public static Point2D_F64 center( Quadrilateral_F64 quad , Point2D_F64 center ) {
		if( center == null )
			center = new Point2D_F64();

		center.x = quad.a.x + quad.b.x + quad.c.x + quad.d.x;
		center.y = quad.a.y + quad.b.y + quad.c.y + quad.d.y;

		center.x /= 4.0;
		center.y /= 4.0;

		return center;
	}
public static Point2D_F64 center( Quadrilateral_F64 quad , Point2D_F64 center ) {
		if( center == null )
			center = new Point2D_F64();

		center.x = quad.a.x + quad.b.x + quad.c.x + quad.d.x;
		center.y = quad.a.y + quad.b.y + quad.c.y + quad.d.y;

		center.x /= 4.0;
		center.y /= 4.0;

		return center;
	}
public static Point2D_F64 center ( Quadrilateral_F64 quad , Point2D_F64 center ) { if ( center == null ) center = new Point2D_F64 ( ) ; center . x = quad . a . x + quad . b . x + quad . c . x + quad . d . x ; center . y = quad . a . y + quad . b . y + quad . c . y + quad . d . y ; center . x /= 4.0 ; center . y /= 4.0 ; return center ; }
Computes the center or average point in the quadrilateral.

@param quad (Input) Quadrilateral
@param center (output) Center point of the quadrilateral.  Can be null.
@return The center point.
Computes the center or average point in the quadrilateral .