[lltx] LuaLaTeX and the unicode-math package

[Khaled Hosny]

On Wed, May 23, 2012 at 08:48:41PM +0200, Andrea del Monaco wrote:
> 
>     May be it would be simpler if you told us what you are trying to achieve
>     here, using a regular font for math is just asking for trouble, there
>     are too many issues you need to work around before you get decent
>     output.
> 
> and why is that? and more important, which troubles?
> anyways, I just want to use some regular font to replace the latin alphabet,
> for example.

Because math typesetting is not a simple business, even the most
innocent expressions might turn not to be simple at all. On top of may
head, you will get 1) wrong accent placement 2) no italic correction 3)
wrong sub/superscript placement, and we are not even talking about using
it for non-alphabetic symbols.

You can write some heuristics to guess italic correction, try to fix
accent placement etc. but then modifying the font using a specialised
font editor would be much easier. In either case, you have to reasearch
the OpenType math stuff on your own, there is just too much things to
discuss over email. Or you can just accept the limitations and live with
it.

> I won't touch symbols and operators, I'll just keep them the way they are, of
> course.
> 
> 
> 
>     >     Anyway,
>     >     the default is to center the accent on the glyph box, are you getting
>     >     something different?
>     >
>     >  yep: the accents aren't on the center.
>     > Sometimes they aren't even "on" the glyph, but totally outside of it.
> 
>     An example file would help.
> 
>  
> I'm sending you a pdf file.
> As you can see, kerning is not adjusted properly when passing from one shape to
> another.

The accent issue might be fixed in next luatex, not exactly sure. The
italic correction might be related to this:
http://tex.stackexchange.com/questions/31438/how-can-i-enable-italic-correction-for-luatex

No idea about the wrong superscript placement, this shouldn't happen
with XITS Math.

Regards,
 Khaled