After 1000 messages to this list and no reply, I'm resubmitting my
question about bitmap fonts, hoping to get any bit of help or any
pointer at all (docs, other mailing lists, etc.)
Basically, I would like to know what are the best practices and
recommended programs for preparing bitmap fonts for use in Cocoa
applications. I'm also reporting what is probably a bug in either OS
X or the available font editors.
If there is a list better suited to this question, please point me to
I'm trying to convert the well known X11 fixed unicode fonts to a
format usable in Cocoa text editors and terminal programs. These
fonts are available under a free license on Markus Kuhn's website: http://www.cl.cam.ac.uk/~mgk25/ucs-fonts.html
and are provided in source BDF format.
The problem is that the generated dfont is rendered by OS X with 4px
of additional ascent (or line-height) and we can't figure out where it
comes from. If I convert only the ASCII subset of the original
Unicode font, the line-height is correct. As soon as I add more than
a couple of non-ASCII characters, the 4px bug comes out.
I tried doing the same conversion using a trial version of the
commercial BitFonter 3.0 editor ($500) and I got the same results as
Here is a zip http://gruppo4.com/~tobia/osx-font-problem.zip where
I've put two OS X dfont files I created from 9x18.bdf, using
Fontforge, plus a text file with the font tables I extracted using the
In "test3" I converted the full Latin 1 charset (Unicode points < 256)
and it shows the 4px bug; in "test7" I deleted all glyphs other than
ASCII and a couple of Latin 1 accented letters, and it displays
correctly in all Cocoa apps.
What am I doing wrong? What's different in the two files? Can you
replicate this bug? Is this a bug in OS X, a weird setting in the
original BDF, or a bug shared between Fontforge and BitFonter?
Can you think of any workaround or alternative program I could try?