AudioPluginDemo VST3 problem in Reaper

Audio Plugins
1

Hello,
Seeing a problem with saving/persisting state from JUCE VST3 plugins, specifically using Reaper as the host.

Posted the problem on the Reaper forum: Reaper not tracking VST3 plugin state changes while AU version of plugin is okay - Cockos Incorporated Forums

To reproduce the problem:

  • Build JUCE AudioPluginDemo plugin in VST3 format
  • Add AudioPluginDemo.VST3 to a Reaper project
  • Change a knob in the AudioPluginDemo GUI
  • Exit the Reaper project
  • Reaper does not present the dialog prompt: “Save Changes?” (Problem)

This does work in the AU version of AudioPluginDemo in Reaper.
And it does work in Cubase using AudioPluginDemo.VST3.

Since there are three technologies involved here: Steinberg VST3, Cockos Reaper and JUCE, it feels like it will be difficult to pin down the root cause.

Any advice would be appreciated. Thanks,
-Mike

2

Please can you confirm that you’re using the latest version of JUCE (7.0.5) and the latest version of REAPER (6.79)?

I’m guessing there’s a step missing in your instructions - are you saving after adding the plugin to the project, and before changing a parameter?

In any case, REAPER asks me whether to resave when I try to quit, whether or not I have previously saved the project.

Looking at REAPER’s titlebar, there’s a very short delay (less than a second) between releasing the parameter, and the “unsaved changes” indicator becoming visible inside the “close” button. If I change a parameter and then immediately hit cmd+q, then I don’t get a prompt to save. Are you perhaps quitting very quickly after making a change? Do you see the expected behaviour if you wait for a few seconds before quitting?

3

Yes, Reaper is 6.79 and JUCE is 7.0.5

Yes, some clarification needed on the steps:

  • Start Reaper
  • Insert Virtual Instrument on New Track
  • Choose: VST3i: AudioPluginDemo (JUCE)
  • Save Reaper project
  • Exit Reaper
  • Restart Reaper
  • Reopen last project, if not automatically opened
  • Change a knob in the AudioPluginDemo GUI
  • Close Reaper

At the last step above (“Close Reaper”), when the only thing that has changed in the Reaper project is a knob value, Reaper does not realize that the plugin state needs to be persisted and just exists without prompting the user regarding whether to save the changes in the project.

For comparison, using AU it works as expected.

Thanks for looking!

4

Does it work correctly if you wait a little bit longer before quitting REAPER?

5

Waiting for a while has no effect.

Another clue:
For AudioPluginDemo AU once a knob is changed Reaper title bar does change to include the text “[modified]” => okay
For AudioPluginDemo VST3 once a knob is changed Reaper title bar DOES NOT change to include the text “[modified]” => PROBLEM

Thanks

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