Recommend using z8::fix32
Hi, I’ve seen that you implemented the API mostly with `int` types. You should be aware that some functions use fractional arguments, for instance [`w` and `h` in `spr()`](http://pico-8.wikia.com/wiki/Spr) which let you blit partial sprites.

If you want better compatibility, I suggest using the `z8::fix32` fixed-point type from z8lua (which can be cast to and back from `int`, `float`, etc.) in all API calls.

(Also if you would like to collaborate I’d be glad to share insight!)