Copying AudioProcessorGraphs

Development
1

HI Jules and community,

I am currently working on a modular synth. I decided to create a Module class which inherits from AudioProcessor, and at the moment 2 class (VCO and SmartPan), which both inherit from the Module class.
I put 2 instances of the VCO module and 1 of the SmartPan module in an AudioProcessorGraph, using the addNode() method.
At the moment everything is working fine, but I am trying not to generate loops inside the graph. So I am trying to run Kahn’s algorythm (which checks if the graph has loops or not) after a connection is made, so that if it generate a loop, it’s possible to go back.
My question is: how can I copy the graph before adding the last connection to another AudioProcessorGraph? Should I just remove the last connection?
Also, I am declaring the graph in a “Rack.h” like this:

  std::unique_ptr<juce::AudioProcessorGraph> chain; //as private member of a Rack class

I am inizializing it in the “Rack.cpp” constructor this way:

 : chain(new juce::AudioProcessorGraph())

Am I doing everything correctly? I am able to call the chain->setPlayConfigDetails() method as well as prepareToPlay, processBlock and releaseResources methods.

Thanks in advance!

Giacomo

2

I am still trying to resolve this problem. Alternatives to copying the intire graph are well accepted! Maybe I could add the last node as bypassed, test Kahn on the graph and if it has no loops set the bypass to false?

3

Why don’t you just do something like

auto node;

do
{
   auto connection = getAnotherConnection();
   graph.addConnection(node, connection);

   if (!okFromKahn())
       graph.removeConnection(connection);
} while (notDone())

Or is there a special reason you can’t do this?

4

Thank you for the answer!
That’s actually what I discovered I could do, today! I made another Post about it: AudioProcessorGraph and loops with addConnection(). What's really happening?
I was afraid that adding a node that generates loops would call some assertions on the buffers (either read or write), or even worse, that the plugin would crash.
Well, I still don’t know how the AudioProcessorGraph already manages loops, but adding a node that generates one is not lethal, apparently. Checking if Kahn works after adding it to the graph while stuff’s playing is kinda dangerous, so I was trying to find a way of checking a copy of the graph that’s not actually connected. I guess it’s not necessary.

Thanks again!