Ann: fontinst v1.9 prerelease
Tue, 18 May 1999 04:34:34 -0400
Lars Hellström wrote:
> Hilmar Schlegel wrote:
> >What do you think about composites using a character bbox which is
> >enlarged like in the vertical direction also in the horizontal direction
> >if the accent lies outside the base bbox? If this behaviour is used only
> >for those glyph-not composites which must be composed in the VF this
> >would be of course against the convention how Type 1 composites actually
> >work in a printer but it allows to specify dquoteright and such as
> >normal composites in AFM files. I use this feature without interference
> >with other common composites since in most cases the accent is inside
> >the base character's width. The geometrically placed x-quoteright is
> >usually less acceptable.
> Frankly, I don't see what you mean. Width, height, depth, and italic
> correction of glyphs generated from CC instructions in an AFM file are all
> set to exactly the values that the corresponding "-not" glyph have; none of
> them take any notice of the internal structure of the glyph.
The problem is that CC instructions intended for the Type 1 SEAC
operator have the limitation that a CC character inherits its width from
the base character. For the type of accented characters where the accent
extents beyond the width of the base character the CC construction is
not usable due to the realization of that character via SEAC. A VF
however has no problem here (as long as it is sure that it uses a "-not"
For fontinst one can assign those characters needed for Tex just like
other composite characters individually for the fonts, which provides a
way for better positioning without the need to use fakes.
The argument of Alan contra was that the positioning via VF would then
be different from what would happen in a Type 1 font. If one uses the
alternative positioning scheme exclusively for "-not"s there is no
interference. (Few fonts have dquoteright and a CC line in the AFM would
do no harm.)