startshape Vortex

rule PIXEL 19 { CIRCLE { } }
# rule PIXEL { Vortex { s 0.05 } }
# rule PIXEL { SQUARE { } }

rule Arc {
  PIXEL { x 10.0 y 0.0 } 
  PIXEL { x 9.8078528040323 y 1.95090322016128 } 
  PIXEL { x 9.23879532511287 y 3.8268343236509 } 
  PIXEL { x 8.31469612302545 y 5.55570233019602 } 
  PIXEL { x 7.07106781186548 y 7.07106781186547 } 
  PIXEL { x 5.55570233019602 y 8.31469612302545 } 
  PIXEL { x 3.8268343236509 y 9.23879532511287 } 
  PIXEL { x 1.95090322016128 y 9.8078528040323 } 
}

rule Vortex  {
  Arc { }
  Arc { r 90 }
  Arc { r 180 }
  Arc { r 270 }
  Vortex { r -5 s 0.95 b 0.06 }
}