Support multiple controllers for local multiplayer (#1583)

* Support multiple controllers for local co-op

src/common/emulatorConfig.cpp

@@ -24,6 +24,7 @@ void Load(const ConfigOptions& cfg) {
 	EXIT_IF(cfg.user_name.empty() || cfg.user_name.size() > MAX_USER_NAME_LENGTH);
 	EXIT_IF(!IsConfiguredUserIdValid(cfg.user_id));
 	EXIT_IF(cfg.controller_speaker_volume > 100 || cfg.controller_vibration_intensity > 100);
+	EXIT_IF(cfg.keyboard_player > static_cast<uint32_t>(MAX_PLAYERS));
 
 	*g_config = cfg;
 }
@@ -60,6 +61,27 @@ uint32_t GetControllerVibrationIntensity() {
 	return g_config->controller_vibration_intensity;
 }
 
+uint32_t GetKeyboardPlayer() {
+	return g_config->keyboard_player;
+}
+
+int32_t GetPlayerUserId(int player) {
+	return g_config->user_id + player * PLAYER_USER_ID_STEP;
+}
+
+int GetPlayerFromUserId(int32_t user_id) {
+	for (int player = 0; player < MAX_PLAYERS; player++) {
+		if (user_id == GetPlayerUserId(player)) {
+			return player;
+		}
+	}
+	return -1;
+}
+
+bool IsGuestUserId(int32_t user_id) {
+	return GetPlayerFromUserId(user_id) > 0;
+}
+
 PresentMode GetPresentMode() {
 	return g_config->present_mode;
 }

src/common/emulatorConfig.h

@@ -6,6 +6,7 @@
 #include <cstddef>
 #include <array>
 #include <filesystem>
+#include <limits>
 #include <optional>
 #include <string>
 #include <vector>
@@ -35,10 +36,16 @@ constexpr uint32_t MAX_CONSOLE_LANGUAGE     = 29;
 constexpr std::size_t MAX_USER_NAME_LENGTH = 16;
 constexpr int32_t DEFAULT_USER_ID           = 1000;
 
+constexpr int     MAX_PLAYERS         = 4;
+constexpr int32_t PLAYER_USER_ID_STEP = 0x100;
+constexpr int32_t MAX_USER_ID =
+    std::numeric_limits<int32_t>::max() - (MAX_PLAYERS - 1) * PLAYER_USER_ID_STEP;
+
 constexpr bool IsConfiguredUserIdValid(int32_t user_id) {
 	constexpr int32_t USER_ID_EVERYONE = 0xfe;
 	constexpr int32_t USER_ID_SYSTEM   = 0xff;
-	return user_id >= 0 && user_id != USER_ID_EVERYONE && user_id != USER_ID_SYSTEM;
+	return user_id >= 0 && user_id <= MAX_USER_ID && user_id != USER_ID_EVERYONE &&
+	       user_id != USER_ID_SYSTEM;
 }
 
 struct ConfigOptions {
@@ -50,6 +57,8 @@ struct ConfigOptions {
 	std::optional<ControllerColor> controller_color;
 	uint32_t               controller_speaker_volume      = 50;
 	uint32_t               controller_vibration_intensity = 100;
+	// 0 shares player 1 with the first gamepad; 1..MAX_PLAYERS dedicates that player to the keyboard.
+	uint32_t               keyboard_player                = 0;
 	PresentMode            present_mode                = PresentMode::Mailbox;
 	int32_t                gpu_index                   = -1;
 	bool                   fullscreen_enabled          = false;
@@ -100,6 +109,13 @@ const std::string& GetAudioInputDevice();
 const std::optional<ControllerColor>& GetControllerColor();
 uint32_t GetControllerSpeakerVolume();
 uint32_t GetControllerVibrationIntensity();
+uint32_t GetKeyboardPlayer();
+// Player 0 is the configured user; later players derive their IDs from it.
+int32_t  GetPlayerUserId(int player);
+// Returns -1 when the user ID does not belong to any player.
+int      GetPlayerFromUserId(int32_t user_id);
+// Players after the first are guests: they have no profile, trophies or NP account.
+bool     IsGuestUserId(int32_t user_id);
 PresentMode GetPresentMode();
 int32_t GetGpuIndex();
 bool     FullscreenEnabled();

src/graphics/presentation/window/hostInput.cpp

@@ -254,7 +254,8 @@ public:
 			}
 
 			const bool reserved = binding.key == SDLK_ESCAPE || binding.key == SDLK_F1 ||
-			                      binding.key == SDLK_F7 || binding.key == SDLK_F11;
+			                      binding.key == SDLK_F7 || binding.key == SDLK_F8 ||
+			                      binding.key == SDLK_F11;
 			if (binding.control == INVALID_CONTROL || reserved ||
 			    (binding.key == SDLK_UNKNOWN && binding.mouse_button == 0)) {
 				EXIT("Invalid input mapping: %s\n", value.c_str());

src/graphics/presentation/window/window.cpp

@@ -466,6 +466,13 @@ void WindowContext::ProcessEvent(double time_s) {
 		}
 		return;
 	}
+	if ((event->type == SDL_EVENT_KEY_DOWN || event->type == SDL_EVENT_KEY_UP) &&
+	    event->key.key == SDLK_F8) {
+		if (event->type == SDL_EVENT_KEY_DOWN && event->key.repeat == 0) {
+			Controller::CycleKeyboardPlayer();
+		}
+		return;
+	}
 	if (ProcessSystemOverlayInput(*event)) {
 		return;
 	}

src/launcher/forms/configuration_edit_dialog.ui

@@ -66,7 +66,6 @@
             <item row="1" column="1">
              <widget class="QSpinBox" name="spinBox_user_id">
               <property name="toolTip"><string>Local user ID exposed to games</string></property>
-              <property name="maximum"><number>2147483647</number></property>
              </widget>
             </item>
             <item row="2" column="0">
@@ -347,6 +346,16 @@
             </item>
            </layout>
           </item>
+          <item row="3" column="0">
+           <widget class="QLabel" name="label_keyboard_player">
+            <property name="text"><string>Keyboard player:</string></property>
+           </widget>
+          </item>
+          <item row="3" column="1">
+           <widget class="QComboBox" name="comboBox_keyboard_player">
+            <property name="toolTip"><string>Gamepads fill the remaining players in connection order. Every player uses the same input mapping.</string></property>
+           </widget>
+          </item>
          </layout>
         </widget>
        </item>

src/launcher/include/configuration.h

@@ -48,11 +48,14 @@ struct ControllerSettings {
 	QString color;
 	int     speaker_volume      = 50;
 	int     vibration_intensity = 100;
+	// 0 shares player 1 with the first gamepad; 1..MAX_PLAYERS dedicates that player to the keyboard.
+	int     keyboard_player     = 0;
 
 	void WriteSettings(QSettings* s) const {
 		s->setValue("controller_color", color);
 		s->setValue("controller_speaker_volume", speaker_volume);
 		s->setValue("controller_vibration_intensity", vibration_intensity);
+		s->setValue("controller_keyboard_player", keyboard_player);
 	}
 
 	void ReadSettings(QSettings* s) {
@@ -65,6 +68,8 @@ struct ControllerSettings {
 		};
 		speaker_volume      = read_percent("controller_speaker_volume", 50);
 		vibration_intensity = read_percent("controller_vibration_intensity", 100);
+		keyboard_player = qBound(0, s->value("controller_keyboard_player", 0).toInt(),
+		                         Config::MAX_PLAYERS);
 	}
 };
 

src/launcher/src/configurationEditDialog.cpp

@@ -209,10 +209,19 @@ static void ListInit(QComboBox* combo, T value) {
 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->setMaximum(Config::MAX_USER_ID);
 	m_ui->spinBox_user_id->setValue(info.user_id);
 	UpdateControllerColorButton(m_ui->button_controller_color, info.controller.color);
 	m_ui->slider_controller_vibration->setValue(info.controller.vibration_intensity);
 	m_ui->slider_controller_volume->setValue(info.controller.speaker_volume);
+	auto* keyboard_player = m_ui->comboBox_keyboard_player;
+	keyboard_player->clear();
+	keyboard_player->addItem(tr("Shared with player 1 (default)"), 0);
+	for (int player = 1; player <= Config::MAX_PLAYERS; player++) {
+		keyboard_player->addItem(tr("Player %1").arg(player), player);
+	}
+	keyboard_player->setCurrentIndex(
+	    qMax(0, keyboard_player->findData(info.controller.keyboard_player)));
 	auto* microphone = m_ui->comboBox_audio_input_device;
 	microphone->clear();
 	microphone->addItem(tr("None"), QString {});
@@ -458,6 +467,7 @@ static void UpdateInfo(Configuration& info, Ui::ConfigurationEditDialog& ui, boo
 		info.controller.color = ui.button_controller_color->property("controllerColor").toString();
 		info.controller.vibration_intensity = ui.slider_controller_vibration->value();
 		info.controller.speaker_volume      = ui.slider_controller_volume->value();
+		info.controller.keyboard_player     = ui.comboBox_keyboard_player->currentData().toInt();
 	}
 	info.screen_resolution =
 	    TextToEnum<Configuration::Resolution>(ui.comboBox_screen_resolution->currentText());

src/launcher/src/mainDialog.cpp

@@ -246,6 +246,7 @@ static QStringList CreateEmulatorArgs(const Configuration& info) {
 	}
 	args << "--controller-volume" << QString::number(info.controller.speaker_volume);
 	args << "--controller-vibration" << QString::number(info.controller.vibration_intensity);
+	args << "--keyboard-player" << QString::number(info.controller.keyboard_player);
 	args << "--present-mode" << EnumToText(info.present_mode);
 	if (info.gpu_index >= 0) {
 		args << "--gpu" << QString::number(info.gpu_index);

src/libs/controller.cpp

@@ -18,6 +18,7 @@
 #include <atomic>
 #include <cmath>
 #include <cstring>
+#include <memory>
 #include <vector>
 
 namespace Libs::Controller {
@@ -107,18 +108,19 @@ struct ControllerState {
 
 class GameController {
 public:
-	GameController() = default;
+	explicit GameController(int player): m_player(player) {}
 
 	KYTY_CLASS_NO_COPY(GameController);
 
+	[[nodiscard]] int Handle() const { return PAD_HANDLE + m_player; }
+
 	int InitPort();
 	int OpenPort(int user_id, int type, int index);
 	int GetPortHandle(int user_id, int type, int index);
 	int ClosePort(int handle);
 	int CheckPortHandle(int handle);
 
-	void Connect(int id);
-	void Disconnect(int id);
+	void SetDevices(int active_id);
 	void Button(int id, uint32_t button, bool down);
 	void Axis(int id, Axis axis, int value);
 	void RightStick(int id, int x, int y);
@@ -128,7 +130,6 @@ public:
 	void ResetOrientation();
 	void ToggleGyroEmulation(int id);
 	void ResetInputState();
-	void ReleaseHostPads();
 	void GetConnectionInfo(bool* flag, int* count);
 	void SetVibration(uint8_t large_motor, uint8_t small_motor);
 	int  GetActiveControllerId();
@@ -145,8 +146,10 @@ private:
 	enum class PortState { Uninitialized, Closed, Open };
 
 	int CheckPortHandleLocked(int handle) const;
+	[[nodiscard]] bool PadOpenArgsAreValid(int user_id, int type, int index) const;
+
+	const int m_player;
 
-	void CheckActive();
 	void AddState();
 	// Emulated tilt: the right stick drives pitch and roll instead of the stick axes.
 	void UpdateEmulatedTilt();
@@ -157,7 +160,6 @@ private:
 
 	Common::Mutex    m_mutex;
 	PortState        m_port_state      = PortState::Uninitialized;
-	std::vector<int> m_connected_ids;
 	int              m_active_id       = -1;
 	bool             m_connected       = false;
 	int              m_connected_count = 0;
@@ -184,7 +186,39 @@ private:
 	std::array<std::atomic<uint32_t>, 3> m_setting_steps {};
 };
 
-static GameController* g_controller = nullptr;
+static std::array<std::unique_ptr<GameController>, Config::MAX_PLAYERS> g_players;
+
+// Maps host gamepads to players; the keyboard follows the configured keyboard player.
+static Common::Mutex g_router_mutex;
+static std::vector<std::pair<int, int>> g_pad_players;
+
+static uint32_t g_keyboard_player = 0;
+
+static void RefreshPlayers();
+static void StopHostPad(SDL_Gamepad* pad);
+
+static int KeyboardPlayer() {
+	return g_keyboard_player == 0 ? 0 : static_cast<int>(g_keyboard_player) - 1;
+}
+
+// Caller holds g_router_mutex.
+static GameController* PlayerForDevice(int id) {
+	if (id == HOST_INPUT_CONTROLLER_ID) {
+		return g_players[KeyboardPlayer()].get();
+	}
+	for (const auto& [pad, player]: g_pad_players) {
+		if (pad == id) {
+			return player >= 0 ? g_players[player].get() : nullptr;
+		}
+	}
+	return nullptr;
+}
+
+static GameController* PlayerForHandle(int handle) {
+	return handle >= PAD_HANDLE && handle < PAD_HANDLE + Config::MAX_PLAYERS
+	           ? g_players[handle - PAD_HANDLE].get()
+	           : nullptr;
+}
 
 static void pad_fill_data(PadData* data, const ControllerState& state, bool connected,
                           int connected_count) {
@@ -228,13 +262,15 @@ constexpr std::array SPEAKER_VOLUME = {1.0f, 0.0f, 0.02f, 0.12f, 0.42f};
 constexpr std::array INTENSITY      = {1.0f, 0.0f, 0.33f, 0.66f};
 
 void CycleSetting(Setting setting) {
-	if (g_controller != nullptr) {
-		g_controller->CycleSetting(setting);
+	for (const auto& player: g_players) {
+		if (player != nullptr) {
+			player->CycleSetting(setting);
+		}
 	}
 }
 
 float GetSettingScale(Setting setting) {
-	return g_controller != nullptr ? g_controller->GetSettingScale(setting) : 1.0f;
+	return g_players[0] != nullptr ? g_players[0]->GetSettingScale(setting) : 1.0f;
 }
 
 void GameController::CycleSetting(Setting setting) {
@@ -404,35 +440,53 @@ static int32_t TriggerEffectState(const PadTriggerEffectCommand& command, int va
 }
 
 void Initialize() {
-	EXIT_IF(g_controller != nullptr);
+	EXIT_IF(g_players[0] != nullptr);
 
-	g_controller = new GameController;
-	g_controller->Connect(HOST_INPUT_CONTROLLER_ID);
+	for (int i = 0; i < Config::MAX_PLAYERS; i++) {
+		g_players[i] = std::make_unique<GameController>(i);
+	}
+	g_keyboard_player = Config::GetKeyboardPlayer();
+	RefreshPlayers();
 }
 
 void Shutdown() {
 	EmergencyShutdown();
-	delete g_controller;
-	g_controller = nullptr;
+	for (auto& player: g_players) {
+		player.reset();
+	}
 }
 
 void EmergencyShutdown() {
-	if (g_controller != nullptr) {
-		g_controller->ReleaseHostPads();
+	Common::LockGuard lock(g_router_mutex);
+	DualSenseHaptics::Shutdown();
+	std::vector<SDL_Gamepad*> pads;
+	for (const auto& [id, player]: g_pad_players) {
+		if (auto* pad = SDL_GetGamepadFromID(static_cast<SDL_JoystickID>(id))) {
+			StopHostPad(pad);
+			pads.push_back(pad);
+		}
+	}
+	if (!pads.empty()) {
+		SDL_Delay(RELEASE_FLUSH_MS);
+		for (auto* pad: pads) {
+			SDL_CloseGamepad(pad);
+		}
+	}
+	g_pad_players.clear();
+	for (const auto& player: g_players) {
+		if (player != nullptr) {
+			player->SetDevices(-1);
+		}
 	}
 }
 
-void GameController::Connect(int id) {
+void GameController::SetDevices(int active_id) {
 	Common::LockGuard lock(m_mutex);
-
-	if (std::find(m_connected_ids.begin(), m_connected_ids.end(), id) != m_connected_ids.end()) {
+	if (m_active_id == active_id) {
 		return;
 	}
-
-	m_connected_ids.push_back(id);
-
-	if (id != HOST_INPUT_CONTROLLER_ID) {
-		if (auto* pad = SDL_GetGamepadFromID(static_cast<SDL_JoystickID>(id));
+	if (active_id != HOST_INPUT_CONTROLLER_ID && active_id != -1) {
+		if (auto* pad = SDL_GetGamepadFromID(static_cast<SDL_JoystickID>(active_id));
 		    pad != nullptr) {
 			if (const auto& color = Config::GetControllerColor()) {
 				(void)SDL_SetGamepadLED(pad, (*color)[0], (*color)[1], (*color)[2]);
@@ -446,42 +500,11 @@ void GameController::Connect(int id) {
 		}
 	}
 
-	CheckActive();
-}
-
-void GameController::Disconnect(int id) {
-	Common::LockGuard lock(m_mutex);
-
-	const auto it = std::find(m_connected_ids.begin(), m_connected_ids.end(), id);
-	EXIT_IF(it == m_connected_ids.end());
-
-	m_connected_ids.erase(it);
-
-	CheckActive();
-}
-
-void GameController::CheckActive() {
-	int  new_active_id = -1;
-	bool new_connected = false;
-
-	if (!m_connected_ids.empty()) {
-		new_active_id = m_connected_ids[0];
-		for (const auto id: m_connected_ids) {
-			if (id != HOST_INPUT_CONTROLLER_ID) {
-				new_active_id = id;
-				break;
-			}
-		}
-		new_connected = true;
-	}
-
-	if (m_connected == new_connected && m_active_id == new_active_id) {
-		return;
-	}
+	const bool new_connected = active_id != -1;
 	if (!m_connected && new_connected) {
 		m_connected_count++;
 	}
-	m_active_id     = new_active_id;
+	m_active_id     = active_id;
 	m_connected     = new_connected;
 	m_state         = {};
 	m_gyro_time     = 0;
@@ -513,7 +536,7 @@ void GameController::AddState() {
 void GameController::Button(int id, uint32_t button, bool down) {
 	Common::LockGuard lock(m_mutex);
 
-	// The keyboard shares the player-1 pad with the active gamepad.
+	// Keyboard events are routed to the configured player's port.
 	if (m_active_id == id || id == HOST_INPUT_CONTROLLER_ID) {
 		m_state.time = LibKernel::KernelGetProcessTime();
 
@@ -798,39 +821,16 @@ void GameController::ResetInputState() {
 	AddState();
 }
 
-void GameController::ReleaseHostPads() {
-	Common::LockGuard lock(m_mutex);
-	DualSenseHaptics::Shutdown();
-
-	std::vector<SDL_Gamepad*> pads;
-	for (const auto id: m_connected_ids) {
-		if (id == HOST_INPUT_CONTROLLER_ID) {
-			continue;
-		}
-		if (auto* pad = SDL_GetGamepadFromID(static_cast<SDL_JoystickID>(id));
-		    pad != nullptr) {
-			if (SDL_GetGamepadType(pad) == SDL_GAMEPAD_TYPE_PS5) {
-				DualSenseEffects effect {};
-				effect.enable_bits     = 0x0c;
-				effect.right_trigger[0] = 0x05;
-				effect.left_trigger[0]  = 0x05;
-				(void)SDL_SendGamepadEffect(pad, &effect, sizeof(effect));
-			}
-			(void)SDL_RumbleGamepad(pad, 0, 0, 0);
-			(void)SDL_SetGamepadLED(pad, 0, 0, 0);
-			pads.push_back(pad);
-		}
+static void StopHostPad(SDL_Gamepad* pad) {
+	if (SDL_GetGamepadType(pad) == SDL_GAMEPAD_TYPE_PS5) {
+		DualSenseEffects effect {};
+		effect.enable_bits     = 0x0c;
+		effect.right_trigger[0] = 0x05;
+		effect.left_trigger[0]  = 0x05;
+		(void)SDL_SendGamepadEffect(pad, &effect, sizeof(effect));
 	}
-
-	if (!pads.empty()) {
-		SDL_Delay(RELEASE_FLUSH_MS);
-		for (auto* pad: pads) {
-			SDL_CloseGamepad(pad);
-		}
-	}
-
-	m_connected_ids.clear();
-	CheckActive();
+	(void)SDL_RumbleGamepad(pad, 0, 0, 0);
+	(void)SDL_SetGamepadLED(pad, 0, 0, 0);
 }
 
 void GameController::SetVibration(uint8_t large_motor, uint8_t small_motor) {
@@ -847,7 +847,9 @@ void GameController::ApplyVibration() {
 	const auto scale       = duration != 0 ? GetSettingScale(Setting::VibrationIntensity) : 0.0f;
 	const auto large_motor = Scale(m_vibration[0], scale);
 	const auto small_motor = Scale(m_vibration[1], scale);
-	if (DualSenseHaptics::SetVibration(m_active_id, large_motor, small_motor, duration)) {
+	// The DualSense haptics backend drives a single pad, so only player 1 uses it.
+	if (m_player == 0 &&
+	    DualSenseHaptics::SetVibration(m_active_id, large_motor, small_motor, duration)) {
 		return;
 	}
 
@@ -999,49 +1001,149 @@ int GameController::ReadStates(ControllerState* states, int states_num, bool* fl
 	return ret_num;
 }
 
+// Keep every opened pad, including those waiting for a free player slot.
+// Caller holds g_router_mutex.
+static void RefreshPlayers() {
+	std::array<bool, Config::MAX_PLAYERS> taken {};
+	const int keyboard = KeyboardPlayer();
+	if (g_keyboard_player != 0) {
+		taken[keyboard] = true;
+	}
+	for (auto& [id, player]: g_pad_players) {
+		if (g_keyboard_player != 0 && player == keyboard) {
+			player = -1;
+		}
+		if (player >= 0) {
+			taken[player] = true;
+		}
+	}
+	for (auto& [id, player]: g_pad_players) {
+		if (player >= 0) {
+			continue;
+		}
+		const auto free = std::find(taken.begin(), taken.end(), false);
+		if (free != taken.end()) {
+			player = static_cast<int>(free - taken.begin());
+			*free  = true;
+			LOGF("Controller %d assigned to player %d\n", id, player + 1);
+		}
+	}
+	std::array<int, Config::MAX_PLAYERS> active;
+	active.fill(-1);
+	active[keyboard] = HOST_INPUT_CONTROLLER_ID;
+	for (const auto& [id, player]: g_pad_players) {
+		if (player >= 0) {
+			active[player] = id;
+		}
+	}
+	// Stop old owners before configuring new owners of the same physical pad.
+	for (int player = 0; player < Config::MAX_PLAYERS; player++) {
+		const int previous = g_players[player]->GetActiveControllerId();
+		if (previous != active[player]) {
+			if (player == 0) {
+				(void)DualSenseHaptics::SetVibration(previous, 0, 0, 0);
+			}
+			if (auto* pad = SDL_GetGamepadFromID(static_cast<SDL_JoystickID>(previous))) {
+				StopHostPad(pad);
+			}
+		}
+	}
+	for (int player = 0; player < Config::MAX_PLAYERS; player++) {
+		g_players[player]->SetDevices(active[player]);
+	}
+}
+
 void Connect(int id) {
-	g_controller->Connect(id);
+	Common::LockGuard lock(g_router_mutex);
+	if (std::any_of(g_pad_players.begin(), g_pad_players.end(),
+	                [id](const auto& pad) { return pad.first == id; })) {
+		return;
+	}
+	g_pad_players.emplace_back(id, -1);
+	RefreshPlayers();
 }
 
 void Disconnect(int id) {
-	g_controller->Disconnect(id);
+	Common::LockGuard lock(g_router_mutex);
+	std::erase_if(g_pad_players, [id](const auto& pad) { return pad.first == id; });
+	RefreshPlayers();
+}
+
+void CycleKeyboardPlayer() {
+	Common::LockGuard lock(g_router_mutex);
+	g_keyboard_player = (g_keyboard_player + 1) % (Config::MAX_PLAYERS + 1);
+	RefreshPlayers();
+	if (g_keyboard_player == 0) {
+		LOGF("Keyboard shared with player 1\n");
+	} else {
+		LOGF("Keyboard assigned to player %u\n", g_keyboard_player);
+	}
 }
 
 void SetButton(int id, uint32_t button, bool down) {
-	g_controller->Button(id, button, down);
+	Common::LockGuard lock(g_router_mutex);
+	if (auto* player = PlayerForDevice(id)) {
+		player->Button(id, button, down);
+	}
 }
 
 void SetAxis(int id, Axis axis, int value) {
-	g_controller->Axis(id, axis, value);
+	Common::LockGuard lock(g_router_mutex);
+	if (auto* player = PlayerForDevice(id)) {
+		player->Axis(id, axis, value);
+	}
 }
 
 void SetRightStick(int id, int x, int y) {
-	g_controller->RightStick(id, x, y);
+	Common::LockGuard lock(g_router_mutex);
+	if (auto* player = PlayerForDevice(id)) {
+		player->RightStick(id, x, y);
+	}
 }
 
 void SetTouchPad(int id, int finger, bool down, float x, float y) {
-	g_controller->TouchPad(id, finger, down, x, y);
+	Common::LockGuard lock(g_router_mutex);
+	if (auto* player = PlayerForDevice(id)) {
+		player->TouchPad(id, finger, down, x, y);
+	}
 }
 
 void SetSensor(int id, Sensor sensor, const float* data, uint64_t time_us) {
-	g_controller->Motion(id, sensor, data, time_us);
+	Common::LockGuard lock(g_router_mutex);
+	if (auto* player = PlayerForDevice(id)) {
+		player->Motion(id, sensor, data, time_us);
+	}
 }
 
 void ToggleGyroEmulation(int id) {
-	g_controller->ToggleGyroEmulation(id);
+	Common::LockGuard lock(g_router_mutex);
+	if (auto* player = PlayerForDevice(id)) {
+		player->ToggleGyroEmulation(id);
+	}
 }
 
 void ResetInputState() {
-	g_controller->ResetInputState();
+	for (const auto& player: g_players) {
+		if (player != nullptr) {
+			player->ResetInputState();
+		}
+	}
 }
 
 int GetActiveControllerId() {
-	return g_controller != nullptr ? g_controller->GetActiveControllerId() : -1;
+	return g_players[0] != nullptr ? g_players[0]->GetActiveControllerId() : -1;
 }
 
-static bool PadOpenArgsAreValid(int user_id, int type, int index) {
-	// The host keyboard and gamepad feed one standard port for the configured user.
-	return user_id == Config::GetUserId() && type == 0 && index == 0;
+bool IsPlayerConnected(int player) {
+	if (player < 0 || player >= Config::MAX_PLAYERS || g_players[player] == nullptr) {
+		return false;
+	}
+	return g_players[player]->GetActiveControllerId() != -1;
+}
+
+bool GameController::PadOpenArgsAreValid(int user_id, int type, int index) const {
+	// The host keyboard and gamepads of a player feed one standard port for that player's user.
+	return user_id == Config::GetPlayerUserId(m_player) && type == 0 && index == 0;
 }
 
 int GameController::InitPort() {
@@ -1064,7 +1166,7 @@ int GameController::OpenPort(int user_id, int type, int index) {
 		return PAD_ERROR_ALREADY_OPENED;
 	}
 	m_port_state = PortState::Open;
-	return PAD_HANDLE;
+	return Handle();
 }
 
 int GameController::GetPortHandle(int user_id, int type, int index) {
@@ -1072,15 +1174,16 @@ int GameController::GetPortHandle(int user_id, int type, int index) {
 	if (m_port_state == PortState::Uninitialized) {
 		return PAD_ERROR_NOT_INITIALIZED;
 	}
-	return m_port_state == PortState::Open && PadOpenArgsAreValid(user_id, type, index) ? PAD_HANDLE
-	                                                                               : PAD_ERROR_NO_HANDLE;
+	return m_port_state == PortState::Open && PadOpenArgsAreValid(user_id, type, index)
+	           ? Handle()
+	           : PAD_ERROR_NO_HANDLE;
 }
 
 int GameController::CheckPortHandleLocked(int handle) const {
 	if (m_port_state == PortState::Uninitialized) {
 		return PAD_ERROR_NOT_INITIALIZED;
 	}
-	return m_port_state == PortState::Open && handle == PAD_HANDLE ? OK : PAD_ERROR_INVALID_HANDLE;
+	return m_port_state == PortState::Open && handle == Handle() ? OK : PAD_ERROR_INVALID_HANDLE;
 }
 
 int GameController::CheckPortHandle(int handle) {
@@ -1098,12 +1201,19 @@ int GameController::ClosePort(int handle) {
 }
 
 int PadCheckHandle(int handle) {
-	return g_controller->CheckPortHandle(handle);
+	if (g_players[0] == nullptr) {
+		return PAD_ERROR_NOT_INITIALIZED;
+	}
+	auto* player = PlayerForHandle(handle);
+	return player != nullptr ? player->CheckPortHandle(handle) : PAD_ERROR_INVALID_HANDLE;
 }
 
 int KYTY_SYSV_ABI PadInit() {
 	PRINT_NAME();
-	return g_controller->InitPort();
+	for (const auto& player: g_players) {
+		(void)player->InitPort();
+	}
+	return OK;
 }
 
 int KYTY_SYSV_ABI PadOpen(int user_id, int type, int index, const void* param) {
@@ -1115,7 +1225,8 @@ int KYTY_SYSV_ABI PadOpen(int user_id, int type, int index, const void* param) {
 	     "\t param   = 0x%016" PRIx64 "\n",
 	     user_id, type, index, reinterpret_cast<uint64_t>(param));
 
-	return g_controller->OpenPort(user_id, type, index);
+	const int player = Config::GetPlayerFromUserId(user_id);
+	return player >= 0 ? g_players[player]->OpenPort(user_id, type, index) : PAD_ERROR_INVALID_ARG;
 }
 
 int KYTY_SYSV_ABI PadGetHandle(int user_id, int type, int index) {
@@ -1126,13 +1237,19 @@ int KYTY_SYSV_ABI PadGetHandle(int user_id, int type, int index) {
 	     "\t index   = %d\n",
 	     user_id, type, index);
 
-	return g_controller->GetPortHandle(user_id, type, index);
+	const int player = Config::GetPlayerFromUserId(user_id);
+	return player >= 0 ? g_players[player]->GetPortHandle(user_id, type, index)
+	                   : PAD_ERROR_NO_HANDLE;
 }
 
 int KYTY_SYSV_ABI PadClose(int handle) {
 	PRINT_NAME();
 	LOGF("\t handle = %d\n", handle);
-	return g_controller->ClosePort(handle);
+	auto* player = PlayerForHandle(handle);
+	if (player == nullptr) {
+		return PAD_ERROR_INVALID_HANDLE;
+	}
+	return player->ClosePort(handle);
 }
 
 int KYTY_SYSV_ABI PadSetMotionSensorState(int handle, bool enable) {
@@ -1143,7 +1260,7 @@ int KYTY_SYSV_ABI PadSetMotionSensorState(int handle, bool enable) {
 	}
 
 	LOGF("\t enable = %s\n", (enable ? "true" : "false"));
-	g_controller->SetMotionSensorState(enable);
+	PlayerForHandle(handle)->SetMotionSensorState(enable);
 
 	return OK;
 }
@@ -1167,7 +1284,7 @@ int KYTY_SYSV_ABI PadResetOrientation(int handle) {
 		return error;
 	}
 
-	g_controller->ResetOrientation();
+	PlayerForHandle(handle)->ResetOrientation();
 	return OK;
 }
 
@@ -1183,7 +1300,7 @@ int KYTY_SYSV_ABI PadGetControllerInformation(int handle, PadControllerInformati
 
 	int  connected_count = 0;
 	bool connected       = false;
-	g_controller->GetConnectionInfo(&connected, &connected_count);
+	PlayerForHandle(handle)->GetConnectionInfo(&connected, &connected_count);
 
 	std::memset(info, 0, sizeof(*info));
 
@@ -1228,7 +1345,7 @@ int KYTY_SYSV_ABI PadReadState(int handle, PadData* data) {
 	bool            connected       = false;
 	ControllerState state;
 
-	g_controller->ReadState(&state, &connected, &connected_count);
+	PlayerForHandle(handle)->ReadState(&state, &connected, &connected_count);
 
 	pad_fill_data(data, state, connected, connected_count);
 
@@ -1252,11 +1369,12 @@ int KYTY_SYSV_ABI PadRead(int handle, PadData* data, int num) {
 	bool            connected       = false;
 	ControllerState states[64]      = {};
 
-	int ret_num = g_controller->ReadStates(states, num, &connected, &connected_count);
+	auto* player  = PlayerForHandle(handle);
+	int   ret_num = player->ReadStates(states, num, &connected, &connected_count);
 
 	if (!connected || ret_num == 0) {
 		if (connected) {
-			g_controller->ReadState(&states[0], &connected, &connected_count);
+			player->ReadState(&states[0], &connected, &connected_count);
 		}
 		ret_num = 1;
 	}
@@ -1270,6 +1388,7 @@ int KYTY_SYSV_ABI PadRead(int handle, PadData* data, int num) {
 
 int KYTY_SYSV_ABI PadSetVibration(int handle, const PadVibrationParam* param) {
 	PRINT_NAME();
+	Common::LockGuard lock(g_router_mutex);
 
 	if (const auto error = PadCheckHandle(handle); error != OK) {
 		return error;
@@ -1282,7 +1401,7 @@ int KYTY_SYSV_ABI PadSetVibration(int handle, const PadVibrationParam* param) {
 	     "\t small_motor = %d\n",
 	     static_cast<int>(param->large_motor), static_cast<int>(param->small_motor));
 
-	g_controller->SetVibration(param->large_motor, param->small_motor);
+	PlayerForHandle(handle)->SetVibration(param->large_motor, param->small_motor);
 
 	return OK;
 }
@@ -1299,6 +1418,7 @@ int KYTY_SYSV_ABI PadResetLightBar(int handle) {
 
 int KYTY_SYSV_ABI PadSetLightBar(int handle, const PadLightBarParam* param) {
 	PRINT_NAME();
+	Common::LockGuard lock(g_router_mutex);
 
 	if (const auto error = PadCheckHandle(handle); error != OK) {
 		return error;
@@ -1307,13 +1427,14 @@ int KYTY_SYSV_ABI PadSetLightBar(int handle, const PadLightBarParam* param) {
 		return PAD_ERROR_INVALID_ARG;
 	}
 
-	g_controller->SetLightBar(param->r, param->g, param->b);
+	PlayerForHandle(handle)->SetLightBar(param->r, param->g, param->b);
 
 	return OK;
 }
 
 int KYTY_SYSV_ABI PadSetTriggerEffect(int handle, const PadTriggerEffectParam* param) {
 	PRINT_NAME();
+	Common::LockGuard lock(g_router_mutex);
 
 	if (const auto error = PadCheckHandle(handle); error != OK) {
 		return error;
@@ -1322,7 +1443,7 @@ int KYTY_SYSV_ABI PadSetTriggerEffect(int handle, const PadTriggerEffectParam* p
 		return PAD_ERROR_INVALID_ARG;
 	}
 
-	return g_controller->SetTriggerEffect(*param) ? OK : PAD_ERROR_INVALID_ARG;
+	return PlayerForHandle(handle)->SetTriggerEffect(*param) ? OK : PAD_ERROR_INVALID_ARG;
 }
 
 int KYTY_SYSV_ABI PadGetTriggerEffectState(int handle, PadTriggerEffectStateInformation* info) {
@@ -1337,7 +1458,7 @@ int KYTY_SYSV_ABI PadGetTriggerEffectState(int handle, PadTriggerEffectStateInfo
 		return PAD_ERROR_INVALID_ARG;
 	}
 
-	g_controller->GetTriggerEffectState(info);
+	PlayerForHandle(handle)->GetTriggerEffectState(info);
 
 	return OK;
 }

src/libs/controller.h

@@ -68,6 +68,8 @@ inline int controller_get_axis(int min, int max, int value) {
 
 void Connect(int id);
 void Disconnect(int id);
+// Moves the keyboard to the next player (shared with player 1, then 1-4) while the game runs.
+void CycleKeyboardPlayer();
 void SetButton(int id, uint32_t button, bool down);
 void SetAxis(int id, Axis axis, int value);
 void SetRightStick(int id, int x, int y);
@@ -76,6 +78,8 @@ void SetSensor(int id, Sensor sensor, const float* data, uint64_t time_us);
 void ToggleGyroEmulation(int id);
 void ResetInputState();
 int  GetActiveControllerId();
+// True when the player has a keyboard or gamepad assigned.
+bool IsPlayerConnected(int player);
 
 enum class Setting { SpeakerVolume, VibrationIntensity, TriggerEffectIntensity };
 

src/libs/libSaveData.cpp

@@ -1,6 +1,7 @@
 #include "common/abi.h"
 #include "common/assert.h"
 #include "common/common.h"
+#include "common/emulatorConfig.h"
 #include "common/file.h"
 #include "common/logging/log.h"
 #include "common/stringUtils.h"
@@ -300,15 +301,23 @@ static std::string memory_dir_name(uint32_t slot_id) {
 	return "sce_sdmemory" + (slot_id == 0 ? std::string() : std::to_string(slot_id));
 }
 
+static std::filesystem::path save_user_directory(std::string_view title_id, int32_t user_id) {
+	auto directory = std::filesystem::path(SAVE_DATA_DIR);
+	if (Config::IsGuestUserId(user_id)) {
+		directory /= std::filesystem::path("[users]") / std::to_string(user_id);
+	}
+	return directory / title_id;
+}
+
 static std::filesystem::path save_directory(std::string_view title_id, std::string_view dir_name,
                                             int32_t user_id) {
-	const auto directory = std::filesystem::path(SAVE_DATA_DIR) / title_id / dir_name;
 	for (uint32_t slot = 0; slot < 4; slot++) {
 		if (dir_name == memory_dir_name(slot)) {
-			return directory / std::to_string(user_id);
+			return std::filesystem::path(SAVE_DATA_DIR) / title_id / dir_name /
+			       std::to_string(user_id);
 		}
 	}
-	return directory;
+	return save_user_directory(title_id, user_id) / dir_name;
 }
 
 static std::filesystem::path memory_directory(int32_t user_id, uint32_t slot_id) {
@@ -590,7 +599,7 @@ int KYTY_SYSV_ABI SaveDataDirNameSearch(const SaveDataDirNameSearchCond* cond,
 
 	Common::LockGuard lock(g_mount_mutex);
 	const std::string title_id = cond->title_id != nullptr ? cond->title_id->data : get_title_id();
-	const auto        root     = std::filesystem::path(SAVE_DATA_DIR) / title_id;
+	const auto        root     = save_user_directory(title_id, cond->user_id);
 	std::vector<std::string> dir_list;
 
 	if (Common::File::IsDirectoryExisting(root)) {

src/libs/libTrophy.cpp

@@ -105,6 +105,8 @@ struct TrophyState {
 	const Trophies::Package* package = nullptr;
 	Trophies::UnlockData     unlocks;
 	std::filesystem::path    path;
+	// Guests (players 2+) have no profile: nothing is loaded, saved or announced.
+	bool guest = false;
 };
 
 struct TrophyContext {
@@ -153,9 +155,12 @@ static TrophyState* LoadTrophyState(TrophyKey key) {
 			     package.event_rules.size(), uds_filename.c_str());
 		}
 	}
-	auto path    = Trophies::UnlocksPath({}, title_id, key.first, key.second);
-	auto unlocks = Trophies::LoadUnlockData(path);
-	return &g_states.emplace(key, TrophyState {&package, std::move(unlocks), std::move(path)})
+	const bool guest = Config::IsGuestUserId(key.first);
+	auto       path  = guest ? std::filesystem::path {}
+	                         : Trophies::UnlocksPath({}, title_id, key.first, key.second);
+	auto unlocks = guest ? Trophies::UnlockData {} : Trophies::LoadUnlockData(path);
+	return &g_states
+	            .emplace(key, TrophyState {&package, std::move(unlocks), std::move(path), guest})
 	            .first->second;
 }
 
@@ -240,6 +245,10 @@ static void FillGroupInfo(const TrophyState& state, int group_id, const std::str
 }
 
 static void RecordTrophyUnlock(TrophyState& state, int trophy_id, bool from_stat = false) {
+	if (state.guest) {
+		LOGF("[Trophy] guest users cannot earn trophies (trophy %d)\n", trophy_id);
+		return;
+	}
 	const auto found = state.package->trophies.find(trophy_id);
 	if (found == state.package->trophies.end()) {
 		LOGF("[Trophy] ignored unknown trophy ID %d\n", trophy_id);

src/libs/libUserService.cpp

@@ -1,12 +1,14 @@
 #include "common/abi.h"
 #include "common/assert.h"
 #include "common/emulatorConfig.h"
+#include "common/localization.h"
+#include "libs/controller.h"
 #include "libs/errno.h"
 #include "libs/libs.h"
 #include "loader/symbolDatabase.h"
 
-#include <cstdio>
 #include <cstring>
+#include <string>
 
 namespace Libs {
 
@@ -39,6 +41,15 @@ struct UserServiceGamePresets {
 
 static_assert(sizeof(UserServiceGamePresets) == 40);
 
+static bool IsPlayerLoggedIn(int player) {
+	return player == 0 || (player > 0 && Controller::IsPlayerConnected(player));
+}
+
+static int GetLoggedInPlayer(int user_id) {
+	const int player = Config::GetPlayerFromUserId(user_id);
+	return IsPlayerLoggedIn(player) ? player : -1;
+}
+
 static KYTY_SYSV_ABI int UserServiceInitialize(const void* /*params*/) {
 	PRINT_NAME();
 
@@ -66,13 +77,16 @@ static KYTY_SYSV_ABI int UserServiceGetEvent(SceUserServiceEvent* event) {
 
 	EXIT_NOT_IMPLEMENTED(event == nullptr);
 
-	static bool logged_in = false;
+	static bool logged_in[Config::MAX_PLAYERS] = {};
 
-	if (!logged_in) {
-		logged_in         = true;
-		event->event_type = UserServiceEventTypeLogin;
-		event->user_id    = Config::GetUserId();
-		return OK;
+	for (int player = 0; player < Config::MAX_PLAYERS; player++) {
+		const bool connected = IsPlayerLoggedIn(player);
+		if (connected != logged_in[player]) {
+			logged_in[player] = connected;
+			event->event_type = connected ? UserServiceEventTypeLogin : UserServiceEventTypeLogout;
+			event->user_id    = Config::GetPlayerUserId(player);
+			return OK;
+		}
 	}
 
 	return USER_SERVICE_ERROR_NO_EVENT;
@@ -83,24 +97,36 @@ static KYTY_SYSV_ABI int UserServiceGetLoginUserIdList(UserServiceLoginUserIdLis
 
 	EXIT_NOT_IMPLEMENTED(user_id_list == nullptr);
 
-	user_id_list->user_id[0] = Config::GetUserId();
-	user_id_list->user_id[1] = -1;
-	user_id_list->user_id[2] = -1;
-	user_id_list->user_id[3] = -1;
+	int count = 0;
+	for (int player = 0; player < Config::MAX_PLAYERS; player++) {
+		if (IsPlayerLoggedIn(player)) {
+			user_id_list->user_id[count++] = Config::GetPlayerUserId(player);
+		}
+	}
+	while (count < Config::MAX_PLAYERS) {
+		user_id_list->user_id[count++] = -1;
+	}
 
 	return OK;
 }
 
 static KYTY_SYSV_ABI int UserServiceGetUserName(int user_id, char* name, size_t size) {
-	if (user_id != Config::GetUserId()) {
+	if (name == nullptr) {
+		return USER_SERVICE_ERROR_INVALID_ARGUMENT;
+	}
+	const int player = GetLoggedInPlayer(user_id);
+	if (player < 0) {
 		return USER_SERVICE_ERROR_NOT_LOGGED_IN;
 	}
-	EXIT_NOT_IMPLEMENTED(size < 5);
 
-	const auto& user_name = Config::GetUserName();
-	int         s         = snprintf(name, size, "%s", user_name.c_str());
-
-	EXIT_NOT_IMPLEMENTED(static_cast<size_t>(s) >= size);
+	const auto  user_name =
+	    player > 0 ? std::string(Common::Localization::Get(Config::GetConsoleLanguage(), "user.guest")) +
+	                     " " + std::to_string(player + 1)
+	               : Config::GetUserName();
+	if (size <= user_name.size()) {
+		return USER_SERVICE_ERROR_BUFFER_TOO_SHORT;
+	}
+	std::memcpy(name, user_name.c_str(), user_name.size() + 1);
 
 	return OK;
 }
@@ -111,11 +137,12 @@ static KYTY_SYSV_ABI int UserServiceGetUserNumber(int user_id, int32_t* number)
 	if (number == nullptr) {
 		return USER_SERVICE_ERROR_INVALID_ARGUMENT;
 	}
-	if (user_id != Config::GetUserId()) {
+	const int player = GetLoggedInPlayer(user_id);
+	if (player < 0) {
 		return USER_SERVICE_ERROR_NOT_LOGGED_IN;
 	}
 
-	*number = 1;
+	*number = player + 1;
 
 	return OK;
 }
@@ -126,7 +153,7 @@ static KYTY_SYSV_ABI int UserServiceGetGamePresets(int user_id, UserServiceGameP
 	if (presets == nullptr) {
 		return USER_SERVICE_ERROR_INVALID_ARGUMENT;
 	}
-	if (user_id != Config::GetUserId()) {
+	if (GetLoggedInPlayer(user_id) < 0) {
 		return USER_SERVICE_ERROR_NOT_LOGGED_IN;
 	}
 
@@ -147,7 +174,7 @@ static KYTY_SYSV_ABI int UserServiceGetAccessibilityVibration(int user_id, int32
 	if (vibration == nullptr) {
 		return USER_SERVICE_ERROR_INVALID_ARGUMENT;
 	}
-	if (user_id != Config::GetUserId()) {
+	if (GetLoggedInPlayer(user_id) < 0) {
 		return USER_SERVICE_ERROR_NOT_LOGGED_IN;
 	}
 
@@ -163,7 +190,7 @@ static KYTY_SYSV_ABI int UserServiceGetAccessibilityTriggerEffect(int      user_
 	if (trigger_effect == nullptr) {
 		return USER_SERVICE_ERROR_INVALID_ARGUMENT;
 	}
-	if (user_id != Config::GetUserId()) {
+	if (GetLoggedInPlayer(user_id) < 0) {
 		return USER_SERVICE_ERROR_NOT_LOGGED_IN;
 	}
 
@@ -178,7 +205,7 @@ static KYTY_SYSV_ABI int UserServiceGetAgeLevel(int user_id, uint32_t* age_level
 	if (age_level == nullptr) {
 		return USER_SERVICE_ERROR_INVALID_ARGUMENT;
 	}
-	if (user_id != Config::GetUserId()) {
+	if (GetLoggedInPlayer(user_id) < 0) {
 		return USER_SERVICE_ERROR_NOT_LOGGED_IN;
 	}
 
@@ -194,7 +221,7 @@ static KYTY_SYSV_ABI int UserServiceGetAccessibilityChatTranscription(int      u
 	if (chat_transcription == nullptr) {
 		return USER_SERVICE_ERROR_INVALID_ARGUMENT;
 	}
-	if (user_id != Config::GetUserId()) {
+	if (GetLoggedInPlayer(user_id) < 0) {
 		return USER_SERVICE_ERROR_NOT_LOGGED_IN;
 	}
 
@@ -210,7 +237,7 @@ UserServiceGetAccessibilityPressAndHoldDelay(int user_id, int32_t* press_and_hol
 	if (press_and_hold_delay == nullptr) {
 		return USER_SERVICE_ERROR_INVALID_ARGUMENT;
 	}
-	if (user_id != Config::GetUserId()) {
+	if (GetLoggedInPlayer(user_id) < 0) {
 		return USER_SERVICE_ERROR_NOT_LOGGED_IN;
 	}
 
@@ -226,7 +253,7 @@ static KYTY_SYSV_ABI int UserServiceGetAccessibilityZoomEnabled(int      user_id
 	if (zoom_enabled == nullptr) {
 		return USER_SERVICE_ERROR_INVALID_ARGUMENT;
 	}
-	if (user_id != Config::GetUserId()) {
+	if (GetLoggedInPlayer(user_id) < 0) {
 		return USER_SERVICE_ERROR_NOT_LOGGED_IN;
 	}
 
@@ -242,7 +269,7 @@ static KYTY_SYSV_ABI int UserServiceGetAccessibilityZoomFollowFocus(int      use
 	if (zoom_follow_focus == nullptr) {
 		return USER_SERVICE_ERROR_INVALID_ARGUMENT;
 	}
-	if (user_id != Config::GetUserId()) {
+	if (GetLoggedInPlayer(user_id) < 0) {
 		return USER_SERVICE_ERROR_NOT_LOGGED_IN;
 	}
 

src/main.cpp

@@ -57,6 +57,7 @@ static void PrintUsage() {
 	::printf("  --controller-color <#RRGGBB>        Override the controller lightbar color.\n");
 	::printf("  --controller-volume <0-100>         DualSense speaker volume. Default: 50.\n");
 	::printf("  --controller-vibration <0-100>      DualSense vibration intensity. Default: 100.\n");
+	::printf("  --keyboard-player <0-4>             Keyboard player; 0 shares player 1 with the gamepad. Default: 0.\n");
 	::printf(
 	    "  --present-mode <value>               Fifo, Mailbox, or Immediate. Default: Mailbox.\n");
 	::printf(
@@ -378,6 +379,12 @@ static bool ParseArgs(int argc, char* argv[], RunOptions& options, bool& show_he
 				::printf("invalid controller vibration intensity: %s\n", value.c_str());
 				return false;
 			}
+		} else if (arg == "--keyboard-player") {
+			if (!ParseUint32(value, options.config.keyboard_player) ||
+			    options.config.keyboard_player > static_cast<uint32_t>(Config::MAX_PLAYERS)) {
+				::printf("invalid keyboard player: %s\n", value.c_str());
+				return false;
+			}
 		} else if (arg == "--present-mode") {
 			if (!ParseEnum(value, options.config.present_mode)) {
 				::printf("invalid present mode: %s\n", value.c_str());