Supporting optional logging to user-provided callback.

[sherief]

Some users might want to redirect this, or reconcile it with logging from other subsystems in a single sink.

[flibitijibibo]

Sadly we can't change the public structs but we can totally add something similar to FNA3D's log rerouting:

https://github.com/FNA-XNA/FNA3D/blob/master/include/FNA3D.h#L496

[sherief]

I see, makes sense. Would it be acceptable if I were to add a new struct / function for this?

[flibitijibibo]

Definitely- we can do FAudio_HookLogFunction(s)EXT and have it be global like FNA3D, so that we don't have to fuss with object lifetime to get logs routed properly.

[sherief]

I host multiple instances in the same process and would prefer their output be separated - what do you think is the best path forward here?

[flibitijibibo]

If you've got an active test case then we can accommodate that - usually I just shotgun blast debug stuff unless somebody has a specific need, so if we need to put a function pointer in the FAudio object that's fine too.