Package pi provides the core Pi functions for the game loop, screen, color palette, and drawing pixels, shapes, and sprites. This package and all other pi* packages are not thread-safe. This is an intentional design choice to significantly improve performance. You should not call Pi's API from any goroutine other than the one running your `pi.Update` and `pi.Draw` functions. You can still create your own goroutines in your game, but they must not call any Pi functions or access Pi state.