[XeTeX] Charis SIL glyph variants

[Jonathan Kew]

On 17 Nov 2008, at 19:10, Benct Philip Jonsson wrote:

> Is it possible to select the different glyph
> variants in Charis SIL with commands or do I
> have to hack the font itself?  Specifically
> I need to use the capital Eng with hook at
> the baseline, but only in some documents.
> I'm on Ubuntu, in case that matters.

You can do this by loading Charis SIL with the Graphite rendering  
option, which allows you to access the optional features (as mentioned  
in the documentation at http://scripts.sil.org/cms/scripts/page.php?site_id=nrsi&item_id=CharisSIL_Technical#14f962c7 
, although I just noticed that some feature names may not be quite  
accurate there).

%%%%%% test file %%%%%%%
\font\x="Charis SIL" at 12pt
\font\y="Charis SIL/GR:Uppercase Eng alternates=Large eng on baseline"  
at 12pt

\x This is Charis with the default capital Eng, Ŋ.

\y This is Charis with an alternate capital Eng, Ŋ.

\end
%%%%%% end %%%%%%%

Although both capital Eng characters in the source are simply U+014A,  
they will render with different glyphs because of the optional feature  
applied in the second font definition.

**WARNING**

Unfortunately, it turns out that a bug in xetex 0.999.6 (and earlier)  
means that it will go into an infinite loop if you try this, but if  
you can build 0.999.7 from the source in Subversion (from either the  
xetex or texlive repositories), it should work.


JK