Configuration

RetroFont uses a configuration file for:

• Specifying the base font.

• Glyph mirroring.

• Character set mapping.

• Primary font mapping.

The package includes a configuration file, the location of which is shown by the following command.

retrofont show_config

To modify the configuration, a copy can be placed in the user’s home directory.

mkdir -p ~/.config/retrofont/
cp $(retrofont show_config) ~/.config/retrofont/config.yaml

This new configuration file will now be used instead of the one provided in the package.

Base font

font:
  base: /usr/share/fonts/truetype/dejavu/DejaVuSansMono.ttf

To change the base font, the base variable in the font section should be set to the file name of a TrueType font. Make sure this is a monospaced font.

Systems

System configurations reside in the systems section. A system configuration must contain one mandatory key name, which value must be a unique identifier. All other keys are optional.

The mirror key, when set to true will instruct RetroFont to mirror all glyphs in the vertical axis.

The map_offset key, when defined will instruct RetroFont to extract a permutation table from a binary file, usually a firmware ROM image. The value of this key must be set to the offset of a 256 byte table in the provided file, which on the command line must be given via the -f option.

Under the primary key, optional character_blocks and characters keys are found. A character block consists of two elements: a destination and a source range. A character only contains a destination and a source.

systems:
  # ...
  - name: C64
    primary:
      character_blocks:
        - [0x20, [0x20, 0x60]]
        - [0x60, [0x00, 0x20]]
      characters: [
        [0x40, 0x00], [0x5f, 0x64], [0x7c, 0x5d]]
  # ...

In the following figures, we see how the ROM font is mapped to the primary font.

Commodore 64 ROM font.

Commodore 64 font as primary font.

In this instance, characters from 0x20 to 0x5f are mapped to position 0x20 onward in the primary character set. Likewise characters from 0x00 to 0x1f are mapped to position 0x60 onward. Additionally, character 0x00 (@) is mapped to position 0x40, character 0x64 (_) to position 0x5f and character 0x5d (|) to position 0x7c.

Contributing

Additions are welcome [link to contributing].