Cleanup source tree

Move all C++ source files in the src subfolder. Adapted the cmake process accordingly and cleanup.

src/MixingView.h

@@ -0,0 +1,49 @@
+#ifndef MIXINGVIEW_H
+#define MIXINGVIEW_H
+
+#include "View.h"
+
+//class MixingGroup;
+
+class MixingView : public View
+{
+public:
+    MixingView();
+    // non assignable class
+    MixingView(MixingView const&) = delete;
+    MixingView& operator=(MixingView const&) = delete;
+
+    void draw () override;
+    void update (float dt) override;
+    void resize (int) override;
+    int  size () override;
+    void centerSource(Source *) override;
+
+    std::pair<Node *, glm::vec2> pick(glm::vec2) override;
+    Cursor grab (Source *s, glm::vec2 from, glm::vec2 to, std::pair<Node *, glm::vec2>) override;
+    void terminate(bool force) override;
+    Cursor over (glm::vec2) override;
+    void arrow (glm::vec2) override;
+
+    void setAlpha (Source *s);
+
+private:
+    void updateSelectionOverlay() override;
+
+    float limbo_scale_;
+
+    Group *slider_root_;
+    Disk *slider_;
+    Disk *button_white_;
+    Disk *button_black_;
+//    Disk *stashCircle_;
+    Mesh *mixingCircle_;
+    Mesh *circle_;
+    Mesh *limbo_;
+    Group *limbo_slider_root_;
+    Mesh *limbo_up_, *limbo_down_;
+    Disk *limbo_slider_;
+};
+
+
+#endif // MIXINGVIEW_H