I wrote a 12x12 tilemapper today in case you wanted to use it or base yours off of it, it got a bit messy since every other tile is unaligned, and i didn't bother drawing the last row (there are four empty pixels at the bottom), but i think you can get the basic idea behind a 12x12 mapper from it. Feel free to use it (or anyone else who wants it) for whatever you want, sharing is caring so use it without restrictions, it's in the PD. And of course if you've got any questions (about this or your own mapper) don't hesitate to ask

Slight update to metadata, now that I've actually begun implementing some code.