[Fontinst] Kerning

[Lars Hellström]

At 10.17 +0200 2003-08-26, Hilmar Schlegel wrote:
>Hi,
>
>Indeed it would be nice to automate kerning a bit for those cases when
>synthetic kerns are sufficient.
[snip]
>To make this work one would either build in a test (for certain
>parameters) or set up some character classes (which are then selected).
>
>No idea if that would be too complex for an implementation in TeX. I
>think low performance would be less critical than faulty kern pairs.
>
>Anyway, some restriction to the total number of mechanically created
>kern pairs would be very sensible for fonts which already provide lots
>of kerns, esp. OT. To throw out kerns between accented characters has
>proved to help considerably for practical purposes but this may be
>language dependent.

One thing that is already available and can be used is the \unsetkerns
command. Quoting fimain.dtx:

  |\unsetkerns|\marg{left~glyph~list}\marg{right~glyph~list}

  This command unsets all kerns with a glyph in the \meta{left~glyph~list}
  on the left and a glyph in the \meta{right~glyph~list} on the right.
  The lists themselves are ordinary comma-separated lists. Unlike
  |\setkern| and |\resetkern|, |\unsetkerns| actually removes the
  kerning pairs from \TeX's memory.

Thus you can do

\unsetkerns{<the list of "exotic" letters>}{<the list of "exotic" letters>}

to get rid of a large class of kerns.

Lars Hellström