Implement Fast Inverse Square Root in Javascript?
- by BBz
The Fast Inverse Square Root from Quake III seems to use a floating-point trick. As I understand, floating-point representation can have some different implementations.
So is it possible to implement the Fast Inverse Square Root in Javascript?
Would it return the same result?
float Q_rsqrt(float number) {
long i;
float x2, y;
const float threehalfs = 1.5F;
x2 = number * 0.5F;
y = number;
i = * ( long * ) &y;
i = 0x5f3759df - ( i >> 1 );
y = * ( float * ) &i;
y = y * ( threehalfs - ( x2 * y * y ) );
return y;
}
