bionic (5) lj4_font.5.gz

Provided by: groff_1.22.3-10_amd64 bug

NAME

       lj4_font - groff fonts for use with devlj4

DESCRIPTION

       Nominally,  all  Hewlett-Packard  LaserJet 4–series  and  newer printers have the same internal fonts: 45
       scalable fonts and one bitmapped Lineprinter font.  The scalable fonts are  available  in  sizes  between
       0.25  point  and  999.75  points,  in  0.25-point  increments;  the Lineprinter font is available only in
       8.5-point size.

       The LaserJet font files included with groff assume that all printers since the LaserJet 4 are  identical.
       There  are  some  differences  between  fonts  in  the  earlier  and  more recent printers, however.  The
       LaserJet 4 printer used Agfa Intellifont technology for 35 of the internal scalable fonts; the  remaining
       10  scalable  fonts  were TrueType.  Beginning with the LaserJet 4000–series printers introduced in 1997,
       all scalable internal fonts have been TrueType.  The number of printable glyphs differs slightly  between
       Intellifont  and  TrueType  fonts (generally, the TrueType fonts include more glyphs), and there are some
       minor differences in glyph metrics.   Differences  among  printer  models  are  described  in  the  PCL 5
       Comparison  Guide  and  the  PCL 5 Comparison Guide Addendum (for printers introduced since approximately
       2001).

       LaserJet printers reference a glyph by a combination of a 256-glyph symbol set and an index  within  that
       symbol  set.   Many  glyphs  appear in more than one symbol set; all combinations of symbol set and index
       that reference the same glyph are equivalent.  For each glyph, hpftodit(1)  searches  a  list  of  symbol
       sets,  and  selects the first set that contains the glyph.  The printing code generated by hpftodit(1) is
       an integer that encodes a numerical value for the symbol set in the high byte(s), and the  index  in  the
       low  byte.   See  groff_font(5)  for  a  complete  description  of  the font file format; symbol sets are
       described in greater detail in the PCL 5 Printer Language Technical Reference Manual.

       Two of the scalable fonts, Symbol and Wingdings, are  bound  to  256-glyph  symbol  sets;  the  remaining
       scalable  fonts,  as  well  as  the  Lineprinter font, support numerous symbol sets, sufficient to enable
       printing of more than 600 glyphs.

       The metrics generated by hpftodit(1) assume that the DESC file contains values of 1200 for res  and  6350
       for  unitwidth  (or any combination (e.g., 2400 and 3175) for which res × unitwidth = 7620000).  Although
       HP PCL 5 LaserJet printers support an internal resolution of 7200 units  per  inch,  they  use  a  16-bit
       signed integer for cursor positioning; if devlj4 is to support U.S. ledger paper (11" × 17"), the maximum
       usable resolution is 32767 / 17, or 1927, units per inch, which rounds down to 1200 units per  inch.   If
       the  largest  required  paper  size  is  less  (e.g., 8.5" × 11" or A5), a greater resolution (and lesser
       unitwidth) can be specified.

LIMITATIONS

       Font metrics for Intellifont fonts were provided by Tagged Font Metric (TFM) files  originally  developed
       by  Agfa/Compugraphic.   The  TFM  files  provided  for  these  fonts supported 600+ glyphs and contained
       extensive lists of kern pairs.

       To accommodate developers who had become accustomed to TFM files, HP also provided TFM files for  the  10
       TrueType  fonts  included  in  the  LaserJet 4.  The TFM files for TrueType fonts generally included less
       information than the Intellifont TFMs, supporting fewer glyphs, and in most cases, providing  no  kerning
       information.  By the time the LaserJet 4000 printer was introduced, most developers had migrated to other
       means of obtaining font metrics, and support for new TFM files was very limited.  The TFM files  provided
       for the TrueType fonts in the LaserJet 4000 support only the Latin 2 (ISO 8859-2) symbol set, and include
       no kerning information; consequently, they  are  of  little  value  for  any  but  the  most  rudimentary
       documents.

       Because the Intellifont TFM files contain considerably more information, they generally are preferable to
       the TrueType TFM files even for use with the TrueType fonts in the newer printers.  The metrics  for  the
       TrueType  fonts  are  very close, though not identical, to those for the earlier Intellifont fonts of the
       same names.  Although most output using  the  Intellifont  metrics  with  the  newer  printers  is  quite
       acceptable,  a  few  glyphs  may  fail  to  print  as  expected.  The differences in glyph metrics may be
       particularly noticeable with composite parentheses, brackets, and  braces  used  by  eqn(1).   A  script,
       located  in  /usr/share/groff/1.22.3/font/devlj4/generate,  can  be  used to adjust the metrics for these
       glyphs in the special font S for use with printers that have all TrueType fonts.

       At the time HP last supported  TFM  files,  only  Version  1  of  the  Unicode  standard  was  available.
       Consequently, many glyphs lacking assigned code points were assigned by HP to the Private Use Area (PUA).
       Later versions of the Unicode standard included code points outside the PUA for  many  of  these  glyphs.
       The HP-supplied TrueType TFM files use the PUA assignments; TFM files generated from more recent TrueType
       font files require the later Unicode values to access  the  same  glyphs.   Consequently,  two  different
       mapping files may be required: one for the HP-supplied TFM files, and one for more recent TFM files.

FILES

       /usr/share/groff/1.22.3/font/devlj4/DESC  Device description file.

       /usr/share/groff/1.22.3/font/devlj4/F     Font description file for font F.

SEE ALSO

       groff(1), groff_diff(1), hpftodit(1), grolj4(1), groff_font(5)

COPYING

       Copyright © 2004-2014 Free Software Foundation, Inc.

       Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice
       and this permission notice are preserved on all copies.

       Permission is granted to copy and distribute modified versions of this manual under the conditions for
       verbatim copying, provided that the entire resulting derived work is distributed under the terms of a
       permission notice identical to this one.

       Permission is granted to copy and distribute translations of this manual into another language, under the
       above conditions for modified versions, except that this permission notice may be included in
       translations approved by the Free Software Foundation instead of in the original English.