These are BDF fonts, a simple bitmap font-format that can be created by many font tools. Given that these are bitmap fonts, they will look good on very low resolution screens such as the LED displays.
Important
The fonts in this directory are only the ones used in the FlightGazer project! Additional ones that were originally bundled can be sourced here.
Fonts in this directory (except 3x5.bdf, 4x5.bdf, 3x3.bdf, 4x4.bdf) are public domain (see the README).
Doing things with bdf fonts (Show/Hide)
Fonts are in a human readable and editbable *.bdf format, but unless you
like reading and writing pixels in hex, generating them is probably easier :)
You can use any font-editor to generate a BDF font or use the conversion tool otf2bdf to create one from some other font format.
Here is an example how you could create a 30pixel high BDF font from some TrueType font:
otf2bdf -v -o myfont.bdf -r 72 -p 30 /path/to/font-Bold.ttfInstalling the tool should be fairly straight-foward
sudo apt-get install otf2bdf
If you like to compile otf2bdf, you might notice that the configure script uses some old way of getting the freetype configuration. There does not seem to be much activity on the mature code, so let's patch that first:
sudo apt-get install -y libfreetype6-dev pkg-config autoconf
git clone https://github.com/jirutka/otf2bdf.git # check it out
cd otf2bdf
patch -p1 <<"EOF"
--- a/configure.in
+++ b/configure.in
@@ -5,8 +5,8 @@ AC_INIT(otf2bdf.c)
AC_PROG_CC
OLDLIBS=$LIBS
-LIBS="$LIBS `freetype-config --libs`"
-CPPFLAGS="$CPPFLAGS `freetype-config --cflags`"
+LIBS="$LIBS `pkg-config freetype2 --libs`"
+CPPFLAGS="$CPPFLAGS `pkg-config freetype2 --cflags`"
AC_CHECK_LIB(freetype, FT_Init_FreeType, LIBS="$LIBS -lfreetype",[
AC_MSG_ERROR([Can't find Freetype library! Compile FreeType first.])])
AC_SUBST(LIBS)
EOF
autoconf # rebuild configure script
./configure # run configure
make # build the software
sudo make install # install it