FWIW, for a game controller, I’m absolutely certain that f32 is already overkill and that a half float or even a byte per axis, u16/u8, is sufficient. The only

FWIW, for a game controller, I’m absolutely certain that f32 is already overkill and that a half float or even a byte per axis, u16/u8, is sufficient. The only reason to need f32 or f64 is if you’re rounding direction vectors for some other purpose than a game controller. But in graphics we frequently use f16 for direction vectors even when f32 is needed for positions. Normals and unit sphere directions usually require less precision than other operations. Using f64 for a game controller stick input isn’t justifiable, even if it isn’t measurable in code speed, I don’t think it would fly or pass code review in a real game engine. My next concern would be whether using doubles willy-nilly leads to the compiler spilling registers to memory more often. That could easily undo the 40ns optimization, and it would be difficult to measure or blame the direction rounding code, it would diffuse the cost to other parts of the code.