Provide ASin, ATan, ATan2 functions about handmademath

[bvisness]

The math functions provided by Handmade Math are those used internally by Handmade Math. We don't actually provide the implementations of any trig functions; they are always a proxy to some underlying implementation.

The HANDMADE_MATH_USE_X defines were designed to give you flexibility in how you use Handmade Math itself, but Handmade Math is not a trig library and we don't intend for it to be. We didn't really intend for users to use the trig functions directly.

That said, I understand why you might find yourself doing so in the process of using the library. We could add ASinF, ATanF, and ATan2F, but in non-stdlib use cases this would require people to provide implementations for these three functions even though they're not actually used by Handmade Math at all. Maybe that's fine, though, since you'd typically have such an implementation close at hand if you already are doing SinF and ACosF?

[occivink]

Thanks for the context, I understand the reasoning.
I do think that if you're doing graphics math you'll need to use directly some trigonometry functions, at which point chances are that you will need all of them (especially atan2 imo). So if you use a non-standard angle representation like turns, you'll need to do some back-and-forth conversions, which I think lowers the value of using this representation in the first place.

If you're concerned about increasing the requirement for non-stdlib cases, maybe these could be defined conditionally, such that users can decide to opt-in?