[openal] Synchronizing 3D sources

[Chris Robinson]

On 01/24/2014 03:43 AM, Doug Binks wrote:
> That sounds similar to what we were thinking.
>
> For device clock, one extra issue is that the programmer needs to know when
> to submit the play request in order to ensure the buffer can be queued
> before the device mixes the next output buffer. So we may also need to
> query the device output buffer size - I'm not sure if that's already in the
> extension spec.

It should be enough for the app to know the update/period time and add 
that to the retrieved clock time (i.e. a time or frequency derived from 
UpdateSize). So even if the clock updates just after you read it, you 
will still specify an equal or larger clock time to get accurate timing.

Currently you could get that info with the ALC_REFRESH value (update 
time = clock_res / refresh), although like I noted in another message, 
that's not the best idea because the refresh is not a logical product of 
the update size (it currently is, but that's an implementation detail 
that could change).