Re: What's the relationship between vfs and tfms?

[Thierry Bouche <Thierry.Bouche@ujf-grenoble.fr>]

Concernant « Re: What's the relationship between vfs and tfms? », Berthold K.P. Horn écrit :
« Agreed.  But that still doesn't address the question of why yet another layer
« of remapping is needed (VF).

historically, afm2tfm was not able to produce ligfull & kernfull TFMs
for reencoded fontes, VFS were mandatory. There has been an interim
state of the art, where 8r fontes were made by a patched afm2tfm,
could someone tell if afm2tfm is still able to do ligfull 8r TFMs or
not?

Now the remaining reason is obviously fontinst's ability of faking
missing charachters. this heavily requires VF machinery, hence a base
TFM from which building fakable chars. The point of 8r here is simply
to have all charachters accessible (encoded) and to minimize problems
for systems that do not support reencoding or `deviant' encodings
(windows & textures were cited, if i recall?).

OK this is useless in OT1, but as we already have a base font needed
for T1, why multiply base (PS) (re)encodings?

I know that Berthold prefers the `buy Y&Y font manipulation tools
software' scheme which in my opinion is not a bad idea if you have
some money to spare, and like manipulating  fontes. 

What is the real discussion underlying this? it's not tex  related
indeed. It is true that what a program like fontinst can do on
metrics, a program like y&y's can do on PFBs (using SEAC?). Let's talk
of some T1  charachter  missing in the `standard glyph set' like
Abreve in Palatino-Roman. And imagine you're talking a language that
requires that one. 

If you use some external program to draw figures, and you (of course)
want the words in the figure to be set in the same fonte as the ones
in your text, (and of course the names in your diagrams require the
letter Abreve...) you need that this letter be _real_  so you have to
modify your fonte. 

By chance, this is not needed with TeX thanks to VFs! Remember  that
Palatino is resident, and of course not editable: if you do the faking
with VFs you can share your PS files with anybody, and they will print
on any PS device: no need to even buy palatino's PFB to alter it! for
writing on figures, you still have the psfrag or 0-surface picture
approach... 

   Thierry Bouche.       -----       thierry.bouche@ujf-grenoble.fr
          http://www-fourier.ujf-grenoble.fr/~bouche/