\input texinfo @c -*-texinfo-*-

@setfilename README.info
@settitle  mftrace - Scalable Fonts for MetaFont


@ignore

Copyright (c) 1999--2006 by the authors

Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU General Public License.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 

@end ignore

@include version.texi

@node Top, , , 
@top

@chapter mftrace - Scalable PostScript Fonts for MetaFont

@section Introduction

@code{mftrace} is a small Python program that lets you trace a @TeX{}
bitmap font into a PFA or PFB font (A PostScript Type1 Scalable Font)
or TTF (TrueType) font.  It is licensed under the GNU GPL.

Scalable fonts offer many advantages over bitmaps, as they allow
documents to render correctly at many printer resolutions. Moreover,
Ghostscript can generate much better PDF, if given scalable PostScript
fonts.   

Versions prior to 1.0.5 were called `pktrace'.

@section Download

@itemize
@item @uref{http://lilypond.org/downloads/sources/mftrace/mftrace-@mftversion{}.tar.gz}
@item GIT at @uref{https://github.com/hanwen/mftrace}
@end itemize


@section Required

@file{mftrace} is a thin Python wrapper around some other programs that
do the real work: a tracing program and t1asm.  To run mftrace you need:
@itemize @bullet
@item A tracing program:
      autotrace >= 0.30 (see @uref{http://autotrace.sourceforge.net}
      or potrace (see @uref{http://potrace.sourceforge.net}).

      Potrace is recommended as it runs quicker than autotrace.
      
@item Python--2.2 or later. See @uref{http://www.python.org/}
@item t1utils. See @uref{http://www.lcdf.org/~eddietwo/type/}
@item  TeX--your tex installation should include
@itemize @bullet
  @item  kpsewhich,
  @item  MetaFont
@end itemize
@end itemize

@section Recommended

@itemize @bullet
@item A recent version (040215 or newer) of
@uref{http://fontforge.sourceforge.net,FontForge}. Some of @code{mftrace}
functionality requires FontForge to be present on user's system. This
includes rounding to integer, simplifying and autohinting font outlines,
as well as generating any output formats except PFA, PFB and AFM. You
should not request any of these features using @code{mftrace} options if
you don't like your font to be run through FontForge (note that in this
case you also have to explicitly specify @code{--noround} to disable 
rounding to integer).

@item Alternatively, you need GhostScript with its @file{printafm}
utility, available somethere in your PATH. @code{mftrace} uses
@file{printafm} to generate AFM files in case there is no need to
process the font with FontForge.

@end itemize

@section Red Hat

A RPM may be built by issuing
@example

        rpmbuild -tb mftrace-@var{version}.tar.gz

@end example



@section Debian GNU/Linux

Users of Debian unstable (and Debian 3.0 when it is released) can
install all requirements by running (as root):
@example

    apt-get install mftrace

@end example
If you wish to also install the FontForge package to simplify and
autohint the font, then run the command
@example

    apt-get install fontforge

@end example


@section Install

Install the prerequite packages. Then run
@example

    ./configure
    make install

@end example
in the mftrace directory. Run as follows:
@example

mftrace cmr10

@end example

@section Invoking mftrace.

Command line options:
@table @code
@item --formats=LIST
 A comma-separated list of formats to generate. Choices include:  AFM, 
 PFA, PFB, TTF and SVG. Default is to generate a PFA file. Note that 
 @file{fontforge} (formerly called @file{pfaedit}) needs to be installed
 in order to generate any format except PFA or PFB. For generating AFM 
 you need either @file{fontforge} or @file{ghostscript}.
@item -e,--encoding=@var{enc}   
 Use encoding file @var{enc}. Encoding files used by @code{mftrace} are 
 basically in the  GhostScript/dvips format, but you may use a special
 @code{.notavail} glyph name in order to tell mftrace not to process
 a specific glyph. If this option is not specified,  mftrace will try to 
 determine the encoding file automatically, from the encoding specified 
 in the TFM file.
@item --glyphs=@var{list}
  Only process glyphs in @var{list}, which is a  comma-delimited  list of
  decimal numbers or ranges.
@example
  --glyphs 1-10,50,55,90-100
@end example
@item --gffile=@var{name}
=  Take glyphs from file @var{name}. 
@item --grid @var{gridsize}
Set reciprocal grid size in em units multiplied by ratio magnification/1000. 
For example @code{--grid 10 --magnification 1000} will round
coordinates of control points to 1/10 of em unit. Useful simultaneously
with @code{--noround}  option. Default @var{gridsize} value is 1, i. e. round to integer.
@item -h,--help 
 help on options.
@item -k,--keep 
 Retain all temporary files in the directory @file{mftrace.dir/}. This
 is useful for debugging problems.
@item --keep-trying
 Try to continue if external programs called by mftrace fail. If METAFONT
 crashes with overflow errors, but nevertheless outputs a GF file, try to 
 process its output as is (useful for some buggy fonts, see below). If 
 potrace/autotrace fails to trace a specific character, first try it with 
 a less smoothed curve, and if that fails, skip the character.

 By default mftrace outputs @file{trace-bug-FONTNAME-NUMBER.pbm} and
stops the process with a request to file a bugreport.
@item --magnification
The magnification to use for the PFA file. The default is 1000. The
larger the more precise the PFA file will be. However, when
magnification is too large METAFONT can crash with overflow errors.

Sadly, many MF fonts contain resolution checks
@example
  if dots_per_inch * design_size > 1500:  
    ...
@end example
This check is susceptible to overflow errors.  Such code should be
reported as a bug, and changed to
@example
  if dots_per_inch > (1500 / design_size):
    ...
@end example

@item --noround 
Don't round coordinates of control points to integer
values. Useful simultaneously  with
@code{--grid} option. Disabled by default.

@item -o,--output-base=FILE
 Output to FILE.pfa or FILE.pfb.
@item --simplify
 Pass the font through FontForge for automatic  simplification and hinting.
@item --tfmfile=FILE   
 Use @var{file} for the TFM file.  This file is needed to determine at
 what resolution to run MetaFont.
@item  -V,--verbose 
 Be verbose: print all commands as they are invoked. This is useful
 for debugging.
@item -v,--version 
 Print version number
@item --dos-kpath
 Try to kludge up the paths coming from MikTeX for a cygwin
environment. If this doesn't work, specify @code{--tfmfile} and
@code{--encoding} manually.
@item -w,--warranty  
show warranty and copyright
@item --potrace
use Potrace (default).
@item --autotrace
use AutoTrace.

@item -D,--define=@var{symbol}=@var{value}
Set the font info @var{symbol} to the given @var{value}. For example
@code{-DFamilyName=Foo} sets the font family name to @code{Foo}.

Mftrace tries to fill in sensible values for the FontName, FamilyName,
FullName and Weight fields. It does so by guessing values for the CM font
series. For other fonts, it tries to read an AFM file (which is not likely
to exist). Suggestions for a more generic way to handle this are welcome.

@end table

Mftrace uses kpathsea for finding fonts, so any kpathsea variable can
be used to fine-tune which files should be loaded.  For example, you
can set @code{MFINPUTS} to specify which paths to search for
@file{.mf} files.

Additional options may be passed to the backend program (potrace or autotrace)
with the @code{MFTRACE_BACKEND_OPTIONS} environment variable.


@section Discussion

Why use @code{mftrace} over
@uref{http://textrace.sourceforge.net,textrace}?  Textrace and mftrace
are functionally similar. However, mftrace is quicker, more cleanly
written and can be installed using standard methods. Additionally,
textrace requires perl, ghostscript and dvips.

How about @uref{http://www.truetex.com,MetaFog}? MetaFog operates
directly on the curves that generate the bitmap font, its outlines will
probably be smaller and better. However, MetaFog is a proprietary
product: its source code is not available, and it will only run on a
limited number of platforms.

How about @uref{ftp://bop.eps.gda.pl/pub/metatype1/,MetaType1}?
MetaType1 is an approach that puts severe constraints on what may be
done in a font program. It does not work for fonts containing overlaps
and shaped pens.

How about @uref{http://fontforge.sourceforge.net/,FontForge} itself?
FontForge is an interactive editor, but it can be scripted. Since it
supports bitmap tracing and @TeX{} bitmap fonts, it is possible to
duplicate the functionality of mftrace.  However, out of the box,
FontForge does not recognize TeX encodings.


@section Bugs and todo

@itemize
@item Environment variables containing relative directories,
  such as MFINPUTS or TFMINPUTS, are not handled correctly.

@item Discuss fonts & copyright.
@item Submit @file{tfm.py} to www.python.org. @file{tfm.py}  is a python
  module to parse Tex Font Metric file.
@end itemize 

Should you encounter any bug or problem, then please send a bugreport
to @email{hanwen@@xs4all.nl,Han-Wen Nienhuys}.

@section Author

@email{hanwen@@xs4all.nl,Han-Wen Nienhuys}


@section Credits

Gf2pbm, the utility to convert a MetaFont GF file to a PBM file was
based on Paul Vojta's Xdvi. The license notice is reproduced below.

Thanks to all bughunters and contributors: Andrey V. Panov, Geoffrey
Alan Washburn, @uref{http://www.maths.qmul.ac.uk/~jdg/,Julian Gilbey}
G@"{u}nther Spahlinger, Richard Mahoney, Stanislav Brabec, and Thomas
Bushnell BSG.


@quotation
Copyright (c) 1990-1999  Paul Vojta

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to
deal in the Software without restriction, including without limitation the
rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
sell copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
PAUL VOJTA BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
@end quotation

The rest of the package mftrace  script itself is licensed under the
@uref{http://www.gnu.org/licenses/gpl.txt,GNU General Public License}.



@section See also

@itemize @bullet
@item @uref{http://partners.adobe.com/asn/developer/pdfs/tn/T1Format.pdf,Type1
font specification} 
@item @uref{http://partners.adobe.com/asn/developer/pdfs/tn/5015.Type1_Supp.pdf,Supplement
to the Type1 specification}.
@end itemize

@bye


