TTY OFFICE: FONTS
=================

The TTY console makes use of different fonts than X, Wayland, or 
Windows.

On a Debian-based system, the TTY fonts are located in the 
/usr/share/consolefonts/ directory. They have a .psf or a .psf.gz 
filename extension. Many of the available fonts are quite small and 
appear to have been created back when 640x480 and 800x600 resolutions 
were common.


Changing Fonts and Font Sizes
-----------------------------

I know of two ways to change the font:

1. You can edit /etc/default/console-setup as root to specify a new 
   font system-wide. The console-setup file on my laptop looks like 
   this:

# CONFIGURATION FILE FOR SETUPCON

# Consult the console-setup(5) manual page.

ACTIVE_CONSOLES="/dev/tty[1-6]"

CHARMAP="UTF-8"

CODESET="Lat15"
FONTFACE="Terminus"
FONTSIZE="16x32"

VIDEOMODE=

# The following is an example how to use a braille font
# FONT='lat9w-08.psf.gz brl-8x8.psf'

I've increased the default font size in this file. If you want to 
change your font, you can make use of any of the fonts available in 
/usr/share/consolefonts/.

Note that the font size is entered in reverse order in the 
/etc/default/console-setup file. The font file name in 
/usr/share/consolefonts/ is Lat15-Terminus32x16.psf.gz. I'm not sure 
why that's inverted in console-setup.


2. You can use the 'setfont' command to change the font for an 
   individual user. Again, you may make use of any of the fonts 
   contained in /usr/share/consolefonts/.

   Here's an example of the syntax:

   $ setfont /usr/share/consolefonts/Lat15-Terminus24x12.psf.gz

   You can use setfont to change fonts and font sizes 'on the fly.' 
   The change is not persistent across boots.

   The 'setfont' command can be quite handy. For example, you could 
   add it to your .bashrc to set the TTY font for your user account 
   alone.

   Or you could add a number of aliases to your .bashrc to allow you 
   to quickly change fonts or font sizes:

   alias bigfont='setfont /usr/share/consolefonts/Lat15-Terminus32x16.psf.gz'
   alias medfont='setfont /usr/share/consolefonts/Lat15-Terminus24x12.psf.gz'
   alias smallfont='setfont /usr/share/consolefonts/Lat15-Terminus20x10.psf.gz'


Converting TrueType fonts to PSF format
---------------------------------------

The default choice of fonts for the TTY on a Debian-based system is 
quite limited. Perhaps you'd like a Courier font? Maybe you pine for 
Lucida Sans? Here's how you can convert them to .psf format.[1] Note 
that you need to do this from an X or Wayland session:

1. Install fontforge and bdf2psf

   $ sudo apt install fontforge bdf2psf

2. Open the TTF font in fontforge (the initial dialog is a file 
   selection box).

3. From the menu, select Element > Bitmap Strikes Available > and put 
   the appropriate font size number (something between 12 and 32 is 
   likely) in the pixel sizes box > Press OK[1]

4. Select File > Generate Fonts > choose No Outline Font from the 
   first drop-down and BDF from the other drop-down > and press 
   Generate.

5. Specify a resolution. I've used 75, 96, and 100. They all work.

6. Press OK.

   There should now be a .bdf font in the same directory as the TTF font.

7. Open the BDF file with a text editor. Change the AVERAGE_WIDTH 
   value to the nearest multiple of 10. If you don't make this change, 
   the next step will produce an error.

8. Open a terminal and run the following command on the .bdf file to 
   convert it to .psf:

   $ bdf2psf --fb myfilename.bdf /usr/share/bdf2psf/standard.equivalents /usr/share/bdf2psf/ascii.set 256 myfilename.psf

Now you can move the .psf file to /usr/share/consolefonts/ and make 
use of it by editing /etc/default/console-setup or by using the 
setfont command. 

I'd suggest trying it out temporarily with setfont first, just in case 
something went wrong in the conversion process and your new font 
produces garbled output.

Bonus: you can edit individual .psf font glyphs with psftools, 
available here:

https://codeberg.org/gnarz/psftools


--------------

[1] This part of the how-to is adapted from:
    https://darrengoossens.wordpress.com/2021/07/30/a-truetype-font-in-a-tty-glass_tty/comment-page-1/

[2] For more information on the bitmap strike operation, see:
    https://fontforge.org/docs/tutorial/editexample8.html#opening-importing-bitmap-strikes, especially Section 11.2.