Build fails with Juce 6

[Xenakios]

The plugin processor code has at least this piece of code that is no longer compatible with Juce :

myVoice->getEnvelopeParams(tree.getRawParameterValue("attack"), tree.getRawParameterValue("decay"), tree.getRawParameterValue("sustain"), tree.getRawParameterValue("release"));

getRawParameterValue now returns std::atomic<float>* and it won't work with the getEnvelopeParams call that expects plain float*'s.

[mhschmieder]

It works for me, running JUCE 6.0.8, Xcode 12.4, and targeting both C++14 and C++17 (non-Gnu compiler choices, but it didn't matter) as well as both macOS 10.11 and macOS 10.15 as the deployment target.

According to the C++ language spec, a scalar variable (whether volatile or not) of type T can be expressed as std::atomic (with reverse-casting allowed), so it is legitimate to cast those arguments to (float*), and just to verify that it had no effect on behaviour, I spent some time in the debugger to verify that the returned values were always correct and stayed in sync between the GUI and the cached variables.

I actually had more issues with Maximilian than with this Projucer project, having to move some files to the top level of its installation directory and also fix some compiler errors that did not go away if switching the C++ version or the compiler vendor (not that I expected them to, based on the nature of the problems).

I didn't make a fork of either GitHub project, as I'm new to all of this tonight, and generally assume that I'm the one who's wrong until proven otherwise -- especially as I am having to develop on macOS during pandemic lockdown and am more of a Windows developer (I bought my home computer for audio production, not coding).

I'm still not quite used to Xcode, and it does seem that fewer things get by the compiler on macOS than on Windows, so some projects may not have had the opportunity to get thoroughly checked across the platforms. If that is indeed the case, I may try to find time to create some forks with fixes for Mac builds.

[mhschmieder]

I just created a fork and committed my JUCE 6 and C++17 compiler fixes there. Not sure yet if I'll make a fork for Maximilian; I have to first see whether there were compiler errors that I fixed, or just compiler warnings and unfortunate hacks to the file system structure to make it compile with this project properly.

[mhschmieder]

I went ahead and made a fork for Maximilian and committed those structural changes. Due to all the files moving around in order to compile properly with this project, it was too time-consuming to check manually for whether I made any changes to the source code, but I seem to recall fixing a few compiler warnings here and there, most of which are new to C++17.