[Freetype] kerning questions/problem

[Jeff Chow]

Hi Gang,

I'm trying to understand why a string rasterized with truetype has kerning
that's different from a string that's drawn in a Windows app like Word or
Notepad. My first question has to do with the actual kerning distances and
the fact that I'm seeing *positive* kerning distances in my font. If the
whole purpose of kerning pairs is to decrease the spacing between characters
to make them fit better, why would a font have a positive value?

Now I realize that the TTF itself can be malformed and require manual
tweaking, but when loaded into MSWord or Photoshop the pairs kern perfectly
and without problems whatsoever. Does anyone know what Windows could be
doing differently? I tried turning on the
TT_CONFIG_OPTION_BYTECODE_INTERPRETER flag in hopes that it would make a
difference but its effect in terms of kerning was negligible.

Thanks in advance,
Jeff