librecad-data 1.0.2+nolibs-1 / usr / share / librecad / fonts / hershey.readme

Hershey fonts for Ghostscript

This file, unlike the rest of Ghostscript, consists entirely of information
copied from public sources. It therefore is not covered by the Ghostscript
copyright or license: it is in the public domain.

For other information, see the Ghostscript overview. You can also read about
Ghostscript fonts in general.

Mod.sources:  Volume 4, Issue 42
Submitted by: pyramid!octopus!pete (Pete Holzmann)

This is part 1 of five parts of the first Usenet distribution of
the Hershey Fonts. See the README file for more details.

Peter Holzmann, Octopus Enterprises
USPS: 19611 La Mar Court, Cupertino, CA 95014
UUCP: {hplabs!hpdsd,pyramid}!octopus!pete
Phone: 408/996-7746

This distribution is made possible through the collective encouragement
of the Usenet Font Consortium, a mailing list that sprang to life to get
this accomplished and that will now most likely disappear into the mists
of time... Thanks are especially due to Jim Hurt, who provided the packed
font data for the distribution, along with a lot of other help.

This file describes the Hershey Fonts in general, along with a description of
the other files in this distribution and a simple re-distribution restriction.

USE RESTRICTION:
  This distribution of the Hershey Fonts may be used by anyone for
  any purpose, commercial or otherwise, providing that:
    1. The following acknowledgements must be distributed with
      the font data:
      - The Hershey Fonts were originally created by Dr.
        A. V. Hershey while working at the U. S.
        National Bureau of Standards.
      - The format of the Font data in this distribution
        was originally created by
          James Hurt
          Cognition, Inc.
          900 Technology Park Drive
          Billerica, MA 01821
          (mit-eddie!ci-dandelion!hurt)
    2. The font data in this distribution may be converted into
      any other format *EXCEPT* the format distributed by
      the U.S. NTIS (which organization holds the rights
      to the distribution and use of the font data in that
      particular format). Not that anybody would really
      *want* to use their format... each point is described
      in eight bytes as "xxx yyy:", where xxx and yyy are
      the coordinate values as ASCII numbers.

*PLEASE* be reassured: The legal implications of NTIS' attempt to control
a particular form of the Hershey Fonts *are* troubling. HOWEVER: We have
been endlessly and repeatedly assured by NTIS that they do not care what
we do with our version of the font data, they do not want to know about it,
they understand that we are distributing this information all over the world,
etc etc etc... but because it isn't in their *exact* distribution format, they
just don't care!!! So go ahead and use the data with a clear conscience! (If
you feel bad about it, take a smaller deduction for something on your taxes
next week...)

The Hershey Fonts:
  - are a set of more than 2000 glyph (symbol) descriptions in vector
    ( <x,y> point-to-point ) format
  - can be grouped as almost 20 'occidental' (english, greek,
    cyrillic) fonts, 3 or more 'oriental' (Kanji, Hiragana,
    and Katakana) fonts, and a few hundred miscellaneous
    symbols (mathematical, musical, cartographic, etc etc)
  - are suitable for typographic quality output on a vector device
    (such as a plotter) when used at an appropriate scale.
  - were digitized by Dr. A. V. Hershey while working for the U.S.
    Government National Bureau of Standards (NBS).
  - are in the public domain, with a few caveats:
    - They are available from NTIS (National Technical Info.
      Service) in a computer-readable from which is *not*
      in the public domain. This format is described in
      a hardcopy publication "Tables of Coordinates for
      Hershey's Repertory of Occidental Type Fonts and
      Graphic Symbols" available from NTIS for less than
      $20 US (phone number +1 703 487 4763).
    - NTIS does not care about and doesn't want to know about
      what happens to Hershey Font data that is not
      distributed in their exact format.
    - This distribution is not in the NTIS format, and thus is
      only subject to the simple restriction described
      at the top of this file.

Hard Copy samples of the Hershey Fonts are best obtained by purchasing the
book described above from NTIS. It contains a sample of all of the Occidental
symbols (but none of the Oriental symbols).

This distribution:
  - contains
    * a complete copy of the Font data using the original
      glyph-numbering sequence
    * a set of translation tables that could be used to generate
      ASCII-sequence fonts in various typestyles
    * a couple of sample programs in C and Fortran that are
      capable of parsing the font data and displaying it
      on a graphic device (we recommend that if you
      wish to write programs using the fonts, you should
      hack up one of these until it works on your system)

  - consists of the following files...
    hershey.doc - details of the font data format, typestyles and
        symbols included, etc.
    hersh.oc[1-4] - The Occidental font data (these files can
          be catenated into one large database)
    hersh.or[1-4] - The Oriental font data (likewise here)
    *.hmp - Occidental font map files. Each file is a translation
        table from Hershey glyph numbers to ASCII
        sequence for a particular typestyle.
    hershey.f77 - A fortran program that reads and displays all
        of the glyphs in a Hershey font file.
    hershey.c   - The same, in C, using GKS, for MS-DOS and the
        PC-Color Graphics Adaptor.

Additional Work To Be Done (volunteers welcome!):

  - Integrate this complete set of data with the hershey font
    typesetting
    program recently distributed to mod.sources
  - Come up with an integrated data structure and supporting routines
    that make use of the ASCII translation tables
  - Digitize additional characters for the few places where non-ideal
    symbol substitutions were made in the ASCII translation
tables.
  - Make a version of the demo program (hershey.c or hershey.f77) that
    uses the standard Un*x plot routines.
  - Write a banner-style program using Hershey Fonts for input and
    non-graphic terminals or printers for output.
  - Anything else you'd like!

This file provides a brief description of the contents of the Occidental
Hershey Font Files. For a complete listing of the fonts in hard copy, order
NBS Special Publication 424, "A contribution to computer typesetting
techniques: Tables of Coordinates for Hershey's Repertory of Occidental
Type Fonts and Graphic Symbols". You can get it from NTIS (phone number is
+1 703 487 4763) for less than twenty dollars US.

Basic Glyph (symbol) data:

  hersh.oc1       - numbers 1 to 1199
  hersh.oc2       - numbers 1200 to 2499
  hersh.oc3       - numbers 2500 to 3199
  hersh.oc4       - numbers 3200 to 3999

  These four files contain approximately 19 different fonts in
the A-Z alphabet plus greek and cyrillic, along with hundreds of special
symbols, described generically below.

  There are also four files of Oriental fonts (hersh.or[1-4]). These
files contain symbols from three Japanese alphabets (Kanji, Hiragana, and
Katakana). It is unknown what other symbols may be contained therein, nor
is it known what order the symbols are in (I don't know Japanese!).

  Back to the Occidental files:

Fonts:
  Roman: Plain, Simplex, Duplex, Complex Small, Complex, Triplex
  Italic: Complex Small, Complex, Triplex
  Script: Simplex, Complex
  Gothic: German, English, Italian
  Greek: Plain, Simplex, Complex Small, Complex
  Cyrillic: Complex

Symbols:
  Mathematical (227-229,232,727-779,732,737-740,1227-1270,2227-2270,
      1294-1412,2294-2295,2401-2412)
  Daggers (for footnotes, etc) (1276-1279, 2276-2279)
  Astronomical (1281-1293,2281-2293)
  Astrological (2301-2312)
  Musical (2317-2382)
  Typesetting (ffl,fl,fi sorts of things) (miscellaneous places)
  Miscellaneous (mostly in 741-909, but also elsewhere):
    - Playing card suits
    - Meteorology
    - Graphics (lines, curves)
    - Electrical
    - Geometric (shapes)
    - Cartographic
    - Naval
    - Agricultural
    - Highways
    - Etc...

ASCII sequence translation files:

  The Hershey glyphs, while in a particular order, are not in an
  ASCII sequence. I have provided translation files that give the
  sequence of glyph numbers that will most closely approximate the
  ASCII printing sequence (from space through ~, with the degree
  circle tacked on at the end) for each of the above fonts:

  File names are made up of fffffftt.hmp,

    where ffffff is the font style, one of:
      roman   Roman
      greek   Greek
      italic  Italic
      script  Script
      cyril   Cyrillic (some characters not placed in
             the ASCII sequence)
      gothgr  Gothic German
      gothgb  Gothic English
      gothit  Gothic Italian

    and tt is the font type, one of:
        p       Plain (very small, no lower case)
        s       Simplex (plain, normal size, no serifs)
        d       Duplex (normal size, no serifs, doubled lines)
        c       Complex (normal size, serifs, doubled lines)
        t       Triplex (normal size, serifs, tripled lines)
        cs      Complex Small (Complex, smaller than normal size)

The three sizes are coded with particular base line (bottom of a capital
  letter) and cap line (top of a capital letter) values for 'y':

  Size      Base Line       Cap Line

  Very Small   -5        +4
  Small        -6        +7
  Normal       -9        +12

  (Note: some glyphs in the 'Very Small' fonts are actually 'Small')

The top line and bottom line, which are normally used to define vertical
  spacing, are not given. Maybe somebody can determine appropriate
  values for these!

The left line and right line, which are used to define horizontal spacing,
  are provided with each character in the database.

Format of Hershey glyphs:

5 bytes - glyphnumber
3 bytes - length of data  length in 16-bit words including left&right numbers
1 byte  - x value of left margin
1 byte  - x value of right margin
(length*2)-2 bytes      - stroke data

left&right margins and stroke data are biased by the value of the letter 'R'
Subtract the letter 'R' to get the data.

e.g. if the data byte is 'R', the data is 0
     if the data byte is 'T', the data is +2
     if the data byte is 'J', the data is -8

and so on...

The coordinate system is x-y, with the origin (0,0) in the center of the
glyph.  X increases to the right and y increases *down*.

The stroke data is pairs of bytes, one byte for x followed by one byte for y.

An 'R' in the stroke data indicates a 'lift pen and move' instruction.

Public Domain. Distributed with Ghostscript 6.50, November 2000