# Main Command: Go
# Spirals 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 p2r :radius :angle
  Make "X :Radius * Cos :Angle
  Make "Y :Radius * Sin :Angle
  Output List :X :Y
end

to spiral :angle
  # Archimides Spiral 
  Make "Radius :Angle/20
end

to go
  New SetPC Yellow
  For [Angle 0 3600] [
    Spiral :Angle
    SetPos P2R :Radius :Angle PenDown]
end

to spiral1 :angle
  # Fermats Spiral 
  Make "Radius 3*Power :Angle 0.5
end

to spiral2 :angle
  # Equiangular Spiral
  Make "Radius Power 1.002 :Angle
end

to spiral3 :angle
  # Archimides Daisy
  Make "Offset Sin 7.05*:Angle
  Make "Radius :Angle/52 + (Power (:Angle/2000) 2) * :Offset
  SetPC ( List 0 (Round 127.5 * (1+:Offset)) 255 )
end