Copy TrueType fonts. ".ttf" and ".ttc" files can be used.
The X has a private library named libfont.a. XTT patch changes this library public named libfont.so and add TrueType fonts ability. Therefore both the X server and the xfs program get such ability throught libfont.so by using traditional X API.
You can replace only a xfs program. For example, you can use special X server for your hardware and use TrueType fonts through new xfs program.
TrueType fonts must be registered in a X system. First of all, we have to create a fonts.dir file for those fonts.
$ mkdir /usr/local/share/fonts/truetype
$ cd /usr/local/share/fonts/truetype
$ cp /cdrom/truetype/* .
Copy TrueType fonts. ".ttf" and ".ttc" files can be used.
$ vi fonts.dir
Create your fonts.dir with same format of traditional fonts.dir. Here is my example for Microsoft's free True Type Fonts. You can also use my mkttfdir to create fonts.dir file automatically.
Second, we have to register the directory containing fonts.dir to the X system. You can use TrueType fonts from X server directly only If you are using a XTT server by doing like following.
$ xset +fp /usr/local/share/fonts/truetype
Register a directory to the X system.
Otherwise, we have to register the directory containing fonts.dir to the xfs program, and then register the xfs to the X system like follwoing.
$ vi /usr/X11R6/lib/X11/fs/config
Add "/usr/local/share/fonts/truetype/" as one of catalogue.
$ xfs
$ xset +fp tcp/localhost:7100
Register the xfs to the X system.
What is font file?
There are kinds of extentions. I made following list.
.otf
It contains only CFF data (no TrueType outlines)
.ttf
It contains both of them. So it can be used from OLDER version of Windows in which a CFF rasterizer may not be installed.
.ttc
It contains multiple Open Type fonts. The CFF rasterizer does not currently support TTC files. To know more, read TrueType Typography.
What is the Open Type font file?
Please read The OpenType Font File.
What is the structure of fonts?
TTC file has some fonts called faces. The number of faces are declared in the TTC file. Each font has 'cmap', 'name' and 'OS/2' separately.