public bool IsIdentity()
{
if ( m[0, 0] != 1.0f || m[1, 1] != 1.0f || m[2, 2] != 1.0f || m[3, 3] != 1.0f ) return false; if ( m[0, 1] != 0.0f || m[0, 2] != 0.0f || m[0, 3] != 0.0f || m[1, 0] != 0.0f || m[1, 2] != 0.0f || m[1, 3] != 0.0f || m[2, 0] != 0.0f || m[2, 1] != 0.0f || m[2, 3] != 0.0f || m[3, 0] != 0.0f || m[3, 1] != 0.0f || m[3, 2] != 0.0f ) return false; return true;
}