4 ms·

Origin of Quake3's Fast InvSqrt()

• henning 19y ago
  when you use code that obfuscatory, wouldn't you want to give a comment explaining its origin and where to go for further info? i never understood why the origin of any piece of code that shipped in a major game from a high-profile development team would ever be hard to track down. you should know who added it, when, and why (the code should be self-explanatory, or be refactored, or a comment should be provided for cutesy performance hacks like this).
  • aston 19y ago
    This code was written when the software industry looked very different. Particularly, the teams were super tiny, and cleverness won out over code clarity every time due to the relatively weak computation power that was readily accessible. I would have been surprised to hear that any of the dirty/genius hacks found in apps written in the 80's and early 90's was well documented. That good sqrt code made it into Quake 3 from previous codebases is also not surprising. If it ain't broke...
• gb 19y ago
  There's a short follow up that identifies the author too: http://www.beyond3d.com/content/articles/15/ http://www.beyond3d.com/content/articles/15/