public void TestInverse()
{
float x = TK.MathHelper.PiOver6;
float y = TK.MathHelper.Pi;
TK.Matrix4 tkM = TK.Matrix4.CreateRotationX(x) * TK.Matrix4.CreateRotationY(y);
Matrix3x3 m = Matrix3x3.FromRotationX(x) * Matrix3x3.FromRotationY(y);
tkM.Invert();
m.Inverse();
TestHelper.AssertEquals(tkM, m, "Testing inverse");
}
/// <summary>Transform a Normal by the given Matrix</summary>
/// <remarks>
/// This calculates the inverse of the given matrix, use TransformNormalInverse if you
/// already have the inverse to avoid this extra calculation
/// </remarks>
/// <param name="norm">The normal to transform</param>
/// <param name="mat">The desired transformation</param>
/// <returns>The transformed normal</returns>
public static Vector3 TransformNormal(Vector3 norm, Matrix4 mat)
{
mat.Invert();
return(TransformNormalInverse(norm, mat));
}
/// <summary>Transform a Normal by the given Matrix</summary>
/// <remarks>
/// This calculates the inverse of the given matrix, use TransformNormalInverse if you
/// already have the inverse to avoid this extra calculation
/// </remarks>
/// <param name="norm">The normal to transform</param>
/// <param name="mat">The desired transformation</param>
/// <param name="result">The transformed normal</param>
public static void TransformNormal(ref Vector3 norm, ref Matrix4 mat, out Vector3 result)
{
Matrix4 Inverse = Matrix4.Invert(mat);
Vector3.TransformNormalInverse(ref norm, ref Inverse, out result);
}