public void WorldViewPerspectiveProjectionTests()
{
var world = new WorldView(1, 1);
Assert.IsTrue(world.EyePosition.Equals(Vector3.UnitZ * 7, 1e-3));
world.CalculatePerspectiveMatrixOffCenter(567, 123, -200, 5, 55);
Assert.IsTrue(world.GetScreenPosition(new Vector3(0, 0, 0)).Equals(new Vector2((567 - 200) / 2.0, 123 / 2.0), 1e-3));
Assert.AreEqual(5, world.NearZ, 1e-3);
Assert.AreEqual(55, world.FarZ, 1e-3);
Assert.AreEqual(4.14213562373095, world.NearPlaneHeightInViewspace, 1e-3);
var ray = world.GetRayForLocalBounds(new Vector2((567 - 200) / 2.0, 123)); // top center
Assert.AreEqual(WorldView.DefaultPerspectiveVFOVDegrees / 2, MathHelper.RadiansToDegrees(Math.Atan2(ray.directionNormal.Y, -ray.directionNormal.Z)), 1e-3);
Assert.IsTrue((Vector3.UnitZ * 7).Equals(ray.origin, 1e-3));
Assert.AreEqual(world.NearPlaneHeightInViewspace * 2, world.GetViewspaceHeightAtPosition(new Vector3(1, 1, -10)), 1e-3);
world.Scale = 3;
Assert.AreEqual(world.NearPlaneHeightInViewspace * 2 / 3, world.GetWorldUnitsPerScreenPixelAtPosition(new Vector3(1, 1, (7 - 10) / 3.0)) * 123, 1e-3);
}