https://betterexplained.com/articles/understanding-quakes-fast-inverse-square-root/ Math lessons that click Sun, 19 Apr 2026 14:40:47 +0000 hourly 1 https://betterexplained.com/articles/understanding-quakes-fast-inverse-square-root/#comment-568415 Sun, 19 Apr 2026 14:40:47 +0000 http://betterexplained.com/articles/understanding-quakes-fast-inverse-square-root/#comment-568415 Just fyi. Another reason why its fast, at least on the 486/Pentium side, is that floating point operations can run at the same time as integer operations. So if you do the float operations, do some other integer math, they by that time you can pull the float answer for the rest.

]]> https://betterexplained.com/articles/understanding-quakes-fast-inverse-square-root/#comment-568354 Wed, 27 Nov 2024 21:27:06 +0000 http://betterexplained.com/articles/understanding-quakes-fast-inverse-square-root/#comment-568354 This is widely used and predates Quake by decades! Modern processors have a fast approximate inverze square root which can then be improved by Newton iteration. Two iterations give double precision accuracy.

]]> https://betterexplained.com/articles/understanding-quakes-fast-inverse-square-root/#comment-568323 Fri, 22 Dec 2023 03:15:20 +0000 http://betterexplained.com/articles/understanding-quakes-fast-inverse-square-root/#comment-568323 This very much reminds me of Kaze Emanuar's work with optimizing Mario 64 for the past two years.

]]> https://betterexplained.com/articles/understanding-quakes-fast-inverse-square-root/#comment-395384 Wed, 11 Aug 2021 00:03:14 +0000 http://betterexplained.com/articles/understanding-quakes-fast-inverse-square-root/#comment-395384 […] : 1. Quake3의 빠른 InvSqrt ()의 기원-1 페이지 2. Quake의 빠른 역 제곱근 이해 3. FAST INVERSE SQUARE ROOT.pdf 4. 소스 코드 : q_math.c # […]

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