arrow keys to move
this is a proof of concept for an efficient way to render a grid to the screen. it does this by only looping through the tiles on the screen, as opposed to all of them. this way, it runs about as well with a 1000x1000 grid as it does with a 100x100 grid. it is possible to use this same strategy to efficiently find collisions with a player, only checking the tiles surrounding the player, but i was too lazy to try doing that. feel free to do whatever you want with this project, not that you'd want to, it's pretty messy
