# Main Command: Go 3
# Grate Curve by Guy Walker
# www.logoarts.co.uk

to new
  # set default screen, pen and turtle 
  ResetAll SetScreenSize [400 400] HideTurtle 
  SetSC Black SetPC Green SetPS 1 PenUp 
end

to square :angle :width :height
  Forward :Width Two :Angle :Width :Height-1
end

to two :angle :width :height
  If :Height < 1 [Stop]  # ie if = 0
  Right :Angle Forward 1 Right :Angle Forward :Width Left :Angle
  If :Height > 0 [ Forward 1]
  Left :Angle Forward :Width 
  Two :Angle :Width :Height -2
end

to grate :order :angle :width :height
  If :Order < 1 [Square :Angle :Width :Height Stop]  # ie if = 0
  Right :Angle
  Grate :Order-1 Minus :Angle :Height/4 :Width
  Forward :Height/8
  Grate :Order-1 :Angle :Height/4 :Width
  Forward :Height/8
  Grate :Order-1 Minus :Angle :Height/4 :Width
  Left :Angle
end

to go :order
  New
  SetPos [-192 -190] SetPC Brown PenDown
  Grate :Order 90 380 380
end