[XeTeX] Comic Sans and mboxes in xelatex

[Jonathan Kew]

On 13 Oct 2005, at 8:24 pm, nachman wrote:

> Folks,
>
> I use Comic Sans at 24.88pt in XeLaTeX in conjunction with Keynote  
> for math lectures.  I use Comic Sans in math expressions like
>
>     $\vec{\mbox{n}} = (a,b)$ or  ${\stackrel{\longleftrightarrow} 
> {\mbox{AB}}}$
>
> Overlines and underlines are always way too high or to low.  It  
> seems that the mbox for this and similar fonts has a lot of extra  
> vertical space.  Is there a (relatively) simple way to get rid of  
> the space above the letters so that vector smybols, etc., hug the  
> top of the charcters as in plain vanilla LaTeX?


No, not really -- sorry!

The reason is that fonts used directly from the operating system  
don't provide per-glyph height and depth information -- TeX normally  
gets this from .tfm files. All XeTeX knows is the overall "ascent"  
and "descent" of the font, which are typically large enough to leave  
room for ascenders/descenders, accents over capital letters, and  
perhaps a little extra -- depending on the choices made by the font  
designer.

Basically, as mentioned in the (sketchy, I admit!) notes on XeTeX  
that are available, math typesetting still requires TFM-based fonts;  
the precise metric information that's needed simply isn't provided by  
other fonts. You can manually tweak positioning with various TeX  
commands, if you really want to, but the magic that math mode  
performs to make everything automatically look good just isn't going  
to happen.

JK