_draw() function is the second part of the game loop.
If a cartridge's source code includes both an
_update() function and a
_draw() function, then Pico-8 will attempt to call these functions once for each animation frame, at a rate of 30 frames per second.
You define this function in your game's source code. It takes no arguments.
The intended purpose of
_draw() is to draw the state of the game onto the screen, such as with calls to map() and spr(). A typical
_draw() function starts with a call to cls() to clear the screen then draws all of the game elements, but this is not required.
_draw() together take longer than 1/30th of a second to complete, Pico-8 may decide not to call
_draw() for a given frame. See the entry on the game loop.