Inverse Square

float Q_rsqrt( float number )
{
	long i;
	float x2, y;
	const float threehalfs = 1.5F;

	x2 = number * 0.5F;
	y  = number;
	i  = * ( long * ) &y;                       // evil floating point bit level hacking
	i  = 0x5f3759df - ( i >> 1 );               // what the fuck? 
	y  = * ( float * ) &i;
	y  = y * ( threehalfs - ( x2 * y * y ) );   // 1st iteration
//	y  = y * ( threehalfs - ( x2 * y * y ) );   // 2nd iteration, this can be removed

	return y;
}

Source: en.wikipedia.org

Similar codes

0 vote291 views1 answer
C++ rainbow text
C++
0 vote295 views1 answer
Vector int initialize with increasing numbers
C++
0 vote264 views1 answer
Getline(cin string) not working
C++
84 votes409 views4 answers
Php string
C++
22 votes257 views4 answers
Height of the tree
C++
0 vote263 views1 answer
Fname from FString
C++
1 vote266 views2 answers
C++ regex to validate indian phone number pattern
C++
2 votes258 views2 answers
Include cpp
C++
0 vote295 views1 answer
Export gcc g++
C++
6 votes262 views2 answers
Stoi
C++