public void ParallelIntersectionPointTest( float ax1, float ay1, float ax2, float ay2, float bx1, float by1, float bx2, float by2 )
{
LineSegment segA = new LineSegment( new Point( ax1, ay1 ), new Point( ax2, ay2 ) );
LineSegment segB = new LineSegment( new Point( bx1, by1 ), new Point( bx2, by2 ) );
// are we really parallel?
Assert.AreEqual( null, ( (Line) segA ).GetIntersectionWith( (Line) segB ) );
Assert.AreEqual( null, segA.GetIntersectionWith( (Line) segB ) );
Assert.AreEqual( null, ( (Line) segA ).GetIntersectionWith( segB ) );
Assert.AreEqual( null, segB.GetIntersectionWith( (Line) segA ) );
Assert.AreEqual( null, ( (Line) segB ).GetIntersectionWith( segA ) );
Assert.AreEqual( null, segB.GetIntersectionWith( segA ) );
Assert.AreEqual( null, segA.GetIntersectionWith( segB ) );
}