Re: Future of the `Karl Berry Font Naming Scheme'...

["Nelson H. F. Beebe" <beebe@csc-sun.math.utah.edu>]

Rebecca and Rowland <rebecca@astrid.u-net.com> write(s):

>> Adobe has adopted a semi-consistent naming scheme for
>> fount files on Macs ... It's called the `5+3+3' scheme,
>> because you take the first 5 characters
>> from the first element in the name, the first three from the next, and so
>> on until you run out of name elements.

I wrote a small test program in awk to process the output of

	grep -h ^FullName *.afm

It looks like this:

/^FullName / {
        name533 = substr($2,1,5) substr($3,1,3) substr($4,1,3)
        if (name533 in used) collisions++
        used[name533]++
}

END {
  print collisions, "collisions"
}

For 1036 unique font names from Monotype and Bitstream fonts in my
file tree, there are 292 collisions.  For a set of 97 unique font
names in PostScript fonts collected from various UNIX vendor font
sets, I found 37 collisions.  That is 28% and 38% respectively.

I don't have a similar set of .afm files for Adobe fonts, so I cannot
make the experiment for them, but at least for non-Adobe fonts, the
5+3+3 algorithm is unusable.

What is wanted here is a perfect hashing algorithm that produces names
that are short and guaranteed unique.  If it should also be generable
by a human, then the only algorithm that suffices is to use the full
name.  But that requirement conflicts with about 200M desktop
computers that are stuck with 8+3 limits.  That is why font vendors
have gone to arbitrary names like 1097a___.afm for Bitstream's
"Venetian 301 Demi", and most PostScript software supports mapping
files to convert long font names to short file names.

Adobe software, for example, uses the PSres.upr file, which contains
entries like this:

...
FontAFM
AGaramond-Bold=metrics/adobe/adobegar/afm/padb0.afm
AGaramond-BoldItalic=metrics/adobe/adobegar/afm/padbi0.afm
AGaramond-Italic=metrics/adobe/adobegar/afm/padri0.afm
AGaramond-Regular=metrics/adobe/adobegar/afm/padr0.afm
...

and the mkpsres program (e.g., in the ps2pk15/PSres distribution) can
build such a file given a top-level directory under which fonts are
found.

I think Karl Berry did an excellent job in his font naming package,
and we need to stick with it, though, by all means, let us also
support name mapping files.

----------------------------------------------------------------------------
- Nelson H. F. Beebe                  Tel: +1 801 581 5254                 -
- Center for Scientific Computing     FAX: +1 801 581 4148                 -
- University of Utah                  Internet e-mail: beebe@math.utah.edu -
- Department of Mathematics, 105 JWB                   beebe@acm.org       -
- 155 S 1400 E RM 233                                  beebe@ieee.org      -
- Salt Lake City, UT 84112-0090, USA  URL: http://www.math.utah.edu/~beebe - 
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----------------------------------------------------------------------------
- Nelson H. F. Beebe                  Tel: +1 801 581 5254                 -
- Center for Scientific Computing     FAX: +1 801 581 4148                 -
- University of Utah                  Internet e-mail: beebe@math.utah.edu -
- Department of Mathematics, 105 JWB                   beebe@acm.org       -
- 155 S 1400 E RM 233                                  beebe@ieee.org      -
- Salt Lake City, UT 84112-0090, USA  URL: http://www.math.utah.edu/~beebe - 
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