Exponential/Power Functions about vult

[Miserlou]

If it helps nudge you, this function is used for peak/shelf filters..

[Miserlou]

(My interim solution so far has been to compute and cache it in C++, then pass that value into Vult, but it feels very inelegant.)

[ritschwumm]

it might be better to support a natural logarithm, as it is used in many DSP algorithms.
then one can build on pow(a,x) == exp(x * ln(a))

[modlfo]

There's the function pow(a,b) It's undocumented. I added it not so long ago. Here's the part of the code that lists all the builtins.

https://github.com/modlfo/vult/blob/master/src/core/env.ml#L593

I try to avoid it because it's slow. You can cache it directly in Vult if you have one of the arguments fixed. For example:

fun pow1_4(x) @[table(size=127,min=0.0,max=10)] {
   return pow(x, 1.4);
}

[modlfo]

In general, you can add missing functions as follows:

external atan2(x:real, y:real) : real "atan2f";

That adds the C++ atan2f and can be used for code generation. The problem when using external function is that the code becomes less portable.