This project is incredible. I was wondering whether why right-to-left rendering fails. Currently, all text appears as if it were in visual order (in practice: reversed), and shaping does not work at all.

The first order of things should be to fix ordering. One could hack the order by piping relevant RTL strings through fribidi, but Chrome already has icu library. I wonder why that does not work. The output renderer doesn't seem to have a notion of direction, yet it receives logical order strings?