@taktik sorry for tagging you right off the bat here but i think this one will end up with you anyway.
Specifically talking about these VST3 interfaces here: Data Exchange - VST 3 Developer Portal . Reason I ask is because until recently there was apparently a bug in the VST3 SDK impacting specifically the data exchange stuff on Linux, see DataExchange on linux? - #5 by recallmenot - VST 3 SDK - Steinberg Forums .
The actual problem I run into is that I’m using those interfaces in my synth to copy over a bunch of audio-thread state to the UI thread in order to paint oscilloscopes etc. Works like a charm on Win/Mac + anything, Linux+Reaper, but not Linux+Renoise (and to be fair also not Linux+Bitwig).
Tested on Renoise 3.4.4, but I don’t see anything related in the changelog of the newer versions.
Sorry I know this is a bit of an open-ended question, but it’s near impossible for me to debug and i just hope you can shed some light on this stuff.
To reproduce, get binaries from over here Release 2.0.3-alpha11 · sjoerdvankreel/firefly-synth-2 · GitHub ., load the vst3 in renoise, click the “osc 1” tab. On both win and mac, that gets you something like this, but on linux, the oscilloscope just won’t show.
