make basic audio engine parameters configurable

src/ui/MainWindow.cpp

@@ -8,7 +8,7 @@
 MainWindow::MainWindow(QWidget *parent) :
     QMainWindow(parent),
     ui_(new Ui::MainWindow),
-    audio_(new AudioEngine()),
+    audio_(new AudioEngine(&config_)),
     keyboard_(audio_->noteQueue()),
     midi_(audio_->noteQueue()) {
 

src/ui/MainWindow.h

@@ -6,6 +6,7 @@
 
 #include "../synth/AudioEngine.h"
 #include "../MidiController.h"
+#include "../ConfigInterface.h"
 
 QT_BEGIN_NAMESPACE
 namespace Ui { class MainWindow; }
@@ -32,5 +33,6 @@ private:
     AudioEngine* audio_ = nullptr;
     KeyboardController keyboard_;
     MidiController midi_;
+    ConfigInterface config_;
 
 };