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 Display :PolyA :PolyB
  # write header title and footer values
  PenUp SetPC White SetH 0
  SetPos [-190 182] Label "PolyWeaver
  SetPos [-190 -190] Label ( List "A\ B\ = :PolyA :PolyB )
  SetPos [134 -190] Label ( List "Rep\ = :Rep )
End

To Init
  Make "Side 52
  Make "PolyA Pick [3 4 5 6 7 8 9 10 11 12]
  Make "PolyB Pick [2 3 4 5 6 7 8]
  Make "Rep HCF :PolyA :PolyB
  Make "Rep (:PolyA/:Rep) * :PolyB
End

To HCF :I :J
  # return highest common factor of two integers
  LocalMake "Rem Modulo :I :J
  If :Rem =0 [Output :J] [Output HCF :J :Rem]
End

To Weave :PolyA :PolyB :OffSet :Draw
  Make "A 90 Make "B 90
  Repeat :Rep [
    SetH :A
    If :Draw [SetPC Green] Forward :Side
    SetH :B + :OffSet + :A
    If :Draw [SetPC Yellow] Forward :Side
    Make "A :A-(360/:PolyA)
    Make "B :B-(360/:PolyB) ]
End

To Go
  New Animation
  Forever [
    Wash Init Display :PolyA :PolyB
    SetPos List Minus :Side/2 Minus 60 PenDown
      For [OffSet 0 480 5] [
      Weave :PolyA :PolyB :OffSet True
      Refresh Wait 3
      SetPC Black
      Weave :PolyA :PolyB :OffSet False]
    Wait 60]
End