private static void Rotate (ref int fx, ref int fy, int fr)
{
int cx = fx;
int cy = fy;
//sin(x) ~~ x
//cos(x)~~ 1 - x^2/2
fx = cx - ((cy >> 8) * fr >> 8) - ((cx >> 14) * (fr * fr >> 11) >> 8);
fy = cy + ((cx >> 8) * fr >> 8) - ((cy >> 14) * (fr * fr >> 11) >> 8);
}
#endregion