Quad.copy constructor

Quad.copy(Quad other)

Create a quad as a copy of other.

Implementation 

Quad.copy(Quad other)
    : _point0 = new Vector3.copy(other._point0),
      _point1 = new Vector3.copy(other._point1),
      _point2 = new Vector3.copy(other._point2),
      _point3 = new Vector3.copy(other._point2);