macOS multi-touch support

I’m a developer working on the UPDD, a third party macOS touch driver from Touch-Base. We’ve received a number of requests from users of software developed using JUCE to get multi-touch support working in their apps and VST plug-ins, especially so that they can use touches to adjust multiple sliders and knobs simultaneously. The trouble is that macOS doesn’t support multi-touch from a touch screen natively, so up until now there’s been no way to do that.

However I recently submitted a pull request that implements macOS multi-touch in JUCE using Touch-Base’s driver and API. You can check it out here.

We also have instructions for developers who want to make use of these changes now.

This would allow anyone who uses the UPDD to have full multi-touch in a JUCE application. On the software developer’s end, there’s no code changes required in their app, other than incorporating in the changes we made to JUCE.

We’re hoping that this PR will be merged into JUCE so that all macOS JUCE software can support multi-touch.