[XeTeX] Latin Modern, from TFM to Unicode

[Arthur Reutenauer]

	Hi Doug,

  In addition to the answers that have already been made, I wish to
stress one point:

>                                           Since there's no mapping from 
> Unicode, then the outside process either needs to know the absolute glyph 
> IDs inside the font, or it needs to cause the font to go into some 
> internal construction mode, like building a ligature, where the font 
> itself knows the sequence and position of the glyphs to use to construct 
> the tall symbol.  The latter seems impossible, because the font can't 
> know the threshold height at which to stop construction.

  Actually it can, and should.  A correctly implemented OpenType shaping
engine would then use that information to build the final glyph.
Unicode and other text encodings are irrelevant here, since all that
construction is purely internal to OpenType, including the glyph IDs.

>                                                           The former 
> means hard coding internal glyph IDs somewhere outside the font, which 
> I'm hoping is not fragile, but worrying might be.

  It is fragile.  Don't do it.

  As Khaled already said, it really sounds like what you need is simply
to convert lmex10, and the other fonts you're using, to TrueType format.
You'll then have a straightforward way to access the glyphs you need,
since they'll have the same position as in the Metafont versions.  Latin
Modern Math, on the other hand, provides something different: it aims at
enabling full OpenType layout, not just to be a clone of TeX's
traditional maths fonts in a different format.

	Arthur