I've got all that. I just needed to convert a string of characters into a list of glyph IDs.

For context, I'm doing a code editor.

I don't use harfbuzz for shaping or whatever, since I planned on rendering single lines of mono spaced text. I can do everything except string->glyphs conversion.

Just trying to implement basic features such as ligatures is incredibly hard, since there's almost no documentation. Therefore you can't make assumptions that are necessary to take shortcuts and make optimizations. I don't know if harfbuzz uses a source of documentation that I haven't been able to find, or maybe they are just way smarter than me, or if fonts are made in a way that they work with harfbuzz instead of the other way around.

As someone trying to have as little dependencies as possible, it is a struggle. But at the same time, harfbuzz saved me soo much time.

EDIT: I don't do my own glyph rasterization, but that's because I haven't gotten to it yet, so I do use a library. I don't know if it's going to be harder than string->glyphs, but I doubt so.