[texhax] xetex: using fonts with missing glyphs

[Uwe Lueck]

"Susan Dittmar" <Susan.Dittmar at gmx.de>, 26.11.2010 13:57:11:
> I just did my first steps with xelatex and immediately ran into a problem.
> I would like to use a font which has only a very sparse set of glyphs. Even
> comma and fullstop are missing.
>
> Is there an easy way to tell xelatex which font to use as fallback for
> missing glyphs? (This is for glyphs that are missing completely, like the
> comma.)
>
> Is there an easy way to tell xelatex on a case-by-case basis which
> glyph (or combination of glyphs) to use for a special missing glyph? (This
> is for glyphs that can be replaced by existing glyphs.)

I even never have tried xelatex at all and may be the wrong one to answer. 

Just curious: How can this happen? What are you doing? 
Does this mean you see a glyph in the editor but it is omitted 
in the .pdf? 

If you have a font to which you want to "fall back," why don't 
you just use that other font?

For combining fonts, there have been virtual fonts, but I still must 
learn this myself, and I wonder whether it really still works with 
XeTeX.

If an extra glyph is rare, it should be possible to call it by a macro 
that simply internally and locally switches to the font containing 
the glyph.

Another solution could be with active characters in the good 
old way, but with unicode the active character is rather something 
like an active byte working like a macro with parameters 
(I guess ...)

Cheers, 

    Uwe.