Reaper automation doesn't trigger AudioProcessorParameter listener?


I’ve created a subclass of my plugin processor to trigger some async calculations for the plugin when parameters are changed. It’s inheriting both AudioProcessorParameterListener and AsyncUpdater. It works so that when AudioProcessorParameterChanged() is called, it in turn calls the triggerAsyncUpdate().

When the parameters are changed from the GUI, this is working just fine, and the updating happens as supposed. However, when I try to automate the plugin parameters with Reaper, or change the parameters without the plugins GUI, the AudioProcessorParameterChanged() doesn’t seem to get called at all. I don’t the same problem with Juce’s own Plugin Host that I use for debugging.

Is there something obvious I’m not getting right here?



This sounds like a threading issue, any parameter updates need to happen on the message thread, some hosts are more fussy about this than others.

There is a good example of creating your own callback that inherits from the Message class in JUCE examples/MidiTest.