OG Doom engine uses pre-built lookup tables for fixed point trigonometry. (table captures the full 360 degrees for sine and cosine with 10240 elements)
And CPUs still do it to this day. Nasty, nasty maths involved in figuring out an optimal combination between lookup table size and refinement calculations because that output can’t be approximate, it has to work how IEEE floats are supposed to work. Pure numerology.
OG Doom engine uses pre-built lookup tables for fixed point trigonometry. (table captures the full 360 degrees for sine and cosine with 10240 elements)
Tons of software did this for the longest time. Lookup tables have been a staple of home computing for as long as home computers have existed.
And CPUs still do it to this day. Nasty, nasty maths involved in figuring out an optimal combination between lookup table size and refinement calculations because that output can’t be approximate, it has to work how IEEE floats are supposed to work. Pure numerology.