Example
It's entirely possible to use PICO-8 as an interactive shell, but you probably want to tap into the game loop. In order to do that, you must create at least one of these callback functions:
_update()_update60()(after v0.1.8)_draw()
A minimal "game" might simply draw something on the screen:
function _draw()
cls()
print("a winner is you")
end
If you define _update60(), the game loop tries to run at 60fps and ignores update() (which runs at 30fps). Either update function is called before _draw(). If the system detects dropped frames, it'll skip the draw function every other frame, so it's best to keep game logic and player input in the update function:
function _init()
x = 63
y = 63
cls()
end
function _update()
local dx = 0 dy = 0
if (btn(0)) dx-=1
if (btn(1)) dx+=1
if (btn(2)) dy-=1
if (btn(3)) dy+=1
x+=dx
y+=dy
x%=128
y%=128
end
function _draw()
pset(x,y)
end
The _init() function is, strictly speaking, optional as commands outside of any function are run at startup. But it's a handy way to reset the game to initial conditions without rebooting the cartridge:
if (btn(4)) _init()
