Re: Font references and info

[Steven Yap <syap@shaw.ca>]

On Thu, 2003-07-10 at 04:20, Aaron wrote:
>
> I don't really care about bitmap fonts, but I am still very unclear
> how X11 is made aware of the availability of the FreeType fonts. 

Sorry for the rather long delay for this reply.  Procastination is my
weakness. :)

I am assuming that you're using at least XFree86 4.2.

  - Applications can use a particular font only if the applications
    know it's there.

      So, first thing first, how to let the application knows that a
      font exist?  Nowadays, X11 appplications get access to fonts
      (i.e. knows about a font) either through:

        1. Asking the X11 Server
        2. Fontconfig
        3. Application-specific procedure.
       
      For (1), the X11 Server needs to have the appropriate
      directories listed in its FontPath.

      We're mainly talking about TrueType fonts here, so, the
      directory /usr/share/fonts/truetype should be listed in your
      FontPath in XF86Config-4.  You can check if you have the
      directory listed if you do "xset q" in an xterm and check the
      values for the "FontPath:" entry.  If you do have the TTF
      directory in your X11 server's font path, there still two more
      things to do -- creating the fonts.dir and fonts.scale files.
      The X server needs this two files, and you create them by using
      the following commands in the TTF directory:
     
       ttmkfdir -o fonts.scale
       mkfontdir

      If you're doing this while in X, you might need to do
      
       xset fp rehash

      before the fonts will show up when doing an "xlsfonts".

      Now, if you're using defoma (Debian Font Manager) to managed
      your fonts, the actual directory should be
      /var/lib/defoma/x-ttcidfont-conf.d/dirs/TrueType.  Just having
      this directory in the X server's font path, AND loading the
      freetype or xtt module in XF86config-4 should make the TrueType
      fonts available to your applications.  All that mucking about
      with creating fonts.scale and fonts.dir files is done for you by
      defoma.

      In either case, the actual font files themselves should be in
      /usr/share/fonts/truetype.

      Now, this WON'T give you anti-aliased fonts at all, but at least
      you do get access to the TrueType fonts on your system when
      you're using applications which relies on the X11 font protocol.
      If you want anti-aliased fonts (both TrueType and Postscript
      Type 1), see (2).



      For (2), all you have to do is put the directory containing the
      fonts you want to use in the fontconfig configuration file.
      This applies to both Xft and Xft2.

      Xft is the old and deprecated.  If possible, upgrade to Xft2.
      Xft's configuration file is XftConfig and it lives in /etc/X11/.
      Just add lines like:

         dir "/usr/X11R6/lib/X11/fonts/Type1"
         dir "/usr/share/fonts/truetype"

      to the beginning of the file.
     
      Xft2's configuration file lives in /etc/fonts/fonts.conf and is
      an XML file.  Check that entries like:

         <dir>/usr/share/fonts</dir>
         <dir>/usr/X11R6/lib/X11/fonts/Type1</dir>
         <dir>/var/lib/defoma/x-ttcidfont-conf.d/dirs</dir>
         <dir>~/.fonts</dir>

      are found in it.  Technically, if the directories where you have
      your font files are not found in it, you should put them in
      /etc/fonts/local.conf instead of modifying fonts.conf itself.

      Note that there was no need to make fonts.scale and fonts.dir
      files at all.


      For (3), you're only your own buddy. :)  Look to GhostScript for
an
      example of an application which uses it's own font access
mechanism.


  - Now that applications have been made aware of the fonts, give the
    X server a mechanism to actually display the fonts.

    Load the modules "freetype" or "xtt" in XF86Config-4, one or the
    other, but NOT both.

    If your video card supports RENDER extension, the X server will do
    the anti-aliasing on fonts accessed through fontconfig.
    Otherwise, what happens is that the X server renders the fonts
    non-antialiased and ship it back to the application.  The Xft/Xft2
    library used by the application will then do the actual
    antialiasing.  This is slower and uses more network bandwidth if
    you're displaying applications remotely.


> My understanding was that FreeType could rasterize TTFs on request
> so that the application thinks it's dealing with a bitmap or pixmap
> or what have you, when in fact it was derived from a TTF.

That's correct (more or less, depending on how pedantic one wants to
be).

> Yet "verdana" doesn't appear in any of my available font lists in
> various applications (xfontsel, openoffice.org). I just want to know
> what I'm doing wrong.

For xfontsel (which uses the "legacy" X11 font mechanism) you have to
do the steps in (1) above.  For openoffice.org and other Xft-aware
(both version 1 and 2) applications, you have to do the steps in (2)
above.  

Hope that helps.  

-- 
Steven Yap <syap@shaw.ca>