Add joystick vibration support on Linux (#5043)

7 files changed, 189 insertions, 2 deletions

diff --git a/core/os/input.cpp b/core/os/input.cpp
index a766ef87fc..005a248aac 100644
--- a/core/os/input.cpp
+++ b/core/os/input.cpp
@@ -59,6 +59,10 @@ void Input::_bind_methods() {
 	ObjectTypeDB::bind_method(_MD("get_joy_axis","device","axis"),&Input::get_joy_axis);
 	ObjectTypeDB::bind_method(_MD("get_joy_name","device"),&Input::get_joy_name);
 	ObjectTypeDB::bind_method(_MD("get_joy_guid","device"),&Input::get_joy_guid);
+	ObjectTypeDB::bind_method(_MD("get_joy_vibration_strength", "device"), &Input::get_joy_vibration_strength);
+	ObjectTypeDB::bind_method(_MD("get_joy_vibration_duration", "device"), &Input::get_joy_vibration_duration);
+	ObjectTypeDB::bind_method(_MD("start_joy_vibration", "device", "weak_magnitude", "strong_magnitude", "duration"), &Input::start_joy_vibration);
+	ObjectTypeDB::bind_method(_MD("stop_joy_vibration", "device"), &Input::stop_joy_vibration);
 	ObjectTypeDB::bind_method(_MD("get_accelerometer"),&Input::get_accelerometer);
 	ObjectTypeDB::bind_method(_MD("get_magnetometer"),&Input::get_magnetometer);
 	//ObjectTypeDB::bind_method(_MD("get_mouse_pos"),&Input::get_mouse_pos); - this is not the function you want
diff --git a/core/os/input.h b/core/os/input.h
index 46edb30aa1..6364d597b0 100644
--- a/core/os/input.h
+++ b/core/os/input.h
@@ -67,6 +67,11 @@ public:
 	virtual void remove_joy_mapping(String p_guid)=0;
 	virtual bool is_joy_known(int p_device)=0;
 	virtual String get_joy_guid(int p_device) const=0;
+	virtual Vector2 get_joy_vibration_strength(int p_device)=0;
+	virtual float get_joy_vibration_duration(int p_device)=0;
+	virtual uint64_t get_joy_vibration_timestamp(int p_device)=0;
+	virtual void start_joy_vibration(int p_device, float p_weak_magnitude, float p_strong_magnitude, float p_duration)=0;
+	virtual void stop_joy_vibration(int p_device)=0;
 
 	virtual Point2 get_mouse_pos() const=0;
 	virtual Point2 get_mouse_speed() const=0;
diff --git a/doc/base/classes.xml b/doc/base/classes.xml
index 0d8f7eecdd..71e972bac6 100644
--- a/doc/base/classes.xml
+++ b/doc/base/classes.xml
@@ -15788,6 +15788,23 @@ Example: (content-length:12), (Content-Type:application/json; charset=UTF-8)
 			Returns a SDL2 compatible device guid on platforms that use gamepad remapping. Returns "Default Gamepad" otherwise.
 			</description>
 		</method>
+		<method name="get_joy_vibration_strength">
+			<return type="Vector2">
+			</return>
+			<argument index="0" name="device" type="int">
+			</argument>
+			<description>
+			Returns the strength of the joystick vibration: x is the strength of the weak motor, and y is the strength of the strong motor.
+			</description>
+		</method>
+		<method name="get_joy_vibration_duration">
+			<return type="float">
+			</return>
+			<argument index="0" name="device" type="int">
+			</argument>
+			<description>
+			Returns the duration of the current vibration effect in seconds.
+			</description>
 		<method name="get_accelerometer">
 			<return type="Vector3">
 			</return>
@@ -15830,6 +15847,26 @@ Example: (content-length:12), (Content-Type:application/json; charset=UTF-8)
 			Return the mouse mode. See the constants for more information.
 			</description>
 		</method>
+		<method name="start_joy_vibration">
+			<argument index="0" name="device" type="int">
+			</argument>
+			<argument index="1" name="weak_magnitude" type="float">
+			</argument>
+			<argument index="2" name="strong_magnitude" type="float">
+			</argument>
+			<argument index="3" name="duration" type="float">
+			</argument>
+			<description>
+			Starts to vibrate the joystick. Joysticks usually come with two rumble motors, a strong and a weak one. weak_magnitude is the strength of the weak motor (between 0 and 1) and strong_magnitude is the strength of the strong motor (between 0 and 1). duration is the duration of the effect in seconds (a duration of 0 will play the vibration indefinitely).
+			</description>
+		</method>
+		<method name="stop_joy_vibration">
+			<argument index="0" name="device" type="int">
+			</argument>
+			<description>
+			Stops the vibration of the joystick.
+			</description>
+		</method>
 		<method name="warp_mouse_pos">
 			<argument index="0" name="to" type="Vector2">
 			</argument>
diff --git a/main/input_default.cpp b/main/input_default.cpp
index e36306727d..a6f14ae1f5 100644
--- a/main/input_default.cpp
+++ b/main/input_default.cpp
@@ -137,6 +137,30 @@ String InputDefault::get_joy_name(int p_idx) {
 	return joy_names[p_idx].name;
 };
 
+Vector2 InputDefault::get_joy_vibration_strength(int p_device) {
+	if (joy_vibration.has(p_device)) {
+		return Vector2(joy_vibration[p_device].weak_magnitude, joy_vibration[p_device].strong_magnitude);
+	} else {
+		return Vector2(0, 0);
+	}
+}
+
+uint64_t InputDefault::get_joy_vibration_timestamp(int p_device) {
+	if (joy_vibration.has(p_device)) {
+		return joy_vibration[p_device].timestamp;
+	} else {
+		return 0;
+	}
+}
+
+float InputDefault::get_joy_vibration_duration(int p_device) {
+	if (joy_vibration.has(p_device)) {
+		return joy_vibration[p_device].duration;
+	} else {
+		return 0.f;
+	}
+}
+
 static String _hex_str(uint8_t p_byte) {
 
 	static const char* dict = "0123456789abcdef";
@@ -294,6 +318,29 @@ void InputDefault::set_joy_axis(int p_device,int p_axis,float p_value) {
 	_joy_axis[c]=p_value;
 }
 
+void InputDefault::start_joy_vibration(int p_device, float p_weak_magnitude, float p_strong_magnitude, float p_duration) {
+	_THREAD_SAFE_METHOD_
+	if (p_weak_magnitude < 0.f || p_weak_magnitude > 1.f || p_strong_magnitude < 0.f || p_strong_magnitude > 1.f) {
+		return;
+	}
+	VibrationInfo vibration;
+	vibration.weak_magnitude = p_weak_magnitude;
+	vibration.strong_magnitude = p_strong_magnitude;
+	vibration.duration = p_duration;
+	vibration.timestamp = OS::get_singleton()->get_unix_time();
+	joy_vibration[p_device] = vibration;
+}
+
+void InputDefault::stop_joy_vibration(int p_device) {
+	_THREAD_SAFE_METHOD_
+	VibrationInfo vibration;
+	vibration.weak_magnitude = 0;
+	vibration.strong_magnitude = 0;
+	vibration.duration = 0;
+	vibration.timestamp = OS::get_singleton()->get_unix_time();
+	joy_vibration[p_device] = vibration;
+}
+
 void InputDefault::set_accelerometer(const Vector3& p_accel) {
 
 	_THREAD_SAFE_METHOD_
diff --git a/main/input_default.h b/main/input_default.h
index 8f6a430436..01b813f3ca 100644
--- a/main/input_default.h
+++ b/main/input_default.h
@@ -3,6 +3,7 @@
 
 #include "os/input.h"
 
+
 class InputDefault : public Input {
 
 	OBJ_TYPE( InputDefault, Input );
@@ -19,6 +20,16 @@ class InputDefault : public Input {
 	MainLoop *main_loop;
 
 	bool emulate_touch;
+
+	struct VibrationInfo {
+		float weak_magnitude;
+		float strong_magnitude;
+		float duration; // Duration in seconds
+		uint64_t timestamp;
+	};
+
+	Map<int, VibrationInfo> joy_vibration;
+
 	struct SpeedTrack {
 
 		uint64_t last_tick;
@@ -129,6 +140,9 @@ public:
 
 	virtual float get_joy_axis(int p_device,int p_axis);
 	String get_joy_name(int p_idx);
+	virtual Vector2 get_joy_vibration_strength(int p_device);
+	virtual float get_joy_vibration_duration(int p_device);
+	virtual uint64_t get_joy_vibration_timestamp(int p_device);
 	void joy_connection_changed(int p_idx, bool p_connected, String p_name, String p_guid = "");
 	void parse_joystick_mapping(String p_mapping, bool p_update_existing);
 
@@ -147,6 +161,9 @@ public:
 	void set_magnetometer(const Vector3& p_magnetometer);
 	void set_joy_axis(int p_device,int p_axis,float p_value);
 
+	virtual void start_joy_vibration(int p_device, float p_weak_magnitude, float p_strong_magnitude, float p_duration);
+	virtual void stop_joy_vibration(int p_device);
+
 	void set_main_loop(MainLoop *main_loop);
 	void set_mouse_pos(const Point2& p_posf);
 
diff --git a/platform/x11/joystick_linux.cpp b/platform/x11/joystick_linux.cpp
index 2793cc5734..5ce0219df7 100644
--- a/platform/x11/joystick_linux.cpp
+++ b/platform/x11/joystick_linux.cpp
@@ -316,13 +316,21 @@ void joystick_linux::setup_joystick_properties(int p_id) {
 			}
 		}
 	}
-}
 
+	joy->force_feedback = false;
+	joy->ff_effect_timestamp = 0;
+	unsigned long ffbit[NBITS(FF_CNT)];
+	if (ioctl(joy->fd, EVIOCGBIT(EV_FF, sizeof(ffbit)), ffbit) != -1) {
+		if (test_bit(FF_RUMBLE, ffbit)) {
+			joy->force_feedback = true;
+		}
+	}
+}
 
 void joystick_linux::open_joystick(const char *p_path) {
 
 	int joy_num = get_free_joy_slot();
-	int fd = open(p_path, O_RDONLY | O_NONBLOCK);
+	int fd = open(p_path, O_RDWR | O_NONBLOCK);
 	if (fd != -1 && joy_num != -1) {
 
 		unsigned long evbit[NBITS(EV_MAX)] = { 0 };
@@ -392,6 +400,55 @@ void joystick_linux::open_joystick(const char *p_path) {
 	}
 }
 
+void joystick_linux::joystick_vibration_start(int p_id, float p_weak_magnitude, float p_strong_magnitude, float p_duration, uint64_t p_timestamp)
+{
+	Joystick& joy = joysticks[p_id];
+	if (!joy.force_feedback || joy.fd == -1 || p_weak_magnitude < 0.f || p_weak_magnitude > 1.f || p_strong_magnitude < 0.f || p_strong_magnitude > 1.f) {
+		return;
+	}
+	if (joy.ff_effect_id != -1) {
+		joystick_vibration_stop(p_id, p_timestamp);
+	}
+
+	struct ff_effect effect;
+	effect.type = FF_RUMBLE;
+	effect.id = -1;
+	effect.u.rumble.weak_magnitude = floor(p_weak_magnitude * (float)0xffff);
+	effect.u.rumble.strong_magnitude = floor(p_strong_magnitude * (float)0xffff);
+	effect.replay.length = floor(p_duration * 1000);
+	effect.replay.delay = 0;
+
+	if (ioctl(joy.fd, EVIOCSFF, &effect) < 0) {
+		return;
+	}
+
+	struct input_event play;
+	play.type = EV_FF;
+	play.code = effect.id;
+	play.value = 1;
+	write(joy.fd, (const void*)&play, sizeof(play));
+
+	joy.ff_effect_id = effect.id;
+	joy.ff_effect_timestamp = p_timestamp;
+}
+
+void joystick_linux::joystick_vibration_stop(int p_id, uint64_t p_timestamp)
+{
+	Joystick& joy = joysticks[p_id];
+	if (!joy.force_feedback || joy.fd == -1 || joy.ff_effect_id == -1) {
+		return;
+	}
+
+	struct input_event stop;
+	stop.type = EV_FF;
+	stop.code = joy.ff_effect_id;
+	stop.value = 0;
+	write(joy.fd, (const void*)&stop, sizeof(stop));
+
+	joy.ff_effect_id = -1;
+	joy.ff_effect_timestamp = p_timestamp;
+}
+
 InputDefault::JoyAxis joystick_linux::axis_correct(const input_absinfo *p_abs, int p_value) const {
 
 	int min = p_abs->minimum;
@@ -485,6 +542,19 @@ uint32_t joystick_linux::process_joysticks(uint32_t p_event_id) {
 		if (len == 0 || (len < 0 && errno != EAGAIN)) {
 			close_joystick(i);
 		};
+
+		if (joy->force_feedback) {
+			uint64_t timestamp = input->get_joy_vibration_timestamp(i);
+			if (timestamp > joy->ff_effect_timestamp) {
+				Vector2 strength = input->get_joy_vibration_strength(i);
+				float duration = input->get_joy_vibration_duration(i);
+				if (strength.x == 0 && strength.y == 0) {
+					joystick_vibration_stop(i, timestamp);
+				} else {
+					joystick_vibration_start(i, strength.x, strength.y, duration, timestamp);
+				}
+			}
+		}
 	}
 	joy_mutex->unlock();
 	return p_event_id;
diff --git a/platform/x11/joystick_linux.h b/platform/x11/joystick_linux.h
index 4f0533721b..7ea2664ebb 100644
--- a/platform/x11/joystick_linux.h
+++ b/platform/x11/joystick_linux.h
@@ -61,6 +61,10 @@ private:
 		String devpath;
 		input_absinfo *abs_info[MAX_ABS];
 
+		bool force_feedback;
+		int ff_effect_id;
+		uint64_t ff_effect_timestamp;
+
 		Joystick();
 		~Joystick();
 		void reset();
@@ -88,6 +92,9 @@ private:
 	void run_joystick_thread();
 	void open_joystick(const char* path);
 
+	void joystick_vibration_start(int p_id, float p_weak_magnitude, float p_strong_magnitude, float p_duration, uint64_t p_timestamp);
+	void joystick_vibration_stop(int p_id, uint64_t p_timestamp);
+
 	InputDefault::JoyAxis axis_correct(const input_absinfo *abs, int value) const;
 };