\input texinfo
@setfilename dvips.info
@settitle Dvips: A DVI driver

@set version 5.66a
@set month-year February 1997

@c Define a new index for filenames and options.
@defcodeindex fl
@defcodeindex op

@c Put everything in one index (arbitrarily chosen to be the concept index).
@syncodeindex fl cp
@syncodeindex fn cp
@syncodeindex ky cp
@syncodeindex op cp
@syncodeindex pg cp
@syncodeindex vr cp

@ifclear INSTALLONLY

@dircategory TeX
@direntry
* DVI-to-Postscript: (dvips).        Translating TeX DVI files to PostScript.
* afm2tfm: (dvips)Invoking afm2tfm.  Making Type 1 fonts available to TeX.
* dvips: (dvips)Invoking Dvips.      DVI-to-PostScript translator.
@end direntry

@titlepage
@title Dvips: A DVI-to-PostScript Translator
@subtitle for version @value{version}
@subtitle @value{month-year}
@author Tomas Rokicki
@author (edited for Dvipsk by @email{kb@@mail.tug.org})

@page
@vskip 0pt plus 1filll
This document is based on @file{dvips.tex} by Tomas Rokicki.  It is
in the public domain.
@end titlepage

@ifinfo
@node Top
@top Dvips

This manual documents Dvips, a program to translate a DVI file into
PostScript.  It corresponds to version @value{version}
(@value{month-year}) of the Dvipsk distribution, a slightly modified
variant of the original Dvips program with path searching rules
consistent with the Web2c @TeX{} implementation, the GNU font utilities,
Xdvik, and Dviljk.

@menu
* Why Dvips::                   Why use Dvips?
* Installation::                How to compile and install Dvips.
* Invoking Dvips::              Command-line options, configuration files, etc.
* Paper size and landscape::    Changing the paper dimensions.
* Interaction with PostScript:: TeX meets Dvips meets PostScript.
* PostScript fonts::            Installing and using PostScript fonts.
* Color::                       Using color with Dvips.
* Index::                       General index.
@end menu
@end ifinfo


@node Why Dvips
@chapter Why use Dvips?

The Dvips program has a number of features that set it apart from
other PostScript drivers for @TeX{}.  This rather long section describes
the advantages of using Dvips, and may be skipped if you are just
interested in learning how to use the program.  @xref{Installation}, for
details of compilation and installation.

The Dvips driver generates excellent, standard PostScript, that
can be included in other documents as figures or printed through a
variety of spoolers.  The generated PostScript requires very little
printer memory, so very complex documents with a lot of fonts can easily
be printed even on PostScript printers without much memory, such as the
original Apple LaserWriter.  The PostScript output is also compact,
requiring less disk space to store and making it feasible as a transfer
format.

Even those documents that are too complex to print in their entirety on
a particular printer can be printed, since Dvips will
automatically split such documents into pieces, reclaiming the printer
memory between each piece.

The Dvips program supports graphics in a natural way, allowing
PostScript graphics to be included and automatically scaled and
positioned in a variety of ways.

Printers with any resolution are supported, even if they have different
resolutions in the horizontal and vertical directions.  High resolution
output is supported for typesetters, including an option that compresses
the bitmap fonts so that typesetter virtual memory is not exhausted.
This option also significantly reduces the size of the PostScript file
and decoding in the printer is very fast.

Missing fonts can be automatically generated if Metafont exists on
the system, or fonts can be converted from GF to PK format
on demand.  If a font cannot be generated, a scaled version of the same
font at a different size can be used instead, although Dvips will
complain loudly about the poor aesthetics of the resulting output.

Users will appreciate features such as collated copies and support for
@file{tpic}, @file{psfig}, @file{emtex}, and @file{METAPOST}; system
administrators will love the support for multiple printers, each with
their own configuration file, and the ability to pipe the output
directly to a program such as @file{lpr}.  Support for MS-DOS, OS/2, and
VMS in addition to Unix is provided in the standard distribution, and
porting to other systems is easy.

One of the most important features is the support of virtual fonts,
which add an entirely new level of flexibility to @TeX{}.  Virtual fonts
are used to give Dvips its excellent PostScript font support, handling
all the font remapping in a natural, portable, elegant, and extensible
way.  Dvips even comes with its own Afm2tfm program that creates
the necessary virtual fonts and @TeX{} font metric files automatically
from the Adobe font metric files.

Source is provided and freely distributable, so adding a site-specific feature
is possible.  Adding such features is made easier by the highly modular
structure of the program.

There is really no reason to use another driver, and the more people use
Dvips, the less time will be spent fighting with PostScript and the
more time will be available to create beautiful documents.
So if you don't use Dvips on your system, get it today.

@cindex Rokicki, Tomas
Tom Rokicki wrote and maintains the original Dvips program.

@end ifclear
@c INSTALLONLY


@node Installation
@chapter Installation

@cindex configuration, of Dvips
@cindex compilation
@cindex installation, of Dvips

@ifset version
(A copy of this chapter is in the distribution file @file{dvipsk/INSTALL}.)
@end ifset

Installing Dvips is mostly the same as installing any Kpathsea-using
program.  Therefore, for the basic steps involved,
@pxref{Installation,,, kpathsea, Kpathsea}.  (A copy is in the file
@file{kpathsea/INSTALL}.)

For solutions to common installation problems and information on how to
report a bug, see the file @file{kpathsea/BUGS} (@pxref{Bugs,,,
kpathsea, Kpathsea}).  For solutions to Dvips-specific problems,
@pxref{Debug options}.  Also see the Dvips home page at
@url{http://www.radicaleye.com/dvips}.

Dvips does require some additional installation, detailed in the
sections below.  Also, to configure color devices, @pxref{Color device
configuration}.

@menu
* config.ps installation::        Printer and site Dvips configuration.
* PostScript font installation::  Many PostScript fonts are freely available.
* Ghostscript installation::      A free PostScript interpreter.
* Diagnosing problems::           Some common runtime difficulties.
@end menu


@node config.ps installation
@section @file{config.ps} installation

@flindex config.ps @r{installation}
@cindex installation of @file{config.ps}
@cindex printer configuration
@cindex paper size, default
@cindex configuration files, creating

Dvips has its own configuration files: a file @file{config.ps} for
sitewide defaults, and a file @file{config.@var{printer}} for each
printer (output device).  Since these are site-specific, @code{make
install} does not create them; you must create them yourself.

(These Dvips configuration files are independent of the Kpathsea
onfiguration file @file{texmf.cnf} (@pxref{Config files,,,kpathsea,
Kpathsea}).

@flindex config.proto
@cindex prototype printer configuration file
@cindex printer configuration file, prototype
@cindex configuration files, prototype
Dvips configuration files contents and searching are described fully in
@ref{Config files}.  The simplest way to create a new configuration file
is to copy and modify the file @file{dvipsk/contrib/config.proto},
seasoning with options to your taste from @ref{Config files}.  Here is
@file{config.proto}
for your reading pleasure:
@example
@include contrib/config.proto
@end example


@node PostScript font installation
@section PostScript font installation

@cindex installation of PostScript fonts
@cindex fonts, installation of PostScript
@cindex PostScript fonts, installing

To use PostScript fonts with @TeX{} and Dvips, you need both metric
files (@file{.tfm} and @file{.vf}) and the outlines (@file{.pfa} or
@file{.pfb}).  @xref{Font concepts}.

@cindex Adobe fonts
@cindex Bigelow & Holmes fonts
@cindex Lucida, installing
@cindex Monotype fonts
@cindex Softkey fonts
To support the basic PostScript font set, the recommended (and simplest)
approach is to retrieve @url{ftp://ftp.tug.org/tex/psfonts.tar.gz} and
unpack it in your @code{$(fontdir)} directory
(@file{/usr/local/share/texmf/fonts} by default).  This archive contains
metrics, outlines, and bitmaps (for previewing) for the 35 de facto
standard fonts donated by URW and the additional high-quality freely
available PostScript fonts donated by Adobe, Bitstream, and URW,
including geometrically-created variants such as oblique and small caps.

@cindex Adobe fonts, installing
@cindex Bitstream fonts, installing
@cindex Monotype fonts, installing
@cindex Softkey fonts, installing
@cindex Y&Y fonts, installing
@file{@var{CTAN:}/fonts/psfonts} contains support for many additional
fonts for which you must buy outlines (Adobe, Bigelow & Holmes,
Monotype, Softkey, Y&Y).  @file{psfonts.tar.gz} is a small extract from
this directory.  (For CTAN info, @pxref{unixtex.ftp,,, kpathsea,
Kpathsea}; a copy is in the top-level file @file{INSTALL}.)

@cindex fonts, system PostScript
@cindex PostScript fonts, on your system
@flindex psfonts.map
If you have additional PostScript fonts, you can make them available to
Dvips by (1) giving them with appropriate filenames; and (2) running
Afm2tfm (@pxref{Making a font available}) to make TFM and VF metrics for
@TeX{} and Dvips to use.  Also add them to @file{psfonts.map} if
necessary (@pxref{psfonts.map}); it contains everything contained in
@file{psfonts.tar.gz} and most fonts that come with Unix systems.

Following are locations for vendor-supplied fonts.  Please mail
@email{tex-k@@mail.tug.org} if you find fonts elsewhere on your system.

@table @asis
@item DEC Ultrix
@t{/usr/lib/DPS/outline/decwin}

@item DEC Digital Unix
@t{/usr/lib/X11/fonts/Type1Adobe}

@item HP HP-UX 9, 10
@t{/usr/lib/X11/fonts/type1.st/typefaces}

@item IBM AIX
@t{/usr/lpp/DPS/fonts/outlines}@*
@t{/usr/lpp/X11/lib/X11/fonts/Type1}@*
@t{/usr/lpp/X11/lib/X11/fonts/Type1/DPS}

@item NeXT
@t{/NextLibrary/Fonts/outline}

@item SGI IRIX
@t{/usr/lib/DPS/outline/base}
@t{/usr/lib/X11/fonts/Type1}

@item Sun SunOS 4.x
(NeWSprint only)@*
@t{newsprint_2.5/SUNWsteNP/reloc/$BASEDIR/}@*
@t{   NeWSprint/small_openwin/lib/fonts}@*
@t{/usr/openwin/lib/X11/fonts/Type1/outline}

@item Sun Solaris 2
@t{/usr/openwin/lib/X11/fonts/Type1/outline}

@item VMS
@t{SYS$COMMON:[SYSFONT.XDPS.OUTLINE]}
@end table

@noindent The NeXT system supplies more fonts than any others, but
there's a lot of overlap.

@cindex HP printers and Type 1 fonts
Finally, if you have an Hewlett-Packard printer, you should be able to
get Type 1 font files for the standard 35 fonts from HP, if the freely
available URW Type 1's do not satisfy for whatever reason.  The phone
number for HP Printer Drivers is (in the United States) 303-339-7009.
The driver set to ask for is Adobe Type Manager 2.51, and the disk set
number is @samp{MP210en3}.  Mentioning anything other than Microsoft
Windows when you ask for the driver set will likely lead to great
confusion on the other end.


@node Ghostscript installation
@section Ghostscript installation

@cindex Ghostscript installation
@pindex gs @r{installation}

@cindex Deutsch, Peter
@cindex Epson printers
@cindex previewing Dvips output
@cindex PostScript previewers
@cindex PDF files, making
@cindex Aladdin Ghostscript
Ghostscript is a PostScript interpreter freely available to end-users,
written by Peter Deutsch.  It can read the PostScript produced by Dvips
and render it on your monitor, or for another device (e.g., an Epson
printer) that does not support PostScript, or in PDF format.  The latest
version is available via @url{http://www.cs.wisc.edu/~ghost/index.html}
and @url{ftp://ftp.cs.wisc.edu/pub/ghost/aladdin/}.

@cindex GNU Ghostscript
A somewhat older version of Ghostscript is available under the GNU
General Public License, free to everyone.  You can get that from
@url{ftp://prep.ai.mit.edu/pub/gnu/}.

@cindex Theisen, Tim
@pindex ghostview
@cindex Ghostview, and no @samp{N}
@cindex EPS, and Ghostview
@cindex standard PostScript, required by Ghostview
@findex %%Page@r{, required by Ghostview}
The program Ghostview, written by Tim Theisen, provides typical
previewing capabilities (next page/previous page, magnification, etc.).
It requires Ghostscript to run, and files in structured Postscript,
specifically with @samp{%%Page} comments (no @samp{N} in
@file{config.ps}).  You can get Ghostview from the same places as
Ghostscript.


@node Diagnosing problems
@section Diagnosing problems

@cindex problems
@cindex trouble
@cindex debugging

You've gone through all the trouble of installing Dvips, carefully read
all the instructions in this manual, and still can't get something to
work.  The following sections provide some helpful hints if you find
yourself in such a situation.

For details on effective bug reporting, common installation problems,
and @code{mktexpk} problems, @pxref{Bugs,,, kpathsea, Kpathsea}.

@menu
* Debug options::               Getting diagnostics.
* No output::                   No output at all.
* Small or inverted::           Output too small or inverted.
* Printer errors::              The printer sends back errors.
* Long documents fail::         Long documents fail to print.
* Including graphics fails::    Figures don't work.
@end menu


@node Debug options
@subsection Debug options

@cindex debugging options
@cindex options, debugging

The @samp{-d} flag to Dvips helps in tracking down certain errors.  The
parameter to this flag is an integer that tells what errors are
currently being tracked.  To track a certain class of debug messages,
simply provide the appropriate number given below; if you wish to track
multiple classes, sum the numbers of the classes you wish to track.  To
track all classes, you can use @code{-1}.  Another useful value is
@code{3650}, which tracks everything having to do with file searching
and opening.

Some of these debugging options are actually provided by Kpathsea
(@pxref{Debugging, , , kpathsea, Kpathsea}).

The classes are:
@table @asis
@item 1 
specials
@item 2
paths
@item 4
fonts
@item 8
pages
@item 16
headers
@item 32
font compression
@item 64
files
@item 128
config files
@item 256
Partial Type 1 font encoding vectors
@item 512
Partial Type 1 subr calls
@item 1024
Kpathsea @code{stat} calls
@item 2048
Kpathsea hash table lookups
@item 4096
Kpathsea path element expansion
@item 8192
Kpathsea path searches
@end table


@node No output
@subsection No output at all

@cindex output, none
@cindex no output at all
@cindex failure, to print at all

If you are not getting any output at all, even from the simplest
one-character file (for instance, @samp{\ \bye}), then something is very
wrong.  Practically any file sent to a PostScript laser printer should
generate some output, at the very least a page detailing what error
occurred, if any.  Talk to your system administrator about downloading a
PostScript error handler.  (Adobe distributes a good one called
@samp{ehandler.ps}.)
@flindex ehandler.ps

@cindex PowerPage PostScript implementation
@cindex Shinko CHC-S446i printer
@cindex Mitsubishi Shinko CHC-S446i printer
It is possible, especially if you are using non-Adobe PostScript, that
your PostScript interpreter is broken.  Even then it should generate an
error message.  Dvips tries to work around as many bugs as possible in
common non-Adobe PostScript interpreters, but doubtless it misses a few.
PowerPage Revision 1, Interpreter Version 20001.001, on a Mitsubishi
Shinko CHC-S446i color thermal dye sublimation printer is known to be
unable to print with any but builtin fonts.

If Dvips gives any strange error messages, or compilation on your
machine generated a lot of warnings, perhaps the Dvips program itself is
broken.  Try using the debug options to determine where the error
occurred (@pxref{Debug options}).

It is possible your spooler is broken and is misinterpreting the
structured comments.  Try the @samp{-N} flag to turn off structured
comments and see what happens.


@node Small or inverted
@subsection Output too small or inverted

@cindex output, too small
@cindex output, inverted
@cindex inverted output
@cindex too-small output

@cindex save/restore, and inverted output
If some documents come out inverted or too small, probably your spooler
is not supplying an end of job indicator at the end of each file.  (This
commonly happens on small machines that don't have spoolers.)  You can
force Dvips to do this with the @samp{-F} flag (or @samp{F} config file
option), but this generates files with a terminating binary character
(control-D).  You can also try using the @samp{-s} flag (or @samp{s}
config file option) to enclose the entire job in a save/restore pair.
@xref{Command-line options}, and @ref{Config files}.


@node Printer errors
@subsection Error messages from printer

@cindex printer errors
@cindex error messages from printer
@cindex failure, and printer errors

@cindex @t{bop undefined} error
If your printer returns error messages, the error message gives very
good information on what might be going wrong.  One of the most common
error messages is @samp{bop undefined}.  This is caused by old versions
of Transcript and other spoolers that do not properly parse the setup
section of the PostScript.  To fix this, turn off structured comments
with the @samp{-N} option, but it'd be best to get your spooling
software updated.

@cindex VM exhausted
@cindex printer memory exhausted
@cindex memory of printer exhausted
Another error message is @samp{VM exhausted}.  Some printers indicate
this error by locking up, others quietly reset.  This is caused by Dvips
thinking that the printer has more memory than it actually does, and
then printing a complicated document.  To fix this, try lowering the
@samp{m} parameter in the configuration file; use the debug option to
make sure you adjust the correct file.

Other errors may indicate you are trying to include graphics that don't
nest properly in other PostScript documents, among other things.  Try
the PostScript file on a QMS PS-810 or other Adobe PostScript printer if
you have one, or Ghostscript (@pxref{Ghostscript installation}); it
might be a problem with the printer itself.


@node Long documents fail
@subsection Long documents fail to print

@cindex long documents not printing
@cindex failure, of long documents

This is usually caused by incorrectly specifying the amount of memory
the printer has in the configuration file; see the previous section.


@node Including graphics fails
@subsection Including graphics fails

@cindex including graphics fails
@cindex graphics inclusion fails
@cindex failure, to include graphics

The most common problem with including graphics is an incorrect bounding
box (@pxref{Bounding box}). Complain to whoever wrote the software that
generated the file if the bounding box is indeed incorrect.

@cindex Illustrator, workaround for
Another possible problem is that the figure you are trying to include
does not nest properly; there are certain rules PostScript applications
must follow when generating files to be included.  The Dvips program
includes work-arounds for such errors in Adobe Illustrator and other
programs, but there are certainly applications that haven't been tested.

One possible thing to try is the @samp{-K} flag which strips the comments
from an included figure.  This might be necessary if the PostScript
spooling software does not read the structured comments correctly.  Use
of this flag will break graphics from some applications, though, since
some applications read the PostScript file from the input stream,
looking for a particular comment.

@cindex binary files, not supported
Any application which generates graphics output containing raw binary
(not ASCII hex) will probably fail with Dvips.


@ifclear INSTALLONLY
@node Invoking Dvips
@chapter Invoking Dvips

@cindex command-line options
@cindex options, Dvips
@cindex invoking Dvips

Dvips reads a DVI file as output by (for example) @TeX{}, and converts
it to PostScript, taking care of builtin or downloaded PostScript fonts,
font reencoding, color, etc.  These features are described in other
chapters in this document.

There many ways to control Dvips' behavior: configuration files,
environment variables, and command-line options.

@menu
* Basic usage::
* Command-line options::        
* Environment variables::       
* Config files::                
@end menu


@node Basic usage
@section Basic usage of Dvips

To use Dvips at its simplest, simply type
@example
dvips foo
@end example
@noindent
where @file{foo.dvi} is the output of @TeX{} that you want to print.  If
Dvips has been installed correctly, the document will probably roll out
of your default printer.

If you use fonts that have not been used on your system before, they may
be automatically generated; this process can take a few minutes, so
progress reports appear by default.  The next time that document is
printed, these fonts will have been saved in the proper directories, so
printing will go much faster.  (If Dvips tries to endlessly generate the
same fonts over and over again, it hasn't been installed properly.
@xref{Unable to generate fonts,,, kpathsea, Kpathsea}.)

Many options are available (see the next section).  For a brief summary
of available options, just type
@example
dvips --help
@end example


@node Command-line options
@section Command-line options

Dvips has a plethora of command line options.  Reading through this
section will give a good idea of the capabilities of the driver.

@menu
* Option summary::              Quick listing, from Dvips --help.
* Option details::              More information about each option.
@end menu


@node Option summary
@subsection Option summary

@cindex options, summary
Here is a handy summary of the options; it is printed out when you run
Dvips with no arguments or with the standard @samp{--help} option.
@opindex --help

@example
@include dvips.help
@end example


@node Option details
@subsection Option details

@cindex option, details of

Many of the parameterless options listed here can be turned off by
suffixing the option with a zero (@samp{0}); for instance, to turn off
page reversal, use @samp{-r0}.  Such options are marked with a trailing
@samp{*}.

@table @samp
@item -
@opindex -
@cindex options, reading from standard input
@cindex standard input, reading options from
Read additional options from standard input after processing the command
line.

@item --help
@opindex --help
Print a usage message and exit.

@item --version
@opindex --version
Print the version number and exit.

@item -a*
@opindex -a
@cindex memory, conserving
Conserve memory by making three passes over the DVI file instead
of two and only loading those characters actually used.  Generally only
useful on machines with a very limited amount of memory, like some PCs.

@item -A
@opindex -A
@cindex odd pages only
Print only the odd pages.  This option uses @TeX{}
page numbers, not physical page numbers.

@item -b @var{num}
@opindex -b @var{num}
@vindex /#copies
@cindex copies, duplicated page bodies
@cindex color separations
Generate @var{num} copies of each page, but duplicating the page body
rather than using the @samp{/#copies} PostScript variable.  This can
be useful in conjunction with a header file setting @samp{bop-hook} to
do color separations or other neat tricks.

@item -B
@opindex -B
@cindex even pages only
@cindex double-sided printing
Print only the even pages.  This option uses @TeX{} page numbers, not
physical page numbers.

@item -c @var{num}
@opindex -c @var{num}
@vindex /#copies
@cindex copies, uncollated
@cindex uncollated copies
Generate @var{num} consecutive copies of every page, i.e., the output is
uncollated.  This merely sets the builtin PostScript variable
@samp{/#copies}.

@item -C @var{num}
@opindex -C @var{num}
@cindex copies, collated
@cindex collated copies
Generate @var{num} copies, but collated (by replicating the data in the
PostScript file).  Slower than the @samp{-c} option, but easier on the
hands, and faster than resubmitting the same PostScript file multiple
times.

@item -d @var{num}
@opindex -d @var{num}
@cindex debugging
Set the debug flags, showing what Dvips (thinks it) is doing.  This will
work unless Dvips has been compiled without the @samp{DEBUG} option (not
recommended).  @xref{Debug options}, for the possible values of
@var{num}.  Use @samp{-d -1} as the first option for maximum output.

@item -D @var{num}
@opindex -D @var{num}
@cindex resolution, setting
Set both the horizontal and vertical resolution to @var{num}, given in
dpi (dots per inch). This affects the choice of bitmap fonts that are
loaded and also the positioning of letters in resident PostScript
fonts. Must be between 10 and 10000.  This affects both the horizontal
and vertical resolution.  If a high resolution (something greater than
400 dpi, say) is selected, the @samp{-Z} flag should probably also be
used.  If you are using fonts made with Metafont, such as Computer
Modern, @file{mktexpk} needs to know about the value for @var{num}
that you use or Metafont will fail.  See the file
@url{ftp://ftp.tug.org/tex/modes.mf} for a list of resolutions and mode
names for most devices.

@item -e @var{num}
@opindex -e @var{num}
@cindex maxdrift
@cindex accuracy in positioning
@cindex positioning accuracy
Maximum drift in pixels of each character from its `true'
resolution-independent position on the page. The default value of this
parameter is resolution dependent (it is the number of entries in the
list [100, 200, 300, 400, 500, 600, 800, 1000, 1200, 1600, 2000, 2400,
2800, 3200, @dots{}] that are less than or equal to the resolution in
dots per inch). Allowing individual characters to `drift' from their
correctly rounded positions by a few pixels, while regaining the true
position at the beginning of each new word, improves the spacing of
letters in words.

@item -E*
@opindex -E
@cindex EPSF, generating
@cindex tight bounding box, finding
@cindex bounding box, finding tight
Generate an EPSF file with a tight bounding box.  This only looks at
marks made by characters and rules, not by any included graphics.  In
addition, it gets the glyph metrics from the TFM file, so characters
that print outside their enclosing TFM box may confuse it.  In addition,
the bounding box might be a bit too loose if the character glyph has
significant left or right side bearings.  Nonetheless, this option works
well enough for creating small EPSF files for equations or tables or the
like.  (Of course, Dvips output, especially when using bitmap fonts, is
resolution-dependent and thus does not make very good EPSF files,
especially if the images are to be scaled; use these EPSF files with
care.)  For multiple page input files, also specify @samp{-i} to get
each page as a separate EPSF file; otherwise, all the pages are overlaid
in the single output file.

@item -f*
@opindex -f
@cindex filter, running as a
@cindex standard I/O
@cindex pipes, not readable
@vindex PRINTER@r{, avoided with @samp{-f}}
Run as a filter.  Read the DVI file from standard input and write the
PostScript to standard output.  The standard input must be seekable, so
it cannot be a pipe.  If your input must be a pipe, write a shell script
that copies the pipe output to a temporary file and then points Dvips at
this file.  This option also disables the automatic reading of the
@code{PRINTER} environment variable; use @samp{-P$PRINTER} after the
@samp{-f} to read it anyway.  It also turns off the automatic sending of
control-D if it was turned on with the @samp{-F} option or in the
configuration file; use @samp{-F} after the @samp{-f} to send it anyway.

@item -F*
@opindex -F
@cindex EOF
@cindex control-D
@cindex printer, driving directly
@cindex spooler, lacking
Write control-D (ASCII code 4) as the very last character of the
PostScript file.  This is useful when Dvips is driving the printer
directly instead of working through a spooler, as is common on personal
systems.  On systems shared by more than one person, this is not
recommended.

@item -h @var{name}
@opindex -h @var{name}
@cindex header file, downloading
@cindex userdict@r{, used for header files}
Prepend @var{name} as an additional header file, or, if @var{name} is
@samp{-}, suppress all header files.  Any definitions in the header file
get added to the PostScript @samp{userdict}.

@item -i*
@opindex -i
@cindex sections output, in separate files
@cindex multiple output files
@cindex output files, multiple
Make each section be a separate file; a @dfn{section} is a part of the
document processed independently, most often created to avoid memory
overflow.  The filenames are created replacing the suffix of the
supplied output file name by a three-digit sequence number.  This option
is most often used in conjunction with the @samp{-S} option which sets
the maximum section length in pages; if @samp{-i} is specified and
@samp{-S} is not, each page is output as a separate file.  For instance,
some phototypesetters cannot print more than ten or so consecutive pages
before running out of steam; these options can be used to automatically
split a book into ten-page sections, each to its own file.

@item -j*
@opindex -j @r{for partial font downloading}
Download only needed characters from Type 1 fonts. This is the
default in the current release.  Some debugging flags trace this operation
(@pxref{Debug options}).  You can also control partial downloading on a
per-font basis (@pxref{psfonts.map}).

@item -k*
@opindex -k @r{for cropmarks}
@cindex cropmarks
@flindex crop.pro
Print crop marks.  This option increases the paper size (which should be
specified, either with a paper size special or with the @samp{-T}
option) by a half inch in each dimension.  It translates each page by a
quarter inch and draws cross-style crop marks.  It is mostly useful with
typesetters that can set the page size automatically.  This works by
downloading @file{crop.pro}.

@item -K*
@opindex -K
@cindex comments, removing included
@findex %%Page@r{, removing}
Remove comments in included PostScript graphics, font files, and
headers; only necessary to get around bugs in spoolers or PostScript
post-processing programs.  Specifically, the @samp{%%Page}
comments, when left in, often cause difficulties.  Use of this flag can
cause other graphics to fail, however, since the PostScript header
macros from some software packages read portion the input stream line by
line, searching for a particular comment.

@item -l [=]@var{num}
@opindex -l [=]@var{num}
@cindex last page printed
@cindex page, last printed
@cindex physical page number, and @samp{-l}
@cindex absolute page number, and @samp{-l}
The last page printed will be the first one numbered @var{num}. Default
is the last page in the document.  If @var{num} is prefixed by an equals
sign, then it (and the argument to the @samp{-p} option, if specified)
is treated as a physical (absolute) page number, rather than a value to
compare with the @TeX{} @samp{\count0} values stored in the DVI file.
Thus, using @samp{-l =9} will end with the ninth page of the document,
no matter what the pages are actually numbered.

@item -m*
@opindex -m
@cindex manual feed
Specify manual feed, if supported by the output device.

@item -mode @var{mode}
@opindex -mode @var{mode}
@opindex -mode
@cindex mode name, specifying
@cindex Metafont mode, specifying
Use @var{mode} as the Metafont device name for path searching and font
generation.  This overrides any value from configuration files.  With
the default paths, explicitly specifying the mode also makes the program
assume the fonts are in a subdirectory named @var{mode}.
@xref{TeX directory structure,, @TeX{} directory structure, kpathsea,
Kpathsea}.  If Metafont does not understand the @var{mode} name, see
@ref{Unable to generate fonts,,, kpathsea, Kpathsea}.

@item -M*
@opindex -M
@cindex font generation, avoiding
@pindex mktexpk@r{, avoiding}
@flindex missfont.log
@comment this description repeated in kpathsea.texi
Turns off automatic font generation (@file{mktexpk}).  If
@code{mktexpk}, the invocation is appended to a file
@file{missfont.log} (by default) in the current directory.  You can then
execute the log file to create the missing files after fixing the
problem.
@vindex TEXMFOUTPUT
@vindex MISSFONT_LOG
If the current directory is not writable and the environment variable or
configuration file value @samp{TEXMFOUTPUT} is set, its value is used.
Otherwise, nothing is written.  The name @samp{missfont.log} is
overridden by the @samp{MISSFONT_LOG} environment variable or
configuration file value.

@item -n @var{num}
@opindex -n @var{num}
@cindex maximum pages printed
@cindex pages, maximum printed
Print at most @var{num} pages. Default is 100000.

@item -N*
@opindex -N
@cindex structured comments
@cindex TranScript
@findex %%Page@r{, not generating}
Turns off generation of structured comments such as @samp{%%Page}; this
may be necessary on some systems that try to interpret PostScript
comments in weird ways, or on some PostScript printers.  Old versions of
TranScript in particular cannot handle modern Encapsulated PostScript.
Beware: This also disables page movement, etc., in PostScript viewers
such as Ghostview.

@item -o @var{name}
@opindex -o @var{name}
@cindex output, redirecting
@cindex standard output, output to
Send output to the file @var{name}.  If @samp{-o} is specified without
@var{name}, the default is @samp{@var{file}.ps} where the input DVI file
was @samp{@var{file}.dvi}.  If @samp{-o} isn't given at all, the
configuration file default is used.

@findex popen @r{for output}
@kindex - @r{as output filename}
@kindex ! @r{starting output filename}
@kindex | @r{starting output filename}
@cindex lpr spooler, MS-DOS emulation
@cindex spooling to lpr on MS-DOS
If @var{name} is @samp{-}, output goes to standard output.  If the first
character of @var{name} is @samp{!} or @samp{|}, then the remainder will
be used as an argument to @code{popen}; thus, specifying @samp{|lpr} as
the output file will automatically queue the file for printing as
usual.  (The MS-DOS version will print to the local printer device
@file{PRN} when @var{name} is @samp{|lpr} and a program by that name
cannot be found.)

@samp{-o} disables the automatic reading of the @code{PRINTER}
environment variable, and turns off the automatic sending of control-D.
See the @samp{-f} option for how to override this.

@item -O @var{x-offset},@var{y-offset}
@opindex -O @var{x-offset},@var{y-offset}
@cindex offset pages
@cindex printer offset
Move the origin by @var{x-offset},@var{y-offset}, a comma-separated
pair of dimensions such as @samp{.1in,-.3cm} (@pxref{papersize
special}).  The origin of the page is shifted from the default position
(of one inch down, one inch to the right from the upper left corner of
the paper) by this amount.  This is usually best specified in the
printer-specific configuration file.

@flindex testpage.tex
This is useful for a printer that consistently offsets output pages by a
certain amount.  You can use the file @file{testpage.tex} to determine
the correct value for your printer.  Be sure to do several runs with the
same @code{O} value---some printers vary widely from run to run.

@findex bop-hook@r{, and offset pages}
If your printer offsets every other page consistently, instead of every
page, your best recourse is to use @samp{bop-hook} (@pxref{PostScript
hooks}).

@item -p [=]@var{num}
@opindex -p [=]@var{num}
@cindex first page printed
@cindex page, first printed
@cindex physical page number, and @samp{-p}
@cindex absolute page number, and @samp{-p}
The first page printed will be the first one numbered @var{num}. Default
is the first page in the document.  If @var{num} is prefixed by an
equals sign, then it (and the argument to the @samp{-l} option, if
specified) is treated as a physical (absolute) page number, rather than
a value to compare with the @TeX{} @samp{\count0} values stored in the
DVI file.  Thus, using @samp{-p =3} will start with the third page of
the document, no matter what the pages are actually numbered.

@item -pp @var{first}-@var{last}
@opindex -pp @var{first}-@var{last}
@cindex page range
@opindex -pp @var{range}
Print pages @var{first} through @var{last}; equivalent to @samp{-p
@var{first} -l @var{last}}, except that multiple @samp{-pp} options
accumulate, unlike @samp{-p} and @samp{-l}.  The @samp{-} separator can
also be @samp{:}.

@item -P @var{printer}
@opindex -P @var{printer}
@flindex config.ps
Read the configuration file @file{config.@var{printer}}
(@file{@var{printer}.cfg} on MS-DOS), which can set the output name
(most likely @samp{o |lpr -P@var{printer}}), resolution, Metafont mode,
and perhaps font paths and other printer-specific defaults.  It works
best to put sitewide defaults in the one master @samp{config.ps} file
and only things that vary printer to printer in the
@samp{config.@var{printer}} files; @samp{config.ps} is read before
@samp{config.@var{printer}}.

If no @samp{-P} or @samp{-o} is given, the environment variable
@code{PRINTER} is checked.  If that variable exists, and a corresponding
@file{config.@var{printer}} (@file{@var{printer}.cfg} on MS-DOS) file
exists, it is read.
@xref{Configuration file searching}.

@item -q*
@opindex -q
@cindex quiet operation
@cindex silent operation
@cindex warnings, suppressing
Run quietly.  Don't chatter about pages converted, etc.@: to standard
output; report no warnings (only errors) to standard error.

@item -r*
@opindex -r
@cindex reverse pagination
Output pages in reverse order.  By default, page 1 is output first.

@item -R
@opindex -R
@cindex security
@cindex shell command execution, disabling
@cindex absolute filenames, disabling
@cindex pipes, disabling output to
Run securely.  This disables shell command execution in @code{\special}
(via @samp{`}, @pxref{Dynamic creation of graphics}) and config files
(via the @samp{E} option, @pxref{Configuration file commands}), pipes as
output files, and opening of any absolute filenames.

@item -s*
@opindex -s
@cindex save/restore, generating global
Enclose the output in a global save/restore pair.  This causes the file
to not be truly conformant, and is thus not recommended, but is useful
if you are driving a deficient printer directly and thus don't care too
much about the portability of the output to other environments.

@item -S @var{num}
@opindex -S @var{num}
Set the maximum number of pages in each `section'.  This option is most
commonly used with the @samp{-i} option; see its description above for
more information.

@item -t @var{papertype}
@opindex -t @var{papertype}
@cindex paper type
@cindex media
@cindex letter papertype
@cindex legal papertype
@cindex ledger papertype
@cindex a4 papertype
@cindex a3 papertype
@cindex landscape papertype
Set the paper type to @var{papertype}, usually defined in one of the
configuration files, along with the appropriate PostScript code to
select it (@pxref{Config file paper sizes}).  You can also specify a
@var{papertype} of @samp{landscape}, which rotates a document by 90
degrees.  To rotate a document whose paper type is not the default, you
can use the @samp{-t} option twice, once for the paper type, and once
for @samp{landscape}.

@item -T @var{hsize,vsize}
@opindex -T @var{hsize,vsize}
Set the paper size to (@var{hsize},@var{vsize}), a comma-separated pair
of dimensions such as @samp{.1in,-.3cm} (@pxref{papersize special}).  It
overrides any paper size special in the DVI file.

@item -U*
@opindex -U
@cindex Xerox 4045
Disable a PostScript virtual memory-saving optimization that stores the
character metric information in the same string that is used to store
the bitmap information.  This is only necessary when driving the Xerox
4045 PostScript interpreter, which has a bug that puts garbage on the
bottom of each character.  Not recommended unless you must drive this
printer.

@item -V*
@opindex -V
Download non-resident PostScript fonts as bitmaps.  This requires use
@pindex mtpk
@pindex gsftopk
@pindex pstopk
of @code{mtpk} or @code{gsftopk} or @code{pstopk} or some combination
thereof to generate the required bitmap fonts; these programs are
supplied with Dvips.  The bitmap must be put into @file{psfonts.map} as
the downloadable file for that font.  This is useful only for those
fonts for which you do not have real outlines, being downloaded to
printers that have no resident fonts, i.e., very rarely.


@item -x @var{num}
@opindex -x @var{num}
@cindex magnification, overriding DVI
Set the @math{x} magnification ratio to @math{@var{num}/1000}. Overrides
the magnification specified in the DVI file.  Must be between 10 and
100000.  It is recommended that you use standard magstep values (1095,
1200, 1440, 1728, 2074, 2488, 2986, and so on) to help reduce the total
number of PK files generated.  @var{num} may be a real number, not an
integer, for increased precision.

@item -X @var{num}
@opindex -X @var{num}
@cindex resolution
Set the horizontal resolution in dots per inch to @var{num}.

@item -y @var{num}
@cindex magnification, vertical
Set the @math{y} magnification ratio to @math{@var{num}/1000}.  See
@samp{-x} above.

@item -Y @var{num}
@opindex -Y @var{num}
Set the vertical resolution in dots per inch to @var{num.}
@cindex resolution

@item -z*
@opindex -z @r{for recognizing hyperdvi}
@cindex hyperdvi extensions, enabling
@cindex distillation, and @samp{-z}
@cindex PDF files, option for
@findex html @r{specials, and @samp{-z}}
Pass @samp{html} hyperdvi specials through to the output for eventual
distillation into PDF.  This is not enabled by default to avoid
including the header files unnecessarily, and use of temporary files in
creating the output.  @xref{Hypertext}.

@item -Z*
@opindex -Z @r{for compressing bitmap fonts}
@cindex compressing bitmap fonts
Compress bitmap fonts in the output file, thereby reducing the size of
what gets downloaded.  Especially useful at high resolutions or when
very large fonts are used.  May slow down printing, especially on early
68000-based PostScript printers.  Generally recommend today, and can be
enabled in the configuration file (@pxref{Configuration file commands}).

@end table


@node Environment variables
@section Environment variables

@cindex environment variables

Dvips looks for many environment variables, to define search paths and
other things.  The path variables are read as needed, after all
configuration files are read, so they override values in the
configuration files.  (Except for @code{TEXCONFIG}, which defines where
the configuration files themselves are found.)

@xref{Path specifications,,, kpathsea, Kpathsea}, for details of
interpretation of path and other environment variables common to all
Kpathsea-using programs.  Only the environment variables specific to
Dvips are mentioned here.

@vtable @code
@item DVIPSFONTS
Default path to search for all fonts.  Overrides all the font path
config file options and other environment variables (@pxref{Supported
file formats,,, kpathsea, Kpathsea}).

@item DVIPSHEADERS
Default path to search for PostScript header files.  Overrides the @samp{H}
config file option (@pxref{Configuration file commands}).

@item DVIPSMAKEPK
@pindex mktexpk@r{, changing name}
Overrides @samp{mktexpk} as the name of the program to invoke to
create missing PK fonts.  You can change the arguments passed to the
@code{mktexpk} program with the @code{MAKETEXPK} environment
variable; @pxref{MakeTeX script arguments,,, kpathsea, Kpathsea}.

@item DVIPSRC
Specifies the name of the startup file (@pxref{Configuration file
searching}) which is read after @file{config.ps} but before any
printer-specific configuration files.

@item DVIPSSIZES
@cindex last-resort font scaling, with @code{DVIPSSIZES}
Last-resort sizes for scaling of unfound fonts.  Overrides the @samp{R}
definition in config files (@pxref{Configuration file commands}).

@item PRINTER
Determine the default printer configuration file.  (Dvips itself does
not use @code{PRINTER} to determine the output destination in any way.)

@item TEXCONFIG
@cindex configuration file path
Path to search for Dvips' @file{config.@var{printer}} configuration
files, including the base @file{config.ps}.  Using this single
environment variable, you can override everything else.  (The
printer-specific configuration files are called @file{@var{printer}.cfg}
on MS-DOS, but @file{config.ps} is called by that name on all
platforms.)

@item TEXPICTS
Path to search for included graphics files.  Overrides the @samp{S}
config file option (@pxref{Configuration file commands}).  If not set,
@code{TEXINPUTS} is looked for.  @xref{Supported file formats,,,
kpathsea, Kpathsea}.

@end vtable


@node Config files
@section Dvips configuration files

@cindex configuration files

This section describes in detail the Dvips-specific @file{config.*}
device configuration files (called @file{*.cfg} on MS-DOS), which
override the @file{texmf.cnf}
configuration files generic to Kpathsea which Dvips also reads
(@pxref{Config files,,, kpathsea, Kpathsea}).

For information about installing these files, including a prototype file
you can copy, @pxref{config.ps installation}.

@menu
* Configuration file searching:: Where config.* files are searched for.
* Configuration file commands::  What can go in a config.* file.
@end menu


@node Configuration file searching
@subsection Configuration file searching

@cindex configuration file searching
@cindex searching config files, order of

The Dvips program loads many different configuration files, so that
parameters can be set globally across the system, on a per-device basis,
or individually by each user.

@enumerate
@item
@flindex config.ps@r{, searched for}
Dvips first reads (if it exists) @file{config.ps}; it is searched for
along the path for Dvips configuration files, as described in
@ref{Supported file formats,,, kpathsea, Kpathsea}.

@item
@flindex .dvipsrc@r{, searched for}
A user-specific startup file is loaded, so individual users can override
any options set in the global file.  The environment variable
@code{DVIPSRC}, if defined, is used as the specification of the startup
file.  If this variable is undefined, Dvips uses a platform-specific
default name.  On Unix Dvips looks for the default startup file under
the name @file{$HOME/.dvipsrc}, which is in the user's home directory.
On MS-DOS and MS-Windows, where users generally don't have their private
directories, the startup file is called @file{dvips.ini} and it is
searched for along the path for Dvips configuration files (as described
in @ref{Supported file formats,,, kpathsea, Kpathsea}.); users are
expected to set this path as they see fit for their taste.

@item
@opindex -P@var{printer}@r{, and config file searching}
The command line is read and parsed: if the @samp{-P@var{device}} option
is encountered, at that point @file{config.@var{device}} is loaded.
Thus, the printer configuration file can override anything in the
site-wide or user configuration file, and it can also override options
in the command line up to the point that the @samp{-P} option was
encountered.  (On MS-DOS, the printer configuration files are called
@file{@var{device}.cfg}, since DOS doesn't allow more than 3 characters
after the dot in filenames.)

@item
@vindex PRINTER@r{, and config file searching}
If no @samp{-P} option was specified, and also the @samp{-o} and
@samp{-f} command line options were not used, Dvips checks the
environment variable @code{PRINTER}.  If it exists, then
@file{config.@var{$PRINTER}} (@file{@var{$PRINTER}.cfg} on MS-DOS) is
loaded (if it exists).

@end enumerate

Because the @file{.dvipsrc} file is read before the printer-specific
configuration files, individual users cannot override settings in the
latter.  On the other hand, the @code{TEXCONFIG} path usually includes
the current directory, and can in any case be set to anything, so the
users can always define their own printer-specific configuration files
to be found before the system's.

A few command-line options are treated specially, in that they are not
overridden by configuration files:

@table @samp
@item -D
As well as setting the resolution, this unsets the mode, if the mode was
previously set from a configuration file.  If @file{config.$PRINTER} is
read, however, any @samp{D} or @samp{M} lines from there will take
effect.

@item -mode
This overrides any mode setting (@samp{M} line) in configuration files.
@samp{-mode} does not affect the resolution.

@item -o
This overrides any output setting (@samp{o} line) in configuration files.

@end table

The purpose of these special cases is to (1) minimize the chance of
having a mismatched mode and resolution (which @samp{mktexpk} cannot
resolve), and (2) let command-line options override config files where
possible.


@node Configuration file commands
@subsection Configuration file commands

@cindex configuration file options
@cindex Dvips configuration file options

Most of the configuration file commands are similar to corresponding
command line options, but there are a few exceptions.  When they are the
same, we omit the description here.

As with command line options, many may be turned off by suffixing the
letter with a zero (@samp{0}).

@cindex comments, in configuration files
@cindex continuation lines, not supported
Within a configuration file, empty lines, and lines starting with a
space, asterisk, equal sign, percent sign, or pound sign are ignored.
There is no provision for continuation lines.

@table @samp
@item @@ @var{name hsize vsize}
@opindex @@ @r{paper size config command}
Define paper sizes.  @xref{Config file paper sizes}.

@item a*
@opindex a @r{config command (memory conservation)}
Memory conservation.  Same as @samp{-a}, @pxref{Option details}.

@item b @var{#copies}
@opindex b @r{config command (#copies)}
Multiple copies.  Same as @samp{-b}, @pxref{Option details}.

@item D @var{dpi}
@opindex D @r{config command (dpi)}
Output resolution.  Same as @samp{-D}, @pxref{Option details}.

@item e @var{num}
@opindex e @r{config command (maxdrift)}
Max drift.  Same as @samp{-e}, @pxref{Option details}.

@item E @var{command}
@opindex E @r{config command (shell escape)}
@findex system @r{in config file}
@cindex datestamp, in output
@cindex shell escape, in config file
Executes the command listed with @code{system}(3); can be used to get
the current date into a header file for inclusion, for instance.
Possibly dangerous; this may be disabled, in which case a warning will
be printed if the option is used (and warnings are not suppressed).

@item f*
@itemx F
@opindex f @r{config command (filter)}
@opindex F @r{config command (filter)}
Run as a filter.  Same as @samp{-f}, @pxref{Option details}.

@item h @var{header}
@opindex h @r{header downloading config command}
Prepend @var{header} to output.  Same as @samp{h-}, @pxref{Option details}.

@item H @var{path}
@opindex H @r{header path config command}
@cindex header path, defining
@vindex DVIPSHEADERS@r{, overrides} H
Use @var{path} to search for PostScript header files.  The environment
variable @code{DVIPSHEADERS} overrides this.

@item i @var{n}
@opindex i @r{config command (pages/section)}
Make multiple output files.  Same as @samp{-i -S @var{n}}, @pxref{Option
details}.

@item j*
@opindex j @r{config command (partial font downloading)}
Partially download Type 1 fonts.  Same as @samp{-j}, @pxref{Option details}.

@item K*
@opindex K @r{config command (comment-removeal)}
Remove comments from included PostScript files.  Same as @samp{-K},
@pxref{Option details}.

@item m @var{num}
@opindex m @r{config command (available memory)}
@cindex memory available
@cindex printer memory
Declare @var{num} as the memory available for fonts and strings in the
printer.  Default is 180000.  This value must be accurate if memory
conservation and document splitting is to work correctly.  To determine
this value, send the following file to the printer:

@example
%! Hey, we're PostScript
/Times-Roman findfont 30 scalefont setfont 144 432 moveto
vmstatus exch sub 40 string cvs show pop showpage
@end example

@noindent
The number printed by this file is the total memory free; it is usually
best to tell Dvips that the printer has slightly less memory, because
many programs download permanent macros that can reduce the memory in
the printer.  Some systems or printers can dynamically increase the
memory available to a PostScript interpreter, in which case this file
might return a ridiculously low number; for example, the NeXT computer
and Ghostscript.  In these cases, a value of one million works fine.

@item M @var{mode}
@opindex M @r{config command (mf mode)}
Metafont mode.  Same as @samp{-mode}, @pxref{Option details}.

@item N*
@opindex N @r{EPS-disabling config command}
Disable structured comments.  Beware: This also turns off displaying
page numbers or changing to specific pagenumbers in PostScript viewers.
Same as @samp{-N}, @pxref{Option details}.

@item o @var{name}
@opindex o @r{config command (output file)}
@cindex output file, setting
Send output to @var{name}.  Same as @samp{-}, @pxref{Option details}.
In the file @file{config.foo}, a setting like this is probably
appropriate:
@example
o |lpr -Pfoo
@end example
The MS-DOS version will emulate spooling to @code{lpr} by printing to
the local printer device @file{PRN} if it doesn't find an executable
program by that name in the current directory or along the @code{PATH}.

@item O @var{xoff},@var{yoff}
@opindex O @r{config command (offset)}
Origin offset.  Same as @samp{-O}, @pxref{Option details}.

@item p @r{[+]}@var{name}
@opindex p @r{config command (font aliases)}
@cindex PostScript font alias file
@cindex resident fonts, different in different printers
@kindex +@var{psmapfile}
Examine @var{name} for PostScript font aliases.  Default is
@file{psfonts.map}.  This option allows you to specify different resident
fonts that different printers may have.  If @var{name} starts with a
@samp{+} character, then the rest of the name (after any leading spaces)
is used as an additional map file; thus, it is possible to have local
map files pointed to by local configuration files that append to the
global map file.  This can be used for font families.

@item P @var{path}
@opindex P @r{config command (PK path)}
@vindex PKFONTS@r{, overrides} P
@vindex TEXPKS@r{, overrides} P
@vindex GLYPHFONTS@r{, overrides} P
@vindex TEXFONTS@r{, overrides} P
Use @var{path} to search for bitmap PK font files is @var{path}.  The
@code{PKFONTS}, @code{TEXPKS}, @code{GLYPHFONTS}, and @code{TEXFONTS}
environment variables override this.  @xref{Supported file formats,,,
kpathsea, Kpathsea}.

@item q*
@itemx Q
@opindex q @r{config command (quiet)}
@opindex Q @r{config command (quiet)}
Run quietly.  Same as @samp{-q}, @pxref{Option details}.

@item r*
@opindex r @r{config command (page reversal)}
Page reversal.  Same as @samp{-r}, @pxref{Option details}.

@item R @var{num1 num2 @dots{}}
@opindex R @r{fallback resolution config command}
@cindex fallback resolutions
@cindex default resolutions
@cindex last-resort scaling, with @code{R}
Define the list of default resolutions for PK fonts.  If a font size
actually used in a document is not available and cannot be created,
Dvips will scale the font found at the closest of these resolutions to
the requested size, using PostScript scaling.  The resulting output may
be ugly, and thus a warning is issued.  To turn this last-resort scaling
off, use a line with just the @samp{R} and no numbers.

The given numbers must be sorted in increasing order; any number smaller
than the preceding one is ignored.  This is because it is better to
scale a font up than down; scaling down can obliterate small features in
the character shape.

@vindex DVIPSSIZES@r{, overrides} R
@vindex TEXSIZES@r{, overrides} R
The environment and config file values @samp{DVIPSSIZES} or
@samp{TEXSIZES} override this configuration file setting.

@vindex default_texsizes @r{Make variable}
If no @samp{R} settings or environment variables are specified, a list
compiled in during installation is used. This default list is defined by
the Makefile variable @samp{default_texsizes}, defined in the file
@file{make/paths.make}.

@item s*
@opindex s @r{config command (save/restore)}
Output global save/restore.  Same as @samp{-s}, @pxref{Option details}.

@item S @var{path}
@opindex S @r{config command (pict path)}
@vindex TEXPICTS@r{, overrides} S
@vindex TEXINPUTS@r{, overrides} S
Use @var{path} to search for special illustrations (Encapsulated
PostScript files or psfiles).  The @code{TEXPICTS} and then
@code{TEXINPUTS} environment variables override this.

@item T @var{path}
@opindex T @r{config command (TFM path)}
@vindex TFMFONTS@r{, overrides} T
@vindex TEXFONTS@r{, overrides} T
Use @var{path} to search for TFM files.  The @code{TFMFONTS} and then
@code{TEXFONTS} environment variables overrides this.  This path is used
for resident fonts and fonts that can't otherwise be found.

@item U*
@opindex U @r{config command (Xerox 4045)}
Work around bug in Xerox 4045 printer.  Same as @samp{-U}, @pxref{Option
details}.

@item V @var{path}
@opindex V @r{config command (vf path)}
@cindex virtual font path
@cindex device dependency, and virtual fonts
Use @var{path} to search for virtual font files.  This may be
device-dependent if you use virtual fonts to simulate actual fonts on
different devices.

@item W @r{[@var{string}]}
@opindex W @r{config command (warning)}
@cindex warning messages, defining
If @var{string} is supplied, write it to standard error after reading
all the configuration files; with no @var{string}, cancel any previous
@samp{W} message.  This is useful in the default configuration file to
remind users to specify a printer, for instance, or to notify users
about special characteristics of a particular printer.

@item X @var{num}
@opindex X @r{config command (horizontal resolution)}
Horizontal resolution.  Same as @samp{-X}, @pxref{Option details}.

@item Y @var{num}
@opindex Y @r{config command (vertical resolution)}
Vertical resolution.  Same as @samp{-Y}, @pxref{Option details}.

@item Z*
@opindex Z @r{config command (compression)}
Compress bitmap fonts.  Same as @samp{-Z}, @pxref{Option details}.

@end table


@node Paper size and landscape
@chapter Paper size and landscape orientation

@cindex paper size, general

Most @TeX{} documents at a particular site are designed to use the
standard paper size (letter size in the United States, A4 in Europe).
The Dvips program can be customized either sitewide or for a particular
printer.

@cindex landscape orientation, defined
But many documents are designed for other paper sizes.  For instance,
you may want to design a document that has the long edge of the paper
horizontal.  This can be useful when typesetting booklets, brochures,
complex tables, or many other documents.  This type of paper orientation
is called @dfn{landscape} orientation (the default orientation is
@dfn{portrait}).  Alternatively, a document might be designed for ledger
or A3 paper.

Since the intended paper size is a document design decision, not a
printing decision, such information should be given in the @TeX{} file
and not on the Dvips command line.  For this reason, Dvips supports a
@samp{papersize} special.  It is hoped that this special will become
standard over time for @TeX{} previewers and other printer drivers.

@menu
* papersize special::           Specifying the paper size in TeX.
* Config file paper sizes::     Specifying printer- and site-specific sizes.
* Paper trays::                 Changing paper trays automatically.
@end menu


@node papersize special
@section @samp{papersize} special

@findex papersize @r{special}

The format of the @samp{papersize} special is

@example
\special@{papersize=@var{width},@var{height}@}
@end example

@noindent
@var{width} is the horizontal size of the page, and @var{height} is the
vertical size.  The dimensions supported are the same as for @TeX{};
namely, in (inches), cm (centimeters), mm (millimeters), pt (points), sp
(scaled points), bp (big points, the same as the default PostScript
unit), pc (picas), dd (didot points), and cc (ciceros).

@findex landscape@r{, as @code{\special}}
For a US letter size landscape document, the @code{papersize} would be:
@example
\special@{papersize=11in,8.5in@}
@end example

@noindent
An alternate specification of @code{landscape}:
@example
\special@{landscape@}
@end example

@noindent
This is supported for backward compatibility, but it is hoped that
reventually the @code{papersize} comment will dominate.

Of course, such a @code{\special} only informs Dvips of the desired
paper size; you must also adjust @code{\hsize} and @code{\vsize} in your
@TeX{} document typeset to those dimensions.

The @code{papersize} special must occur somewhere on the first page of
the document.


@node Config file paper sizes
@section Configuration file paper size command

@cindex paper size configuration file command
@cindex configuration file paper size command

The @samp{@@} command in a configuration file sets the paper size
defaults and options.  The first @samp{@@} command defines the default
paper size.  It has three possible parameters:

@example
@@ @r{[}@var{name} @r{[}@var{hsize} @var{vsize}@r{]]}
@end example

If @samp{@@} is specified on a line by itself, with no parameters, it
instructs Dvips to discard all previous paper size information (possibly
from another configuration file).

If three parameters are given, with the first parameter being a name and
the second and third being a dimension (as in @samp{8.5in} or
@samp{3.2cc}, just like in the @samp{papersize} special), then the
option is interpreted as starting a new paper size description, where
@var{name} is the name and @var{hsize} and @var{vsize} define the
horizontal and vertical size of the sheet of paper, respectively. For
example:

@example
@@ letterSize 8.5in 11in
@end example

If both @var{hsize} and @var{vsize} are zero (you must still specify
units!) then any page size will match.  If the @samp{@@} character is
immediately followed by a @samp{+} sign, then the remainder of the line
(after skipping any leading blanks) is treated as PostScript code to
send to the printer, presumably to select that particular paper size:

@example
@@ letter 8.5in 11in
@@+ %%BeginPaperSize: Letter
@@+ letter
@@+ %%EndPaperSize
@end example

After all that, if the first character of the line is an exclamation
point, then the line is put in the initial comments section of the final
output file; else, it is put in the setup section of the output file.
For example:

@example
@@ legal 8.5in 14in
@@+ ! %%DocumentPaperSizes: Legal
@@+ %%BeginPaperSize: Legal
@@+ legal
@@+ %%EndPaperSize
@end example

When Dvips has a paper format name given on the command line, it looks
for a match by the @var{name}; when it has a @samp{papersize} special,
it looks for a match by dimensions.  The first match found (in the order
the paper size information is found in the configuration file) is used.
If nothing matches, a warning is printed and the first paper size is
used.  The dimensions must match within a quarter of an inch.  Landscape
mode for all paper sizes is automatically supported.

If your printer has a command to set a special paper size, then give
dimensions of @samp{0in 0in}; the PostScript code that sets the paper
size can refer to the dimensions the user requested as @samp{hsize} and
@samp{vsize}; these will be macros defined in the PostScript that return
the requested size in default PostScript units.  Virtually all of the
PostScript commands you use here are device-dependent and degrade the
portability of the file; that is why the default first paper size entry
should not send any PostScript commands down (although a structured
comment or two would be okay).  Also, some printers want
@samp{BeginPaperSize} comments and paper size setting commands; others
(such as the NeXT) want @samp{PaperSize} comments and they will handle
setting the paper size.  There is no solution I could find that works
for both (except maybe specifying both).

@flindex mkdvipspapers
The Perl 5 script @file{contrib/mkdvipspapers} in the distribution
directory may help in determining appropriate paper size definitions.

@cindex a4 paper size, as default
If your printers are configured to use A4 paper by default, the
configuration file (probably the global @file{config.ps} in this case)
should include this as the first @samp{@@} command:

@example
@@ A4size 210mm 297mm
@@+ %%PaperSize: A4
@end example

@noindent
so that @code{A4size} is used as the default, and not @code{A4} itself;
thus, no PostScript @code{a4} command is added to the output file,
unless the user explicitly says to use paper size @samp{a4}.  That is,
by default, no paper size PostScript command should be put in the
output, but Dvips will still know that the paper size is A4 because
@samp{A4size} is the first (and therefore default) size in the
configuration file.

Executing the @samp{letter} or @samp{a4} or other PostScript operators
cause the document to be nonconforming and can cause it not to print on
certain printers, so the default paper size should not execute such an
operator if at all possible.


@node Paper trays
@section Paper trays

@cindex paper trays
@cindex dual paper trays
@cindex multiple paper trays
@cindex HP4Si printer and paper trays

Some printers, such as the Hewlett-Packard HP4si, have multiple paper
trays.  You can set up Dvips to take advantage of this using the
@code{bop-hook} PostScript variable (@pxref{PostScript hooks}).

@cindex letterhead tray
For example, suppose you have an alternate tray stocked with letterhead
paper; the usual tray has the usual paper.  You have a document where
you want the first page printed on letterhead, and the remaining pages
on the usual paper. You can create a header file, say
@file{firstletterhead.PS}, with the following (PostScript) code
(@code{bop-hook} is passed the current physical page number, which
starts at zero):

@example
/bop-hook @{ dup 0 eq @{ @var{alternatetray} @} @{ @var{normaltray} @} ifelse @} def
@end example

@noindent where @var{alternatetray} and @var{normaltray} are the appropriate
commands to select the paper trays.  On the 4SI, @var{alternatetray} is
@samp{statusdict begin 1 setpapertray end} and @var{normaltray} is
@samp{statusdict begin 0 setpapertray end}.

Then, include the file with either
@itemize @bullet
@item the @samp{-h} command-line option (@pxref{Option details}); or

@item the @samp{h} config file option (@pxref{Configuration file
commands}); or

@item @samp{\special@{header=@var{file}@}} in your @TeX{} document
(@pxref{Including headers from TeX,, Including headers from @TeX{}}).

@end itemize


@node Interaction with PostScript
@chapter Interaction with PostScript

@cindex interaction with PostScript
@cindex PostScript interaction

Dvips supports inclusion of PostScript figure files (e.g., Encapsulated
PostScript), downloading other header files (e.g., fonts), including
literal PostScript code, and hypertext.

@menu
* PostScript figures::          Including an Encapsulated PostScript figure.
* Header files::                Downloading extra definitions.
* Literal PS::                  Writing literal PostScript code.
* Hypertext::                   Producing HyperPostScript to make PDF.
@end menu


@node PostScript figures
@section PostScript figures

Scaling and including PostScript graphics is a breeze---if the PostScript
file is correctly formed.  Even if it is not, however, the file can usually
be accommodated with just a little more work.

@menu
* Bounding box::                The %%BoundingBox EPS comment.
* EPSF macros::                 Including the file in TeX.
* psfile special::              The basic special.
* Dynamic creation of graphics:: Handling compressed or generated figures.
* Fonts in figures::            The %*Font comment.
@end menu


@node Bounding box
@subsection The bounding box comment

@cindex bounding box, comment for

The most important feature of a good PostScript file from the standpoint
of including it in another document is an accurate bounding box comment.
Every well-formed PostScript file has a comment describing where on the
page the graphic is located, and how big that graphic is.

@cindex big points
@cindex PostScript units
@cindex bounding box, defined
This information is given as the lower left and upper right corners of
the box just enclosing the graphic, and is thus referred to as the
@dfn{bounding box}.  These coordinates are given in the default
PostScript units (there are precisely 72 PostScript units to the inch,
like @TeX{} big points) with respect to the lower left corner of the
sheet of paper.

@findex %%BoundingBox
To see if a PostScript file has a bounding box comment, just look at the
first few lines of the file.  PostScript files are standard ASCII, so
you can use any text editor to do this.  If within the first few dozen
lines there is a line like

@example
%%BoundingBox: 25 50 400 300
@end example

@noindent
(with any reasonable numbers), chances are very good that the file is
Encapsulated PostScript and will work easily with Dvips.  If the file
contains instead a line like

@findex atend@r{, bounding box specification}
@findex (atend)@r{, bounding box specification}
@example
%%BoundingBox: (atend)
@end example

@noindent
the file is still probably Encapsulated PostScript, but the bounding box
is given at the end of the file.  Dvips needs it at the beginning.  You
can move it with that same text editor, or a simple script.  (The
bounding box is given in this way when the program that generated the
PostScript couldn't know the size in advance, or was too lazy to compute
it.)

@pindex bbfig
@cindex bounding box, determining
If the document lacks a @samp{%%BoundingBox:} altogether, you can
determine one in a couple of ways.  One is to use the @samp{bbfig}
program distributed with Dvips in the @file{contrib} directory. This can
usually find the correct bounding box automatically; it works best with
Ghostscript.

@vindex 612 792 @r{bounding box size}
If the comment looks like this:
@example
%%BoundingBox: 0 0 612 792
@end example

@noindent
the graphic claims to take up an entire sheet of paper.  This is
usually a symptom of a bug in the program that generated it.

The other is to do it yourself: print the file.  Now, take a ruler, and
make the following measurements (in PostScript units, so measure in
inches and multiply by 72): From the left edge of the paper to the
leftmost mark on the paper is @var{llx}, the first number.  From the
bottom edge of the paper to the bottommost mark on the paper is
@var{lly}, the second number.  From the left edge of the paper to the
rightmost mark on the paper is @var{urx}, the third number.  The fourth
and final number, @var{ury}, is the distance from the bottom of the page
to the uppermost mark on the paper.

Once you have the numbers, add a comment of the following form as the
second line of the document.  (The first line should already be a line
starting with the two characters @samp{%!}; if it is not, the file
probably isn't PostScript.)

@example
%%BoundingBox: @var{llx} @var{lly} @var{urx} @var{ury}
@end example

@noindent
Or, if you don't want to modify the file, you can simply write these
numbers down in a convenient place and give them in your @TeX{} document
when you import the graphic, as described in the next section.

If the document does not have such a bounding box, or if the bounding
box is given at the end of the document, or the bounding box is wrong,
please complain to the authors of the software package that generated
the file.


@node EPSF macros
@subsection Using the EPSF macros

@cindex EPSF macros
@cindex macros for epsf inclusion

Once the figure file has a bounding box comment (see the previous
section,) you are ready it the graphic into a @TeX{} document.  Many
packages for using EPS files exist.  One distributed with Dvips is the
files @file{epsf.tex} (for plain @TeX{}) and @file{epsf.sty} (for
La@TeX{}).  For plain @TeX{}, add a line like this near the top of your
input file:

@flindex epsf.tex
@example
\input epsf
@end example

@noindent
If you are using La@TeX{} 2e, use the @samp{graphics} or @samp{graphicx}
package.  
@flindex epsf.sty
If you are using La@TeX{} 2.09, add the @samp{epsf} style option, as in:

@example
\documentstyle[12pt,epsf]@{article@}
@end example

@noindent
In any case, the above only needs to be done once, no matter how many
figures you plan to include.

Now, at the point you want to include a file, enter a line such as:

@example
\epsffile@{foo.eps@}
@end example

@findex \leavevmode
@cindex bounding box, supplying to @TeX{}
If you are using La@TeX{}, you may need to add @code{\leavevmode}
immediately before the @code{\epsffile} command to get certain
environments to work correctly.  If your file does not have a bounding
box comment, you can supply the numbers as determined in the previous
section, in the same order they would have been in a normal bounding box
comment:

@example
\epsffile[100 100 500 500]@{foo.ps@}
@end example

@noindent
Now, save your changes and run @TeX{} and Dvips; the output should have
your graphic positioned at precisely the point you indicated, occupying
the proper amount of space.

@findex \epsffile @r{macro}
@cindex figures, natural size
The @code{\epsffile} macro typesets the figure as a @TeX{} @code{\vbox}
at the point of the page that the command is executed.  By default, the
graphic will have its `natural' width (namely, the width of its bounding
box).  The @TeX{} box will have depth zero and its natural height.  By
default, the graphic will be scaled by any DVI magnification in effect,
just as is everything else in your document.  See the next section for
more information on scaling.

@vindex \epsfverbosetrue
@cindex verbose EPSF processing
If you want @TeX{} to report the size of the figure as a message on your
terminal when it processes each figure, give the command:

@example
\epsfverbosetrue
@end example

@menu
* EPSF scaling::                
* EPSF clipping::               
@end menu


@node EPSF scaling
@subsubsection EPSF scaling

@cindex scaling of figures
@cindex figures, scaling

Usually, you will want to scale an EPSF figure to some size appropriate
for your document, since its natural size is determined by the creator
of the EPS file.

The best way to do this is to assign the desired size to the @TeX{}
@code{\epsfxsize} or @code{\epsfysize} variables, whichever is more
convenient for you.  That is, put

@vindex \epsfxsize
@example
\epsfxsize=@var{dimen}
@end example

@noindent
right before the call to @code{\epsffile}.  Then the width of the @TeX{}
box will be @var{dimen} and its height will be scaled proportionately.
Similarly, you can set the vertical size with

@vindex \epsfysize
@example
\epsfysize=@var{dimen}
@end example

@noindent
in which case the height will be set and the width scaled
proportionally.

If you set both, both will be honored, but the aspect ratio of the
included graphic may necessarily be distorted, i.e., its contents
stretched in one direction or the other.

@findex \epsfsize
You can resize graphics in a more general way by redefining the
@code{\epsfsize} macro.  @code{\epsffile} calls this with two
parameters: the natural horizontal and vertical sizes of the PostScript
graphic.  @code{\epsfsize} must expand to the desired horizontal size,
that is, the width of the @code{\vbox}.  Schematically:

@example
\def\epsfsize#1#2@{@var{body}@}
@end example

Some useful definitions of @var{body}:

@table @samp
@item \epsfxsize
This definition (the default) enables the default features listed above,
by setting @code{\epsfxsize} to the same value it had before the macro
was called.

@item #1
Force the natural size by returning the first parameter (the original
width).

@item 0pt
A special case, equivalent to @samp{#1}.

@item 0.5#1
Scale to half the natural size.

@item \hsize
Scale to the current @code{\hsize}.  (In La@TeX{}, use @code{\textwidth}
instead of @code{\hsize}.)

@item \ifnum#1>\hsize\hsize\else#1\fi
If the natural width is greater than the current @code{\hsize}, scale to
@code{\hsize}, otherwise use the natural width.

@end table

@cindex DVI magnification
@cindex magnification, DVI
@vindex \magnification
For compatibility with other PostScript drivers, it is possible to turn
off the default scaling of included figures by the DVI magnification
with the following @TeX{} command:

@vindex /magscale
@example
\special@{! /magscale false def@}
@end example

@noindent
Use of this command is not recommended because it will make the
@code{\epsffile} graphics the ``wrong'' size if global magnification is
being used, and it will cause any PostScript graphics to appear
improperly scaled and out of position if a DVI to DVI program is used to
scale or otherwise modify the document.

@findex bop-hook
DVI magnification is not applied to any output from code you write in
@samp{bop-hook} or its ilk (@pxref{PostScript hooks}),


@node EPSF clipping
@subsubsection EPSF clipping

@cindex clipping of EPSF
@cindex bounding box, inaccurate
@cindex text in figures, chopped off
@cindex lines in figures, wrong width

By default, clipping is disabled for included EPSF images.  This is
because clipping to the bounding box dimensions often cuts off a
small portion of the figure, due to slightly inaccurate bounding
box arguments.  The problem might be subtle; lines around the boundary
of the image might be half their intended width, or the tops or
bottoms of some text annotations might be sliced off.  If you want to
turn clipping on, just use the command

@example
\epsfclipon
@end example

@noindent
and to turn clipping back off, use

@example
\epsfclipoff
@end example


@node psfile special
@subsection @samp{psfile} special

@findex psfile @r{special}

The basic special for file inclusion is as follows:

@example
\special@{psfile=@var{filename}.ps @r{[}@var{key}=@var{value}@r{]} @dots{} @}
@end example

@noindent
This downloads the PostScript file @file{@var{filename}.ps} such that
the current point will be the origin of the PostScript coordinate
system.  The optional @var{key}@t{=}@var{value} assignments allow you to
specify transformations on the PostScript.

The possible @var{key}s are:

@table @samp

@item hoffset
The horizontal offset (default 0)
@item voffset
The vertical offset (default 0)
@item hsize     
The horizontal clipping size (default 612)
@item vsize     
The vertical clipping size (default 792)
@item hscale    
The horizontal scaling factor (default 100)
@item vscale    
The vertical scaling factor (default 100)
@item angle     
The rotation (default 0)
@item clip    
Enable clipping to the bounding box
@end table

The dimension parameters are all given in PostScript units.
The @samp{hscale} and @samp{vscale} are given in non-dimensioned percentage
units, and the rotation value is specified in degrees.
Thus

@example
\special@{psfile=foo.ps hoffset=72 hscale=90 vscale=90@}
@end example

@noindent
will shift the graphics produced by file @file{foo.ps} right by one inch
and will draw it at 0.9 times normal size.  Offsets are given relative
to the point of the special command, and are unaffected by scaling or
rotation.  Rotation is counterclockwise about the origin.  The order of
operations is to rotate the figure, scale it, then offset it.

For compatibility with older PostScript drivers, it is possible to change
the units that @samp{hscale} and @samp{vscale} are given in.  This can be
done by redefining @samp{@@scaleunit}
@vindex scaleunit
in @samp{SDict}
@vindex SDict
by a @TeX{} command such as

@example
\special@{! /@@scaleunit 1 def@}
@end example

@noindent
The @samp{@@scaleunit} variable, which is by default 100, is what
@samp{hscale} and @samp{vscale} are divided by to yield an absolute
scale factor.


@node Dynamic creation of graphics
@subsection Dynamic creation of PostScript graphics files

@cindex dynamic creation of graphics
@cindex compressed PostScript
@cindex uncompressing PostScript

PostScript is an excellent page description language---but it does tend
to be rather verbose.  Compressing PostScript graphics files can reduce
them by factor of five or more.  For this reason, if the name of an
included PostScript file ends with @file{.Z} or @file{.gz}, Dvips
automatically runs @samp{gzip -d}.  For example:

@example
\epsffile[72 72 540 720]@{foo.ps.gz@}
@end example

@noindent
Since the results of such a command are not accessible to @TeX{}, if you
use this facility with the @file{epsf} macros, you need to supply the
bounding box parameter yourself, as shown.

More generally, if the filename parameter to one of the graphics
inclusion techniques starts with a left quote (@samp{`}), the parameter
is instead interpreted as a command to execute that will send the actual
file to standard output.  For example:

@example
\special@{psfile="`gnuplot foo"@}
@end example

@noindent
@flindex gnuplot
to include the file @file{foo}.  Of course, the command to be executed
can be anything, including using a file conversion utility such as
@file{tek2ps} or whatever is appropriate.  This feature can be disabled
with the @samp{-R} command-line option or @samp{R} configuration option.


@node Fonts in figures
@subsection Fonts in figures

@cindex figures and fonts
@cindex fonts, in PostScript figures
@findex %*Font

You can use any font available to @TeX{} and Dvips within a graphics
file by putting a @code{%*Font:} line in the leading commentary of the
file.  Schematically, this looks like:

@example
%*Font: @var{tfmname} @var{scaledbp} @var{designbp} @var{hex-start}:@var{hex-bitstring}
@end example

Here is the meaning of each of these elements:

@table @var
@item tfmname
The @TeX{} TFM filename, e.g., @file{cmr10}.  You can give the same
@var{tfmname} on more than one @samp{%*Font} line; this is useful when
the number of characters from the font used needs a longer
@var{hex-bitstring} (see item below) than conveniently fits on one line.

@item scaledbp
The size at which you are using the font, in PostScript points (@TeX{}
big points).  72@dmn{bp} = 72.27@dmn{pt} = 1@dmn{in}.

@item designbp
The designsize of the font, again in PostScript points.  This should
match the value in the TFM file @var{tfmname}.  Thus, for @file{cmr10},
it should be @samp{9.96265}.

@item hex-start
The character code of the first character used from the font, specified
as two ASCII hexadecimal characters, e.g., @samp{4b} or @samp{4B} for
@samp{K}.

@item hex-bitstring
An arbitrary number of ASCII hexadecimal digits specifying which
characters following (and including) @var{hex-start} are used.  This is
treated as a bitmap.  For example, if your figure used the single letter
@samp{K}, you would use @samp{4b:8} for @var{hex-start} and
@var{hex-bitstring}.  If it used @samp{KLMNP}, you would use
@samp{4b:f4}.

@end table

MetaPost's output figures contain lines like this for bitmap fonts used
in a MetaPost label (@pxref{MetaPost,,, web2c, Web2c}).


@node Header files
@section PostScript header files

@cindex header files, defined
@cindex PostScript header files

@dfn{Header files} are bits of PostScript included in the output file;
generally they provide support for special features, rather than
producing any printed output themselves.  You can explicitly request
downloading header files if necessary for some figure, or to achieve
some special effect.

@vindex psheaderdir
@flindex .pro @r{prologue files}
@flindex .lpro @r{long prologue files}
Dvips includes some headers on its own initiative, to implement features
such as PostScript font reencoding, bitmap font downloading, handling of
@code{\special}'s, and so on.  These standard headers are the
@file{.pro} files (for ``prologue'') in the installation directory
@samp{$(psheaderdir)}; they are created from the @file{.lpro} (``long
prologue'') files in the distribution by stripping
comments, squeezing blank lines, etc., for maximum efficiency.  If you
want to peruse one of the standard header files, read the @file{.lpro}
version.

@vindex userdict@r{, and dictionary files}
@cindex dictionary, @code{userdict}
The PostScript dictionary stack will be at the @samp{userdict} level
when header files are included.

@menu
* Including headers from TeX::  
* Including headers from the command line::  
* Headers and memory usage::
@end menu


@node Including headers from TeX
@subsection Including headers from @TeX{}

@cindex including headers in @TeX{}
@findex header=@var{file} \special
@cindex @TeX{}, including headers in

@cindex headers, including in @TeX{}
In order to get a particular graphic file to work, a certain font or
header file might need to be sent first.  The Dvips program provides
support for this with the @samp{header} @code{\special}.  For instance,
to ensure that @file{foo.ps} gets downloaded:

@example
\special@{header=foo.ps@}
@end example

@cindex fonts, as header files
As another example, if you have some PostScript code that uses a
PostScript font not built into your printer, you must download it to the
printer. If the font isn't used elsewhere in the document, Dvips can't
know you've used it, so you must include it in the same way, as in:

@example
\special@{header=putr.pfa@}
@end example

@noindent
to include the font definition file for Adobe Utopia Roman.


@node Including headers from the command line
@subsection Including headers from the command line

@cindex including headers from the command line
@cindex command line, including headers from
@cindex headers, including from the command line

You can include headers when you run Dvips, as well as from your
document (see the previous section).  To do this, run Dvips with the
option @samp{-P @var{header}}; this will read the file
@file{config.@var{header}}, which in turn can specify a header file to
be downloaded with the @samp{h} option. @xref{Configuration file
commands}.  These files are called @file{@var{header}.cfg} on MS-DOS.

@cindex duplex printers
@cindex simplex mode on duplex printers
@cindex screen frequencies, setting
You can arrange for the same file to serve as a @samp{-P} config file
and the downloadable header file, by starting the lines of PostScript
code with a space, leaving only the @samp{h} line and any comments
starting in the first column.  As an example, see
@file{contrib/volker/config.*} (@file{contrib/volker/*.cfg} on MS-DOS).
(These files also perform useful functions: controlling duplex/simplex
mode on duplex printers, and setting various screen frequencies;
@file{contrib/volker/README} explains further.)


@node Headers and memory usage
@subsection Headers and memory usage

@cindex headers and memory usage
@cindex memory usage, and headers

@cindex sections of output file, and memory
@cindex output file, sectioning of
Dvips tries to avoid overflowing the printer's memory by splitting the
output files into ``sections'' (see the @samp{-i} option in @ref{Option
details}).  Therefore, for all header files, Dvips debits the printer VM
budget by some value.  If the header file has, in its leading
commentary a line of the form

@findex VMusage
@findex %%VMusage
@example
%%VMusage: @var{min} @var{max}
@end example

@noindent
then @var{max} is used.  If there is no @code{%%VMusage} line, then
the size (in bytes) of the header file is used as an approximation.

Illustrations (figure files) are also checked for @code{%%VMusage} line.


@node Literal PS
@section Literal PostScript

@cindex literal PostScript, using
@cindex PostScript code, literal

You can include literal PostScript code in your document in several ways.

@menu
* " special::                   To include inline PostScript code.
* ps special::                  Inline PostScript without save/restore.
* PostScript hooks::            Specifying code to run in the PS interpreter.
* Literal headers::             Literal PostScript for the whole document.
* Literal examples::            Neat example.
@end menu


@node " special
@subsection @code{"} special: Literal PostScript

@findex " @r{special (literal PostScript)}

For simple graphics, or just for experimentation, literal PostScript
code can be included.  Simply use a @code{\special} beginning with a
double quote character @samp{"}; there is no matching closing @samp{"}.

For instance, the following (simple) graphic:

@iftex 
@tex
\vskip\baselineskip
\vbox to 100bp{\vss % a bp is the same as a PostScript unit
\special{" newpath 0 0 moveto 100 100 lineto 394 0 lineto
closepath gsave 0.8 setgray fill grestore stroke}}
@end tex
@end iftex
@ifinfo
[ picture of a grey triangle ]
@end ifinfo

@noindent
was created by typing:

@example
\vbox to 100bp@{\vss % a bp is the same as a PostScript unit
  \special@{" newpath 0 0 moveto 100 100 lineto 394 0 lineto
  closepath gsave 0.8 setgray fill grestore stroke@}@}
@end example

You are responsible for leaving space for such literal graphics, as with
the @code{\vbox} above.


@node ps special
@subsection @samp{ps} special

@findex ps @r{special}

@cindex save/restore, and specials
Generally, Dvips encloses specials in a PostScript save/restore pair,
guaranteeing that the special will have no effect on the rest of the
document.  The @samp{ps} special, however, allows you to insert literal
PostScript instructions without this protective shield; you should
understand what you're doing (and you shouldn't change the PostScript
graphics state unless you are willing to take the consequences).  This
command can take many forms because it has had a torturous history; any
of the following will work:

@example
\special@{ps:@var{text}@}
\special@{ps::@var{text}@}
\special@{ps::[begin]@var{text}@}
\special@{ps::[end]@var{text}@}
@end example

@noindent
(with longer forms taking precedence over shorter forms, when they are
present).  @samp{ps::} and @samp{ps::[end]} do no positioning, so they
can be used to continue PostScript literals started with @samp{ps:} or
@samp{ps::[begin]}.

@findex plotfile@r{, @samp{ps} subspecial}
In addition, the variant

@example
\special@{ps: plotfile @var{filename}@}
@end example

@noindent
@flindex rotate.tex
inserts the contents of @var{filename} verbatim into the output (except
for omitting lines that begin with %).  An example of the proper use of
literal specials can be found in the file @file{rotate.tex}, which makes
it easy to typeset text turned in multiples of 90 degrees.


@node Literal headers
@subsection Literal headers: @samp{!} @code{\special}

@cindex literal headers
@vindex SDict @r{dictionary}

@findex ! @r{special (literal PS header)}
@cindex dictionary, @code{SDict}
You can download literal PostScript header code in your @TeX{} document,
for use with (for example) literal graphics code that you include later.
The text of a @code{\special} beginning with an @samp{!} is copied into
the output file.  A dictionary @code{SDict} will be current when this
code is executed; Dvips arranges for @code{SDict} to be first on the
dictionary stack when any PostScript graphic is included, whether
literally (the @samp{"} special) or through macros (e.g.,
@file{epsf.tex}).

For example:

@example
\special@{! /reset @{ 0 0 moveto@} def@}
@end example


@node PostScript hooks
@subsection PostScript hooks

@cindex PostScript hooks

Besides including literal PostScript at a particular place in your
document (as described in the previous section), you can also arrange to
execute arbitrary PostScript code at particular times while the
PostScript is printing.

@findex bop-hook
@findex eop-hook
@findex start-hook
@findex end-hook
If any of the PostScript names @code{bop-hook}, @code{eop-hook},
@code{start-hook}, or @code{end-hook} are defined in @code{userdict},
they will be executed at the beginning of a page, end of a page, start
of the document, and end of a document, respectively.

@cindex draft copies
@cindex dated output
When these macros are executed, the default PostScript coordinate system
and origin is in effect.  Such macros can be defined in headers added by
the @samp{-h} option or the @samp{header=} special, and might be useful
for writing, for instance, `DRAFT' across the entire page, or, with the
aid of a shell script, dating the document.  These macros are executed
outside of the save/restore context of the individual pages, so it is
possible for them to accumulate information, but if a document must be
divided into sections because of memory constraints, such added
information will be lost across section breaks.

@cindex physical page number, and @code{bop-hook}
The single argument to @code{bop-hook} is the physical page number; the
first page gets zero, the second one, etc.  @code{bop-hook} must leave
this number on the stack.  None of the other hooks are passed arguments.

As an example of what can be done, the following special will write
a light grey `DRAFT' across each page in the document:

@example
\special@{!userdict begin /bop-hook@{gsave 200 30 translate
65 rotate /Times-Roman findfont 216 scalefont setfont
0 0 moveto 0.7 setgray (DRAFT) show grestore@}def end@}
@end example

@findex %%Page@r{, and multi-page information}
Using @code{bop-hook} or @code{eop-hook} to preserve information across
pages breaks compliance with the Adobe document structuring conventions,
so if you use any such tricks, you may also want to use the @samp{-N}
option to turn off structured comments (such as @samp{%%Page}).
Otherwise, programs that read your file will assume its pages are
independent.


@node Literal examples
@subsection Literal examples

@cindex literal PostScript, examples
@cindex examples of literal PostScript

To finish off this section, the following examples of literal PostScript
are presented without explanation:

@example
\def\rotninety@{\special@{ps:currentpoint currentpoint translate 90
rotate neg exch neg exch translate@}@}\font\huge=cmbx10 at 14.4truept
\setbox0=\hbox to0pt@{\huge A\hss@}\vskip16truept\centerline@{\copy0
\special@{ps:gsave@}\rotninety\copy0\rotninety\copy0\rotninety
\box0\special@{ps:grestore@}@}\vskip16truept
@end example

@iftex
@tex
\def\rotninety{\special{ps:currentpoint currentpoint translate 90
rotate neg exch neg exch translate}}
\font\huge=cmbx10 at 14.4truept
\setbox0=\hbox to0pt {\huge A\hss}
\vskip16truept
\centerline{\copy0\special{ps:gsave}
            \rotninety\copy0\rotninety\copy0\rotninety
\box0\special{ps:grestore}}
\vskip16truept
@end tex
@end iftex
@ifinfo
[ There are 4 @samp{A} characters, each rotated 90 degrees about a
  common center point ]
@end ifinfo


@example
\vbox to 2truein@{\special@{ps:gsave 0.3 setgray@}\hrule height 2in
width\hsize\vskip-2in\special@{ps:grestore@}\font\big=cminch\big
\vss\special@{ps:gsave 1 setgray@}\vbox to 0pt@{\vskip2pt
\line@{\hss\hskip4pt NEAT\hss@}\vss@}\special@{ps:0 setgray@}%
\hbox@{\raise2pt\line@{\hss NEAT\hss@}\special@{ps:grestore@}@}\vss@}
@end example

@iftex
@tex
\smallskip
\vbox to 2truein{\special{ps:gsave 0.3 setgray}\hrule height 2in
width\hsize\vskip-2in\special{ps:grestore}\font\big=cminch\big
\vss\special{ps:gsave 1 setgray}\vbox to 0pt{\vskip2pt
\line{\hss\hskip4pt NEAT\hss}\vss}\special{ps:0 setgray}%
\hbox{\raise2pt\line{\hss NEAT\hss}\special{ps:grestore}}\vss}
@end tex
@end iftex
@ifinfo
[ There is a big gray box with the word @samp{NEAT} inside in big letters ]
@end ifinfo

@findex \rotninety
@findex gsave@r{/}grestore@r{, and literal PS}
@findex save@r{/}restore@r{, and literal PS}
Some caveats are in order, however. Make sure that each @code{gsave} is
matched with a @code{grestore} on the same page.  Do not use @code{save}
and @code{restore}; they can interact with the PostScript generated by
Dvips if care is not taken.  Try to understand what the above macros are
doing before writing your own.  The @code{\rotninety} macro especially
has a useful trick that appears again and again.


@node Hypertext
@section Hyper@TeX{}t

@cindex hypertext support

@opindex -z
@findex html @r{specials}
@findex pdfmark
Dvips has support for producing hypertext PostScript documents.  If you
specify the @samp{-z} option, the @file{html:} specials described below
will be converted into @samp{pdfmark} PostScript operators to specify
links.  Without @samp{-z}, @file{html:} specials are ignored.

@cindex distiller, for PDF files
@cindex PDF files, making
The resulting PostScript can then be processed by a distiller program to
make a PDF file.  (It can still be handled by ordinary PostScript
interpreters as well.)  Various versions of both PC and Unix distillers
are supported; Ghostscript includes limited distiller support
(@pxref{Ghostscript installation}).

Macros you can use in your @TeX{} document to insert the specials in the
first place are available from @file{@var{CTAN:}/support/hypertex}.  For
CTAN info, @pxref{unixtex.ftp,,, kpathsea, Kpathsea}.

@flindex @code{http://www.win.tue.nl/~dickie/idvi}
@flindex @code{http://xxx.lanl.gov/hypertex}
@cindex Doyle, Mark
@cindex Bhattacharya, Tanmoy
@cindex Java DVI reader
@pindex idvi @r{Java DVI reader}
@pindex dvihps@r{, hyperdvi to PostScript}
This hypertext support (and original form of the documentation) was
written by Mark Doyle and Tanmoy Bhattacharya as the @samp{dvihps}
program. You can retrieve their software and additional documentation
via the CTAN reference above.  You may also be interested in the Java
previewer IDVI, available at @url{http://www.win.tue.nl/~dickie/idvi},
and/or in @url{http://www.emrg.com/texpdf.html}, which describes
the process of making PDF files from TeX files in more detail.

Mail archives for the original project are at
@url{http://math.albany.edu:8800/hm/ht/}.


@menu
* Hypertext caveats::       Bitmaps poorly supported, psi.
* Hypertext specials::      The details on the specials.
@end menu


@node Hypertext caveats
@subsection Hypertext caveats

@cindex hypertext caveats

@cindex Computer Modern in PostScript
@cindex hypertext and bitmap fonts
If you intend to go all the way to PDF, you will probably want to use
PostScript fonts exclusively, since the Adobe PDF readers are extremely
slow when dealing with bitmap fonts.  Commercial versions of the
Computer Modern fonts are available from Blue Sky; public domain
versions are available from CTAN sites (for CTAN info,
@pxref{unixtex.ftp,,, kpathsea, Kpathsea}) in:
@example
fonts/postscript/bakoma
fonts/postscript/paradissa
@end example
@noindent You may need to modify these fonts; see
@url{http://xxx.lanl.gov/faq/bakoma.html}.

@cindex psi character missing
@cindex trailing spaces, dropped
@cindex spaces, dropped trailing
Also, the Adobe distillers prior to 2.1 drop trailing space characters
(character code 32) from strings.  Unfortunately, the PostScript fonts
use this character code for characters other than space (notably the
Greek letter psi in the @code{Symbol} font), and so these characters are
dropped.  This bug is fixed in version 2.1.

If you can't upgrade, One workaround is to change all the trailing
blanks in strings to a character code that isn't in the font. This works
because the default behavior is to substitute a blank for a missing
character, i.e., the distiller is fooled into substituting the right
character. For instance, with the Blue Sky fonts, you can globally
replace @samp{ )} with @samp{\200)} (with @code{sed}, for example) and
get the desired result.  With the public domain fonts, you will probably
have to use a character code in the range 128 to 191 since these fonts
duplicate the first 32 characters starting at 192 to avoid MS-DOS
problems.


@node Hypertext specials
@subsection Hypertext specials

@cindex hypertext specials
@cindex specials, hypertext

@cindex Smith, Arthur
Current support for the World Wide Web in the @TeX{} system does not
involve modifying @TeX{} itself.  We need only define some specials;
Arthur Smith (@email{apsmith@@aps.org}), Tanmoy Bhattacharya, and Paul
Ginsparg originally proposed and implemented the following:
@example
html:<a href="@var{xurl}">
html:<a name="@var{name}">
html:</a>
html:<img src="@var{xurl}">
html:<base href="@var{xurl}">
@end example

Like all @TeX{} @code{\special}'s, these produce no visible output, and
are uninterpreted by @TeX{} itself.  They are instructions to DVI
processors only.

@cindex uniform resource locator
@cindex extended URL
@cindex URL, extended for @TeX{}
@cindex Murphy, Tim
Here, @var{xurl} is a standard WWW uniform resource locator (URL),
possibly extended with a @samp{#@var{type}.@var{string}} construct,
where @var{type} is @samp{page}, @samp{section}, @samp{equation},
@samp{reference} (for bibliographic references), @samp{figure},
@samp{table}, etc.  For example, 
@smallexample
\special@{html:<a href="http://www.maths.tcd.ie/~tim/ch1.dvi#equation.1.1">@}
@end smallexample
@noindent is a link to equation (1.1) in an example document by Tim Murphy.

@cindex URL, definition
See @url{http://www.w3.org/hypertext/WWW/Addressing/Addressing.html}
for a precise description of base URL's.  (That itself is a URL, in case
you were wondering.)

Descriptions of the @code{\special}'s:
@ftable @samp
@item href
@cindex links, hypertext
Creates links in your @TeX{} document. For example:
@example
\special@{html:<a href="http://www.tug.org/">@}\TeX\ Users
Group\special@{html:</a>@}
@end example
@noindent The user will be able to click on the text `@TeX{} Users
Group' while running Xdvi and get to the TUG home page.  (By the way,
this is for illustration. In practice, you most likely want to use
macros to insert the @code{\special} commands; reference above.)

@item name
@cindex Anderson, Laurie
Defines URL targets in your @TeX{} documents, so links can be
resolved. For example:
@example
\special@{html:<a name="#paradise">@}Paradise\special@{html:</a>@}
is exactly where you are right now.
@end example
This will resolve an @samp{href="paradise"}.

@item img
@flindex mailcap @r{and hypertext}
Links to an arbitrary external file.  Interactively, a viewer is spawned
to read the file according to the file extension and your @file{mailcap}
file (see the Xdvi documentation).

@item base
Defines a base URL that is prepended to all the @code{name} targets.
Typically unnecessary, as the name of the DVI file being read is used by
default.
@end ftable

The @samp{img} and @samp{base} tags are not yet implemented in Dvips or
the NeXTSTEP DVI viewer.


@node PostScript fonts
@chapter PostScript fonts

@cindex PostScript fonts

Dvips supports the use of PostScript fonts in @TeX{} documents.  To use
a PostScript font conveniently, you need to prepare a corresponding
virtual font; the program Afm2tfm, supplied with Dvips, helps
with that.

All the necessary support for the standard 35 PostScript fonts
(@samp{AvantGarde-Book} through @samp{ZapfDingbats}), plus other freely
or commonly available PostScript fonts is available along with Dvips.
To use these fonts, you need do nothing beyond what is mentioned in the
installation procedure (@pxref{Installation}).  This chapter is
therefore relevant only if you are installing new PostScript fonts not
supplied with Dvips. (Or if you're curious.)

@menu
* Font concepts::               Metrics, glyphs, virtual fonts, and encodings.
* Making a font available::     Installing and using a PostScript font.
* Invoking afm2tfm::            Creating TFM and AFM files for a virtual font.
* psfonts.map::                 Defining available PostScript fonts.
@end menu


@node Font concepts
@section Font concepts

@cindex font concepts

The information needed to typeset using a particular font is contained
in two files: a @dfn{metric file} that contains shape-independent
information and a @dfn{glyph file} that contains the actual shapes of
the font's characters.  A @dfn{virtual font} is an optional additional
file that can specify special ways to construct the characters.  @TeX{}
itself (or La@TeX{}) look only at the metric file, but DVI drivers such
as Dvips look at all three of these files.

An @dfn{encoding file} defines the correspondence between the code
numbers of the characters in a font and their descriptive names.  Two
encoding files used together can describe a reencoding that rearranges,
i.e., renumbers, the characters of a font.

@menu
* Metric files::                Shape-independent font information.
* Glyph files::                 Character shapes.
* Virtual fonts::               Constructing one font from others.
* Encodings::                   Character codes and character names.
* PostScript typesetting::      How PostScript typesets a character.
@end menu


@node Metric files
@subsection Metric files

@cindex metric files

A @dfn{metric file} describes properties of the font that are
independent of what the characters actually look like.  Aside from
general information about the font itself, a metric file has two kinds
of information: information about individual characters, organized by
character code, and information about sequences of characters.

The per-character information specifies the width, height, depth, and
italic correction of each character in the font.  Any might be zero.

@cindex kerning, defined
@cindex ligature, defined
In addition to information on individual characters, the metric file
specifies @dfn{kerning}, i.e., adding or removing space between
particular character pairs.  It further specifies @dfn{ligature}
information: when a sequence of input characters should be typeset as a
single (presumably different) ``ligature'' character.  For example, it's
traditional for the input @samp{fi} to be typeset as `fi', not as
`@r{f}@r{i}' (with the dot of the `i' colliding with `f').  (In English,
the only common ligatures are fi, fl, ff, ffi, and ffl.)

Different typesetting systems use different metric file formats:

@itemize @bullet
@item
@cindex afm files
@flindex .afm @r{Adobe metric files}
Each Postscript font has an @dfn{Adobe font metrics} (@samp{.afm})
file. These files are plain text, so you can inspect them easily.  You
can get AFM files for Adobe's fonts from
@url{ftp://ftp.adobe.com/pub/adobe/Fonts/AFMs}.

@item 
@cindex tfm files
@flindex .tfm @r{@TeX{} font metric files}
@TeX{} uses @dfn{@TeX{} font metrics} (@samp{.tfm}) files. When you say
@samp{\font = @var{font}} in your @TeX{} document, @TeX{} reads a file
named @samp{@var{font}.tfm}.  (Well, except for the @file{texfonts.map}
feature; @pxref{Fontmap,,, kpathsea, Kpathsea}).  @TeX{} can then
calculate the space occupied by characters from the font when
typesetting. In addition, the DVI drivers you use to print or view the
DVI file produced by @TeX{} may need to look at the TFM file.

@cindex property list files
@pindex tftopl
@pindex pltotf
@flindex .pl @r{property list files}
TFM files are binary (and hence are typically much smaller than AFM
files). You can use the @code{tftopl} program (@pxref{tftopl
invocation,,, web2c, Web2c}) that comes with @TeX{} to transform a TFM
file into a human-readable ``property list'' (@samp{.pl}) file.  You can
also edit a PL file and transform it back to a @TeX{}-readable TFM with
the companion program @code{pltotf} (@pxref{pltotf invocation,,, web2c,
Web2c}).  Editing metrics by hand is not something you're likely to want
to do often, but the capability is there.

@item
@cindex pfm files
@flindex .pfm @r{printer font metric files}
ATM and other typesetting systems use @dfn{printer font metric}
(@samp{.pfm}) files. These are binary files. They are irrelevant in the
@TeX{} world, and not freely available, so we will not discuss them
further.

@end itemize

The Afm2tfm program distributed with Dvips converts an AFM file
to a TFM file and performs other useful transformations as well.
@xref{Invoking afm2tfm}.


@node Glyph files
@subsection Glyph files

@cindex glyph files

Although a metric file (see the previous section) contains information
about the spatial and other properties of the character at position 75,
say, it contains nothing about what the character at position 75
actually looks like. The glyphs---the actual shapes of the letterforms
in a font---are defined by other files, which we call glyph files.
@TeX{} itself only reads the TFM file for a font; it does not need to
know character shapes.

A @dfn{glyph file} is a file that defines the shapes of the characters
in a font.  The shapes can be defined either by outlines or by bitmaps.

@cindex outline fonts
@cindex arcs
@cindex splines
PostScript fonts are defined as @dfn{outline fonts}: Each character in
the font is defined by giving the mathematical curves (lines, arcs, and
splines) that define its contours.  Different sizes of a character are
generated by linearly scaling a single shape. For example, a 10-point
`A' is simply half the size of a 20-point `A'.  Nowadays, outline fonts
usually also contain @dfn{hints}---additional information to improve the
appearance of the font at small sizes or low resolutions.

@cindex Type 1 fonts
@cindex pfa files
@cindex pfb files
@flindex .pfa @r{printer font ascii files}
@flindex .pfb @r{printer font binary files}
Although various kinds of PostScript outline fonts exist, by far the
most common, and the only one we will consider, is called @dfn{Type 1}.
The glyph files for Postscript Type 1 fonts typically have names ending
in @samp{.pfa} (``printer font ASCII'') or @samp{.pfb} (``printer font
binary'').

@cindex bitmap fonts
@flindex .mf @r{Metafont source files}
@cindex Metafont source files
In contrast, glyph files for Computer Modern and the other standard
@TeX{} fonts are @dfn{bitmap fonts}, generated from Metafont
(@samp{.mf}) descriptions.  The Metafont program distributed with @TeX{}
generates bitmaps from these descriptions.

@cindex pk files
@flindex .@var{nnn}pk @r{packed font bitmaps}
The glyph files for @TeX{} bitmap fonts are usually stored in
@dfn{packed font} (PK) files.  The names of these files end in
@samp{.@var{nnn}pk}, where @var{nnn} is the resolution of the font in
dots per inch.  For example, @file{cmr10.600pk} contains the bitmaps for
the @samp{cmr10} font at a resolution of 600@dmn{dpi}.  (On DOS
filesystems, it's more likely @file{dpi600\cmr10.pk}.)

@cindex gf files
@pindex gftopk
Metafont actually outputs @dfn{generic font} (GF) files, e.g.,
@file{cmr10.600gf}, but the GF files are usually converted immediately
to PK format (using the @code{gftopk} utility that comes with @TeX{})
since PK files are smaller and contain the same information. (The GF
format is a historical artifact.)


@node Virtual fonts
@subsection Virtual fonts

@cindex virtual fonts

A @dfn{virtual font} is constructed by extracting characters from one or
more existing fonts and rearranging them, or synthesizing new characters
in various ways.  The explanation in this manual is intended to suffice
for understanding enough about virtual fonts to use them with Dvips. It
isn't a reference manual on virtual fonts.  For more information: The
primary document on virtual fonts is Donald E. Knuth, @cite{TUGboat}
11(1), Apr.@: 1990, pp.@: 13--23, ``Virtual Fonts: More Fun for Grand
Wizards'' (@file{@var{CTAN:}/info/virtual-fonts.knuth}; for CTAN info,
@pxref{unixtex.ftp,,, kpathsea, Kpathsea}).  (Don't be intimidated by
the subtitle.)

@cindex vf files
@cindex vpl files
A virtual font (@samp{.vf}) file specifies, for each character in the
virtual font, a recipe for typesetting that character.  A VF file, like
a TFM file, is in a compressed binary format.  The @code{vftovp} and
@code{vptovf} programs convert a VF file to a human-readable VPL
(virtual property list) format and back again.  @xref{vftovp
invocation,,, web2c, Web2c}, and @ref{vptovf invocation,,, web2c,
Web2c}.

@cindex base fonts
In the case of a PostScript font @var{f} being used in a straightforward
way, the recipe says: character @var{i} in the VF font is character
@var{j} in font @var{f}.  The font @var{f} is called a @dfn{base font}.
For example, the VF file could remap the characters of the PostScript
font to the positions where @TeX{} expects to find them.
@xref{Encodings}.

Since @TeX{} reads only TFM files, not VF's, each VF must have a
corresponding TFM for use with @TeX{}.  This corresponding TFM is
created when you run @code{vptovf}.

@cindex expansion, of virtual fonts
@cindex virtual font expansion
You can @dfn{expand} virtual fonts into their base fonts with DVIcopy
(@pxref{dvicopy invocation,,, web2c, Web2c}).  This is useful if you are
using a DVI translator that doesn't understand vf's itself.


@node Encodings
@subsection Encodings

@cindex encodings

Every font, whatever its type, has an @dfn{encoding}, that specifies the
correspondence between ``logical'' characters and character codes.  For
example, the ASCII encoding specifies that the character numbered 65
(decimal) is an uppercase `A'.  The encoding does not specify what the
character at that position looks like; there are lots of ways to draw an
`A', and a glyph file (@pxref{Glyph files}) tells how.  Nor does it
specify how much space that character occupies; that information is in a
metric file (@pxref{Metric files}).

@cindex Computer Modern, encoding of
@TeX{} implicitly assumes a particular encoding for the fonts you use
with it.  For example, the plain @TeX{} macro @code{\'}, which typesets
an acute accent over the following letter, assumes the acute accent is
at position 19 (decimal). This happens to be true of standard @TeX{}
fonts such as Computer Modern, as you might expect, but it is not true
of normal PostScript fonts.

It's possible but painful to change all the macros that assume
particular character positions.  A better solution is to create a new
font with the information for the acute accent at position 19, where
@TeX{} expects it to be.  @xref{Making a font available}.

@cindex PostScript encoding
@cindex encoding files
@cindex encoding vectors, defined

PostScript represents encodings as a sequence of 256 character names
called an @dfn{encoding vector}.  An @dfn{encoding file} (@samp{.enc})
gives such a vector, together with ligature and kerning information
(with which we are not concerned at the moment).  These encoding files
are used by the Afm2tfm program.  Encoding files are also downloaded to
the PostScript interpreter in your printer if you use one of them in
place of the default encoding vector for a particular PostScript font.

@flindex dvips.enc
@flindex 8r.enc
@flindex texmext.enc
@flindex texmital.enc
@flindex texmsym.enc
@flindex reencode/*.enc
Examples of encodings: the @file{dvips.enc} encoding file that comes
with Dvips in the @samp{reencode} directory is a good (but not perfect)
approximation to the @TeX{} encoding for @TeX{}'s Computer Modern text
fonts.  This is the encoding of the fonts that originated with Dvips,
such as @file{ptmr.tfm}.  The distribution includes many other encoding
files; for example, @file{8r.enc}, which is the base font for the
current PostScript font distribution, and three corresponding to the
@TeX{} mathematics fonts: @file{texmext.enc} for math extensions,
@file{texmital.enc} for math italics, and @file{texmsym.enc} for math
symbols.


@node PostScript typesetting
@subsection How PostScript typesets a character

@cindex typesetting in PostScript
@cindex character lookup procedure in PostScript

The output of Dvips is a program in the PostScript language that
instructs your (presumably PostScript-capable) printer how to typeset
your document by transforming it into toner on paper.  Your printer, in
turn, contains a PostScript interpreter that carries out the
instructions in this typesetting program.

The program must include the definition of any PostScript fonts that you
use in your document.  Fonts built into your printer (probably the
standard 35: @samp{Times-Roman}, @samp{ZapfDingbats}, @dots{}) are
defined within the interpreter itself.  Other fonts must be downloaded
as pfa or pfb files (@pxref{Glyph files}) from your host (the computer
on which you're running Dvips).

You may be wondering exactly how a PostScript interpreter figures out
what character to typeset, with this mass of metrics, glyphs, encodings,
and other information.  (If you're not wondering, skip this section
@dots{})

@findex show @r{PostScript operator}
The basic PostScript operator for imaging characters is
@code{show}. Suppose you've asked @TeX{} to typeset an `S'. This will
eventually wind up in the Dvips output as the equivalent of this
PostScript operation:

@example
(S) show
@end example

@noindent Here is how PostScript typesets the `S':

@enumerate
@item
@cindex ASCII character codes, used by PostScript
PostScript interpreters use ASCII; therefore `S' is represented as the
integer 83. (Any of the 256 possible characters representable in a
standard 8-bit byte can be typeset.)

@item
@cindex current font, in PostScript
@cindex dictionary, PostScript language
A PostScript @dfn{dictionary} is a mapping of names to arbitrary values.
A font, to the interpreter, is a dictionary which contains entries for
certain names.  (If these entries are missing, the interpreter refuses
to do anything with that font.)

PostScript has a notion of ``the current font''---whatever font is
currently being typeset in.

@item 
@cindex encoding vectors, in Type 1 fonts
@findex Encoding @r{Type 1 dictionary}
One of the mandatory entries in a font dictionary is @samp{Encoding},
which defines the encoding vector (@pxref{Encodings}) for that font.
This vector of 256 names maps each possible input character to a name.

@item
The interpreter retrieves the entry at position 83 of the encoding
vector. This value is a PostScript name: @code{/S}.

@item
@findex CharStrings @r{Type 1 dictionary}
@cindex dictionary, @code{CharStrings}
For Type 1 fonts (we're not going to discuss anything else), the
interpreter now looks up @code{/S} as a key in a dictionary named
@code{CharStrings}, another mandatory entry in a font dictionary.

@item
@cindex hints
@cindex character definitions in PostScript
The value of @code{S} in @code{CharStrings} is the equivalent of a
series of standard PostScript commands like @samp{curveto},
@samp{lineto}, @samp{fill}, and so on. These commands are executed to
draw the character. There can also be @dfn{hint information} that helps
adapt the character to low-resolution rasters.  (@xref{Glyph files}.)
The commands are actually represented in a more compact way than
standard PostScript source; see the Type 1 book for details.

@end enumerate

This method for typesetting characters is used in both Level 1 and Level
2 PostScript.  See the PostScript reference manuals for more
information.


@node Making a font available
@section Making a PostScript font available

@cindex installing fonts
@cindex fonts, installing

To make a PostScript font available in a @TeX{} document, you need to
install the font on your system and then define it within the document.
Once you have installed the font, of course, it is available for any
document thereafter and you don't need to reinstall it.  You must have
an AFM file for any font you install. Unless the font is built into your
printer, you must also have a PFA or PFB file.

In the following examples, we use the font @samp{Times-Roman} to
illustrate the process.  But you should use the prebuilt fonts for Times
and the other standard fonts, rather than rebuilding them.  The prebuilt
fonts are made using a more complicated process than that described
here, to make them work as well as possible with @TeX{}.  So following
the steps in this manual will not generate files identical to the
distributed ones.  @xref{PostScript font installation}, for pointers to
the prebuilt fonts.

Installation of a PostScript font proceeds in three steps.  @xref{Font
concepts}, for descriptions of the various files involved.

@enumerate
@item
Run @code{afm2tfm} to create a TFM file for the original font,
and the VPL form of the virtual font:
@example
afm2tfm Times-Roman -v ptmr rptmr
@end example

@item
Run @code{vptovf} to generate a VF and TFM file for the virtual font
from the VPL file:
@example
vptovf ptmr.vpl ptmr.vf ptmr.tfm
@end example

@item
Insert an entry for the font in @file{psfonts.map} (@xref{psfonts.map}):
@example
rptmr      Times-Roman                 <ptmr8a.pfa
@end example

@item
Install the files in the standard locations, as in:
@example
cp ptmr.vf @var{fontdir}/vf/@dots{}
cp *ptmr.tfm @var{fontdir}/tfm/@dots{}
cp ptmr.afm @var{fontdir}/afm/@dots{}
cp ptmr.pf? @var{fontdir}/type1/@dots{}
@end example
@end enumerate

The simplest invocation of Afm2tfm to make virtual fonts goes something
like this:

@pindex afm2tfm
@example
afm2tfm Times-Roman -v ptmr rptmr
@end example

@noindent
This reads the file @file{Times-Roman.afm}, and produces two files as
output, namely the virtual property list'file @file{ptmr.vpl}, and the
``raw'' font metric file @file{rptmr.tfm}. To use the font in @TeX{},
you first run

@pindex vptovf
@example
vptovf ptmr.vpl ptmr.vf ptmr.tfm
@end example

@noindent
You should then install the virtual font file @file{ptmr.vf} where Dvips
will see it and install @file{ptmr.tfm} and @file{rptmr.tfm} where
@TeX{} and Dvips will see them.

Using these raw fonts is not recommended; there are no raw fonts in the
prebuilt PostScript fonts distributed along with Dvips.  But
nevertheless, that's how Afm2tfm presently operates, so that's what we
document here.  The @samp{r} prefix convention is likewise historical
accident.

You can also make more complex virtual fonts by editing @file{ptmr.vpl}
before running @samp{vptovf}; such editing might add the uppercase Greek
characters in the standard @TeX{} positions, for instance.  (This has
already been done for the prebuilt fonts.)

Once the files have been installed, you're all set. You can now do
things like this in @TeX{}:
@example
\font\myfont = ptmr at 12pt
\myfont Hello, I am being typeset in 12-point Times-Roman.
@end example

Thus, we have two fonts, one actual (@samp{rptmr}, which is analogous to
the font in the printer) and one virtual (@samp{ptmr}, which has been
remapped to the standard @TeX{} encoding (almost)), and has typesetting
know-how added. You could also say

@example
\font\raw = rptmr at 10pt
@end example

@noindent
and typeset directly with that, but then you would have no ligatures or
kerning, and you would have to use Adobe character positions for special
letters like
@tex
\AE.
@end tex
@ifinfo
the ligature `AE'.
@end ifinfo
The virtual font @samp{ptmr} not only has ligatures and kerning, and
most of the standard accent conventions of @TeX{}, it also has a few
additional features not present in the Computer Modern fonts. For
example, it includes all the Adobe characters (such as the Polish ogonek
and the French guillemots).  The only things you lose from ordinary
@TeX{} text fonts are the dotless `j' (which can be hacked into the VPL
file with literal PostScript specials if you have the patience) and
uppercase Greek letters (which just don't exist unless you buy them
separately).  @xref{Reencoding with Afm2tfm}.

As a final step you need to record information about both the virtual
font and the original font (if you ever might want to use it) in the
@file{psfonts.map} file (@pxref{psfonts.map}).  For our example, you'd
insert the following into @file{psfonts.map}:
@example
rptmr      Times-Roman                 <ptmr8a.pfa
@end example

@noindent Of course, @code{Times-Roman} is already built in to most every
printer, so there's no need to download any Type 1 file for it.  But if
you are actually following these instructions for new fonts, most likely
they are not built in to the printer.

@cindex memory, used by PostScript fonts
@cindex efficiency, and fonts
These PostScript fonts can be scaled to any size.  Go wild!  Using
PostScript fonts, however, does use up a great deal of the printer's
memory and it does take time.  You may find downloading bitmap fonts
(possibly compressed, with the @samp{Z} option) to be faster than using
the built-in PostScript fonts.


@node Invoking afm2tfm
@section Invoking Afm2tfm

@pindex afm2tfm

The Afm2tfm program converts an AFM file for a PostScript font to a TFM
file and a VPL file for a corresponding virtual font (or, in its
simplest form, to a TFM file for the PostScript font itself).  The
results of the conversion are affected by the command-line options and
especially by the reencodings you can specify with those options.  You
can also obtain special effects such as an oblique font.

@pindex fontinst
@cindex virtual fonts, creating
@cindex Jeffrey, Alan
An alternative to Afm2tfm for creating virtual fonts is Alan Jeffrey's
@code{fontinst} program, available from
@file{@var{CTAN:}fonts/utilities/fontinst} (for CTAN info,
@pxref{unixtex.ftp,,, kpathsea, Kpathsea}).

@menu
* Changing font encodings::     Reencoding with -t, -p, -T.
* Special font effects::        Oblique fonts, small caps, and such.
* Afm2tfm options::             afm2tfm command-line options.
@end menu


@node Changing font encodings
@subsection Changing font encodings

@cindex encoding changes
@cindex fonts, changing encoding of

Afm2tfm allows you to specify a different encoding for a PostScript font
(for a general introduction to encodings, @pxref{Encodings}). The 
@samp{-t} options changes the @TeX{} encoding, @samp{-p} changes the
PostScript encoding, and @samp{-T} changes both simultaneously, as
detailed in the sections below.

@menu
* Changing TeX encodings::      Where TeX finds a character.
* Changing PostScript encodings::  Where PostScript finds a character.
* Changing both encodings::     One and the same, simultaneously.
* Reencoding with Afm2tfm::     Problems with the default encoding.
* Encoding file format::        Syntax of an encoding file.
@end menu


@node Changing TeX encodings
@subsubsection @samp{-t}: Changing @TeX{} encodings

@cindex changing @TeX{} encodings
@cindex @TeX{} encoding, changing

@opindex -t @var{tex-enc}
To build a virtual font with Afm2tfm, you specify the @samp{-v} or
@samp{-V} option. You can then specify an encoding for that virtual font
with @samp{-t @var{tex-enc}}.  (@samp{-t} is ignored if neither
@samp{-v} nor @samp{-V} is present.)  Any ligature and kerning
information you specify in @var{tex-enc} will be used in the VPL, in
addition to the ligature and kerning information from the AFM file.

If the AFM file has no entry for a character specified in @var{tex-enc},
that character will be omitted from the output VPL.

@flindex texmsym.enc
The @samp{-t} option is likely to be needed when you have a PostScript
font corresponding to a @TeX{} font other than a normal text font such
as Computer Modern.  For instance, if you have a PostScript font that
contains math symbols, you'd probably want to use the encoding in the
@file{texmsym.enc} file supplied with Dvips. (For a start; to actually
get usable math fonts, you have to define much more than just an
encoding.)


@node Changing PostScript encodings
@subsubsection @samp{-p}: Changing PostScript encodings

@cindex changing PostScript encodings
@cindex PostScript encoding, changing
@opindex -p @var{ps-enc}

By default, Afm2tfm uses the encoding it finds in the AFM file.  You can
specify a different PostScript encoding with @samp{-p @var{ps-enc}}.
This makes the raw TFM file (the one output by Afm2tfm) have the
encoding specified in the encoding file @var{ps-enc}.  Any ligature or
kern information specified in @var{ps-enc} is ignored by Afm2tfm, since
ligkern info is always omitted from the raw TFM.

If you use this option, you must also arrange to download @var{ps-enc}
as part of any document that uses this font.  You do this by adding a
line like the following one to @file{psfonts.map} (@pxref{psfonts.map}):
@example
zpopr Optima "MyEncoding ReEncodeFont" <myenc.enc
@end example

@findex trademark @r{character, accessing}
@findex registered @r{character, accessing}
@cindex extra characters, accessing
Using @samp{-p} is the only way to access characters in a PostScript
font that are neither encoded in the AFM file nor constructed from other
characters.  For instance, Adobe's @samp{Times-Roman} font contains the
extra characters @samp{trademark} and @samp{registered} (among others);
these can only be accessed through such a PostScript reencoding.

@findex 8r @r{encoding, and extra characters}
In fact, the `8r' base encoding used for the current PostScript font
distribution (available at @url{ftp://ftp.tug.org/tex/psfonts.tar.gz})
does do this reencoding, for precisely this reason.


@node Changing both encodings
@subsubsection @samp{-T}: Changing both @TeX{} and PostScript encodings

@opindex -T @var{enc-file}

The option @samp{-T @var{enc-file}} is equivalent to @samp{-p
@var{enc-file} -t @var{enc-file}}.  If you make regular use of a private
non-standard reencoding @samp{-T} is usually a better idea than the
individual options, to avoid unexpected inconsistencies in mapping
otherwise.  An example of when you might use this option is a dingbats
font: when you have a @TeX{} encoding that is designed to be used with a
particular PostScript font.


@node Reencoding with Afm2tfm
@subsubsection Reencoding with Afm2tfm

@cindex reencoding
@cindex remapping

The Afm2tfm program creates the TFM and VF files for the virtual font
corresponding to a PostScript font by @dfn{reencoding} the PostScript
font.  Afm2tfm generates these files from two encodings: one for @TeX{}
and one for PostScript.  The @TeX{} encoding is used to map character
numbers to character names while the PostScript encoding is used to map
each character name to a possibly different number.  In combination, you
can get access to any character of a PostScript font at any position for
@TeX{} typesetting.

In the default case, when you specify none of the @code{-t}, @code{-p},
or @code{-T} options, Afm2tfm uses a default @TeX{} encoding (which
mostly corresponds to the Computer Modern text fonts) and the PostScript
encoding found in the AFM file being read.  The reencoding is also
sometimes called a @dfn{remapping}.

For example, the default encodings reencode the acute accent in two
steps: first the default @TeX{} encoding maps the number 19 to the
character name @samp{acute}; then the default PostScript encoding, as
found in the AFM file for an ordinary PostScript font, maps the
character name @samp{acute} to the number 194.  (The PostScript encoding
works in reverse, by looking in the encoding vector for the name and
then yielding the corresponding number.)  The combined mapping of 19 to
194 shows up explicitly in the VF file and also implicitly in the fact
that the properties of PostScript character 194 appear in position 19 of
the TFM file for the virtual font.

@cindex accents, in wrong position
@cindex Hungarian umlaut
@cindex dot accent
@cindex Scandinavian A ring
@cindex A ring, Scandinavian letter
The default encoding of the distributed fonts (e.g., @file{ptmr.tfm})
mostly follows plain @TeX{} conventions for accents.  The exceptions:
the Hungarian umlaut (which is at position @code{0x7D} in @samp{cmr10},
but position @code{0xCD} in @samp{ptmr}); the dot accent (at positions
@code{0x5F} and @code{0xC7}, respectively); and the Scandinavian A ring
@code{\AA}, whose definition needs different tweaking.  In order to use
these accents with PostScript fonts or in math mode when
@code{\textfont0} is a PostScript font, you will need to use the
following definitions.  These definitions will not work with the
Computer Modern fonts for the relevant accents.  They are already part
of the distributed @file{psfonts.sty} for use with La@TeX{}.

@findex \H
@findex \.
@findex \dot
@findex \AA
@example
\def\H#1@{@{\accent"CD #1@}@}
\def\.#1@{@{\accent"C7 #1@}@}
\def\dot@{\mathaccent"70C7 @}
\newdimen\aadimen
\def\AA@{\leavevmode\setbox0\hbox@{h@}\aadimen\ht0
  \advance\aadimen-1ex\setbox0\hbox@{A@}\rlap@{\raise.67\aadimen
  \hbox to \wd0@{\hss\char'27\hss@}@}A@}
@end example

@vindex CODINGSCHEME
As a kind of summary, here are the @samp{CODINGSCHEME}s that result from
the various possible choices for reencoding.

@table @asis
@item default encoding
@example
(CODINGSCHEME TeX text + AdobeStandardEncoding)
@end example

@item @samp{-p dc.enc}
@example
(CODINGSCHEME TeX text + DCEncoding)
@end example

@item @samp{-t dc.enc}
@example
(CODINGSCHEME DCEncoding + AdobeStandardEncoding)
@end example

@item @samp{-T dc.enc}
@example
(CODINGSCHEME DCEncoding + DCEncoding)
@end example

@end table

@noindent The @samp{CODINGSCHEME} line appears in the VPL file but is
ignored by Dvips.


@node Encoding file format
@subsubsection Encoding file format

@cindex encoding file format

Afm2tfm's encoding files have the same format as an encoding vector in a
PostScript font.  Here is a skeletal example:

@example
% @r{Comments are ignored, unless the first word after the percent sign}
% @r{is @samp{LIGKERN}; see below.}
/MyEncoding [ % @r{exactly 256 entries follow, each with a leading @samp{/}}
  /Alpha /Beta /Gamma /Delta @dots{}
  /A /B @dots{} /Z 
  @dots{}  /.notdef /xfooaccent /yfooaccent /zfooaccent
] def
@end example

These encoding files are downloaded as part of changing the encoding at
the PostScript level (see the previous section).

@cindex comments, in encoding files
Comments, which start with a percent sign and continue until the end
of the line, are ignored unless they start with @samp{LIGKERN} (see below).

The first non-comment word of the file must start with a forward slash
@samp{/} (i.e., a PostScript literal name) and defines the name of the
encoding.  The next word must be an left bracket @samp{[}.  Following
that must be precisely 256 character names; use @samp{/.notdef} for any
that you want to leave undefined.  Then there must be a matching right
bracket @code{]}.  A final @samp{def} token is optional.  All names are
case-sensitive.

Any ligature or kern information is given as a comment.  If the first
word after the @samp{%} is @samp{LIGKERN}, then the entire rest of the
line is parsed for ligature and kern information.  This ligature and
kern information is given in groups of words: each group is terminated
by a space and a semicolon and (unless the semicolon is at the end of a
line) another space.

@findex LIGKERN @r{encoding file command}
In these @code{LIGKERN} statements, three types of information may be
specified.  These three types are ligature pairs, kerns to ignore, and
the character value of this font's boundary character. 

@cindex boundary character
Throughout a @code{LIGKERN} statement, the boundary character is
specified as @samp{||}. To set the font's boundary character value for
@TeX{}:

@example
% LIGKERN || = 39 ;
@end example

To indicate a kern to remove, give the names of the two characters
(without the leading slash) separated by @samp{@{@}}, as in @samp{one
@{@} one ;}.  This is intended to be reminiscent of the way you might
use @samp{@{@}} in a @TeX{} file to turn off ligatures or kerns at a
particular location.  Either or both of the character names can be given
as @samp{*}, which is a wild card matching any character; thus, all
kerns can be removed with @samp{* @{@} * ;}.

@cindex ligature operations
@cindex Metafont ligature operations
To specify a ligature, specify the names of the pair of characters,
followed by the ligature operation (as in Metafont), followed by the
replacing character name.  Either (but not both) of the first two
characters can be @samp{||} to indicate a word boundary.

@findex =: @r{ligature operation}
The most common operation is @samp{=:} meaning that both characters are
removed and replaced by the third character, but by adding the @samp{|}
character on either side of the @samp{=:}, you can retain either or both
of the two leading characters.  In addition, by suffixing the ligature
operation with one or two @samp{>} signs, you can make the ligature
scanning operation skip that many resulting characters before
proceeding.  This works just like in Metafont.  For example, the `fi'
ligature is specified with @w{@samp{f i =: fi ;}}.  A more convoluted
ligature is @samp{one one |=:|>> exclam ;} which separates a pair of
adjacent @code{1}'s with an exclamation point, and then skips over two
of the resulting characters before continuing searching for ligatures
and kerns.  You cannot give more @t{>}'s than @t{|}'s in an ligature
operation, so there are a total of eight possibilities:

@example
=: |=: |=:> =:| =:|> |=:| |=:|> |=:|>>
@end example

The default set of ligatures and kerns built in to Afm2tfm is:

@example
% LIGKERN question quoteleft =: questiondown ;
% LIGKERN exclam quoteleft =: exclamdown ;
% LIGKERN hyphen hyphen =: endash ; endash hyphen =: emdash ;
% LIGKERN quoteleft quoteleft =: quotedblleft ;
% LIGKERN quoteright quoteright =: quotedblright ;
% LIGKERN space @{@} * ; * @{@} space ; 0 @{@} * ; * @{@} 0 ;
% LIGKERN 1 @{@} * ; * @{@} 1 ; 2 @{@} * ; * @{@} 2 ; 3 @{@} * ; * @{@} 3 ;
% LIGKERN 4 @{@} * ; * @{@} 4 ; 5 @{@} * ; * @{@} 5 ; 6 @{@} * ; * @{@} 6 ;
% LIGKERN 7 @{@} * ; * @{@} 7 ; 8 @{@} * ; * @{@} 8 ; 9 @{@} * ; * @{@} 9 ;
@end example


@node Special font effects
@subsection Special font effects

@cindex oblique fonts
@cindex slanted fonts
@cindex fonts, slanted
Besides the reencodings described in the previous section, Afm2tfm can
do other manipulations.  (Again, it's best to use the prebuilt fonts
rather than attempting to remake them.)

@samp{-s @var{slant}} makes an obliqued variant, as in:

@example
afm2tfm Times-Roman -s .167 -v ptmro rptmro
@end example

@noindent
This creates @file{ptmro.vpl} and @file{rptmro.tfm}.  To use this font,
put the line

@findex SlantFont
@example
rptmro Times-Roman ".167 SlantFont"
@end example

@noindent
@flindex psfonts.map
into @file{psfonts.map}.  Then @samp{rptmro} (our name for the obliqued
Times) will act as if it were a resident font, although it is actually
constructed from Times-Roman via the PostScript routine @code{SlantFont}
(which will slant everything 1/6 to the right, in this case).

@cindex expanded fonts
@cindex fonts, expanded
Similarly, you can get an expanded font with

@example
afm2tfm Times-Roman -e 1.2 -v ptmrre rptmrre
@end example

@noindent
and by recording the pseudo-resident font
@findex ExtendFont

@example
rptmrre Times-Roman "1.2 ExtendFont"
@end example

@noindent
in @file{psfonts.map}.

You can also create a small caps font with a command such as
@cindex small caps fonts
@cindex fonts, small caps

@example
afm2tfm Times-Roman -V ptmrc rptmrc
@end example

@noindent
This will generate a set of pseudo-small caps mapped into the usual
lowercase positions and scaled down to 0.8 of the normal cap
dimensions.  You can also specify the scaling as something other than
the default 0.8:

@example
afm2tfm Times-Roman -c 0.7 -V ptmrc rptmrc
@end example

It is unfortunately not possible to increase the width of the small caps
independently of the rest of the font.  If you want a really
professional looking set of small caps, you need to acquire a small caps
font.

@findex PaintType
@cindex outline fonts
@cindex fonts, outlined
To change the @code{PaintType} in a font from filled (0) to outlined
(2), you can add @code{"/PaintType 2 store"} to @file{psfonts.map}, as
in the following:

@example
rphvrl   Helvetica "/PaintType 2 store"
@end example

Afm2tfm writes to standard output the line you need to add to
@file{psfonts.map} to use that font, assuming the font is resident in
the printer; if the font is not resident, you must add the
@samp{<@var{filename}} command to download the font.  Each identical
line only needs to be specified once in the @samp{psfonts.map} file,
even though many different fonts (small caps variants, or ones with
different output encodings) may be based on it.


@node Afm2tfm options
@subsection Afm2tfm options

@cindex options, to Afm2tfm
@cindex afm2tfm options

Synopsis:
@example
afm2tfm [@var{option}]@dots{} @var{afmfile}[.afm] [@var{tfmfile}[.tfm]]
@end example

Afm2tfm reads @var{afmfile} and writes a corresponding (but raw) TFM
file. If @var{tfmfile} is not supplied, the base name of the AFM file is
extended with @samp{.tfm} to get the output filename.

The simplest example:

@example
afm2tfm Times-Roman rptmr
@end example

@cindex accents, wrong
@noindent
The TFM file thus created is @dfn{raw} because it omits ligature and
kern information, and does no character remapping; it simply contains
the character information in the AFM file in TFM form, which is the form
that @TeX{} understands.  The characters have the same code in the TFM
file as in the AFM file.  For text fonts, this means printable ASCII
characters will work ok, but little else, because standard PostScript
fonts have a different encoding scheme than the one that plain @TeX{}
expects (@pxref{Encodings}).  Although both schemes agree for the
printable ASCII characters, other characters such as ligatures and
accents vary.  Thus, in practice, it's almost always desirable to create
a virtual font as well with the @samp{-v} or @samp{-V} option.
@xref{Making a font available}.

The command line options to Afm2tfm:

@table @samp
@item -c @var{ratio}
@opindex -c @var{ratio}
@cindex scaling small caps
See @samp{-V}; overrides the default ratio of 0.8 for the
scaling of small caps.

@item -e @var{ratio}
@opindex -e @var{ratio}
@cindex expanded fonts
@cindex condensed fonts
Stretch characters horizontally by @var{ratio}; if less than 1.0, you
get a condensed font.

@item -O
@opindex -O
@cindex octal character codes
Output all character codes in the @samp{vpl} file as octal numbers, not
names; this is useful for symbol or other special-purpose fonts where
character names such as @samp{A} have no meaning.

@item -p @var{ps-enc}
@opindex -p @var{ps-enc}
Use @var{ps-enc} for the destination (PostScript) encoding of the font;
@var{ps-enc} must be mentioned as a header file for the font in
@samp{psfonts.map}.
@xref{Changing PostScript encodings}.

@item -s @var{slant}
@opindex -s @var{slant}
@cindex slanted fonts, making
Slant characters to the right by @var{slant}.  If @var{slant} is
negative, the letters slope to the left (or they might be upright if you
start with an italic font).

@item -t @var{tex-enc}
@opindex -t @var{tex-enc}
Use @var{tex-enc} for the target (@TeX{}) encoding of the font.
Ligature and kern information may also be specified in @var{file}.
@var{file} is not mentioned in @file{psfonts.map}.

@item -T @var{ps-tex-enc}
@opindex -T @var{ps-tex-enc}
Use @var{ps-tex-enc} for both the PostScript and target @TeX{} encodings
of the font.  Equivalent to @samp{-p @var{file} -t @var{file}}.

@item -u
@opindex -u
Use only those characters specified in the @TeX{} encoding, and no
others.  By default, Afm2tfm tries to include all characters in the
input font, even those not present in the @TeX{} encoding (it puts them
into otherwise-unused positions, arbitrarily).

@item -v @var{vpl-file}
@opindex -v @var{vpl-file}
Output a VPL (virtual property list) file, as well as a TFM file.

@item -V @var{vpl-file}
@opindex -V @var{vpl-file}
Same as @samp{-v}, but the virtual font generated is a pseudo small caps
font obtained by scaling uppercase letters by 0.8 to typeset
lowercase. This font handles accented letters and retains proper
kerning.
@end table


@node psfonts.map
@section @file{psfonts.map}: PostScript font catalog

@flindex psfonts.map
@cindex non-resident fonts
@cindex downloading PostScript fonts
@cindex fonts, downloading

The @file{psfonts.map} file associates a PostScript font with related
files and constructs.  Each line has the format:

@example
@var{filename} @var{PostScript-name} @var{options}
@end example

@kindex < @r{font downloading}
For example, the line
@example
rpstrn StoneInformal <StoneInformal.pfb
@end example
@noindent
causes Dvips to download @file{StoneInformal.pfb} if your document (just
as if it were a header file, @pxref{Header files}) uses the font
@samp{StoneInformal}.

@cindex partial font downloading
@cindex downloading fonts partially
If the @samp{j} config file or command-line option is enabled,
@file{StoneInformal.pfb} will be @dfn{partially downloaded}---only those
characters your document actually uses will be extracted and downloaded,
and the remainder discarded.  @xref{Option details}.

Filenames of fonts that are partially downloaded are surrounded by curly
braces (@samp{@{@dots{}@}}) in the progress report Dvips writes to
standard output.  Wholly-downloaded fonts appear inside angle brackets
(@samp{<@dots{}>}), like other downloaded files.

@cindex whole font downloading
@cindex multiple master fonts
@cindex Minion typeface family
@kindex << @r{whole font downloading}
Adobe Multiple Master fonts, such as Minion, cannot be partially
downloaded.  To partially download in general, but avoid partial
downloading for individual fonts, use @samp{<<} instead @samp{<}:
@example
pmnr8r Minion <<Minion.pfb
@end example

@cindex transforming downloaded fonts
@cindex expanded fonts
@cindex wide fonts
@cindex narrow fonts
You can generate transformed fonts with a line like this:
@example
rpstrc StoneInformal <StoneInformal.pfb ".8 ExtendFont"
@end example

@noindent
@xref{Special font effects}, for a
complete list of font effects.

@cindex reencoding PostScript fonts
You can change the encoding of the Type 1 font at the PostScript
level with a @samp{ReEncodeFont} instruction, plus the name of the
encoding file.  This allows you access to characters that may be present
in the Type 1 font file, but not encoded by default---most of the
preaccented characters, for example.  An example:
@smallexample
pstrn8r StoneInformal "TeXBase1Encoding ReEncodeFont" <8r.enc <pstrn8a.pfb
@end smallexample

@cindex 8r font encoding
@cindex base encoding, recommended
The @samp{8r} encoding mentioned here has been designed to serve as a
base for all downloadable fonts; it allows access to all the characters
commonly present in a Type 1 font.  For more details, see the
@file{8r.enc} source file that comes with (and is installed with) Dvips.

@kindex <[ @r{encoding vector downloading}
You may notice that the same syntax is used for downloading encoding
vectors and Type 1 font files. To make your intentions clear, you can
also use @samp{<[} to explicitly indicate you are downloading an
encoding vector, as in:
@smallexample
pstrn8r StoneInformal "TeXBase1Encoding ReEncodeFont" <[8r.enc <pstrn8a.pfb
@end smallexample

@flindex .enc @r{extension for encoding vectors}
If the filename of your encoding vector does not end in @samp{.enc}, and
you are using partial font downloading, you must use the @samp{<[}
syntax, or Dvips will not download the font properly.

@flindex .pfa @r{extension required for partial downloading}
@flindex .pfb @r{extension required for partial downloading}
Similarly, the name of the Type 1 font file itself must have extension
@file{.pfa} or @file{.pfb} for partial downloading to work properly.

@cindex pfb files, automatically unpacked
When using PFB files, Dvips is smart enough to unpack the binary PFB
format into printable ASCII so there is no need to perform this
conversion yourself.  In addition, Dvips scans the font to determine its
memory usage, just as it does for other header files (@pxref{Header
files}).

Here is a brief summary of how @file{psfonts.map} is read:

@enumerate
@item If a line is empty or begins with a space, percent, asterisk,
semicolon, or hash mark, it is ignored.

@item Otherwise, the line is separated into words, where words are
separated by spaces or tabs, except that if a word begins with a double
quote, it extends until the next double quote or the end of the line.

@item If a word starts with @samp{<<}, it is taken as a font file to be
wholly downloaded.  Use this to avoid partial downloading, as described
above.

@item If a word starts with @samp{<[}, it is taken as an encoding file
to be downloaded.  Use this if the name of the encoding file does end in
@samp{.enc}, also as described above.

@item If a word starts with a @samp{<} character, it is
treated as a header file that needs to be downloaded.  If the name ends
in @samp{.pfa} or @samp{.pfb}, it is taken as Type 1 font file that will
be partially downloaded if the @samp{j} option is in effect.  There can
be more than one such header for a given font.  If a @samp{<} is a word
by itself, the next word is taken as the name of the header file.

@item If a word starts with a @samp{"} character, it is taken as PostScript
code used in generating that font, and is inserted into the output
verbatim at the appropriate point.  (And the double quotes beginning and
ending the word are removed.)

@item Otherwise the word is a name. The first such name is the TFM file that
a virtual font file can refer to.  If there is a second name, it is used
as the PostScript name; if there is only one name, it is used for both
the @TeX{} name and the PostScript name.

@end enumerate


@node Color
@chapter Color

@cindex color

@cindex Hafner, Jim
Dvips supports one-pass multi-color printing of @TeX{} documents on any
color PostScript device.  Initially added by Jim Hafner, IBM Research,
@email{hafner@@almaden.ibm.com}, the color support has gone through many
changes by Tomas Rokicki.  Besides the source code support itself, there
are additional @TeX{} macro files: @samp{colordvi.tex} and
@samp{blackdvi.tex}, and corresponding @samp{.sty} versions for use with
La@TeX{}.

In this section we describe the use of color from the document
preparer's point of view and then add some instructions on installation
for the @TeX{} administrator.

@menu
* Color macro files::           TeX macro definitions.
* User-definable colors::       Adding your own colors.
* Color subtleties::            Subtleties in using color.
* Ted Turner::                  Printing in black/white after colorizing.
* Color device configuration::  Configuring Dvips for color devices.
* Color support details::       Color support details
@end menu


@node Color macro files
@section Color macro files

@cindex macros for color
@cindex color macros

All the color macro commands are defined in @samp{colordvi.tex} (or
@samp{colordvi.sty}).  To access these macros simply add to the top of
your plain @TeX{} file the command:
@example
\input colordvi
@end example
@noindent
For (the obsolete) La@TeX{} 2.09, add the @samp{colordvi} style option as in:
@example
\documentstyle[12pt,colordvi]@{article@}
@end example
@noindent
For La@TeX{} 2e, these examples are not applicable.  Instead, please see
the documentation for the graphics package, available from
@file{@var{CTAN}:doc/latex/graphics/}.  See also
@file{@var{CTAN}:doc/epslatex.ps}.

@cindex Crayola crayon box
@cindex Pantone colors
@cindex color names, mixed case
These macros provide two basic kinds of color macros: ones for local
color changes (a few words, a single symbol) and one for global color
changes (the whole document).  All the color names use a mixed case
scheme to avoid conflicts with other macros.  There are 68 predefined
colors, with names taken primarily from the Crayola crayon box of 64
colors, and one pair of macros for the user to set his own color pattern
(@pxref{User-definable colors}).  You can browse the file
@samp{colordvi.tex} for a list of the predefined colors.  The comments
in this file also show a rough correspondence between the crayon names
and Pantones.

A local color command has the form

@example
\@var{ColorName}@{this is the color @var{ColorName}@}
@end example

@findex \@var{ColorName}
@noindent
where @var{ColorName} is the name of a predefined color, e.g.,
@samp{Blue}.  As shown, these macros take one argument, the text to
print in the specified color.  This can be used for nested color changes
since it restores the original color state when it completes.  For
example:

@example
This text is normal but here we are \Red@{switching to red,
\Blue@{nesting blue@}, recovering the red@} and back to original.
@end example

@noindent
@cindex color nesting level
The color nesting level has no hard limit, but it is not advisable to
nest too deeply lest you and the reader lose track of the color history.
 
The global color command has the form

@example
\text@var{ColorName}
@end example

@noindent 
@findex \text@var{ColorName}
These macros take no arguments and changes the default color from that
point on to @var{ColorName}.  This of course can be overridden globally
by another such command or locally by local color commands. For example,
expanding on the example above, we might have

@example
\textGreen 
This text is green but here we are \Red@{switching to red, 
\Blue@{nesting blue@}, recovering the red@} and back to 
original green.
\textCyan 
The text from here on will be cyan until
\Yellow@{locally changed to yellow@}. Now we are back to cyan.
@end example
 
The color commands will even work in math mode and across math mode
boundaries.  This means that if you have a color before going into math
mode, the mathematics will be set in that color as well.  In alignment
environments like @code{\halign}, @samp{tabular} or @samp{eqnarray},
local color commands cannot extend beyond the alignment characters.
 
Because local color commands respect only some environment and
delimiter changes besides their own, care must be taken in setting
their scope.  It is best not to have them stretch too far.
 
At the present time there are no macros for color environments in La@TeX{}
which might have a larger range.  This is primarily to keep the @TeX{}
and La@TeX{} use compatible.


@node User-definable colors
@section User-definable colors
 
@cindex user-definable colors
@cindex colors, user-definable

There are two ways for the user to specify colors not already defined.
For local changes, there is the command @code{\Color} which takes two
arguments.  The first argument is four numbers between zero and one and
specifies the intensity of cyan, magenta, yellow and black (CMYK) in
that order.  The second argument is the text that should appear in the
given color.  For example, suppose you want the words ``this color is
pretty'' to appear in a color which is 50% cyan, 85% magenta, 40% yellow
and 20% black.  You would use the command

@example
\Color@{.5 .85 .4 .2@}@{this color is pretty@}
@end example

For global color changes, there is a command @code{\textColor} which
takes one argument, the CMYK quadruple of relative color intensities.
For example, if you want the default color to be as above, then the
command

@example
\textColor@{.5 .85 .4 .2@}
The text from now on will be this pretty color
@end example

@noindent
will do the trick.
 
Making a global color change in the midst of nested local colors is
highly discouraged.  Consequently, Dvips will give you warning message
and do its best to recover by discarding the current color history.


@node Color subtleties
@section Color subtleties

@cindex color subtleties

Color macros are defined via @code{\special} keywords.  As such, they
are put in the @samp{.dvi} file only as explicit message strings to the
driver.  The (unpleasant) result is that certain unprotected regions of
the text can have unwanted color side effects.  For example, if a color
region is split by @TeX{} across a page boundary, then the footers of
the current page (e.g., the page number) and the headers of the next
page can inherit that color.  To avoid this effect globally, users
should make sure that these special regions of the text are defined with
their own local color commands.  For example, to protect the
header and footer in plain @TeX{}, use

@example
\headline@{\Black@{My Header@}@}
\footline@{\Black@{\hss\tenrm\folio\hss@}@}
@end example

This warning also applies to figures and other insertions, so be careful!

Of course, in La@TeX{}, this is much more difficult to do because of the
complexity of the macros that control these regions.  This is
unfortunate but inevitable, because @TeX{} and La@TeX{} were
not written with color in mind.

Even when writing your own macros, much care must be taken.  The macros
that `colorize' a portion of the text work prefix the text work by
outputting one @code{\special} command to turn the color on before the
text, and outputting another @code{\special} command afterwards to
restore the original color.  It is often useful to ensure that @TeX{} is
in horizontal mode before the first special command is issued; this can
be done by prefixing the color command with @code{\leavevmode}.


@node Ted Turner
@section Printing in black/white after colorizing

If you have a @TeX{} or La@TeX{} document written with color macros and
you want to print it in black and white there are two options.  On all
(good) PostScript devices, printing a color file will print in
corresponding gray levels.  This is useful to get a rough idea of the
colors without using expensive color printing devices.  The second
option is to replace the call to input @file{colordvi.tex} with
@samp{blackdvi.tex} (and similarly for the @samp{.sty} files).  So in
the above example, replacing the word @samp{colordvi} with
@samp{blackdvi} suffices.  @file{blackdvi.tex} defines the color macros
as no-ops, and so will produce normal black/white printing.  By this
simple mechanism, the user can switch to all black/white printing
without having to ferret out the color commands.  Also, some device
drivers, particularly non-PostScript ones like screen previewers, will
simply ignore the color commands and so print in black/white.
Hopefully, in the future screen previewers for color displays will be
compatible with some form of color support.


@node Color device configuration
@section Color device configuration

@cindex color configuration
@cindex configuration, of color devices

To configure Dvips for a particular color device you need to fine tune
the color parameters to match your device's color rendition.  To do this,
you will need a Pantone chart for your device.  The header file
@samp{color.lpro} shows a (rough) correspondence between the Crayola
crayon names and the Pantone numbers and also defines default CMYK
values for each of the colors.  Note that these colors must be defined
in CMYK terms and not RGB, as Dvips outputs PostScript color commands in
CMYK.  This header file also defines (if they are not known to the
interpreter) the PostScript commands @samp{setcmykcolor} and
@samp{currentcmykcolor} in terms of a RGB equivalent so if your device
only understands RGB, there should be no problem.

@cindex Phaser printer, used for color calibration
@cindex Tektronix Phaser printer, used for color calibration
The parameters set in this file were determined by comparing the Pantone
chart of a Tektronix Phaser printer with the actual Crayola Crayons.
Because these were defined for a particular device, the actual color
rendition on your device may be very different.  There are two ways to
adjust this.  One is to use the PAntone chart for your device to rewrite
@samp{color.lpro} prior to compilation and installation.  A better
alternative, which supports multiple devices, is to add a header file
option in the configuration file (@pxref{Configuration file commands})
for each device that defines, in @samp{userdict}, the color parameters
for those colors that need redefining.

For example, if you need to change the parameters defining
@samp{Goldenrod} (approximately Pantone 109 on the Phaser) for your
device @samp{mycolordev}, do the following.  In the Pantone chart for
your device, find the CMYK values for Pantone 109.  Let's say they are
@samp{@{\ 0 0.10 0.75 0.03 @}}. Then create a header file named
@samp{mycolordev.pro} with the commands

@example
userdict begin 
/Goldenrod @{ 0 0.10 0.75 0.03 setcmykcolor@} bind def
@end example

@noindent
Finally, in @samp{config.mycolordev} add the line 

@example
h mycolordev.pro
@end example

@noindent
This will then define @samp{Goldenrod} in your device's CMYK values in
@file{userdict} which is checked before defining it in @file{TeXdict} by
@file{color.pro}.  (On MS-DOS, you will have to call this file
@file{mycolordev.cfg}.)

This mechanism, together with additions to @file{colordvi.tex} and
@file{blackdvi.tex} (and the @samp{.sty} files), can also be used to
predefine other colors for your users.


@node Color support details
@section Color support details

To support color, Dvips recognizes a certain set of specials.  These
specials start with the keyword @samp{color} or the keyword
@samp{background}, followed by a color specification.

@menu
* Color specifications::
* Color specials::
@end menu


@node Color specifications
@subsection Color specifications

@cindex color specifications

What is a color specification?  One of three things.  First, it might be
a PostScript procedure as defined in a PostScript header file.  The
@file{color.pro} file defines 64 of these, including @samp{Maroon}.
This PostScript procedure must set the current color to be some value;
in this case, @samp{Maroon} is defined as @samp{0 0.87 0.68 0.32
setcmykcolor}.

The second possibility is the name of a color model (initially, one of
@samp{rgb}, @samp{hsb}, @samp{cmyk}, or @samp{gray}) followed by the
appropriate number of parameters.  When Dvips encounters such a macro,
it sends out the parameters first, followed by the string created by
prefixing @samp{TeXcolor} to the color model.  Thus, the color
specification @samp{rgb 0.3 0.4 0.5} would generate the PostScript code
@samp{0.3 0.4 0.5 TeXrgbcolor}.  Note that the case of zero arguments is
disallowed, as that is handled by the single keyword case
(@samp{Maroon}) above, where no changes to the name are made before it
is sent to the PostScript file.

The third and final type of color specification is a double quote
followed by any sequence of PostScript.  The double quote is stripped
from the output.  For instance, the color specification
@samp{"AggiePattern setpattern} will set the `color' to the Aggie logo
pattern (assuming such exists.)


@node Color specials
@subsection Color specials

We will describe @samp{background} first, since it is the simplest.  The
@samp{background} keyword must be followed by a color specification.
That color specification is used as a fill color for the background.
The last @samp{background} special on a page is the one that gets
issued, and it gets issued at the very beginning of the page, before any
text or specials are sent.  (This is possible because the prescan phase
of Dvips notices all of the color specials so that the appropriate
information can be written out during the second phase.)

The @samp{color} special itself has three forms.
The first is just @samp{color} followed by a color specification.  In
this case, the current global color is set to that color; the color stack
must be empty when such a command is executed.

The second form is @samp{color push} followed by a color specification.
This saves the current color on the color stack and sets the color to be
that given by the color specification.  This is the most common way to
set a color.

The final version of the @samp{color} special is just @samp{color pop},
with no color specification; this says to pop the color last pushed on
the color stack from the color stack and set the current color to be
that color.

Dvips correctly handles these color specials across pages, even when the
pages are repeated or reversed.

These color specials can be used for things such as patterns or screens
as well as simple colors.  However, note that in the PostScript, only
one color specification can be active at a time.  For instance, at the
beginning of a page, only the bottommost entry on the color stack is
sent; also, when a color is popped, all that is done is that the color
specification from the previous stack entry is sent.  No @samp{gsave} or
@samp{grestore} is used.  This means that you cannot easily mix usage of
the @samp{color} specials for screens and colors, just one or the other.
This may be addressed in the future by adding support for different
categories of color-like state.


@node Index
@unnumbered Index

@printindex cp


@summarycontents
@contents

@end ifclear
@c INSTALLONLY
@bye