[XeTeX] optical sizes not found

[Khaled Hosny]

On Tue, Oct 05, 2010 at 10:32:51PM +0200, Roland Kuhn wrote:
>  Hi,
> 
> a few days back I asked about a problem with optical font sizes: for
> me, the correct fonts are not automatically selected. I can rule out
> a fontspec bug, since the problem exists also in plain XeTeX:
> 
> \font\1="Kepler Std" at 9pt\1
> Hallo Welt!
> \font\2="Kepler Std" at 12pt\2
> Hallo Welt!
> \font\3="Kepler Std" at 14pt\3
> Hallo Welt!
> \font\4="Kepler Std" at 24pt\4
> Hallo Welt!
> \end
> 
> This results in a PDF containing only the KeplerStd-Regular font (no
> Capt, Subh or Disp variants). Now I've had the opportunity to test
> this using the same OTF files on a Windows 7 computer with an
> up-to-date TL2010 installation, and the same happens as on my Mac
> (Snow Leopard, same TL2010 revision).
> 
> Could it be that the fonts do not contain some needed hints? (I'm
> using the version from 2003.) How does font selection work on the
> inside?

The font need to have a "size" feature for automatic optical size
selection to work, you can check with otfinfo (part of texlive) if the
font have such feature. If not, then fontspec has options for manually
selecting optical sizes.

Regards,
 Khaled

-- 
 Khaled Hosny
 Arabic localiser and member of Arabeyes.org team
 Free font developer