/// <summary>
/// Calculates the view matrix.
/// </summary>
/// <param name="position">The position.</param>
/// <param name="direction">The direction.</param>
/// <param name="up">The up direction.</param>
/// <returns>The calculated view matrix.</returns>
public static Matrix CalculateViewMatrix(Vector3 position, Vector3 direction, Vector3 up)
{
var n = -direction.Normalized();
var u = up.Cross(n).Normalized();
var v = n.Cross(u);
var e = -position;
return new Matrix(
u.X, v.X, n.X, 0,
u.Y, v.Y, n.Y, 0,
u.Z, v.Z, n.Z, 0,
u.Dot(e), v.Dot(e), n.Dot(e), 1);
}
public void Normalized()
{
var original = new Vector3(1, 3, 5);
var normalized = original.Normalized();
var expected = new Vector3(original.X / original.Length,
original.Y / original.Length, original.Z / original.Length);
Assert.AreEqual(expected, normalized);
}
public void Position_and_Direction_with_radius_and_declination()
{
var orbitingStand = new OrbitingStand(10, 0, Constants.HALF_PI * 0.5f);
var expectedPosition = new Vector3(10 / Functions.Sqrt(2), 10 / Functions.Sqrt(2), 0);
Assert.AreEqual(expectedPosition,
orbitingStand.Position, new Vector3EqualityComparer());
Assert.AreEqual(-expectedPosition.Normalized(), orbitingStand.Direction,
new Vector3EqualityComparer());
}
public void Position_and_Direction_with_radius_azimuth_and_declination()
{
var orbitingStand = new OrbitingStand(
10, Constants.PI * 0.75f, Constants.HALF_PI * 0.5f);
var expectedPosition = new Vector3(-5, 7.071068f, 5);
Assert.AreEqual(expectedPosition, orbitingStand.Position,
new Vector3EqualityComparer());
Assert.AreEqual(-expectedPosition.Normalized(), orbitingStand.Direction,
new Vector3EqualityComparer());
}
