# Main Command: Go
# Snowflake 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 check
  SetTurtle 0
  Left :Dir Forward :Length
  If (Distance [0 0]) >180 [
    Back :Length Right :Dir Output "True] [Output "False]
end

to snowflake
  Make "Dir 60 * (Random 6)
  Make "Length 1+Random 32
  If Check [Make "Edge "False Stop]
  For [N 1 12] [
    SetTurtle :N
    SetPC 6.5 + (:Parity/2)   # 6 or 7
    Left :Parity * :Dir Forward :Length
    Make "Parity Minus 1 * :Parity] 
end

to go
  New
  # SetPC Red PenDown   # comment in to see check turtle 0
  Forever [
    SetTurtle 0 Home Forward 32 Wash
    Make "Parity 1 Make "Edge "True
    For [N 1 12] [
      SetTurtle :N PenUp Home
      SetH 15+(:N * 30)     # SetHeading 60 * Round (:N/2)
      Forward 32 PenDown] 
      While [:Edge] [ 
      Repeat 16 [Snowflake] ]
    Wait 240] 
end