[NTG-pdftex] kerning

[Taco Hoekwater]

Hans Hagen wrote:
> Hi,
> 
> Given those future font capabilities of pdftex (thanh: what happened 
> with your construct fonts on the fly feature?), i wonder if it is 
> possible to add something
> 
> \kernfont\somefont <char code 1> <charcode 2> <dimen>
> 
> Take for instance:
> 
>   http:\\www.pdftex.org

That's not an url ;-)

As it stands, kerning/ligaturing info is memorized by TeX as a
series of programs-per-font. Each of these contain only character
labels and pointers to kern amounts in another table. All of those
font-specific little programs are collated inside a single array
(indexed per-font by yet another array), and all of that indexing
makes it quite hard to manipulate the individual entries.

This stuff would be a lot easier if there was something like
a 'font object' in TeX, which there isn't (I'll start work on
that as soon as there is a semi-stable 1.30 candidate).

Greetings,

Taco

PS. I can create a series of slides that show internals of the
font reading process for the ntg meeting, if you are interested.