config: Add present mode option. (#3502)

* config: Add present mode option.

* settings_dialog: Add details for present modes.

src/qt_gui/settings_dialog.cpp

@@ -67,6 +67,7 @@ const QVector<int> languageIndexes = {21, 23, 14, 6, 18, 1, 12, 22, 2, 4,  25, 2
 QMap<QString, QString> channelMap;
 QMap<QString, QString> logTypeMap;
 QMap<QString, QString> screenModeMap;
+QMap<QString, QString> presentModeMap;
 QMap<QString, QString> chooseHomeTabMap;
 QMap<QString, QString> micMap;
 
@@ -93,6 +94,9 @@ SettingsDialog::SettingsDialog(std::shared_ptr<gui_settings> gui_settings,
     screenModeMap = {{tr("Fullscreen (Borderless)"), "Fullscreen (Borderless)"},
                      {tr("Windowed"), "Windowed"},
                      {tr("Fullscreen"), "Fullscreen"}};
+    presentModeMap = {{tr("Mailbox (Vsync)"), "Mailbox"},
+                      {tr("Fifo (Vsync)"), "Fifo"},
+                      {tr("Immediate (No Vsync)"), "Immediate"}};
     chooseHomeTabMap = {{tr("General"), "General"},   {tr("GUI"), "GUI"},
                         {tr("Graphics"), "Graphics"}, {tr("User"), "User"},
                         {tr("Input"), "Input"},       {tr("Paths"), "Paths"},
@@ -414,6 +418,7 @@ SettingsDialog::SettingsDialog(std::shared_ptr<gui_settings> gui_settings,
         // Graphics
         ui->graphicsAdapterGroupBox->installEventFilter(this);
         ui->windowSizeGroupBox->installEventFilter(this);
+        ui->presentModeGroupBox->installEventFilter(this);
         ui->heightDivider->installEventFilter(this);
         ui->dumpShadersCheckBox->installEventFilter(this);
         ui->nullGpuCheckBox->installEventFilter(this);
@@ -540,6 +545,9 @@ void SettingsDialog::LoadValuesFromConfig() {
     QString translatedText_FullscreenMode =
         screenModeMap.key(QString::fromStdString(Config::getFullscreenMode()));
     ui->displayModeComboBox->setCurrentText(translatedText_FullscreenMode);
+    QString translatedText_PresentMode =
+        presentModeMap.key(QString::fromStdString(Config::getPresentMode()));
+    ui->presentModeComboBox->setCurrentText(translatedText_PresentMode);
     ui->gameSizeCheckBox->setChecked(toml::find_or<bool>(data, "GUI", "loadGameSizeEnabled", true));
     ui->showSplashCheckBox->setChecked(toml::find_or<bool>(data, "General", "showSplash", false));
     QString translatedText_logType = logTypeMap.key(QString::fromStdString(Config::getLogType()));
@@ -746,6 +754,11 @@ void SettingsDialog::updateNoteTextEdit(const QString& elementName) {
     // Graphics
     if (elementName == "graphicsAdapterGroupBox") {
         text = tr("Graphics Device:\\nOn multiple GPU systems, select the GPU the emulator will use from the drop down list,\\nor select \"Auto Select\" to automatically determine it.");
+    } else if (elementName == "presentModeGroupBox") {
+        text = tr("Present Mode:\\nConfigures how video output will be presented to your screen.\\n\\n"
+                  "Mailbox: Frames synchronize with your screen's refresh rate. New frames will replace any pending frames. Reduces latency but may skip frames if running behind.\\n"
+                  "Fifo: Frames synchronize with your screen's refresh rate. New frames will be queued behind pending frames. Ensures all frames are presented but may increase latency.\\n"
+                  "Immediate: Frames immediately present to your screen when ready. May result in tearing.");
     } else if (elementName == "windowSizeGroupBox") {
         text = tr("Width/Height:\\nSets the size of the emulator window at launch, which can be resized during gameplay.\\nThis is different from the in-game resolution.");
     } else if (elementName == "heightDivider") {
@@ -834,6 +847,8 @@ void SettingsDialog::UpdateSettings() {
                             "Windowed");
     Config::setFullscreenMode(
         screenModeMap.value(ui->displayModeComboBox->currentText()).toStdString());
+    Config::setPresentMode(
+        presentModeMap.value(ui->presentModeComboBox->currentText()).toStdString());
     Config::setIsMotionControlsEnabled(ui->motionControlsCheckBox->isChecked());
     Config::setBackgroundControllerInput(ui->backgroundControllerCheckBox->isChecked());
     Config::setisTrophyPopupDisabled(ui->disableTrophycheckBox->isChecked());

src/qt_gui/settings_dialog.ui

@@ -1096,6 +1096,40 @@
                  </layout>
                 </widget>
                </item>
+               <item>
+                <widget class="QGroupBox" name="presentModeGroupBox">
+                 <property name="title">
+                  <string>Present Mode</string>
+                 </property>
+                 <layout class="QVBoxLayout" name="presentModeLayout">
+                  <item>
+                   <widget class="QComboBox" name="presentModeComboBox">
+                    <property name="sizePolicy">
+                     <sizepolicy hsizetype="Expanding" vsizetype="Fixed">
+                      <horstretch>0</horstretch>
+                      <verstretch>0</verstretch>
+                     </sizepolicy>
+                    </property>
+                    <item>
+                     <property name="text">
+                      <string>Mailbox (Vsync)</string>
+                     </property>
+                    </item>
+                    <item>
+                     <property name="text">
+                      <string>Fifo (Vsync)</string>
+                     </property>
+                    </item>
+                    <item>
+                     <property name="text">
+                      <string>Immediate (No Vsync)</string>
+                     </property>
+                    </item>
+                   </widget>
+                  </item>
+                 </layout>
+                </widget>
+               </item>
                <item>
                 <layout class="QHBoxLayout" name="windowSizeLayout">
                  <item>