VST3: cannot set parameters on Reaper/Linux

[lucianoiam]

Since this plugin format needs some work on Mac and Windows I started by testing it on Linux which is probably the reference platform; VST3 Parameters example works great on Carla indeed.

On Reaper/Linux found the following (again in Parameters):

• UI works as expected
• Updating a parameter using Reaper generic UI is reflected next time UI is opened
• Updating a parameter from the custom plugin UI does not have any effect in the generic UI

In other words VST3 plugins cannot update parameters for the Reaper host. First spotted this in a plugin of my own.

I debugged up to requestParameterValueChange() (DistrhoPluginVST3.cpp) and all seems good, begin_edit and perform_edit returning V3_TRUE.

Any hint on how to further debug this?

[falkTX]

tbh I did the UI -> DSP communication all wrong. have to rework it but this part should work... I would look into what juce does related to host, how it notifies the host of ui parameter changes.

[lucianoiam]

That is a good idea, thanks. I need to read how VST3 works as well lol.

[falkTX]

This should be fixed now, confirmation would be most welcome

[lucianoiam]

Sadly it still seems broken, just tested c2f66ac on Reaper/Mac:

1. Open d_parameters.vst3 UI
2. Click top-left (make it orange)
3. Switch to Reaper generic UI
4. Top-left is zero

[cmarabotto]

VST3 is also broken on Ableton (can see the plugin but can't load it).

[falkTX]

we need to check this again after latest vst3 fixes in dpf.

[falkTX]

and it is still broken.

it behaves properly in other hosts like Carla and FLStudio though.

[falkTX]

Should be fixed with latest code now, I verified with https://github.com/trummerschlunk/master_me that things generally seem to work there.

[lucianoiam]

Just repeated this on Reaper+Linux and it now works great; maybe it is time to close the ticket.

1. Open d_parameters.vst3 UI

2. Click top-left (make it orange)

3. Switch to Reaper generic UI

4. Top-left is zero

[falkTX]

I suspected as such, thanks for confirming!