# Main Command: Go
# Golden Squares 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 fibb :order
  Make "Side Item :Order :FibbList
  Square :Side
  If :Order = 1 [Stop]
  Make "Side2 Item (:Order-1) :FibbList
  LocalMake "Dist (:Side+:Side2)/2
  Repeat 4 [
    Back :Dist Right 90 Back :Dist 
    If (Last FindColor Pos) = 0 [Fibb :Order-1]
    Forward :Dist Left 90 Forward :Dist 
    Right 90]
end

to square :side
  # square drawn from centre (TP) then filled
  Make "Side :Side-1   # subtract 1 for correct size
  Back :Side/2 Right 90 Back :Side/2 PenDown
  Repeat 4 [Forward :Side Left 90] PenUp
  Forward :Side/2 Left 90 Forward :Side/2
  If :Side > 1 [Fill] 
end

to go
  New SetPC Cyan
  Make "FibbList [1 1 2 3 5 8 13 21 34 55 89]
  # remove the first term (or first few terms) of FibbList 
  Fibb Count :FibbList
end