.TH MF 1 "24 Apr 92"
.SH NAME
mf, inimf  \- Metafont, a language for alphabet design
.SH SYNOPSIS
.B mf
[ first line ]
.PP
.B inimf
[ first line ]
.PP
.B virmf
[ first line ]
.ie t .ds TX \fRT\v'+0.3m'E\v'-0.3m'X\fP \" for troff
.el .ds TX TeX \" for nroff
.\" to use, type \*(TX
.ie t .ds OX \fIT\v'+0.3m'E\v'-0.3m'X\fP \" for troff
.el .ds OX TeX \" for nroff
.\" the same but obliqued
.SH DESCRIPTION
M\s-2ETAFONT\s0 reads the program in the specified files
and outputs font rasters (in
.I gf
format) and font metrics (in
.I tfm 
format).  The M\s-2ETAFONT\s0
language is described in
.I The M\s-2ETAFONT\s0\^book
by Donald E. Knuth, published by Addison-Wesley.
.PP
Like
\*(TX, M\s-2ETAFONT\s0
is normally used with a large body of precompiled macros, and font generation
in particular requires the support of several macro files.  The basic
program as compiled is called
.IR inimf ;
it can be used to precompile macros into a 
.I .base
file.  The 
.I virmf
variant is used to reload the
.I .base
files quickly.  Typically,
.I virmf
has links to it by the names of the various base files.
For example, if you link
.I foo
to
.I virmf
and then execute the program 
.IR foo ,
you get the base file
.IR foo.base .
You can load a different base by saying, e.g.,
.IR "virmf \\\\\|&mybase" .
.PP
As described in 
.I The M\s-2ETAFONT\s0\^book,
the command line (or first input line) should otherwise begin with a file name
or a \\\|controlsequence.
The normal usage is to say
.IP
\fBmf\ \fR '\\\|mode=<printengine>\^;\^ [\^mag=magstep(\fI\^n\fR\^)\^;\^]' input\ \^\fI font \fR
.PP
to start processing 
.IR font.mf .
The single quotes are the best way of keeping your
shell from misinterpreting the semicolons and 
from removing the \\ character, which is needed here to
keep M\s-2ETAFONT\s0 from thinking that you want to produce a font called
``mode''. (Or you can just say
.B mf
and give the other stuff on the next line, without quotes.) Other
control sequences, such as 
.B batchmode
(for silent operation) can also appear. 
The name ``font'' will be the ``jobname'', and is used in forming
output file names.
If M\s-2ETAFONT\s0 doesn't get a file name in the first line, 
the jobname is ``mfput''.
The default extension,
.IR .mf ,
can be overridden by specifying an extension explicitly.
.PP
A log of error messages goes into the file \fIjobname\fB\^.\^\fIlog\fR.
The output files are \fIjobname\fB\^.\^\fItfm\fR and
\fIjobname\fB\^.\^\fI<\fR\^number\^\fI>gf\fR, where <number> depends on
the resolution and magnification of the font.  The ``mode'' in this
example is shown generically as <printengine>, a symbolic term for which
the name of an actual device or, most commonly, the name ``localfont''
(see below) must
be substituted. If the mode is not specified or is not valid for your
site, M\s-2ETAFONT\s0 will default to ``proof'' mode which produces
large character images for use in font design and refinement.  Proof
mode can be recognized by the suffix
.I .2602gf
after the jobname.  Examples of proof mode output can be found
in 
.IR "Computer Modern Typefaces" ,
(Volume E of
.IR "Computers and Typesetting" ),
by Donald Knuth.
The system of 
.I magsteps 
is identical to the system used by
\*(TX,
with values generally in the range 0.5, 1.0, 2.0, 3.0, 4.0 and 5.0.
A listing of gf numbers for 118-dpi, 240-dpi and 300-dpi fonts
is shown below.
.ds f. mf.tbl \" tbl output inserted here
.TS 
.if \n+(b.=1 .nr d. \n(.c-\n(c.-1
.de 35
.ps \n(.s
.vs \n(.vu
.in \n(.iu
.if \n(.u .fi
.if \n(.j .ad
.if \n(.j=0 .na
..
.nf
.nr #~ 0
.if n .nr #~ 0.6n
.ds #d .d
.if \(ts\n(.z\(ts\(ts .ds #d nl
.fc
.nr 33 \n(.s
.rm 80 81 82 83
.nr 80 0
.nr 38 \w\s-2MAGSTEP\s0
.if \n(80<\n(38 .nr 80 \n(38
.nr 38 \wmag=magstep(0)
.if \n(80<\n(38 .nr 80 \n(38
.nr 38 \wmag=magstep(0.5)
.if \n(80<\n(38 .nr 80 \n(38
.nr 38 \wmag=magstep(1)
.if \n(80<\n(38 .nr 80 \n(38
.nr 38 \wmag=magstep(2)
.if \n(80<\n(38 .nr 80 \n(38
.nr 38 \wmag=magstep(3)
.if \n(80<\n(38 .nr 80 \n(38
.nr 38 \wmag=magstep(4)
.if \n(80<\n(38 .nr 80 \n(38
.nr 38 \wmag=magstep(5)
.if \n(80<\n(38 .nr 80 \n(38
.80
.rm 80
.nr 81 0
.nr 38 \w118 dpi
.if \n(81<\n(38 .nr 81 \n(38
.nr 38 \w118
.if \n(81<\n(38 .nr 81 \n(38
.nr 38 \w129
.if \n(81<\n(38 .nr 81 \n(38
.nr 38 \w142
.if \n(81<\n(38 .nr 81 \n(38
.nr 38 \w170
.if \n(81<\n(38 .nr 81 \n(38
.nr 38 \w204
.if \n(81<\n(38 .nr 81 \n(38
.nr 38 \w245
.if \n(81<\n(38 .nr 81 \n(38
.nr 38 \w294
.if \n(81<\n(38 .nr 81 \n(38
.81
.rm 81
.nr 82 0
.nr 38 \w240 dpi
.if \n(82<\n(38 .nr 82 \n(38
.nr 38 \w240
.if \n(82<\n(38 .nr 82 \n(38
.nr 38 \w263
.if \n(82<\n(38 .nr 82 \n(38
.nr 38 \w288
.if \n(82<\n(38 .nr 82 \n(38
.nr 38 \w346
.if \n(82<\n(38 .nr 82 \n(38
.nr 38 \w415
.if \n(82<\n(38 .nr 82 \n(38
.nr 38 \w498
.if \n(82<\n(38 .nr 82 \n(38
.nr 38 \w597
.if \n(82<\n(38 .nr 82 \n(38
.82
.rm 82
.nr 83 0
.nr 38 \w300 dpi
.if \n(83<\n(38 .nr 83 \n(38
.nr 38 \w300
.if \n(83<\n(38 .nr 83 \n(38
.nr 38 \w329
.if \n(83<\n(38 .nr 83 \n(38
.nr 38 \w360
.if \n(83<\n(38 .nr 83 \n(38
.nr 38 \w432
.if \n(83<\n(38 .nr 83 \n(38
.nr 38 \w518
.if \n(83<\n(38 .nr 83 \n(38
.nr 38 \w622
.if \n(83<\n(38 .nr 83 \n(38
.nr 38 \w746
.if \n(83<\n(38 .nr 83 \n(38
.83
.rm 83
.nr 38 1n
.nr 79 0
.nr 40 \n(79+(0*\n(38)
.nr 80 +\n(40
.nr 41 \n(80+(3*\n(38)
.nr 81 +\n(41
.nr 42 \n(81+(3*\n(38)
.nr 82 +\n(42
.nr 43 \n(82+(3*\n(38)
.nr 83 +\n(43
.nr TW \n(83
.if t .if \n(TW>\n(.li .tm Table at line 13 file mf.tbl is too wide - \n(TW units
.nr #I \n(.i
.in +(\n(.lu-\n(TWu-\n(.iu)/2u
.fc  
.nr #T 0-1
.nr #a 0-1
.eo
.de T#
.ds #d .d
.if \(ts\n(.z\(ts\(ts .ds #d nl
.mk ##
.nr ## -1v
.ls 1
.ls
..
.ec
.ta \n(80u \n(81u \n(82u \n(83u 
.nr 31 \n(.f
.nr 35 1m
\&\h'|\n(40u'\s-2MAGSTEP\s0\h'|\n(41u'118 dpi\h'|\n(42u'240 dpi\h'|\n(43u'300 dpi
.ta \n(80u \n(81u \n(82u \n(83u 
.nr 31 \n(.f
.nr 35 1m
\&\h'|\n(40u'mag=magstep(0)\h'|\n(41u'118\h'|\n(42u'240\h'|\n(43u'300
.ta \n(80u \n(81u \n(82u \n(83u 
.nr 31 \n(.f
.nr 35 1m
\&\h'|\n(40u'mag=magstep(0.5)\h'|\n(41u'129\h'|\n(42u'263\h'|\n(43u'329
.ta \n(80u \n(81u \n(82u \n(83u 
.nr 31 \n(.f
.nr 35 1m
\&\h'|\n(40u'mag=magstep(1)\h'|\n(41u'142\h'|\n(42u'288\h'|\n(43u'360
.ta \n(80u \n(81u \n(82u \n(83u 
.nr 31 \n(.f
.nr 35 1m
\&\h'|\n(40u'mag=magstep(2)\h'|\n(41u'170\h'|\n(42u'346\h'|\n(43u'432
.ta \n(80u \n(81u \n(82u \n(83u 
.nr 31 \n(.f
.nr 35 1m
\&\h'|\n(40u'mag=magstep(3)\h'|\n(41u'204\h'|\n(42u'415\h'|\n(43u'518
.ta \n(80u \n(81u \n(82u \n(83u 
.nr 31 \n(.f
.nr 35 1m
\&\h'|\n(40u'mag=magstep(4)\h'|\n(41u'245\h'|\n(42u'498\h'|\n(43u'622
.ta \n(80u \n(81u \n(82u \n(83u 
.nr 31 \n(.f
.nr 35 1m
\&\h'|\n(40u'mag=magstep(5)\h'|\n(41u'294\h'|\n(42u'597\h'|\n(43u'746
.fc
.nr T. 1
.T# 1
.in \n(#Iu
.35
.TE
.if \n-(b.=0 .nr c. \n(.c-\n(d.-12

.br
Magnification can also be specified not as a magstep but as an
arbitrary value, such as 1.315, to create special character sizes.
.PP
Before font production can begin, it is necessary to set up the
appropriate base files.  The minimum set of components for font
production for a given print-engine is the 
.I plain.mf
macro file
and the local `mode_def' file.  The macros in 
.I plain.mf
can be
studied in an appendix to the
.I M\s-2ETAFONT\s0\^book;
they were developed by Donald Knuth, and this file should never be
altered except when it is officially upgraded.  
Each mode_def specification helps adapt fonts to a particular print-engine.
There is a regular discussion of mode_defs in the journal of the 
\*(TX
Users Group,
.I TUGboat;
the local ones in use on this computer should be in
.BR /usr/local/lib/mf/macros/modes.mf .
With only 
.I plain.mf 
and the ``modes'' file
loaded it is possible to
create fonts of simple characters, such as those used for the
M\s-2ETAFONT\s0
logo, and those used for the La\*(TX line and circle fonts,
but the production of Computer Modern fonts would be facilitated by
making a 
.I cmmf.base
file (which includes the macros in 
.I cmbase.mf
as
well as those in 
.IR plain.mf ).
.PP
Several environment variables can be used to set up directory
paths to search when M\s-2ETAFONT\s0 opens a file for input.
For example, the
.I csh
command
.br
.in +4
setenv \s-2MFINPUTS\s0\ .\^:\^/usr/me/mylib\^:/usr/local/lib/mf/macros
.in -4
or the
.I sh
command sequence
.br
.in +4
\s-2MFINPUTS\s0\|=\|.\^:\^/usr/me/mylib\^:/usr/local/lib/mf/macros
.br
export \s-2MFINPUTS\s0
.in -4
.br
would cause all invocations of M\s-2ETAFONT\s0 and its derivatives to look for
\\\|input files first in the current directory, then in a hypothetical
user's ``mylib'', and finally in the system library.
Normally, the user will place the command sequence which sets up the
\s-2MFINPUTS\s0 environment variable in his or her
.I .\|login
or
.I .\|profile
file.
.PP
The
.I e
response to M\s-2ETAFONT\s0\|'s error-recovery mode invokes the
system default
editor at the erroneous line of the source file.
There is an environment variable, \s-2MFEDIT\s0, 
that overrides the default editor.  
It should contain a string with "%s" indicating where the
filename goes and "%d" indicating where the decimal linenumber (if any) goes.
For example, an \s-2MFEDIT\s0 string for the 
.I vi
editor can be set with the
.I csh
command
.br
.ti +3
     setenv \s-2MFEDIT\s0 "/usr/ucb/vi +%d %s"
.br
.sp .7
The environment variables section below lists
the relevant environment variables,
and their defaults.
.PP
A convenient file in the library is 
.IR null.mf ,
containing nothing.
When 
.I mf
can't find the file it thinks you want to input, it keeps
asking you for another file name;  responding `null' gets you out
of the loop if you don't want to input anything.
.SH "ONLINE GRAPHICS OUTPUT"
M\s-2ETAFONT\s0 can use most modern displays, so you can see its output
without printing.  Chapter 23 of
.I The M\s-2ETAFONT\s0\^book
describes what you can do.  This implementation of M\s-2ETAFONT\s0 uses
environment variables to determine which display device you want to use.
First it looks for a variable \s-2MFTERM\s0, and then for \s-2TERM\s0.
If it can't find either, you get no online output.  Otherwise, the value
of the variable determines the device to use:
.BR hp2627 ,
.B sun
(for SunView),
.BR tek ,
.B uniterm 
(for an Atari ST Tek 4014 emulator),
.B xterm 
(for either X10 or X11).
Some of these devices may not be supported in all M\s-2ETAFONT\s0
executables; the choice is made at compilation time.
.SH ENVIRONMENT
The default values for all environment variables are set at the
time of compilation in a file 
.IR site.h .
See
.BR tex (1)
for the details of the searching.  If the environment variable
\s-2TEXMFOUTPUT\s0 is set, M\s-2ETAFONT\s0 attempts to put its output
files in it, if they cannot be put in the current directory.  Again, see
.BR tex (1).
.PP
.IP \s-2MFINPUTS\s0
Search path for 
.B input
and
.B openin
files.  It should be colon-separated, and start with ``.''.  Default:
.BR .:/usr/local/lib/mf/macros .
.IP \s-2MFBASES\s0
Search path for base files.  Default:
.BR /usr/local/lib/mf/bases .
.IP \s-2MFPOOL\s0
Search path for M\s-2ETAFONT\s0 internal
strings.  Default: 
.BR /usr/local/lib/mf .
.IP \s-2MFEDIT\s0
Command template for switching to editor.  Default:
.BR "/usr/bin/vi +%d %s" .
.IP \s-2MFTERM, TERM\s0
Determines the online graphics display.
.SH "FONT UTILITIES"
A number of utility programs are available. 
The following is a partial list of available utilities and their purpose. 
Consult your local M\s-2ETAFONT\s0 guru for details.
.br
.TP 1i
.B gftopk
Takes a GF file and produces a more tightly packed PK font file.
.TP
.B gftodvi
Produces proof sheets for fonts.
.TP
.B gftype
Displays the contents of a GF file in mnemonics and/or images.
.TP
.B pktype
Mnemonically displays the contents of a PK file.
.TP
.B mft
Formats a source file as shown in
.I Computer Modern Typefaces.
.SH "FILES"
.TP 2i
/usr/local/lib/mf
M\s-2ETAFONT\s0's library areas
.TP
/usr/local/lib/mf/mf.pool
Encoded text of M\s-2ETAFONT\s0's messages
.TP
/usr/local/lib/mf/bases/*.base
M\s-2ETAFONT\s0 base files
.TP
/usr/local/lib/mf/macros/plain.mf
The ``standard'' macro package
.TP
/usr/local/lib/mf/macros/modes.mf
The file of ``mode_def''s for your site's various printers
.TP
/usr/local/src/TeX+MF/typefaces/cm/cm*.mf
M\s-2ETAFONT\s0 sources for Computer Modern
.SH "SUGGESTED READING"
Donald E. Knuth,
.I The M\s-2ETAFONT\s0\^book
(Volume C of \fI Computers and Typesetting\fR\|)
.br
Donald E. Knuth,
.I M\s-2ETAFONT:\s0\^ The Program
(Volume D of \fI Computers and Typesetting\fR\|)
.br
Donald E. Knuth,
.I Computer Modern Typefaces 
(Volume E of \fI Computers and Typesetting\fR\|)
.br
.I TUGboat
(the publication of the \*(TX Users Group)
.SH COMMENTS
Warning: ``Type design can be hazardous to your other interests. 
Once you get hooked, you will develop intense feelings about letterforms;
the medium will intrude on the messages that you read.
And you will perpetually be thinking of improvements to the fonts that
you see everywhere, especially those of your own design.''
.SH "SEE ALSO"
gftopk(1), gftodvi(1), gftype(1), mft(1),
pltotf(1), tftopl(1)
.SH BUGS
On January 4, 1986 the ``final'' bug in M\s-2ETAFONT\s0 was discovered
and removed. If an error still lurks in the code, D.E. Knuth promises to
pay a finders fee which doubles every year to the first person who finds
it. Happy hunting.
.SH AUTHORS
M\s-2ETAFONT\s0 was designed by Donald E. Knuth, who implemented it
using his W\s-2EB\s0 system for Pascal programs.  It was originally
ported to Unix by Paul Richards at the University of Illinois at
Urbana-Champaign.  This page was mostly written by Pierre MacKay.