Reminds me of the first time I saw Sin and Cos lookup tables being used in early 3D gaming. The computers could calculate those just fine, especially with a math co-processor. But for 3D gaming it would be too slow to get a good framerate. So lookup tables were used to greatly improve the speed.

Back on those days all sort of neat tricks like that would be used. Often done as little demo programs that were very impressive. Before the internet it was hard to look up something like that and the latest and greatest tricks weren't written in books yet. So often little code snippets and demo programs would be shared amongst programmers using the sneakernet, so we could all learn and get better.

[–] HugeNerd@lemmy.ca 3 points 16 hours ago

On 8 bit CPUs we just "refactor" the circle to have 256 degrees so you can easily use 8 bit math.

[–] Tja@programming.dev 4 points 1 day ago

Yeah, but we didn't have an is_odd npm package, imagine the horror.

[–] xthexder@l.sw0.com 17 points 1 day ago (1 children)

Trigonometry functions are still just a hardware lookup table in most scenarios I believe. One example I've noticed is that you'll get slightly different sin/cos results on AMD vs Nvidia GPUs due to either different lookup table values, or different interpolation functions being applied on top (I'm not sure it's possible to know for sure exactly which without internal knowledge)

[–] gens@programming.dev 8 points 1 day ago

For cpu sine is in code. X87 has a FSIN, but nobody uses it. Afaik it's just worse. Idk about gpus or if there's a standard like there is for floats in general (ieee754).

[–] muusemuuse@sh.itjust.works 4 points 1 day ago

Humans can invent lies. Machines can repeat lies faster.

[–] MonkderVierte@lemmy.zip 1 points 1 day ago

Aren't commonly used math results fix in hardware anyways?