final boolean isReflex(EarClippingVertex vertex){
  Vector2 p=vertex.point;
  Vector2 p0=vertex.prev.point;
  Vector2 p1=vertex.next.point;
  Vector2 v1=p.to(p0);
  Vector2 v2=p.to(p1);
  if (v1.cross(v2) < 0.0) {
    return false;
  }
 else {
    return true;
  }
}

final boolean isReflex ( EarClippingVertex vertex ) { Vector2 p = vertex . point ; Vector2 p0 = vertex . prev . point ; Vector2 p1 = vertex . next . point ; Vector2 v1 = p . to ( p0 ) ; Vector2 v2 = p . to ( p1 ) ; if ( v1 . cross ( v2 ) < 0.0 ) { return false ; } else { return true ; } }
returns true if the given vertex is a reflex vertex . < p > a reflex vertex is a vertex who ' s adjacent vertices create an an angle greater than 180 degrees ( or the cross product is positive ) for ccw vertex winding .
