Compiled latest example projects have weird GUI behavior on some DAWs

Hi everyone. As the title says, I successfully compiled the latest SDK 3 examples, passing all the validation. The plugins, when loaded on FL Studio 20, for example, show weird GUI behavior. I added some images to show what I’m talking about. Should I be concerned? The plugins seem to load fine on other DAWs I tested.

This is an example plugin with VSTGUI:

This is another example plugin without VSTGUI, which should at least show host basic UI but it doesn’t:

Looks like you may should get in contact with the FL Studio developers about it.


What exact version of FL 20 did you test with?

Could I test the plugin in question?

The plugins I tested are the example ones, like gain (with GUI), simple gain, etc…

FL Studio version is 20.0.4

The problem is surely present on this specific DAW, but not on others I tested. Other commercial VST3 plugins I tested don’t have this problem, so I guess it’s a mixture of features/incompatibilities of the latest SDK version (3.6.10) and latest FL Studio versions.

Could you try FL 20.0.5, just in case it makes a difference?

Are you testing in Windows or macOS?

Also, did you build the sample projects from the latest official release 3.6.10, released in June? And could you provide your settings to ‘cmake’ if any, and the compiler version you are using?

Yes, I compiled from the latest SDK. Cmake call I used (as explained in the documentation):

cmake -G"Visual Studio 15 2017 Win64" SMTG_CREATE_BUNDLE_FOR_WINDOWS=ON "..\VST3_SDK"

Since I’m on Windows 10 and I use Visual Studio 2017 to compile.

I think it’s more of a VSTGUI issue rather than a SDK issue. It’s almost like the DAW thinks the plugin has a certain specific GUI size, but instead the real size is smaller. By the way, I don’t use any display scaling, since I’m running at 1080p on a 1080p display.

Tested on 20.0.5 too (Windows 10 64 bit). The same GUI issue as version 20.0.4 is present.

I’ve finally had a chance to look at this.

What does the plugin return in IPlugView::CanResize()?

That virtual method doesn’t seem to be implemented in the examples I checked (like ‘helloworldwithVSTGUI’), however behaviorally on the FL Studio host these plugins show handles for resizing (corners glow blue when attempting to resize), but the plugins won’t resize since they aren’t implementing the functionality. Other commercial VST3 plugins I tested (not resizable) don’t show this type of behavior, probably because they were created using a previous version of the VST3 SDK and/or a previous version of VSTGUI.

Also, is it expected that VST3 plugins without GUI aren’t showing at least a minimal host interface GUI on the FL Studio host?

I’ll have to double-check how I use the function, but it does seem to return a value that indicates the plugin supports resizing.

I have fixed the problem with the initial editor size at least, it will be correct in the next version of FL.

Also, is it expected that VST3 plugins without GUI aren’t showing at least a minimal host interface GUI on the FL Studio host?

In theory they should show the soo-called “interfaceless” GUI, just like it happens for VST plugins. But are there any such VST3 plugins? I’ve never encountered any.

Ehm, like the mda plug-ins in the SDK ?

I’ve never built the SDK examples so far, as I don’t usually work in C++. So I haven’t tested them either.

I haven’t seen any in the wild, however.