# Main Command: Go
# StarMorph 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 :theta
  Make "R 400*Sin (2*:Theta)
  Make "A :R*Sin :Theta
  Make "B :R*Cos :Theta
  Make "X 0 Make "Y 0
end

to starmorph
  Make "Col1 Absolute (:Col1-3)
  Make "Col2 Absolute (:Col2-3)
  For [Theta 0 90 0.5] [
    Init :Theta
    SetH 0 PenUp Right :Theta
    Repeat 9 [
      Forward :A Left 140
      Forward :B Left 140
      Make "X :X + :X 
      Make "Y :Y + :Y]
    SetXY Minus :X/9 Minus :Y/9
    SetH 0 PenDown Right :Theta
    Repeat 9 [
      SetPC :Col1 Forward :A Left 140
      SetPC :Col2 Forward :B Left 140]
    Refresh Wait 2 Wash]
end

to go
  New Animation SetPW 2 Make "Col1 1 Make "Col2 2
  Forever [StarMorph]
end