Logo Arts

To New
  # set default screen, pen and turtle values
  ResetAll SetScreenSize [400 400] HideTurtle
  SetSC Black SetPC Green SetPS 1 PenUp
End

To Init :Order
  Make "Size 112 / Power (Sqrt 2) :Order     # make Size a global value
  Make "D Power 2 Integer (1+0.5*(:Order+1))
  Make "H Power 2 Integer (1+0.5*(:Order)) Make "H :H-1
  Make "Dist (:H*:Size) + (:D * (:Size / Sqrt 2))
End

To Sierpinski :Order :Parity
  If :Order < 1 [Forward :Size Stop]     # ie if = 0
  Right :Parity*45 Sierpinski :Order-1 Minus :Parity Left :Parity*45
  Forward :Size
  Left :Parity*45 Sierpinski :Order-1 Minus :Parity Right :Parity*45
End

To Go :Order
  New Init :Order
  SetPos List Minus :Dist/2 Minus (:Dist/2-(:Size / Sqrt 2)) PenDown
  Repeat 4 [Sierpinski :Order 1 Right 45 Forward :Size Right 45]
  PenUp Home SetPC DarkRed Pendown Fill     # fill curve
End

To GoX
  New Animation
  For [Order 0 10] [Wash     # comment out Wash for overlaid curves
  Init :Order
  SetPos List Minus :Dist/2 Minus (:Dist/2-(:Size / Sqrt 2)) PenDown
  Repeat 4 [Sierpinski :Order 1 Right 45 Forward :Size Right 45]
  PenUp Home SetPC DarkRed Pendown Fill SetPC Green  
  # comment out above line for no fills
  Refresh Wait 80 PenUp Home]
End