public SCNQuaternion(ref Matrix3 matrix)
{
double scale = System.Math.Pow(matrix.Determinant, 1.0d / 3.0d);
float x, y, z;
w = (float)(System.Math.Sqrt(System.Math.Max(0, scale + matrix[0, 0] + matrix[1, 1] + matrix[2, 2])) / 2);
x = (float)(System.Math.Sqrt(System.Math.Max(0, scale + matrix[0, 0] - matrix[1, 1] - matrix[2, 2])) / 2);
y = (float)(System.Math.Sqrt(System.Math.Max(0, scale - matrix[0, 0] + matrix[1, 1] - matrix[2, 2])) / 2);
z = (float)(System.Math.Sqrt(System.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;
}
}
// Apple deprecated initWithName:floatMatrix3: in macOS10.12/iOS10.0
// and made available initWithName:matrixFloat3x3: so we invoke
// the right one at runtime depending on which OS version we are running
public SKUniform(string name, Matrix3 value)
{
if (CheckSystemVersion())
{
InitializeHandle(InitWithNameMatrixFloat3x3(name, value), "initWithName:matrixFloat3x3:");
}
else
{
InitializeHandle(InitWithNameFloatMatrix3(name, value), "initWithName:floatMatrix3:");
}
}
