norm
norm (const complex<_FLT>& x) __attribute__ ((const));
float norm = delta.x * delta.x + delta.y * delta.y;
if (norm > 0.01) {
delta.x /= norm;
delta.y /= norm;
norm = fLastDelta.x * fLastDelta.x + fLastDelta.y * fLastDelta.y;
if (norm > 0.01) {
fLastDelta.x /= norm;
fLastDelta.y /= norm;
template f norm (ccr);