[XeTeX] fontspec v1.7

Peter Dyballa Peter_Dyballa at Web.DE
Tue Jun 28 11:10:04 CEST 2005

Am 27.06.2005 um 02:27 schrieb Ross Moore:

> It does raise some interesting points though.
> e.g.
> For a math-bold letter 'a' the CMap for its font
> ought to have an association:
>                  <61>  <D835DC82>
> But is the PDF world ready for this yet ?
> Alternatively, if XeTeX were to insert  \char"D835\char"DC82
> for this math-bold 'a', then maybe the reverse association
> should be included:
>                  <D835DC82>  <61>
> Would this make the math-character findable as if an ordinary 'a' ?
> What about greek, used as math-symbols ?
> Would the following CMap association:
>    <03B1>  <005C0061006C007000680061>
> allow an 'alpha' glyph to be found by searching for  '\alpha' ?
> Or maybe we are using an italic alpha directly:
>    <D835DEFC>  <005C0061006C007000680061>

Hello Ross!

I think an OML.cmap (or OMS.cmap) should use as entry points the values 
of the letters from the alphabet. That's closest to what we actually 
type (and therefore think of). The Greek α (and math symbols) start to 
become a bit complicated in another way, IMO: how to put them? UCS-2 as 
in <0381> or UTF-8 (CE B1)? When copying such 'text', another area 
where cmap.sty is helpful in removing the extra glyphs from TeX and 
correcting the remainders, what is returned then to make use of that 

I think the contents of OML.cmap would be rather

	<03B1>  <005C0061006C007000680061>

than in a retro-style (the code handles the way back. i.e. when pasting 
the copy into somewhere). In the case of ``a´´ another mapping would be 

	<1D44E>  <005C0061006C007000680061>

the Mathematical Alphanumeric Symbols from the Supplementary 
Multilingual Plane (SMP). Here I've chosen the mapping for an italic a, 
there are bold, italic, bold-italic, script, bold script, Fraktur, bold 
Fraktur, double-struck, sans-serif, bold sans-serif, italic sans-serif, 
bold-italic sans-serif, monospace, bold Greek, italic Greek, 
bold-italic Greek, bold sans-serif Greek, bold-italic sans-serif Greek 
(both uppercase and lowercase), and of course bold, double-struck, 
sans-serif, and monospace digits!

How is XeTeX handling these different mathematical alphabets? Is the 
coding stable? And what other application would make a difference too, 
would keep the different properties of an ``a´´ character?

There is work for some years laying around ... (James Kass' Code2001, a 
vast TrueType font, has them already, although not really pretty)



Chicago, n.:
         Where the dead still vote ... early and often!

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