launcher: configure and preview DualSense lightbar color (#912)

launcher: configure and preview controller lightbar color

Add an optional lightbar color to launcher settings and pass it to the emulator with --controller-color. Preview changes on RGB gamepads, handle controller hotplug events, and restore the saved color when settings dialogs close. Release launcher preview handles when starting a game.

Co-authored-by: m66401970-eng <m66401970@gmail.com>

src/common/emulatorConfig.cpp

@@ -47,6 +47,10 @@ const std::string& GetAudioInputDevice() {
 	return g_config->audio_input_device;
 }
 
+const std::optional<ControllerColor>& GetControllerColor() {
+	return g_config->controller_color;
+}
+
 PresentMode GetPresentMode() {
 	return g_config->present_mode;
 }

src/common/emulatorConfig.h

@@ -4,7 +4,9 @@
 #include "common/common.h"
 
 #include <cstddef>
+#include <array>
 #include <filesystem>
+#include <optional>
 #include <string>
 #include <vector>
 
@@ -26,6 +28,7 @@ enum class LogDirection { Silent, Console, File };
 enum class PresentMode { Fifo, Mailbox, Immediate };
 
 using Keymap = std::vector<std::string>;
+using ControllerColor = std::array<uint8_t, 3>;
 
 constexpr uint32_t DEFAULT_CONSOLE_LANGUAGE = 1;
 constexpr uint32_t MAX_CONSOLE_LANGUAGE     = 29;
@@ -44,6 +47,7 @@ struct ConfigOptions {
 	std::string            user_name                   = "Kyty";
 	int32_t                user_id                     = DEFAULT_USER_ID;
 	std::string            audio_input_device;
+	std::optional<ControllerColor> controller_color;
 	PresentMode            present_mode                = PresentMode::Mailbox;
 	int32_t                gpu_index                   = -1;
 	bool                   fullscreen_enabled          = false;
@@ -81,6 +85,7 @@ uint32_t GetScreenHeight();
 const std::string& GetUserName();
 int32_t  GetUserId();
 const std::string& GetAudioInputDevice();
+const std::optional<ControllerColor>& GetControllerColor();
 PresentMode GetPresentMode();
 int32_t GetGpuIndex();
 bool     FullscreenEnabled();

src/launcher/forms/configuration_edit_dialog.ui

@@ -72,6 +72,27 @@
           <property name="toolTip"><string>Language</string></property>
          </widget>
         </item>
+        <item row="3" column="0">
+         <widget class="QLabel" name="label_controller_color">
+          <property name="text"><string>DualSense lightbar:</string></property>
+         </widget>
+        </item>
+        <item row="3" column="1">
+         <layout class="QHBoxLayout" name="controllerColorLayout">
+          <item>
+           <widget class="QPushButton" name="button_controller_color">
+            <property name="toolTip"><string>Choose and preview a fixed LED color. Bluetooth DualSense may take several seconds to update.</string></property>
+            <property name="text"><string>Custom</string></property>
+           </widget>
+          </item>
+          <item>
+           <widget class="QPushButton" name="button_controller_color_reset">
+            <property name="toolTip"><string>Let the game control the lightbar</string></property>
+            <property name="text"><string>Default</string></property>
+           </widget>
+          </item>
+         </layout>
+        </item>
        </layout>
       </widget>
      </item>

src/launcher/include/configuration.h

@@ -5,6 +5,7 @@
 
 #include <QByteArray>
 #include <QChar>
+#include <QColor>
 #include <QMetaEnum>
 #include <QMetaType>
 #include <QObject>
@@ -88,6 +89,7 @@ public:
 	QString                user_name                   = "Kyty";
 	int                    user_id                     = Config::DEFAULT_USER_ID;
 	QString                audio_input_device;
+	QString                controller_color;
 	PresentMode            present_mode                = PresentMode::Mailbox;
 	int                    gpu_index                   = -1;
 	bool                   fullscreen_enabled          = false;
@@ -119,6 +121,7 @@ public:
 		user_name                   = other.user_name;
 		user_id                     = other.user_id;
 		audio_input_device          = other.audio_input_device;
+		controller_color            = other.controller_color;
 		present_mode                = other.present_mode;
 		gpu_index                   = other.gpu_index;
 		fullscreen_enabled          = other.fullscreen_enabled;
@@ -165,6 +168,7 @@ public:
 		KYTY_CFG_SET(user_name);
 		KYTY_CFG_SET(user_id);
 		KYTY_CFG_SET(audio_input_device);
+		KYTY_CFG_SET(controller_color);
 		KYTY_CFG_SET(present_mode);
 		KYTY_CFG_SET(gpu_index);
 		KYTY_CFG_SET(fullscreen_enabled);
@@ -204,6 +208,8 @@ public:
 		                         ? saved_user_id
 		                         : Config::DEFAULT_USER_ID;
 		audio_input_device = s->value("audio_input_device", audio_input_device).toString();
+		const QColor color(s->value("controller_color", controller_color).toString());
+		controller_color = color.isValid() ? color.name(QColor::HexRgb) : QString {};
 		KYTY_CFG_GET(present_mode);
 		gpu_index = s->value("gpu_index", -1).toInt();
 		if (EnumToText(present_mode).isEmpty()) {

src/launcher/include/configurationEditDialog.h

@@ -31,6 +31,9 @@ public:
 	void                      SetGameDirectories(const QStringList& dirs);
 	[[nodiscard]] QStringList GetGameDirectories() const;
 
+signals:
+	void PreviewControllerColor(const QString& color);
+
 private:
 	Ui::ConfigurationEditDialog* m_ui = nullptr;
 	Configuration&               m_info;

src/launcher/include/configurationListWidget.h

@@ -33,6 +33,9 @@ public:
 	ConfigurationItem*                     GetSelectedItem() { return m_selected_item; }
 
 	[[nodiscard]] const QString& GetSettingsFile() const { return m_settings_file; }
+	[[nodiscard]] const QString& GetGlobalControllerColor() const {
+		return m_global_info.controller_color;
+	}
 	[[nodiscard]] std::unique_ptr<Configuration>
 	CreateConfiguration(const ConfigurationItem& item) const;
 
@@ -44,6 +47,7 @@ signals:
 
 	void Run();
 	void Select();
+	void PreviewControllerColor(const QString& color);
 
 protected:
 	void changeEvent(QEvent* event) override;

src/launcher/include/controllerLightbar.h

@@ -0,0 +1,29 @@
+#ifndef CONTROLLER_LIGHTBAR_H
+#define CONTROLLER_LIGHTBAR_H
+
+#include <QColor>
+#include <QHash>
+#include <QObject>
+#include <QString>
+#include <QTimer>
+
+#include <SDL3/SDL_gamepad.h>
+
+class ControllerLightbar final: public QObject {
+public:
+	explicit ControllerLightbar(QObject* parent = nullptr);
+	~ControllerLightbar() override;
+
+	void SetColor(const QString& color);
+	void Stop();
+
+private:
+	void Refresh();
+	void ApplyColor(SDL_Gamepad* gamepad) const;
+
+	QTimer                              m_timer;
+	QHash<SDL_JoystickID, SDL_Gamepad*> m_gamepads;
+	QColor                              m_color;
+};
+
+#endif // CONTROLLER_LIGHTBAR_H

src/launcher/src/configurationEditDialog.cpp

@@ -7,6 +7,7 @@
 
 #include <QAbstractItemView>
 #include <QCheckBox>
+#include <QColorDialog>
 #include <QComboBox>
 #include <QCoreApplication>
 #include <QDir>
@@ -40,6 +41,22 @@ constexpr char SETTINGS_CFG_DIALOG[]               = "ConfigurationEditDialog";
 constexpr char SETTINGS_CFG_LAST_GEOMETRY[]        = "geometry";
 constexpr int  GLOBAL_SETTINGS_GAME_DIRS_MIN_WIDTH = 560;
 
+static void UpdateControllerColorButton(QPushButton* button, const QString& hex) {
+	const QColor color(hex);
+	if (!color.isValid()) {
+		button->setProperty("controllerColor", QString {});
+		button->setText(QObject::tr("Custom"));
+		button->setStyleSheet({});
+		return;
+	}
+	const auto normalized = color.name(QColor::HexRgb);
+	button->setProperty("controllerColor", normalized);
+	button->setText(normalized.toUpper());
+	button->setStyleSheet(QStringLiteral("background-color: %1; color: %2;")
+	                          .arg(normalized, color.lightness() < 128 ? QStringLiteral("white")
+	                                                                   : QStringLiteral("black")));
+}
+
 const QStringList CONSOLE_LANGUAGE_NAMES = {
     "Japanese",
     "English (United States)",
@@ -110,6 +127,21 @@ ConfigurationEditDialog::ConfigurationEditDialog(Configuration& info, QWidget* p
 	connect(m_ui->ok_button, &QPushButton::clicked, this, &ConfigurationEditDialog::save);
 	connect(m_ui->cancel_button, &QPushButton::clicked, this, &QDialog::reject);
 	connect(m_ui->clear_button, &QPushButton::clicked, this, &ConfigurationEditDialog::clear);
+	connect(m_ui->button_controller_color, &QPushButton::clicked, this, [this]() {
+		const auto current = m_ui->button_controller_color->property("controllerColor").toString();
+		const auto initial =
+		    current.isEmpty() ? QColor(QStringLiteral("#0070d1")) : QColor(current);
+		const auto color = QColorDialog::getColor(initial, this, tr("DualSense lightbar color"));
+		if (color.isValid()) {
+			const auto hex = color.name(QColor::HexRgb);
+			UpdateControllerColorButton(m_ui->button_controller_color, hex);
+			emit PreviewControllerColor(hex);
+		}
+	});
+	connect(m_ui->button_controller_color_reset, &QPushButton::clicked, this, [this]() {
+		UpdateControllerColorButton(m_ui->button_controller_color, {});
+		emit PreviewControllerColor({});
+	});
 	connect(m_ui->comboBox_shader_log_direction, &QComboBox::currentTextChanged, this,
 	        [this](const QString& text) {
 		        auto log = TextToEnum<Configuration::LogDirection>(text);
@@ -169,6 +201,7 @@ void ConfigurationEditDialog::Init(const Configuration& info) {
 	m_ui->lineEdit_user_name->setMaxLength(static_cast<int>(Config::MAX_USER_NAME_LENGTH));
 	m_ui->lineEdit_user_name->setText(info.user_name);
 	m_ui->spinBox_user_id->setValue(info.user_id);
+	UpdateControllerColorButton(m_ui->button_controller_color, info.controller_color);
 	auto* microphone = m_ui->comboBox_audio_input_device;
 	microphone->clear();
 	microphone->addItem(tr("None"), QString {});
@@ -370,6 +403,7 @@ static void UpdateInfo(Configuration& info, Ui::ConfigurationEditDialog& ui) {
 	info.user_name = ui.lineEdit_user_name->text().trimmed();
 	info.user_id   = ui.spinBox_user_id->value();
 	info.audio_input_device = ui.comboBox_audio_input_device->currentData().toString();
+	info.controller_color   = ui.button_controller_color->property("controllerColor").toString();
 	info.screen_resolution =
 	    TextToEnum<Configuration::Resolution>(ui.comboBox_screen_resolution->currentText());
 	info.present_mode =
@@ -427,6 +461,7 @@ void ConfigurationEditDialog::save() {
 void ConfigurationEditDialog::clear() {
 	Configuration default_info;
 	Init(default_info);
+	emit PreviewControllerColor({});
 
 	if (m_show_game_dirs) {
 		m_game_dirs_list->clear();

src/launcher/src/configurationListWidget.cpp

@@ -751,6 +751,8 @@ void ConfigurationListWidget::edit_configuration() {
 	auto                    info = CreateConfiguration(*item);
 	ConfigurationEditDialog dlg(*info, this);
 	dlg.setWindowTitle(tr("Edit game settings"));
+	connect(&dlg, &ConfigurationEditDialog::PreviewControllerColor, this,
+	        &ConfigurationListWidget::PreviewControllerColor);
 
 	if (dlg.exec() == QDialog::Accepted) {
 		info->custom_settings           = true;
@@ -761,6 +763,8 @@ void ConfigurationListWidget::edit_configuration() {
 		WriteSettings();
 		item->Update();
 		SelectItem(item);
+	} else {
+		emit Select();
 	}
 }
 
@@ -788,6 +792,8 @@ void ConfigurationListWidget::edit_global_settings() {
 	ConfigurationEditDialog dlg(info, this);
 	dlg.setWindowTitle(tr("Global settings"));
 	dlg.SetGameDirectories(m_game_dirs);
+	connect(&dlg, &ConfigurationEditDialog::PreviewControllerColor, this,
+	        &ConfigurationListWidget::PreviewControllerColor);
 
 	if (dlg.exec() == QDialog::Accepted) {
 		m_global_info.CopyEmulatorSettingsFrom(info);
@@ -799,6 +805,7 @@ void ConfigurationListWidget::edit_global_settings() {
 			ScanGameDirectory();
 		}
 	}
+	emit Select();
 }
 
 void ConfigurationListWidget::edit_input_mapping() {

src/launcher/src/controllerLightbar.cpp

@@ -0,0 +1,84 @@
+#include "controllerLightbar.h"
+
+#include <QDebug>
+
+#include <SDL3/SDL.h>
+
+ControllerLightbar::ControllerLightbar(QObject* parent): QObject(parent) {
+	m_timer.setInterval(100);
+	connect(&m_timer, &QTimer::timeout, this, &ControllerLightbar::Refresh);
+}
+
+ControllerLightbar::~ControllerLightbar() {
+	Stop();
+}
+
+void ControllerLightbar::SetColor(const QString& color) {
+	const QColor parsed(color);
+	if (!parsed.isValid()) {
+		Stop();
+		return;
+	}
+	if (m_color == parsed) {
+		return;
+	}
+	if (!m_timer.isActive()) {
+		if (!SDL_InitSubSystem(SDL_INIT_GAMEPAD)) {
+			qWarning() << "Cannot initialize controller color preview:" << SDL_GetError();
+			return;
+		}
+		m_timer.start();
+	}
+	m_color = parsed;
+	for (auto* gamepad: m_gamepads) {
+		ApplyColor(gamepad);
+	}
+	Refresh();
+}
+
+void ControllerLightbar::Stop() {
+	if (!m_timer.isActive()) {
+		return;
+	}
+	m_timer.stop();
+	for (auto* gamepad: m_gamepads) {
+		SDL_CloseGamepad(gamepad);
+	}
+	m_gamepads.clear();
+	SDL_QuitSubSystem(SDL_INIT_GAMEPAD);
+	m_color = {};
+}
+
+void ControllerLightbar::Refresh() {
+	// Bluetooth DualSense may defer an accepted LED command until its connection
+	// animation ends. Polling events also delivers those deferred commands.
+	SDL_Event event;
+	while (SDL_PollEvent(&event)) {
+		if (event.type == SDL_EVENT_GAMEPAD_ADDED && !m_gamepads.contains(event.gdevice.which)) {
+			auto* gamepad = SDL_OpenGamepad(event.gdevice.which);
+			if (gamepad == nullptr) {
+				qWarning() << "Cannot open controller color preview:" << SDL_GetError();
+				continue;
+			}
+			if (SDL_GetBooleanProperty(SDL_GetGamepadProperties(gamepad),
+			                           SDL_PROP_GAMEPAD_CAP_RGB_LED_BOOLEAN, false)) {
+				m_gamepads.insert(event.gdevice.which, gamepad);
+				ApplyColor(gamepad);
+			} else {
+				SDL_CloseGamepad(gamepad);
+			}
+		} else if (event.type == SDL_EVENT_GAMEPAD_REMOVED) {
+			if (auto* gamepad = m_gamepads.take(event.gdevice.which); gamepad != nullptr) {
+				SDL_CloseGamepad(gamepad);
+			}
+		}
+	}
+}
+
+void ControllerLightbar::ApplyColor(SDL_Gamepad* gamepad) const {
+	if (!SDL_SetGamepadLED(gamepad, static_cast<Uint8>(m_color.red()),
+	                       static_cast<Uint8>(m_color.green()),
+	                       static_cast<Uint8>(m_color.blue()))) {
+		qWarning() << "Cannot set controller LED:" << SDL_GetError();
+	}
+}

src/launcher/src/mainDialog.cpp

@@ -3,6 +3,7 @@
 #include "configuration.h"
 #include "configurationItem.h"
 #include "configurationListWidget.h"
+#include "controllerLightbar.h"
 #include "gameContent.h"
 #include "patchesDialog.h"
 #include "updateChecker.h"
@@ -88,6 +89,7 @@ private:
 	Ui::MainDialog* m_ui             = {nullptr};
 	MainDialog*     m_main_dialog    = nullptr;
 	UpdateChecker*  m_update_checker = nullptr;
+	ControllerLightbar m_lightbar;
 	QString         m_interpreter;
 
 	QProcess m_process;
@@ -103,6 +105,7 @@ MainDialog::MainDialog(QWidget* parent): QDialog(parent), m_p(new MainDialogPriv
 }
 
 MainDialogPrivate::~MainDialogPrivate() {
+	m_process.disconnect(this);
 	delete m_ui;
 }
 
@@ -121,6 +124,12 @@ void MainDialogPrivate::Setup(MainDialog* main_dialog) {
 	connect(main_dialog, &MainDialog::Start, this, &MainDialogPrivate::FindInterpreter,
 	        Qt::QueuedConnection);
 	connect(m_ui->widget, &ConfigurationListWidget::Select, this, &MainDialogPrivate::Update);
+	connect(m_ui->widget, &ConfigurationListWidget::PreviewControllerColor, this,
+	        [this](const QString& color) {
+		        if (m_process.state() == QProcess::NotRunning) {
+			        m_lightbar.SetColor(color);
+		        }
+	        });
 	connect(m_ui->widget, &ConfigurationListWidget::Run, this, &MainDialogPrivate::Run);
 	connect(m_ui->check_updates_link, &QLabel::linkActivated, this,
 	        [this](const QString&) { m_update_checker->Check(true); });
@@ -135,14 +144,14 @@ void MainDialogPrivate::Setup(MainDialog* main_dialog) {
 		m_ui->widget->WriteSettings();
 	});
 
-	connect(&m_process,
-	        static_cast<void (QProcess::*)(int, QProcess::ExitStatus)>(&QProcess::finished),
-	        [this](int /*exitCode*/, QProcess::ExitStatus /*exitStatus*/) {
-		        if (m_running_item != nullptr) {
-			        m_running_item->SetRunning(false);
-		        }
-		        Update();
-	        });
+	connect(&m_process, &QProcess::stateChanged, this, [this](QProcess::ProcessState state) {
+		if (state == QProcess::NotRunning) {
+			if (m_running_item != nullptr) {
+				m_running_item->SetRunning(false);
+			}
+			Update();
+		}
+	});
 
 	m_ui->label_settings_file->setText(tr("Settings file: ") + m_ui->widget->GetSettingsFile());
 
@@ -219,6 +228,9 @@ static QStringList CreateEmulatorArgs(const Configuration& info) {
 	if (!info.audio_input_device.isEmpty()) {
 		args << "--mic" << info.audio_input_device;
 	}
+	if (!info.controller_color.isEmpty()) {
+		args << "--controller-color" << info.controller_color;
+	}
 	args << "--present-mode" << EnumToText(info.present_mode);
 	if (info.gpu_index >= 0) {
 		args << "--gpu" << QString::number(info.gpu_index);
@@ -493,6 +505,7 @@ void MainDialogPrivate::Run() {
 	}
 
 	m_running_item->SetRunning(true);
+	m_lightbar.Stop();
 
 	auto info = m_ui->widget->CreateConfiguration(*m_running_item);
 	m_main_dialog->RunInterpreter(&m_process, *info);
@@ -512,6 +525,12 @@ void MainDialogPrivate::Update() {
 	}
 
 	m_ui->widget->SetRunEnabled(run_enabled);
+	if (m_process.state() != QProcess::NotRunning) {
+		m_lightbar.Stop();
+		return;
+	}
+	m_lightbar.SetColor(item != nullptr ? m_ui->widget->CreateConfiguration(*item)->controller_color
+	                                    : m_ui->widget->GetGlobalControllerColor());
 }
 
 #include "mainDialog.moc"

src/libs/controller.cpp

@@ -297,6 +297,9 @@ void GameController::Connect(int id) {
 	if (id != HOST_INPUT_CONTROLLER_ID) {
 		if (auto* pad = SDL_GetGamepadFromID(static_cast<SDL_JoystickID>(id));
 		    pad != nullptr) {
+			if (const auto& color = Config::GetControllerColor()) {
+				(void)SDL_SetGamepadLED(pad, (*color)[0], (*color)[1], (*color)[2]);
+			}
 			for (auto sensor: {SDL_SENSOR_ACCEL, SDL_SENSOR_GYRO}) {
 				if (SDL_GamepadHasSensor(pad, sensor) &&
 				    !SDL_SetGamepadSensorEnabled(pad, sensor, true)) {
@@ -581,6 +584,11 @@ int GameController::GetActiveControllerId() {
 
 void GameController::SetLightBar(uint8_t r, uint8_t g, uint8_t b) {
 	Common::LockGuard lock(m_mutex);
+	if (const auto& color = Config::GetControllerColor()) {
+		r = (*color)[0];
+		g = (*color)[1];
+		b = (*color)[2];
+	}
 	if (auto* pad = SDL_GetGamepadFromID(static_cast<SDL_JoystickID>(m_active_id));
 	    pad != nullptr) {
 		(void)SDL_SetGamepadLED(pad, r, g, b);

src/main.cpp

@@ -53,6 +53,7 @@ static void PrintUsage() {
 	::printf("  --user-id <num>                      Local user ID. Default: %d.\n",
 	         Config::DEFAULT_USER_ID);
 	::printf("  --mic <name>                        Capture from this microphone; omit for silence.\n");
+	::printf("  --controller-color <#RRGGBB>        Override the controller lightbar color.\n");
 	::printf(
 	    "  --present-mode <value>               Fifo, Mailbox, or Immediate. Default: Mailbox.\n");
 	::printf(
@@ -145,6 +146,20 @@ static bool ParseUint32(const std::string& value, uint32_t& out) {
 	return true;
 }
 
+static bool ParseControllerColor(const std::string& value, Config::ControllerColor& out) {
+	if (value.size() != 7 || value[0] != '#') {
+		return false;
+	}
+	uint32_t rgb = 0;
+	auto [end, error] = std::from_chars(value.data() + 1, value.data() + value.size(), rgb, 16);
+	if (error != std::errc {} || end != value.data() + value.size()) {
+		return false;
+	}
+	out = {static_cast<uint8_t>(rgb >> 16), static_cast<uint8_t>(rgb >> 8),
+	       static_cast<uint8_t>(rgb)};
+	return true;
+}
+
 static bool ParseInt32(const std::string& value, int32_t& out) {
 	int32_t number    = 0;
 	auto [end, error] = std::from_chars(value.data(), value.data() + value.size(), number);
@@ -302,6 +317,13 @@ static bool ParseArgs(int argc, char* argv[], RunOptions& options, bool& show_he
 			}
 		} else if (arg == "--mic") {
 			options.config.audio_input_device = value;
+		} else if (arg == "--controller-color") {
+			Config::ControllerColor color {};
+			if (!ParseControllerColor(value, color)) {
+				::printf("invalid controller color (expected #RRGGBB): %s\n", value.c_str());
+				return false;
+			}
+			options.config.controller_color = color;
 		} else if (arg == "--present-mode") {
 			if (!ParseEnum(value, options.config.present_mode)) {
 				::printf("invalid present mode: %s\n", value.c_str());