All it would take, AFAIK, would be to compile fltk 1.1.9 with TTF support. I believe some members have done so successfully in the past.
If you wish to try yourself, compiletc, expat2 (plus -devs), fontconfig (plus -devs), and Xorg-7.4-dev extensions should be enough to do it. Afterwards it will depend on fontconfig and expat2.