[ft-devel] Really serious FT bug (was: Kerning problem with capitals)

[Werner LEMBERG]

George, thanks a lot for your help.

> So ftstring gives the distance between d & o as more than the
> counter, while the splines & ff's metricsview suggest it should be
> about half the counter.

Uh, oh, there is a serious bug in FreeType's TT code which apparently
has gone unnoticed *for years*!  In ttgload.c, function
`compute_glyph_metrics', you can find this:

  /* translate array so that (0,0) is the glyph's origin */
  FT_Outline_Translate( &glyph->outline, -loader->pp1.x, 0 );

I think this is wrong.

According to the docs, we have

  pp1 = xMin - lsb
  pp2 = pp1 + aw

Most fonts have xMin = lsb so that pp1 is zero normally.  The gotyk
font has

    xMin = 188
    lsb   = 28

which means that the whole outline is shifted, causing wrong results.

If you comment out this line, the results are fine.

David?


    Werner