Transcompilation Express

I wanted to talk briefly about a surprising new addition to my toolbox: transcompilation. I’ve used it twice this year to startling effect. Lua on SNES? I wanted to make a Super Nintendo (SNES/SFC) game but didn’t fancy learning a new SDK, so I wondered if I could write a game using the tools I know and somehow get it running on hardware. As with many of my projects, it began with thinking about a solution which is not normally advisable and perhaps even impossible. So I wrote a little driving platform game in Lua/Love2D to a point where it was playable on my Mac. I built it to self-imposed SNES-style constraints: 8-bit integer maths (via a small library I wrote), plus aligning all graphics to an 8px grid, and mapping controls to suit the platform. I then transpiled the Lua to C and did a small amount of work to hook it into an existing minimal SNES SDK, my homebrew toolkit, compiled with llvm-mos. It worked really well. I’d say my Lua game was about 90% accurate to SNES hardware…