The code string 5f3763f0d1329aafd8562_sourcerar refers to a version of the fast inverse square root algorithm from Quake III Arena, which uses a "magic" constant for rapid
calculations. A definitive analysis of this method, including the bit-level manipulation and the history of the constant, is provided in the article "Quake III Arena: Fast Inverse Square Root" on Beyond3D. 5f3763f0d1329aafd8562_sourcerar