mkttf: BDF to TTF conversion

The mkttf.py script converts a set of BDF files into a TTF file, automatically generating the required scalable outlines (actually, any font format supported by FontForge is accepted). Call it with the -h option for usage help.

The mkttf.sh script generates medium (normal), bold and italic versions of the Terminus font. It will create three directories ("Normal", "Bold" and "Italic") in the current working directory.

To use mktff.py, you need the following tools installed in your PATH:

• FontForge: This tool and its Python extension enable me to modify the font using Python. You need a version that has Python 3 support enabled (i. e. provides a Python 3 extension).
• Potrace: To generate the scalable outlines.
• A recent version of Python 3.
• ImageMagick: To upscale the bitmaps before tracing them with Potrace. This is done to improve the accuracy of the Potrace algorithm.
• Bash: Should be already installed on most Linux systems.

To use mkttf.sh, you additionally need the following programs in your path:

• mkitalic: To generate the italic font.

The mkttf.sh script takes two mandatory arguments:

1. The directory containing the Terminus BDF files. The italic versions of the BDF files will be placed there.
2. The font version which will be included in the file names of the generated files and in the font files themselves (so it can be e. g. shown to the user).

All other arguments are passed directly to mkttf.py.

Additionally to generating TTF fonts, the script will also generate an SFD file (FontForge's native file format) for each font weight so that the generated fonts can be easily modified, if necessary.

If you want to generate TTF versions of other fonts, you should only need to modify mkttf.sh -- the mkttf.py script is completely generic.

Have fun!

Generating TTF fonts for Windows

Windows, and native Windows programs like Visual Studio, will only use the bitmaps embedded in the TTF fonts generated by mkttf if certain Hiragana characters are present in the fonts (for full details, see Raster fonts in Visual Studio 2010).

mkttf can ensure that those Hiragana characters are present in the generated fonts. To enable this feature, pass the --visual-studio-fixes (or just -s) option to your invocations of mkttf.sh or mkttf.py.

Caveat: mkttf will not add real Hiragana glyphs to the font! Instead, it will try to add a fake glyph for every required Hiragana character that is missing from the font to fool Windows into thinking that the font is an Asian font for which bitmaps should be used.

In detail, mkttf will ensure that glyphs for the following Hiragana characters are present:

• U+3044 "HIRAGANA LETTER I"
• U+3046 "HIRAGANA LETTER U"
• U+304B "HIRAGANA LETTER KA"
• U+3057 "HIRAGANA LETTER SI"
• U+306E "HIRAGANA LETTER NO"
• U+3093 "HIRAGANA LETTER N"

For missing Hiragana characters, mkttf will simply re-use the glyph for another character from the font; it will use the first character from the following list that exists in the font:

• U+0000 "NULL"
• U+003F "QUESTION MARK"
• U+0020 "SPACE"

Doing this has one big drawback: For the above Hiragana characters, the "fake" glyphs will be used instead of real Hiragana glyphs from another suitable font -- i. e. falling back to another font will not work, and those characters will not be displayed correctly. This of course is an issue if you actually need those Hiragana characters to display correctly, so you cannot use this mkttf feature in that case.