CollectInvalidRect( ) crashes with AGain sample Plugin

I reported this issue in detail on the VST3 SDK forum as it is not clear where the problem lies, but I wanted to tag a topic here as well. The VST3 SDK topic is here:

  • Will Pirkle

Hi Will,

Maybe this is in some way related to the following “issue”: Debug assertion in CFrame::CollectInvalidRects::addRect() - VSTGUI - Steinberg Forums ?

It happened when my host implementation called into invalid() from any other thread than the UI thread (a design restriction that goes for all VSTGUI calls except setDirty() afaik).

Best,
Ray

Thanks Ray - yeah, I do remember seeing that and it jogged my memory when I saw the Rect Collection error.

To be clear, this report is for a VST3 SDK Sample Plugin compiled directly from the SDK with no modifications, and not one of my own plugins or GUI objects.

So I think this is an issue for Steinberg first. It also happens in 3 different VST3 hosts from 3 different manufacturers (the user who found this did issue a trouble ticket for Tracktion).

  • Will

Hi Will,

Okay, I see. I was under the impression that it could be a host issue, e.g. if the “perform UI calls from the UI thread exclusively” principle is violated by the implementation for some reason. I agree this seems unlikely if this happens in 3 established hosts.

Best,
Ray