-- title:  testcart
-- author: mieki256
-- desc:   short description
-- script: lua

Obj = {}
Obj.new = function(cx, cy, ang, r)

 local o = {
  id=0, x=0, y=0, t=0,
  cx=cx, cy=cy, ang=ang, r=r
 }
  
 o.update = function(self,dr)
  self.id = 1 + (self.t % 32 // 16)
  local rad = math.rad(self.ang)
  local r = self.r
  self.x = r*math.cos(rad)+self.cx
  self.y = r*math.sin(rad)+self.cy
  self.ang = self.ang + 1.5
  self.r = self.r + dr
  self.t = self.t + 1
 end
  
 o.draw = function(self)
  spr(self.id,self.x-4,self.y-4,0)
 end
  
 setmetatable(o, {__index=Obj})
 return o
end

scrw, scrh = 240, 136
cx, cy = scrw/2, scrh/2
t=0

-- init objs
objs = {}
n = 24
for i=1,n do
 local o = Obj.new(cx, cy, i*360/n, 60)
 table.insert(objs, o)
end

-- main loop
function TIC()

 local r = 0
 if btn(0) then r=-1 end
 if btn(1) then r=1 end

 -- update 
 for i, o in ipairs(objs) do
  o:update(r)
 end

 -- draw
 cls(0)
 for i, o in ipairs(objs) do
  o:draw()
 end
 
 print("Lua: " .. _VERSION,4,8*1,12)
 print("count: " .. t,4,8*2,12)
 print(t//60 .. " sec",4,8*3,12)
 
 t=t+1
end