refs #372 Add audio mixer interface and vatlib implementation

This class is an audio router. In order to route audio connect a
producer to an input port and a consumer to an output port. The
connection is later established by making the mixer connection
between an input and an output port.

src/blackcore/audio_mixer_vatlib.h

@@ -0,0 +1,64 @@
+/* Copyright (C) 2014
+ * swift project community / contributors
+ *
+ * This file is part of swift project. It is subject to the license terms in the LICENSE file found in the top-level
+ * directory of this distribution and at http://www.swift-project.org/license.html. No part of swift project,
+ * including this file, may be copied, modified, propagated, or distributed except according to the terms
+ * contained in the LICENSE file.
+ */
+
+#ifndef BLACKCORE_AUDIOMIXERVATLIB_H
+#define BLACKCORE_AUDIOMIXERVATLIB_H
+
+#include "audio_mixer.h"
+
+#include "vatlib/vatlib2.h"
+#include <QScopedPointer>
+
+namespace BlackCore
+{
+    //! Interface to an audio mixer
+    class CAudioMixerVatlib : public IAudioMixer
+    {
+        Q_OBJECT
+
+    public:
+
+        /*!
+         * \brief Default constructor with parent
+         * \param parent
+         */
+        CAudioMixerVatlib(QObject *parent = nullptr);
+
+        //! Virtual destructor.
+        virtual ~CAudioMixerVatlib() {}
+
+        //! \copydoc IAudioMixer::makeMixerConnection
+        virtual void makeMixerConnection(InputPort inputPort, OutputPort outputPort) override;
+
+        //! \copydoc IAudioMixer::removeMixerConnection
+        virtual void removeMixerConnection(InputPort inputPort, OutputPort outputPort) override;
+
+        //! \copydoc IAudioMixer::hasMixerConnection
+        virtual bool hasMixerConnection(InputPort inputPort, OutputPort outputPort) override;
+
+        //! Return the pointer to vatlib audio mixer
+        VatAudioMixer getVatAudioMixer() { return m_audioMixer.data(); }
+
+    private:
+
+        struct VatAudioMixerDeleter
+        {
+            static inline void cleanup(VatProducerConsumer_tag *obj)
+            {
+                if (obj) Vat_DestroyAudioMixer(obj);
+            }
+        };
+
+        QScopedPointer<VatProducerConsumer_tag, VatAudioMixerDeleter> m_audioMixer;
+
+    };
+
+} // namespace BlackCore
+
+#endif // guard