public void TestExtensions() { // Check Points in Rectangle var rect = new Rectangle(0, 0, 200, 200); Assert.IsTrue(rect.IsPointIn(new Point(100, 100))); Assert.IsTrue(rect.IsPointIn(new Point(200, 200))); Assert.IsFalse(rect.IsPointIn(new Point(201, 201))); Assert.IsTrue(rect.IsPointIn(new Point(0, 0))); Assert.IsFalse(rect.IsPointIn(new Point(-1, -1))); //Check Point Relative To Point var point1 = new Point(100, 100); var point2 = new Point(200, 200); Assert.AreEqual(point2.RelativeTo(point1), point1); Assert.AreNotEqual(point1.RelativeTo(point2), point1); Assert.AreEqual(point1.RelativeTo(point2), new Point(-100, -100)); Assert.AreEqual(point1.RelativeTo(new Point(50, 50)), new Point(50, 50)); }