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 OnStage?
  # check turtle within window edges
  If (Or X<-190 X>190 Y<-190 Y>190) [Output False] [Output True]
End

To RightArc :Angle :Radius
  # arc drawn relative to turtle position, angle & radius positive
  PenUp Left 90 Back :Radius
  Arc :Radius Heading Heading+:Angle
  Right :Angle Forward :Radius Right 90 PenDown
End

To Go
  New
  Repeat 4 [
    PenUp Home SetH RepCount*90 SetPC RepCount PenDown
    While [OnStage?] [
      Make "Parity Pick [-1 1]
      RightArc :Parity *90 12 Wait 2] ]
End