MF(1)MF(1)NAME
cmmf, inimf, virmf - METAFONT, a language for font design
SYNOPSIS
cmmf [ 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 (tfm files). METAFONT
capabilities and language are described in The METAFONTbook by Donald
E. Knuth, published by Addison-Wesley. There is also an older manual,
TeX and METAFONT, which describes the older version of METAFONT, now
called METAFONT-in-SAIL, but this description is now obsolete.
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 programs as compiled are called inimf
and virmf, and are distinguished by the fact that inimf can be used to
precompile macros into a ``*.base'' file, which is used by virmf. Virmf
can read a precompiled ``*.base'' file, but it cannot create one. It
is the version of METAFONT which lies behind most font production
systems.
By convention, the program used to compile the Computer Modern fonts is
called cmmf, which is essentially an alias for virmf with the Computer
Modern support macros loaded in as a ``base'' file. In the following
discussion, the name METAFONT will be used whenever the behavior of all
varieties of the program is the same. Otherwise, it should be assumed
that the behavior described is unique to the program named. Any
arguments given on the command line to one of the METAFONT programs,
such as cmmf, are passed to them as the first input line. As described
in The METAFONTbook, that line should begin with a file name or a
\controlsequence. The normal usage is to say
cmmf ' \mode=<printengine>; [\mag=magstep(n);] ' input font
to start processing font.mf. The single quotes are the best way of
keeping the shell from misinterpreting the semicolons and from removing
the \ characters, which are needed here to keep METAFONT from thinking
that you want to produce a font called ``mode'' or ``mag''. Other
\controlsequences, 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 `.mf' extension can
be overridden by specifying an extension explicitly. There is no way
to read a METAFONT input file with no filename extension.
A log of error messages goes into font.log where font is the jobname.
The output files are font.tfm and font.<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 printengine or 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 immediately be recognized by the appearance
of the suffix .2602gf after the jobname. Examples of proof mode
output can be found in The Computer Modern Fonts, (Volume E of
Computers and Typesetting ), by Donald Knuth. The system of magsteps
is identical to the system used by TeX , with values normally 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 Knuth,
and this file should never be altered except when it is officially
upgraded. Mode_def specifications are tailored to each different
print-engine. There is a regular discussion of them in the journal of
the TeX Users Group, TUGboat, and models can be found in the files
`waits.mf' and `U_Wash.mf' which come in the standard distribution of
TeX for Unix systems. A good `mode_def' file (which we will here call
`<SITE>-modes.mf') should also supply other features in the `gf' and
`tfm' output from cmmf. With only `plain.mf' and `<SITE>-modes.mf'
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 requires that
`cmbase.mf', be loaded as well. The best way to do this is to create a
small ``driver'' file with the lines
input plain
input <SITE>-modes
input cmbase
and name this file `cmplain.mf'. Then run inimf with the arguments
``cmplain dump'', and you will finish up with a file named
cmplain.base. The `base' file is used by virmf. It needs to be given
a base file name as the first thing it reads. A base file name is
preceded by an &, which needs to be quoted or escaped with \ if given
on the command line. One could set up a cshell alias with
alias cmmf "virmf \&cmplain"
to allow regular use of cmmf, but a preferable way is to set up an
executable script with the name cmmf which can ensure that
`cmplain.base' is loaded whenever cmmf is called. In either case, the
message on the screen will tell you that there is ``no format
preloaded'', which is of course perfectly true; the format loading is
achieved by the ``\&cmplain'' part of the alias. The log file will
tell you that cmplain was loaded, and that too is true, because the log
file is written after the loading of ``cmplain.base'' (or whatever base
file you have specified). This mildly confusing conflict in messages
can be avoided if you choose to preload ``cmmf'' using the ``undump''
program. Preloading gives you a fast startup, but only at the price of
lost flexibility and of large storage requirements for the preloaded
version. WARNING. Do not use a base with cmbase.mf preloaded when you
make up the line and circle fonts for LaTeX. It causes subtle errors
in the compiled font and makes the production of clean drawings in
LaTeX picture mode virtually impossible.
There are some environment variables that can be used to set up
directory paths to search when METAFONT opens a file for input. For
example, the csh command
setenv MFINPUTS .:/usr/me/mylib:/usr/lib/mf/inputs
or the sh command sequence
MFINPUTS=.:/usr/me/mylib:/usr/lib/mf/inputs
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 the .cshrc or .profile file.
The e response to METAFONT's error-recovery mode invokes the GNU emacs
editor at the erroneous line of the source file. There is an
environment variable, MFEDITOR, that can be used to specify the 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 MFEDITOR string for the "vi" editor can be set by:
setenv MFEDITOR "/usr/ucb/vi +%d %s"
(replacing the path name for the editor as appropriate on your system).
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.
EXAMPLES
Most sites need at least two families of font resolution: one for
printing and the other for previewing. If both write-white and write-
black printers are used at the same site it may even be necessary to
have two sets of fonts at the same resolution. When preloaded with a
`mode-def' file such as U_Wash.mf, METAFONT has several modes, each
associated with a given print engine or display device. In regular use
the mode `localfont' is made equivalent to the mode for the print-
engine most in use. There are also two styles of proof mode for
character designers.
proof mode Generates full-page font proofs using gray-pixel
fonts
smoke mode Generates full-page font proofs using black-pixel
fonts
localfont mode Generates font at resolution suitable for printing
Once a METAFONT source is written, the following steps may be used to
generate a GF file for proofing, TFM file for the width table, and
raster font files for printing and previewing at each desired
resolution.
STEP 1. Compile font
Input: cmmf myfont
Output: myfont.2602gf, myfont.log
STEP 2. Generate DVI-file
Input: gftodvi myfont.2602gf
Output: myfont.dvi, myfont.log
STEP 3. Produce printable output (e. g. from a
PostScript printer)
Input: dvi2ps myfont | lpr
Note: You need special black, gray and slant fonts
for this.
STEP 4. Generate generic format rastered font:
Input: cmmf ' \mode=localfont; \mag=magstep(1.0); '
input myfont
Output: myfont.360gf, myfont.tfm, myfont.log
Steps 1 through 3 are necessarily only if you are
working on a new design. If all you need is a
specific size and resolution of a well-known font,
then only step 4 is needed.
ENVIRONMENT
The defaults for all environments are set at the time of compilation,
by reference to a file called site.h. The values given below are
preset in this file, and may be different at some sites.
MFINPUTS
Search path for \input and \openin files. It should be colon-
separated, and start with ``.''. The entire path must be no
longer than 700 characters long. Default: .:/usr/lib/mf/inputs
MFBASES
Search path for base files. Default: .:/usr/lib/mf/bases
MFPOOL Search path for METAFONT strings. Default: .:/usr/lib/mf
MFEDITOR
Command template for switching to editor. Default:
/usr/bin/emacs +%d %s
FONT UTILITIES
A number of utility programs are available (see section See Also). 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
pktogf Unpacks a PK file into GF format
gftodvi Produces proof sheets for fonts
gftype Displays the contents of a GF file in mnemonics and
images
pktype Mnemonically displays the contents of a PK file
mft Formats a source file (font.mf) as shown in Computer
Modern Typefaces
FILES
/usr/lib/mf METAFONT's library area
/usr/lib/mf/mf.pool
Encoded text of METAFONT's messages
/usr/lib/mf/bases
METAFONT *.base files and short driver files for inimf
/usr/lib/mf/inputs/plain.mf
The ``standard'' macro package
/usr/lib/mf/inputs/`SITE-modes'.mf
The file of ``mode_def''s for your site's various printers
/usr/lib/mf/inputs/cmbase.mf
METAFONT macros for Computer Modern
SUGGESTED READING
Donald E. Knuth, The METAFONTbook (Volume C of Computers and
Typesetting)
Donald E. Knuth, METAFONT the Program (Volume D of Computers and
Typesetting)
Donald E. Knuth, Computer Modern Typefaces (Volume E of Computers and
Typesetting)
TUGboat (the publication 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.''
BUGS
On January 4, 1986 the ``final'' bug in METAFONT 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.
The ``no format preloaded'' message could be considered an undesirable
fossil, but it is not a bug.
AUTHORS
METAFONT was designed by Donald E. Knuth, who implemented it using his
WEB system for Pascal programs. It was ported to Unix by Paul Richards
at the University of Illinois at Urbana-Champlain. The version now
offered with the Unix TeX distribution is that generated by the WEB to
C system, written by Tomas Rokicki and Tim Morgan. This page written
by Pierre MacKay, with help from the anonymous author of the page in
the jTeX software distribution.
SEE ALSOgftopk(1), gftype(1), pktogf(1), pktype(1)
2/10/89 MF(1)