bool isOverlap(Polygon A, Polygon B){
  foreach(Vertex v in A)
  {
    if(isInside(v, B))
      return true;
  }
  foreach(Vertex v in B)
  {
    if(isInside(v, A ))
      return true;
  }
  return false
}

bool isInside(Vertex v, Polygon p)
{ //you can choose either Crossing Number or Winding Numer, you can google implementation
}