[XeTeX] fontspec's ExternalLocation

[Will Robertson]

Hello,

Since re-installing my OS, I'm inclined not to install too many 3rd  
party fonts due to performance limitations (I've only got an 867MHz  
Powerbook at the moment...). As you can imagine, being active in the  
XeTeX world means that I've got a slew of fonts that I don't use much  
except for testing purposes.

Since xdvipdfmx now allows loading fonts by filename rather than  
having to install them in the system, I've set up a folder to contain  
all my fonts; now I can write
   \fontspec[ExternalLocation=/Users/will/Fonts/]{CharisSILR.ttf}
and it's all good.

But I discovered that the natural
   \defaultfontfeatures{ExternalLocation=/Users/will/Fonts/}
   \fontspec{CharisSILR.ttf}
unfortunately doesn't work (but it should). So I'll fix that at some  
stage.

(You'd think this sort of thing would be pretty straight-forward, but  
fontspec actually parses font features in several stages so that you  
don't have to worry about the logical order of features such as  
Renderer, Script, Language, and ExternalLocation. Still not exactly  
sure what's going wrong, though -- I haven't actually looked in my  
code yet!)

While I'm thinking about it, are there other features that people  
could find useful for this mode? I'm thinking it's annoying to  
type .ttf after every font. Any comments on whether I should parse  
the fontname and add a default if there isn't an extension? (The  
default would probably be initially .ttf but obviously could be  
customised.)

Do people use the ExternalLocation feature much? Has anyone else set  
up an external repository for all the fonts they don't want installed  
in the system proper?

All the best,
Will