* add audio settings dialog

* attempt at betterer mic noise that doesn't work worth a damn

src/frontend/qt_sdl/AudioSettingsDialog.h

@@ -0,0 +1,69 @@
+/*
+    Copyright 2016-2020 Arisotura
+
+    This file is part of melonDS.
+
+    melonDS is free software: you can redistribute it and/or modify it under
+    the terms of the GNU General Public License as published by the Free
+    Software Foundation, either version 3 of the License, or (at your option)
+    any later version.
+
+    melonDS is distributed in the hope that it will be useful, but WITHOUT ANY
+    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+    FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License along
+    with melonDS. If not, see http://www.gnu.org/licenses/.
+*/
+
+#ifndef AUDIOSETTINGSDIALOG_H
+#define AUDIOSETTINGSDIALOG_H
+
+#include <QDialog>
+#include <QButtonGroup>
+
+namespace Ui { class AudioSettingsDialog; }
+class AudioSettingsDialog;
+
+class AudioSettingsDialog : public QDialog
+{
+    Q_OBJECT
+
+public:
+    explicit AudioSettingsDialog(QWidget* parent);
+    ~AudioSettingsDialog();
+
+    static AudioSettingsDialog* currentDlg;
+    static AudioSettingsDialog* openDlg(QWidget* parent)
+    {
+        if (currentDlg)
+        {
+            currentDlg->activateWindow();
+            return currentDlg;
+        }
+
+        currentDlg = new AudioSettingsDialog(parent);
+        currentDlg->show();
+        return currentDlg;
+    }
+    static void closeDlg()
+    {
+        currentDlg = nullptr;
+    }
+
+private slots:
+    void on_AudioSettingsDialog_accepted();
+    void on_AudioSettingsDialog_rejected();
+
+    void on_slVolume_valueChanged(int val);
+    void onChangeMicMode(int mode);
+    void on_btnMicWavBrowse_clicked();
+
+private:
+    Ui::AudioSettingsDialog* ui;
+
+    int oldVolume;
+    QButtonGroup* grpMicMode;
+};
+
+#endif // AUDIOSETTINGSDIALOG_H