[Openal-devel] ALC_ENUMERATE_ALL_EXT and pluggable sound devices

[Guilherme Balena Versiani]

Hello people,

Following the division of the problem, that seems we all agreed, I would 
like to concentrate on the device listing only, and let the device 
notification for another discussion.

We have two solutions until now:

    1) alcGetString always returns a "fresh" list of the available 
devices, in a way opposite to the current Router behavior that is to 
save a list in static memory and return the same list for every 
subsequent call;
    2) The application must call ALC_EXT_disconnect to force the list to 
be cleaned up.

I personally like the first option, as IMHO this is far more simple to 
implement and adapt.

Let me create a metaphore of a real situation:

    1) Suppose you have an application, and in the moment you started 
it, you didn't connect the soundcard device (for example an USB headset).
    2) You start some kind of transaction in the application that won't 
persist if you restart the application (for example a tournament on a game).
    3) You connect an USB headset and now you want to use it in the 
current running application.

How this could be solved (this is one solution, maybe you can have others):

    1) You open a configuration menu of the application and go to sound 
configuration tab.
    2) In this moment, the application just calls alcGetString to create 
the device list combo box and shows to the user.
    3) The user changes the device and the application calls 
alcOpenDevice/alcCreateContext/alcMakeContextCurrent to change OpenAL 
rendering device.

If the alcGetString function just resets the device listing for every 
call, the application will start to work as expected.

Another case is when you disconnect the USB device. If this device was 
selected by the OpenAL library, I think it is expected by the user that 
the application stops to play sounds, and some kind of intervention 
should be executed to adjust the sound playing again.

Regards,

-- Guilherme Balena Versiani.