# Main Command: Go
# Eye by Guy Walker
# www.logoarts.co.uk

To New
  # set default screen, pen and turtle values
  ResetAll SetScreenSize [400 400] HideTurtle
  SetSC Black SetPC Green SetPS 1 PenUp
End

To Init
  # global values for each sector
  GlobalMake "Angle 10 +Random 110
  GlobalMake "Rad1 10 +Random 170
  GlobalMake "Width 130 -:Angle
  GlobalMake "Rad2 :Rad1 +:Width
  If :Rad2 >180 [Make "Rad2 200 -:Width]
  # Make Hue random color except black or white
  Make "Hue [0 0 0]
  While [Or :Hue=[0 0 0] :Hue=[255 255 255] ] [Make "Hue RandRGB 3]
End

To Sector :Angle :Rad1 :Rad2
  # sector shape drawn from centre (tp)
  Make "Offset (:Rad1+:Rad2) /2     # global offset fill
  Arch :Angle :Rad1
  Arch :Angle :Rad2 Left :Angle/2
  Forward :Rad1 PenDown Forward (:Rad2-:Rad1)
  PenUp Back :Rad2 Right :Angle
  Forward :Rad1 PenDown Forward (:Rad2-:Rad1)
  PenUp Back :Rad2 Left :Angle/2     # return to centre
End

To RandRGB :Ord
  # return random RGB color
  Output (List Val :Ord Val :Ord Val :Ord)
End
To Val :Ord
  # return random value 0-255 in steps of 255/:Ord-1
  Output Int (Random :Ord)*(255/(:Ord-1))
End

To Arch :Angle :Radius
  # symmetrical arc drawn relative to turtle heading
  Arc :Radius Heading-:Angle/2 Heading+:Angle/2
End

To Go
  New Repeat 24 [
    Init SetH Random 360 SetPC [9 9 9]
    Sector :Angle :Rad1 :Rad2
    Forward :Offset
    FillZone SetPC :Hue Fill
    Back :Offset
    SetPC White Sector :Angle :Rad1 :Rad2]
End