kerning

[Jeff Kingston]

I've implemented kerning, and it will be available in the next release
of Basser Lout.  I did it by generating multiple show commands separated
by moves to jump the kerned gaps.

It turns out that the kerning information in the Adobe font metrics
files is relatively sparse, which means that relatively little kerning
actually goes on.  Consequently, by the time I finished a careful
optimization of the PostScript output, the PostScript files with kerning
were 10-20% smaller than the old output files without it.  Furthermore
this means that kerning hardly slows Lout down at all, since for most
letters a single test tells you that there is no kerning to do, and for
the rest there is just a small number of second letters that need to be
searched.  Altogether, a very successful little episode, but dependent
on the number of kerning pairs being relatively small.  I doubt it there
is any efficient way to do it in the case of very large numbers of kern
pairs.

Jeff Kingston