BDF Considered Harmful?
BDF font files have not been allowed in Debian packages for a while,
as per Debian policy. I emailed Russ Allbery last year about the
possibility of allowing BDF fonts back into Debian for reasons that
follow. He was willing to entertain the idea. I waited for the lenny
release before bringing up this possible change in policy.
Currently BDF fonts are supposed to be converted to PCF. BDF is a
plain ASCII format, and PCF is binary. Thus a PCF font file will be
more compact than its BDF source.
However, the original BDF version can contain ASCII comments that are
not preserved in the PCF version. These comments often contain
information such as author, copyright, and licensing information.
With the BDF versions discarded, that information is lost -- there is
no round-trip conversion from BDF to PCF to BDF. Thus a blind
BDF-to-PCF conversion can discard valuable information the author
intended to remain with the font. This can be significant given the
abundance of BDF fonts in the early history of X11.
In addition, PCF format fonts are gzipped on Debian systems as per
Debian Policy. If BDF fonts are also gzipped, there is little
difference in size between the two formats so the advantage of the
binary PCF format over the ASCII BDF format disappears. In fact I
created a unifont.bdf.gz file for testing and it was a little smaller
than the derivative unifont.pcf.gz file.
A unifont.bdf file worked fine on Debian, and so did the derived
unifont.pcf.gz file, but unfortunately a unifont.bdf.gz file did not.
Is there a possibility of getting .bdf.gz font files to work in
Debian, then allowing .bdf.gz files in Debian font packages, and
updating Debian Policy to allow installation of BDF fonts compressed
with 'gzip -9'?
Paul Hardy
GPG Key ID: E6E6E390
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