yin-yang.box

// Under a shell type: box -l g yin-yang.box
// ---
// Here we show how Poly can be used to trace curves

include "g"
w = Window[][
  b = 0.4  // border
  r = 10.0 // radius
  rr = 2*r, rs = 0.25*r
  \ .Circle[Style[.Border[b]], color.white, (0, 0), rr]
  \ .Poly[color.black, 1, (0, rr), (r, rr), (r, r), (r, 0), (0, 0), (-r, 0),
          (-r, -r), (-r, -rr), (0, -rr), (rr, -rr), (rr, 0), (rr, rr)]
  \ .Circle[Style[.Fill[";"]], rs, (0, r); color.white, rs, (0, -r)]
  .Save["yin-yang.png"]
  .Save["yin-yang.eps"]
]