Function ovr_GetAudioDeviceOutWaveId

Revive/REV_CAPI_Audio.cpp:89–175

}

OVR_PUBLIC_FUNCTION(ovrResult) ovr_GetAudioDeviceOutWaveId(UINT* deviceOutId)
{
	REV_TRACE(ovr_GetAudioDeviceOutWaveId);

	if (!deviceOutId)
		return ovrError_InvalidParameter;

	// Query and cache the result
	static UINT cachedId = 0;
	if (!cachedId)
	{
		MMRESULT mmr;
		char endpoint[OVR_AUDIO_MAX_DEVICE_STR_SIZE] = {};
		vr::ETrackedPropertyError error = vr::TrackedProp_Success;
		uint32_t size = vr::VRSystem()->GetStringTrackedDeviceProperty(
			vr::k_unTrackedDeviceIndex_Hmd,
			vr::Prop_Audio_DefaultPlaybackDeviceId_String,
			endpoint, OVR_AUDIO_MAX_DEVICE_STR_SIZE, &error);
		if (error != vr::TrackedProp_Success)
		{
			// Return the default without caching so we can attempt again later
			mmr = waveOutMessage((HWAVEOUT)UIntToPtr(WAVE_MAPPER), DRVM_MAPPER_PREFERRED_GET, (DWORD_PTR)deviceOutId, NULL);
			return mmr == MMSYSERR_NOERROR ? ovrSuccess : ovrError_AudioDeviceNotFound;
		}

		WCHAR strEndpointIdKey[OVR_AUDIO_MAX_DEVICE_STR_SIZE] = {};
		if (size > OVR_AUDIO_MAX_DEVICE_STR_SIZE)
			return ovrError_InsufficientArraySize;
		if (!MultiByteToWideChar(CP_UTF8, MB_PRECOMPOSED, endpoint, size, strEndpointIdKey, OVR_AUDIO_MAX_DEVICE_STR_SIZE))
			return ovrError_MemoryAllocationFailure;

		// Get the size of the endpoint ID string.
		size_t cbEndpointIdKey = size * sizeof(WCHAR);

		// Each for-loop iteration below compares the endpoint ID
		// string of the audio endpoint device to the endpoint ID
		// string of an enumerated waveOut device. If the strings
		// match, then we've found the waveOut device that is
		// assigned to the specified device role.
		UINT waveOutId;
		UINT cWaveOutDevices = waveOutGetNumDevs();
		WCHAR strEndpointId[OVR_AUDIO_MAX_DEVICE_STR_SIZE] = {};
		for (waveOutId = 0; waveOutId < cWaveOutDevices; waveOutId++)
		{
			size_t cbEndpointId = 0;

			// Get the size (including the terminating null) of
			// the endpoint ID string of the waveOut device.
			mmr = waveOutMessage((HWAVEOUT)UIntToPtr(waveOutId),
				DRV_QUERYFUNCTIONINSTANCEIDSIZE,
				(DWORD_PTR)&cbEndpointId, NULL);
			if (mmr != MMSYSERR_NOERROR ||
				cbEndpointIdKey != cbEndpointId)  // do sizes match?
			{
				continue;  // not a matching device
			}

			// Get the endpoint ID string for this waveOut device.