public Quaternion(ref Matrix3 matrix)
{
var scale = Math.Pow(matrix.Determinant, 1.0d / 3.0d);
float x, y, z;
w = (float)(Math.Sqrt(Math.Max(0, scale + matrix[0, 0] + matrix[1, 1] + matrix[2, 2])) / 2);
x = (float)(Math.Sqrt(Math.Max(0, scale + matrix[0, 0] - matrix[1, 1] - matrix[2, 2])) / 2);
y = (float)(Math.Sqrt(Math.Max(0, scale - matrix[0, 0] + matrix[1, 1] - matrix[2, 2])) / 2);
z = (float)(Math.Sqrt(Math.Max(0, scale - matrix[0, 0] - matrix[1, 1] + matrix[2, 2])) / 2);
xyz = new Vector3(x, y, z);
if (matrix[2, 1] - matrix[1, 2] < 0)
{
X = -X;
}
if (matrix[0, 2] - matrix[2, 0] < 0)
{
Y = -Y;
}
if (matrix[1, 0] - matrix[0, 1] < 0)
{
Z = -Z;
}
}
public static double NextPowerOfTwo(double n)
{
if (double.IsNaN(n) || double.IsInfinity(n))
{
throw new ArgumentOutOfRangeException(nameof(n), "Must be a number.");
}
if (n <= 0)
{
throw new ArgumentOutOfRangeException(nameof(n), "Must be positive.");
}
// Don't return negative powers of two, that's nonsense.
if (n < 1)
{
return(1.0);
}
return(Math.Pow(2, Math.Floor(Math.Log(n, 2)) + 1));
}