[XeTeX] on fontspec 1.10

[Ralf Stubner]

Pablo Rodríguez <oinos at web.de> writes:

> After paging through fontspec.pdf, I wonder whether there is a method to
> switch a feature (such as UppercaseSmallCaps) without having to mention
> the font. This would be very useful to switch fonts in documents only once.
>
> I have used UppercaseSmallCaps with GFS Didot (the roman font) for
> headers in a document, but for some strange reason, fontspec gives the
> following messages:
>
> Package fontspec Warning: OpenType feature 'Letters=UppercaseSmallCaps'
> (+c2sc) not available in font "GFSDidot-Bold" at 8.0pt, script 'Latin',
> language 'Default' on input line 178.

I have run into a similar problem with a font I am currently developing,
which (like GFS Didot) has small caps only for the regular shape. I
tried to avoid this by changing

\newfontinstance\spacedsc[LetterSpace=5.0,%
                          Letters=SmallCaps,%
                          Letters=UppercaseSmallCaps]{FPL Neu}

to 

\newcommand\spacedsc{\addfontfeature{LetterSpace=5.0,%
                          Letters=SmallCaps,%
                          Letters=UppercaseSmallCaps}}

However, that only shifted the warnings to other places. Fortunately,
fontspec.sty provides the 'quiet' option which supresses such warnings.
One might miss useful warnings that way, though. Hence I take this as a
hint to design small caps for the other shapes ... ;-)

cheerio
ralf