Ear Clipping

Ear Clipping for concave Polygon triangulation

Optimize 12 runs (45%-85%)
Reset       : clear the Polygon
Triangulate : recall triangulation if you want to debug

  add Point : add a new Point to the polygon. Hit first vertex to close Polygon
  Test is In:  true, if click is in polygon
  Test Int. : true, if line intersects with an edge of the polygon