[Groff] Query about .special

[Robert D. Goulding]

I'm *often* confused about how groff finds glyphs etc., so I'm probably
doing something dumb here.

I'm trying to install the handsome Day Roman font (available from
http://www.apostrophiclab.com and now on CTAN) for groff.

It comes as a regular Roman font and an expert set which includes (among
much else) the ligature glyphs ffi ffl and ff.  At the moment, it is
accessing these glyphs which is giving me some difficulty.

I have the main Roman font (DAYROM__.afm etc.) as the groff font DAR; the
expert set (DAYROM_X.afm etc.) is called DAX.  The pfa's are in the right
places, and entries have been added to the `download' file.  In order to
isolate the problem, I have reduced DAX to a minimal size, containing only
the ligatures:

name DAX
internalname DayRoman-Expert
special
spacewidth 250
encoding text.enc
charset
Fi      865,794,11      3       0110    -- H
Fl      902,794,8       3       0111    -- I
ff      616,935,8       3       0167    -- w

The following is a minimal file:

.fam DA \" .ft DAR gives the same result.
.special DAX
.LP
.char \[foo] \f[DAX]\N'73'
.lp
fire flap riffle buffed difficult. \(Fi\(Fl\(ff\[foo]

Now, this is typeset in Day-Roman; but none of the explicitly requested
ffi ffl ff ligatures -- \(Fi etc. -- come out; they are, instead, f
followed by fi ligature etc.  But when I request the character (glyph? I
forget) \[Fi], which is not found in the ordinary mounted font, shouldn't
it be found in the special font DAX?  groff seems to be using the .fchar
definition in ps.tmac rather than the glyph which is actually accessible
to it.  The character \[foo], formed by referring directly to DAX, is a
proper ffl ligature.

My second question.  Assuming that I can map the characters \[Fi] etc.
correctly; how do I get groff to use them automatically for ligatures in
text?  I assume I need a ligatures entry in the font file; but do the more
complex ligatures get added to the line already in DAR, or do I put a line
for them in DAX?

Thanks,
Robert.

-- 
Robert Goulding             Home Phone: 609 430-1091
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