Qt: Fix volume slider slowing down emulation

src/duckstation-qt/audiosettingswidget.cpp

@@ -1,7 +1,9 @@
 #include "audiosettingswidget.h"
 #include "common/audio_stream.h"
+#include "common/log.h"
 #include "settingsdialog.h"
 #include "settingwidgetbinder.h"
+Log_SetChannel(AudioSettingsWidget);
 
 AudioSettingsWidget::AudioSettingsWidget(QtHostInterface* host_interface, QWidget* parent, SettingsDialog* dialog)
   : QWidget(parent), m_host_interface(host_interface)
@@ -16,12 +18,14 @@ AudioSettingsWidget::AudioSettingsWidget(QtHostInterface* host_interface, QWidge
                                                Settings::DEFAULT_AUDIO_BACKEND);
   SettingWidgetBinder::BindWidgetToBoolSetting(m_host_interface, m_ui.syncToOutput, "Audio", "Sync");
   SettingWidgetBinder::BindWidgetToIntSetting(m_host_interface, m_ui.bufferSize, "Audio", "BufferSize");
-  SettingWidgetBinder::BindWidgetToIntSetting(m_host_interface, m_ui.volume, "Audio", "OutputVolume");
-  SettingWidgetBinder::BindWidgetToBoolSetting(m_host_interface, m_ui.muted, "Audio", "OutputMuted");
   SettingWidgetBinder::BindWidgetToBoolSetting(m_host_interface, m_ui.startDumpingOnBoot, "Audio", "DumpOnBoot");
 
+  m_ui.volume->setValue(m_host_interface->GetIntSettingValue("Audio", "OutputVolume"));
+  m_ui.muted->setChecked(m_host_interface->GetBoolSettingValue("Audio", "OutputMuted"));
+
   connect(m_ui.bufferSize, &QSlider::valueChanged, this, &AudioSettingsWidget::updateBufferingLabel);
-  connect(m_ui.volume, &QSlider::valueChanged, this, &AudioSettingsWidget::updateVolumeLabel);
+  connect(m_ui.volume, &QSlider::valueChanged, this, &AudioSettingsWidget::onOutputVolumeChanged);
+  connect(m_ui.muted, &QCheckBox::stateChanged, this, &AudioSettingsWidget::onOutputMutedChanged);
 
   updateBufferingLabel();
   updateVolumeLabel();
@@ -61,3 +65,19 @@ void AudioSettingsWidget::updateVolumeLabel()
 {
   m_ui.volumeLabel->setText(tr("%1%").arg(m_ui.volume->value()));
 }
+
+void AudioSettingsWidget::onOutputVolumeChanged(int new_value)
+{
+  m_host_interface->SetIntSettingValue("Audio", "OutputVolume", new_value);
+  if (!m_ui.muted->isChecked())
+    m_host_interface->setAudioOutputVolume(new_value);
+
+  updateVolumeLabel();
+}
+
+void AudioSettingsWidget::onOutputMutedChanged(int new_state)
+{
+  const bool muted = (new_state != 0);
+  m_host_interface->SetBoolSettingValue("Audio", "OutputMuted", muted);
+  m_host_interface->setAudioOutputVolume(muted ? 0 : m_ui.volume->value());
+}

src/duckstation-qt/audiosettingswidget.h

@@ -18,6 +18,8 @@ public:
 private Q_SLOTS:
   void updateBufferingLabel();
   void updateVolumeLabel();
+  void onOutputVolumeChanged(int new_value);
+  void onOutputMutedChanged(int new_state);
 
 private:
   Ui::AudioSettingsWidget m_ui;

src/duckstation-qt/qthostinterface.cpp

@@ -884,6 +884,18 @@ void QtHostInterface::saveState(bool global, qint32 slot, bool block_until_done
     SaveState(global, slot);
 }
 
+void QtHostInterface::setAudioOutputVolume(int value)
+{
+  if (!isOnWorkerThread())
+  {
+    QMetaObject::invokeMethod(this, "setAudioOutputVolume", Q_ARG(int, value));
+    return;
+  }
+
+  if (m_audio_stream)
+    m_audio_stream->SetOutputVolume(value);
+}
+
 void QtHostInterface::startDumpingAudio()
 {
   if (!isOnWorkerThread())

src/duckstation-qt/qthostinterface.h

@@ -135,6 +135,7 @@ public Q_SLOTS:
   void loadState(const QString& filename);
   void loadState(bool global, qint32 slot);
   void saveState(bool global, qint32 slot, bool block_until_done = false);
+  void setAudioOutputVolume(int value);
   void startDumpingAudio();
   void stopDumpingAudio();
   void saveScreenshot();