Re: [Groff] [off] micro-typography

[Werner LEMBERG]

> > Interestingly, even TeX can't do this, apparently for good
> > reasons.  In groff, .shc only works with real glyphs from the
> > font.  I assume that the insertion of the hyphen in both programs
> > occur at a very late point in the processing; restarting the whole
> > mechanism to parse and handle a macro (via .char, for example)
> > would make the algorithm much more complicated if not impossible
> > to work.
> 
> TeX can do it with real characters from fonts too, but with the
> added possibility to use virtual fonts.  Thus, for example, in the
> Cork (T1) encoded virtual fonts for postscript fonts it is customary
> to add the hanging hyphen by recycling the normal hyphen but
> smashing its width to the left and setting the width to zero.
> 
> Now, if groff could use some sort of virtual fonts..., else you'll
> need to write the routine in PS and attach it to your font instead
> of the original.

Where is the difficulty to simpy copy, say, the TR font to a TRX (for
Times Roman Extended) which contains some more groff glyph entities,
mapping to the same PS glyphs with different metrics?  This is a lot
easier to do than in TeX.

Now, with the introduction of the `.fn' register + the `char' request,
it is easy to implement font-dependent virtual characters also.


    Werner