# Main Command: GoX
# Hilbert 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 init :level
  Make "Size 192/(Power 2 :Level)     # global value 
  PenUp SetXY (:Size/2)-192 (:Size/2)-192
  SetH 90 PenDown
end

to hilbert :level :parity
  If :Level < 0 [Stop]
  Left :Parity*90
  Hilbert :Level-1 Minus :Parity
  Forward :Size
  Right :Parity*90
  Hilbert :Level-1 :Parity
  Forward :Size
  Hilbert :Level-1 :Parity
  Right :Parity*90
  Forward :Size
  Hilbert :Level-1 Minus :Parity
  Left :Parity*90
end

to go :level
  New Init :Level Hilbert :Level 1
end

to gox
  New For [Level 0 4]
  [SetPC :Level+1 SetPW 5-:Level
  Init :Level Hilbert :Level 1 Wait 60]
end