OK I think Jules and I may have a solution to this problem. It is related to the laggy repainting bug since OS X El Capitan. Apple seems to have changed something in their repainting code since El Capitan which makes redraws extremely laggy if you post a lot of setNeedsDisplays.
The same bug is affecting Logic: you can clearly see how the GUI struggles to keep up when moving a JUCE slider. In addition, and more worryingly, Logic seems to be time-stamping and recording parameter events on the UI thread - and therefore the laggy UI seems to affect the timestamps of the recorded parameter changes.
Please let me know if the recent change on develop fixes this bug.
Yes, we do have friends at Apple But with things like this, it’s actually not always useful to call on them, as we need to find workarounds that work with the apps as they currently are.
I do suspect that there’s probably a poorly-made decision in the way Logic time-stamps the incoming events, and this isn’t anything we’re doing “wrong” in juce. But even if we got them to improve that in the next release, we’d need to find a solution for you guys in the meantime.
I filed a bug about the laggy UI in El Capitan a long time ago. We have some friends at Apple in the CoreAudio team but this bug is not really part of CoreAudio. The bug is still marked as open by the way.
Has anyone noticed this issue resurge in recent updates? Have we been actively checking for this? Noticing a regression in a product causing this behavior and I’ve no idea what we would have done to trigger this.