Screen = require("screen")
local brush, s, w, h

function _init()
  scrn = Screen:new(_FILE, 10, 4)
  w, h = view.size(scrn.mainvp)
  scrn:autocolor()
  s = 8
  for a = 0, 360 do
    gfx.line(s, s, s + math.sin(a) * s, s + math.cos(a) * s)
  end
  brush = image.new(s * 2, s * 2, 1)
  image.copy(brush, 0, 0, 0, 0, s * 2, s * 2)
  gfx.cls()
  image.copymode(12)
  sys.stepinterval(1000 / 60)
end

function _step(t)
  t = t / 500
  image.draw(
    brush,
    w * 0.5 + math.sin(t * 1) * w * 0.5 - s,
    h * 0.5 + math.cos(t * math.pi) * h * 0.5 - s,
    0,
    0,
    s * 2,
    s * 2
  )
  if input.hotkey() == "q" then
    sys.exit()
  end
  scrn:step()
end