Select Code to Download

 *--------------------*
  \       A          /
...
 /      \     \   /
*--------*     \ /
                *

 *--------------------*
  \       A          /
...
 / A(2) \     \   /
*--------*     \ /
                *

sub _pointIsInQuadrilateral {
  my ($a_point, $a_x, $a_y) = @_;
...
  # Point is inside quadrilateral!
  return 1;
}