NAME
mf, inimf, virmf - Metafont, a language for font and logo
design
SYNOPSIS
mf [ first line ]
inimf [ first line ]
virmf [ first line ]
DESCRIPTION
Metafont reads the program in the specified files and
outputs font rasters (in gf format) and font metrics (in tfm
format). The Metafont language is described in The
Metafontbook.
Like TeX, Metafont 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 inimf; it can be used to
precompile macros into a .base file. The virmf variant is
used to reload the .base files quickly. Typically, virmf
has links to it by the names of the various base files. For
example, if you link virmf to foo and then execute the
program foo, you get the base file foo.base. You can load a
different base by saying, e.g., virmf &mybase.
As described in The Metafontbook, the command line (or first
input line) should otherwise begin with a file name or a
\controlsequence. The normal usage is to say
mf '\mode=<printengine>; [mag=magstep(n);]' input
font
to start processing font.mf. The single quotes are the best
way of keeping the Unix shell from misinterpreting the
semicolons and from removing the \ character, which is
needed here to keep Metafont from thinking that you want to
produce a font called mode. (Or you can just say mf and
give the other stuff on the next line, without quotes.)
Other control sequences, such as batchmode (for silent
operation) can also appear. The name font will be the
``jobname'', and is used in forming output file names. If
Metafont doesn't get a file name in the first line, the
jobname is mfput. The default extension, .mf, can be
overridden by specifying an extension explicitly.
A log of error messages goes into the file jobname.log. The
output files are jobname.tfm and jobname.<number>gf, 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, Metafont 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 .2602gf after the jobname. Examples of proof mode
output can be found in Computer Modern Typefaces (Volume E
of Computers and Typesetting). The system of magsteps is
identical to the system used by TeX, 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.
MAGSTEP 118 dpi 240 dpi 300 dpi
mag=magstep(0) 118 240 300
mag=magstep(0.5) 129 263 329
mag=magstep(1) 142 288 360
mag=magstep(2) 170 346 432
mag=magstep(3) 204 415 518
mag=magstep(4) 245 498 622
mag=magstep(5) 294 597 746
Magnification can also be specified not as a magstep but as
an arbitrary value, such as 1.315, to create special
character sizes.
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 plain.mf
macro file and the local mode_def file. The macros in
plain.mf can be studied in an appendix to the Metafontbook;
they were developed by Donald E. 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 TUGboat, the journal of the TeX Users Group.
The local ones in use on this computer should be in
@MFINPUTDIR@/@LOCALMODES@.mf. With only plain.mf and the
modes file loaded it is possible to create fonts of simple
characters, such as those used for the Metafont logo, and
those used for the LaTeX line and circle fonts, but the
production of Computer Modern fonts would be speeded by
making a cmmf.base file (which includes the macros in
cmbase.mf as well as those in plain.mf).
Several environment variables can be used to set up
directory paths to search when Metafont opens a file for
input. For example, the csh command
setenv MFINPUTS .:~me/mylib:@MFINPUTDIR@
or the sh command sequence
MFINPUTS=.:~me/mylib:@MFINPUTDIR@
export MFINPUTS
would cause all invocations of Metafont 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 MFINPUTS environment variable in
his or her .login or .profile file.
The e response to Metafont's error-recovery mode invokes the
system default editor at the erroneous line of the source
file. There is an environment variable, MFEDIT, 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 MFEDIT string for the vi editor can be set with
the csh command
setenv MFEDIT "/usr/ucb/vi +%d %s"
The ENVIRONMENT section below lists the relevant environment
variables, and their defaults.
A convenient file in the library is null.mf, containing
nothing. When 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.
ONLINE GRAPHICS OUTPUT
Metafont can use most modern displays, so you can see its
output without printing. Chapter 23 of The Metafontbook
describes what you can do. This implementation of Metafont
uses environment variables to determine which display device
you want to use. First it looks for a variable MFTERM, and
then for TERM. If it can't find either, you get no online
output. Otherwise, the value of the variable determines the
device to use: hp2627, sun (for SunView), tek, uniterm (for
an Atari ST Tek 4014 emulator), xterm (for either X10 or
X11). Some of these devices may not be supported in all
Metafont executables; the choice is made at compilation
time.
ENVIRONMENT
The default values for all environment variables are set at
the time of compilation in the file kpathsea/paths.h. See
the Kpathsearch library documentation (the `Path
specifications' node) for the details of the searching.
If the environment variable TEXMFOUTPUT is set, Metafont
attempts to put its output files in it, if they cannot be
put in the current directory. Again, see tex(1).
MFINPUTS Search path for input and openin files.
Default:
@DEFAULT_MF_PATH@
MFBASES Search path for base files. Default:
@DEFAULT_BASE_PATH@
MFPOOL Search path for Metafont internal strings.
(Used by inimf only.) Default:
@DEFAULT_MFPOOL_PATH@
MFEDIT Command template for switching to editor.
Default: @EDITOR@
MFTERM Determines the online graphics display. If
MFTERM is not set, and DISPLAY is set, the
Metafont window support for X is used.
(DISPLAY must be set to a valid X server
specification, as usual.) If neither MFTERM
nor DISPLAY is set, TERM is used to guess the
window support to use.
MAKETEXMF Analogous to TeX's MAKETEXTEX, q.v.
USE_MAKETEXMF Analogous.
FONT UTILITIES
A number of utility programs are available. The following
is a partial list of available utilities and their purpose.
Consult your local Metafont guru for details.
gftopk Takes a gf file and produces a more tightly packed
pk font file.
gftodvi Produces proof sheets for fonts.
gftype Displays the contents of a gf file in mnemonics
and/or images.
pktype Mnemonically displays the contents of a pk file.
mft Formats a source file as shown in Computer Modern
Typefaces.
FILES
@MFPOOLDIR@/mf.pool Encoded text of Metafont's messages.
@BASEDIR@/*.base Predigested Metafont base files.
@MFINPUTDIR@//plain.mf The standard base.
@MFINPUTDIR@//@LOCALMODES@.mf
The file of mode_defs for your
site's various printers
SUGGESTED READING
Donald E. Knuth, The Metafontbook (Volume C of Computers and
Typesetting), Addison-Wesley, 1986, ISBN 0-201-13445-4.
Donald E. Knuth, Metafont: The Program (Volume D of
Computers and Typesetting), Addison-Wesley, 1986, ISBN 0-
201-13438-1.
Donald E. Knuth, Computer Modern Typefaces (Volume E of
Computers and Typesetting), Addison-Wesley, 1986, ISBN 0-
201-13446-2.
TUGboat (the journal of the TeX Users Group).
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.''
SEE ALSO
gftopk(1), gftodvi(1), gftype(1), mft(1), pltotf(1),
tftopl(1).
BUGS
On January 4, 1986 the ``final'' bug in Metafont was
discovered and removed. If an error still lurks in the code,
Donald E. Knuth promises to pay a finder's fee which doubles
every year to the first person who finds it. Happy hunting.
AUTHORS
Metafont was designed by Donald E. Knuth, who implemented it
using his Web 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.