[9fans] troff to postscript with New Century Schoolbook: discrepancies?

[9fans] troff to postscript with New Century Schoolbook: discrepancies?

[Pietro Gagliardi]

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New Century Schoolbook is a font included in Plan 9. The troff fonts
are NR, NI, NB, NX. -ms has a .FP option "century."

% cat file
\f(NRHello ― world!
% troff file | page
converting from troff to postscript...
reading through postscript...					― works
% cat file2
.FP century
Hello ― world!
% troff -ms file2 | page
converting from troff to postscript...
/386/bin/aux/tr2post: <stdin>:41 :WARNING: cannot find glyph,
rune=0x2014 stoken=<―> troff font NR
reading through postscript...					pjw instead of ―

Why?

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Re: [9fans] troff to postscript with New Century Schoolbook: discrepancies?

[Russ Cox]

>  New Century Schoolbook is a font included in Plan 9.

Included in Plan 9, no.  Known to troff, yes.
When you view a file with this font using page,
what displays on the screen is the Ghostscript
pseudo-equivalent (URW)++ Century Schoolbook L.

> [Why does \f(NR― work while
> .fp 1 NR
> ―
> does not?]

In both cases, the NR font does not have an em dash.
Lucky for you, troff assumes that characters it doesn't
know about have width 1em and passes them through.
\f(NR temporarily mounts NR as font 0 and uses font 0,
while .fp 1 NR mounts NR as font 1.  In the former case,
font 1 is still R; in the latter, it is not.  If tr2post cannot
find a character in the current font, it tries font 1, so that
for example if there isn't an italic dash in font 2, it will
fall back to the roman dash in font 1.  The difference is
that in the first case, font 1 is still a font with a dash.

Russ