Integrating FAudio, a reimplementation of XAudio2

[Ethan Lee]

Tomorrow morning I'll put together CustomAllocatorEXT; I don't think 
I'll go with the structure layout but I can at least get the right idea 
put together and show it as working with the COM wrapper for now. As a 
sample of what an extension would look like, I took a function that was 
previous internal and marked "Do Not Use" and documented it a little better:

https://github.com/FNA-XNA/FAudio/commit/3f7fddc69570ffda25f7be1ddc87151c8ad01c24

-Ethan

On 10/21/18 14:54, Henri Verbeet wrote:
> On Sat, 20 Oct 2018 at 07:28, Ethan Lee <flibitijibibo at flibitijibibo.com> wrote:
>> In this case it would be something like "CustomAllocatorEXT", where all
>> the construction entry points get a new overload like
>> "FAudioCreateWithCustomAllocatorEXT", which is the same as the official
>> FAudioCreate but with added parameters for function pointer types like
>> FAudioCustomMallocEXT, and those would get stored in each context. The
>> nice thing about everything being tied together in an extension is that
>> I can document in big giant letters "DO NOT MIX ALLOCATORS" and avoid
>> both the global variable safety issue as well as the malloc/free
>> mismatch problems.
>>
> That's not that different from the example I gave. I called it
> faudio_create(), but I'm not set on a specific name. Note that the
> "struct faudio_create_info" scheme has API and ABI stability
> advantages though. If you ever need to add some extra optional
> parameters, you can pass those through the "next" pointer without
> breaking either the API or the ABI like this:
>
>      thread_info.type = FAUDIO_STRUCTURE_TYPE_THREAD_CREATE_INFO;
>      thread_info.next = NULL;
>
>      thread_info.pfn_thread_create = pthread_create;
>      thread_info.pfn_thread_join = pthread_join;
>      ...
>      create_info.next = &thread_info;
>      ...
>
> Even when you need to break the API, you can still keep the same ABI
> without having to do symbol versioning by assigning a different ID to
> FAUDIO_STRUCTURE_TYPE_CREATE_INFO.
>