src/metrics/README.md
There are several requirements for generating the metrics used by KaTeX.
You need to have an installation of TeX which supports kpathsea. You can check
this by running tex --version, and seeing if it has a line that looks like
kpathsea version 6.2.0
You need the Perl module JSON. You can install this either from CPAN
(e.g. using the cpan command line tool: cpan install JSON)
or with your package manager.
You need the Python module fonttools. You can install this either from PyPI
(using easy_install or pip: pip install fonttools)
or with your package manager.
Once you have these things, run the following command from the root directory:
sh ./dockers/fonts/buildMetrics.sh
which should generate new metrics and place them into fontMetricsData.json.
You're done!