public void Rot02(ref float c, ref float s)
{
Mat3.CalcSymmetricGivensCoefficients(m00, m02, m22, out c, out s);
float cc = c * c;
float ss = s * s;
float mix = 2 * c * s * m02;
SetSymmetric(cc * m00 - mix + ss * m22, c * m01 - s * m12, 0,
m11, s * m01 + c * m12, ss * m00 + mix + cc * m22);
}