is the
'box direction' of \box255, and \pagedir is the initial location of
the placement origin point on the paper. These have to line up if your
macro page is not shifting \box255 itself.
They are a bit odd in the sense that realistically both of them
are needed once (and exactly once) right at the start of a document,
and that both should have the same value: if they do not agree, text
will normally end up outside of the paper unless the macro package
intervenes explicitly.
Secondly, I'm a bit unsure about the detail on \mathdir when it comes to
numerals. From what I understand, numbers read in decreasing magnitude
left-to-right in both LTR and RTL languages, so for example pi is always
3.1415...
and never
...5141.3
even when using (real) Arabic numerals rather than the 'arabic' ones of
the European tradition. However, \mathdir flips everything: is that
correct, and if so is the expectation that numerals in math mode are
handled using a Lua callback?
A total lack of feedback from an actual knowledgeable person means that
\mathdir does exactly what Aleph did. I *also* suspect it is wrong, but
I am not going to mess with it without a person at hand who can tell me
exactly what *should* happen.
Best wishes,
Taco
