Pico-8 simple screen saver

pi.p8

pico-8 cartridge // http://www.pico-8.com
version 16
__lua__
function _init()
 balls={}
 for i=1,20 do
  add(balls,create_ball())
 end
end

function create_ball()
 local a={}
 a.x=rnd(127)
 a.y=rnd(127)
 a.dx=rnd(2)
 a.dy=rnd(2)
 a.r=4
 a.c=rnd(16)
 return a
end

function _update()
 foreach(balls,update_ball)
end

function update_ball(a)
 a.x+=a.dx
 a.y+=a.dy
 if a.x>127 then a.dx=-rnd(2) end
 if a.x<0 then a.dx=rnd(2) end
 if a.y>127 then a.dy=-rnd(2) end
 if a.y<0 then a.dy=rnd(2) end
end

function _draw()
 cls()
 foreach(balls,draw_ball)
end

function draw_ball(a)
 circfill(a.x,a.y,a.r,a.c)
end