VST3 SDK Note Expression Synth improvements.

[bioroid]

After a 10 year hiatus, I'm looking to dabble with VST plugins again. My first tasks is to learn the new VST3 and VSTGUI 4.2 SDKs. I have built their Note Expression Synth sample on iOS, Windows, and OSX but would like to fix it up to have features I will need in my own projects. Sorry for the noobish questions.

I already modified the uidesc file to enable midi input on iPhone to allow me to tweak the synth with a usb midi knob box. But here are the issues that I still need to resolve. Any tips, suggestions would be appreciated.

1. The UI doesn't update the knob positions when using external midi CCs. How do I tell the UI to refresh from the main process?

2. On Windows/OSX using the VST3 Plugin Test Host, I don't receive any midi CCs, but I do get them on iOS. Other plugins do receive midi CCs from the same controller so I know that the host is getting them and I am selecting the proper midi device in midi input the drop down list. What's missing?

3. What's a good way to handle midi-learn? Are there things in the SDKs to help/hurt the process?

I'm actually surprised that these features aren't already in the sample code.

Thanks!