Hello

Welcome Peter,

In case you haven't seen it yet, here is the well-known classic on font rendering, which is a good starting point:

http://rastertragedy.com/index.htm

Others may suggest more advanced material.

Note that rendering glyphs is just one small part of the pipeline of going from Unicode text to glyphs. Glyphs have to be positioned (involving kerning and perhaps justification). But the big thing is, there is “shaping,” which is a relatively simple thing for English, but can be mind-boggling for some languages.

See for example: https://fonts.google.com/knowledge/glossary/shaping for a super simple intro.

For a deeper level, try: https://learn.microsoft.com/en-us/typography/develop/processing-part1
(both dated and Windows-centered, but still a fabulous intro in many ways)

You could try my book: https://simoncozens.github.io/fonts-and-layout/