[lltx] Kerning OTF fonts: 2 other problems

[Heilmann, Till A.]

Am Sun, 27 Feb 2011 18:50:04 +0100 schrieb Ulrike Fischer:

>> Thanks to your help, I am making progress adjusting the kerning of  
>> OpenType fonts. There are still some problems, though ...
>> 1. Curiously, adjusting the kerning does not work for some letter  
>> pairs and I cannot see a pattern here. Adjusting "ei", for example,  
>> works just fine but "ev" does not. I got the same results with two  
>> different fonts (TeX Gyre Bonum and Linux Libertine), so I think it  
>> is not a font issue but a Lua(La)TeX one.
>> 
> 
> I think it is the font. I don't know much about open type fonts and
> features etc, but a look at the kerning information of "e" in
> fontforge seems to indicate that a kern for "ev" and "ew" already
> exists, and I think this kern "wins". 

Okay, I see what you mean (I just checked in FontForge too).

I cannot comment on the technical aspect of this issue but from a "philosophical" standpoint it is somewhat bizarre: What good is a local or user specific feature file that cannot override the standard settings of a font? Is this how OTF features are supposed to (not) work? (I know this is probably not the right place to ask this kind of question.)

Thanks,
-Till