title: barycentric coordinates using quads
body: <p>some of you know how fill a quads in 2D using barycentric
  coordinates?At the present, I'm splitting the quads into 2 triangles,
  but that way is inefficient because I have to iterate over the second
  bounding box which repeats pixel that were filled previously (by
  example, to fill the 2nd triangle I traversed the 1st triangle that
  belongs at bounding box formed by 2nd triangle)
  Thanks</p>
  
  <p>esmitt</p>