When is activateBus() called in the flow?

Developer VST 3 SDK
1

Is it ever going to be called while the processor is active? Or is it part of the configuration stuff, like bus arrangements?

2

IComponent::activateBus is called in the Setup Done state, the plug-in should be deactivated (setActive (true) not called).
Check here: VST 3 Workflow Diagrams - VST - Steinberg Developer Help

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3

That is a great diagram! Why hadn’t I seen that before?

4

So, to confirm, would it be a mistake that IComponent->activateBus is listed in the “processing” state of the audio processor call sequence?

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5

Yes, it was a copy/paste mistake… thanks for noting it… it is fixed now…

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6

I’m not sure whether it belongs into this thread as it’s AUv2 related, but it affects the activation state of busses so I’ll put this here anyway: I found that AUWrapper::SetConnection() is never called (tested in REAPER, Logic, GarageBand).

If I add an aux bus it might be marked as active although it isn’t because all busses will be set to active in the AUWrapper c’tor.

The current activation state is polled in AUWrapper::Render() so one can still detect the proper activation state, e.g. in order to check whether a sidechain is connected, via the channel buffer pointer which will be set to 0 in case a bus is inactive.

It would be nice to be able to do this using the designated way, i.e. via Bus::isActive().

Any suggestions how to fix this?

Best,
Ray