public static Vec3 ComputePrincipleComponent(Sym3x3 matrix)
{
Vec4 row0 = new Vec4(matrix[0], matrix[1], matrix[2], 0.0f);
Vec4 row1 = new Vec4(matrix[1], matrix[3], matrix[4], 0.0f);
Vec4 row2 = new Vec4(matrix[2], matrix[4], matrix[5], 0.0f);
Vec4 v = new Vec4(1.0f);
for (int i = 0; i < 8; ++i)
{
// matrix multiply
Vec4 w = row0 * v.SplatX();
w = row1.MultiplyAdd(v.SplatY(), w);
w = row2.MultiplyAdd(v.SplatZ(), w);
// get max component from xyz in all channels
Vec4 a = Vec4.Max(w.SplatX(), Vec4.Max(w.SplatY(), w.SplatZ()));
// divide through and advance
v = w * a.Reciprocal();
}
return(v.GetVec3());
}