Re: [Devel] Kerning problem with capitals

[Werner LEMBERG]

> > For us it's easiest if you use ftview from the ft2demos package.
> 
>   I thought that ftview only rendered glyphs and didn't handle
> kerning?

You are right.  My mistake.  I've meant ftstring.

> I've had a go with ftstring and that renders the "bad" way on both
> systems.  I've attached the output from:
> 
>      ftstring -m "Red Ken File Vera" -r 96 9 Vera.ttf

I fear that the `bad' way is the correct one.  Here the details for
the word `Red' (you can this easily verify with fontforge) if handled
without anti-aliasing:

  glyph       left bearing   glyph width   right bearing
  ------------------------------------------------------

    R              1              7              0
    e              1              6              1
    d              1              6              1

The advance width is 8 pixels for all three glyphs.

Kerning values:

  `R' + `e': -92 font units
    -> Vera.ttf has 2048 font units per em
    -> this is -0.539 pixel at 9pt at 96dpi (12ppem) -> -1 pixel

Horizontal coverage before applying kern values:

  012345678901234567890123

   +++++++ ++++++  ++++++

After applying kern values:

  012345678901234567890123

   +++++++++++++  ++++++

As can be easily seen, we have one pixel right bearing for the `e' and
one pixel left bearing for the `d', which makes a two-pixel gap.  The
one-pixel gap between `R' and `e' disappears after applying the
kerning, and this makes the two-pixel gap stick out.

It might be interesting to compare this with Windows, but I doubt that
we get different results.  


    Werner