# Intolerable difference in glyph width: font=vnbx12

Reinhard Kotucha reinhard.kotucha at web.de
Tue Oct 19 23:02:14 CEST 2021

On 2021-10-18 at 07:23:59 +0000, Werner LEMBERG wrote:

> >> In other words, the metrics change for the advance width of 'u
> >> horn' to be identical to 'u' was done in the vnbx12 sources and/or
> >> the TFM files but apparently forgotten in vnbx12.pfb (see
> >> attached images).
> >
> > yes this seems the root of the problem.  The pfb files were
> > converted using a number of tools and I honestly cannot recall
> > exactly how it was done.  Fortunately there is a tugboat article
>
> Interesting, thanks!
>
> > From the article it looks likely that all [uoUo]horn letters (plus
> > their accented variants) from vnr fonts will have this problem, and
> > it will take quite a lot of time/work to fix.  I wish I had the time
> > to fix this problem, but I have other things that have higher
> > priority on my todo list.
>
> As mentioned already in a private mail, the following might be a route
> that shouldn't take too long:
>
> * Find out whether there are more glyph width differences in the vnr
>   family (dvipdfmx shows that).
>
> * Fix the widths by using t1disasm + manual editing + t1asm.  A
>   skilled user might even write a script to automate the manual
>   editing part, i.e., taking the width of the 'u' glyph from the
>   disassembled output and replacing the widths of all other
>   occurrences of 'u + accent(s)'.

Hi Werner,
this is what I had in mind too but it takes some time.  There are some
other things which should be fixed too.

\font\v=vnr12 at 1000pt \v
\setbox0\hbox{0}
\showthe\wd0

> 489.4638pt.
l.8 \showthe\wd0

The tfm file contains (CHARWD R 0.489464).  This looks fine so far

489.464pt * 72.27/72 = 491.29949bp

but the pfb file contains

/zero {
41 490 hsbw

There are many of such rounding errors in the font.  I assume that
it's best to replace all widths in the pfb files by values derived
from the tfm files.  Then xetex

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