[pdftex] Virtual fonts, truetype and tfm

[Thierry Bouche]

Le mercredi 13 novembre 2002 à 20:19:48, Jean-Christophe Dubacq écrivit :

JCD> Hi! Does pdftex need the .tfm for the raw font when composing with
JCD> virtual fonts?

well, pdftex is tex+a pdf driver.

TeX as a typesetting engine only needs the TFM of the virtual font.

The VF and TFM of the base fonts only concern the driver.

A glyph in a VF being a piece of DVI code (it can contain more or less
whatever you can put on a single DVI page: glyphs from any fonts, rules
and skips, the widths of the raw glyphs may be useful to know to the
program which disasembles the VF glyph (but this program could also
"trust" the dimensions given in the VF and thus ignore the TFM of the
base fonts, I think there was a political controversy between dvips and
dvipsone regarding this question).


JCD> According to the definition of virtual fonts and my understanding,
JCD> pdftex should never use the information contained in the .tfm of
JCD> the raw font (TeX composes everything with the virtual font glyphs
JCD> and sizes, and then uses the mapping T1-WGL4.enc and the instructions
JCD> in the .vf to find the right glyphs in the TTF file).

I suspect that pdftex reuses a routine for using glyphs, where the TFM
is opened but maybe unused in this case...?

-- 
 Thierry Bouche