@Test
public void testOrientation()
{

    assertEquals(90.0, Math.toDegrees(ac.calcOrientation(0, 0, 1, 0)), 0.01);
    assertEquals(45.0, Math.toDegrees(ac.calcOrientation(0, 0, 1, 1)), 0.01);
    assertEquals(0.0, Math.toDegrees(ac.calcOrientation(0, 0, 0, 1)), 0.01);
    assertEquals(-45.0, Math.toDegrees(ac.calcOrientation(0, 0, -1, 1)), 0.01);
    assertEquals(-135.0, Math.toDegrees(ac.calcOrientation(0, 0, -1, -1)), 0.01);
    // is symetric?
    assertEquals(90 - 32.76, Math.toDegrees(ac.calcOrientation(49.942, 11.580, 49.944, 11.582)), 0.01);
    assertEquals(-90 - 32.76, Math.toDegrees(ac.calcOrientation(49.944, 11.582, 49.942, 11.580)), 0.01);
}