Implement universal translation of touch to mouse

Now generating mouse events from touch is optional (on by default) and it's performed by `InputDefault` instead of having each OS abstraction doing it. (*)

The translation algorithm waits for a touch index to be pressed and tracks it translating its events to mouse events until it is raised, while ignoring other pointers.

Furthermore, to avoid an stuck "touch mouse", since not all platforms may report touches raised when the window is unfocused, it checks if touches are still down by the time it's focused again and if so it resets the state of the emulated mouse.

*: In the case of Windows, since it already provides touch-to-mouse translation by itself, "echo" mouse events are filtered out to have it working like the rest.

On X11 a little hack has been needed to avoid a case of a spurious mouse motion event that is generated during touch interaction.

Plus: Improve/fix tracking of current mouse position.

16 files changed, 210 insertions, 214 deletions

diff --git a/core/os/input.h b/core/os/input.h
index 9c7595ff7..45a3391f1 100644
--- a/core/os/input.h
+++ b/core/os/input.h
@@ -118,6 +118,7 @@ public:
 	void get_argument_options(const StringName &p_function, int p_idx, List<String> *r_options) const;
 
 	virtual bool is_emulating_touchscreen() const = 0;
+	virtual bool is_emulating_mouse_from_touch() const = 0;
 
 	virtual void set_custom_mouse_cursor(const RES &p_cursor, CursorShape p_shape = CURSOR_ARROW, const Vector2 &p_hotspot = Vector2()) = 0;
 	virtual void set_mouse_in_window(bool p_in_window) = 0;
diff --git a/main/input_default.cpp b/main/input_default.cpp
index 323748346..b3a34a4ef 100644
--- a/main/input_default.cpp
+++ b/main/input_default.cpp
@@ -249,6 +249,11 @@ Vector3 InputDefault::get_gyroscope() const {
 
 void InputDefault::parse_input_event(const Ref<InputEvent> &p_event) {
 
+	_parse_input_event_impl(p_event, false);
+}
+
+void InputDefault::_parse_input_event_impl(const Ref<InputEvent> &p_event, bool p_is_emulated) {
+
 	_THREAD_SAFE_METHOD_
 
 	Ref<InputEventKey> k = p_event;
@@ -272,25 +277,30 @@ void InputDefault::parse_input_event(const Ref<InputEvent> &p_event) {
 			mouse_button_mask &= ~(1 << (mb->get_button_index() - 1));
 		}
 
-		if (main_loop && emulate_touch && mb->get_button_index() == 1) {
+		Point2 pos = mb->get_global_position();
+		if (mouse_pos != pos) {
+			set_mouse_position(pos);
+		}
+
+		if (main_loop && emulate_touch && !p_is_emulated && mb->get_button_index() == 1) {
 			Ref<InputEventScreenTouch> touch_event;
 			touch_event.instance();
 			touch_event->set_pressed(mb->is_pressed());
 			touch_event->set_position(mb->get_position());
 			main_loop->input_event(touch_event);
 		}
-
-		Point2 pos = mb->get_global_position();
-		if (mouse_pos != pos) {
-			set_mouse_position(pos);
-		}
 	}
 
 	Ref<InputEventMouseMotion> mm = p_event;
 
 	if (mm.is_valid()) {
 
-		if (main_loop && emulate_touch && mm->get_button_mask() & 1) {
+		Point2 pos = mm->get_global_position();
+		if (mouse_pos != pos) {
+			set_mouse_position(pos);
+		}
+
+		if (main_loop && emulate_touch && !p_is_emulated && mm->get_button_mask() & 1) {
 			Ref<InputEventScreenDrag> drag_event;
 			drag_event.instance();
 
@@ -302,6 +312,58 @@ void InputDefault::parse_input_event(const Ref<InputEvent> &p_event) {
 		}
 	}
 
+	if (emulate_mouse_from_touch) {
+
+		Ref<InputEventScreenTouch> st = p_event;
+
+		if (st.is_valid()) {
+			bool translate = false;
+			if (st->is_pressed()) {
+				if (mouse_from_touch_index == -1) {
+					translate = true;
+					mouse_from_touch_index = st->get_index();
+				}
+			} else {
+				if (st->get_index() == mouse_from_touch_index) {
+					translate = true;
+					mouse_from_touch_index = -1;
+				}
+			}
+
+			if (translate) {
+				Ref<InputEventMouseButton> button_event;
+				button_event.instance();
+
+				button_event->set_position(st->get_position());
+				button_event->set_global_position(st->get_position());
+				button_event->set_pressed(st->is_pressed());
+				button_event->set_button_index(BUTTON_LEFT);
+				if (st->is_pressed()) {
+					button_event->set_button_mask(mouse_button_mask | (1 << BUTTON_LEFT - 1));
+				} else {
+					button_event->set_button_mask(mouse_button_mask & ~(1 << BUTTON_LEFT - 1));
+				}
+
+				_parse_input_event_impl(button_event, true);
+			}
+		}
+
+		Ref<InputEventScreenDrag> sd = p_event;
+
+		if (sd.is_valid() && sd->get_index() == mouse_from_touch_index) {
+			Ref<InputEventMouseMotion> motion_event;
+			motion_event.instance();
+
+			motion_event->set_position(sd->get_position());
+			motion_event->set_global_position(sd->get_position());
+			motion_event->set_relative(sd->get_relative());
+			motion_event->set_speed(sd->get_speed());
+			motion_event->set_button_mask(mouse_button_mask);
+
+			_parse_input_event_impl(motion_event, true);
+		}
+	}
+
 	Ref<InputEventJoypadButton> jb = p_event;
 
 	if (jb.is_valid()) {
@@ -498,6 +560,36 @@ bool InputDefault::is_emulating_touchscreen() const {
 	return emulate_touch;
 }
 
+// Calling this whenever the game window is focused helps unstucking the "touch mouse"
+// if the OS or its abstraction class hasn't properly reported that touch pointers raised
+void InputDefault::ensure_touch_mouse_raised() {
+
+	if (mouse_from_touch_index != -1) {
+		mouse_from_touch_index = -1;
+
+		Ref<InputEventMouseButton> button_event;
+		button_event.instance();
+
+		button_event->set_position(mouse_pos);
+		button_event->set_global_position(mouse_pos);
+		button_event->set_pressed(false);
+		button_event->set_button_index(BUTTON_LEFT);
+		button_event->set_button_mask(mouse_button_mask & ~(1 << BUTTON_LEFT - 1));
+
+		_parse_input_event_impl(button_event, true);
+	}
+}
+
+void InputDefault::set_emulate_mouse_from_touch(bool p_emulate) {
+
+	emulate_mouse_from_touch = p_emulate;
+}
+
+bool InputDefault::is_emulating_mouse_from_touch() const {
+
+	return emulate_mouse_from_touch;
+}
+
 void InputDefault::set_custom_mouse_cursor(const RES &p_cursor, CursorShape p_shape, const Vector2 &p_hotspot) {
 	if (Engine::get_singleton()->is_editor_hint())
 		return;
@@ -815,6 +907,8 @@ InputDefault::InputDefault() {
 
 	mouse_button_mask = 0;
 	emulate_touch = false;
+	emulate_mouse_from_touch = false;
+	mouse_from_touch_index = -1;
 	main_loop = NULL;
 
 	hat_map_default[HAT_UP].type = TYPE_BUTTON;
diff --git a/main/input_default.h b/main/input_default.h
index 0479fdc0f..acc8fd465 100644
--- a/main/input_default.h
+++ b/main/input_default.h
@@ -60,6 +60,9 @@ class InputDefault : public Input {
 	Map<StringName, Action> action_state;
 
 	bool emulate_touch;
+	bool emulate_mouse_from_touch;
+
+	int mouse_from_touch_index;
 
 	struct VibrationInfo {
 		float weak_magnitude;
@@ -175,6 +178,8 @@ private:
 	void _axis_event(int p_device, int p_axis, float p_value);
 	float _handle_deadzone(int p_device, int p_axis, float p_value);
 
+	void _parse_input_event_impl(const Ref<InputEvent> &p_event, bool p_is_emulated);
+
 public:
 	virtual bool is_key_pressed(int p_scancode) const;
 	virtual bool is_mouse_button_pressed(int p_button) const;
@@ -225,6 +230,10 @@ public:
 
 	void set_emulate_touch(bool p_emulate);
 	virtual bool is_emulating_touchscreen() const;
+	void ensure_touch_mouse_raised();
+
+	void set_emulate_mouse_from_touch(bool p_emulate);
+	virtual bool is_emulating_mouse_from_touch() const;
 
 	virtual void set_custom_mouse_cursor(const RES &p_cursor, CursorShape p_shape = Input::CURSOR_ARROW, const Vector2 &p_hotspot = Vector2());
 	virtual void set_mouse_in_window(bool p_in_window);
diff --git a/main/main.cpp b/main/main.cpp
index 290ab7e65..8c89b1d7c 100644
--- a/main/main.cpp
+++ b/main/main.cpp
@@ -1143,13 +1143,16 @@ Error Main::setup2(Thread::ID p_main_tid_override) {
 	GLOBAL_DEF("application/config/icon", String());
 	ProjectSettings::get_singleton()->set_custom_property_info("application/config/icon", PropertyInfo(Variant::STRING, "application/config/icon", PROPERTY_HINT_FILE, "*.png,*.webp"));
 
-	if (bool(GLOBAL_DEF("display/window/handheld/emulate_touchscreen", false))) {
-		if (!OS::get_singleton()->has_touchscreen_ui_hint() && Input::get_singleton() && !editor) {
-			//only if no touchscreen ui hint, set emulation
-			InputDefault *id = Object::cast_to<InputDefault>(Input::get_singleton());
-			if (id)
+	InputDefault *id = Object::cast_to<InputDefault>(Input::get_singleton());
+	if (id) {
+		if (bool(GLOBAL_DEF("display/window/handheld/emulate_touchscreen", false)) && !editor) {
+			if (!OS::get_singleton()->has_touchscreen_ui_hint()) {
+				//only if no touchscreen ui hint, set emulation
 				id->set_emulate_touch(true);
+			}
 		}
+
+		id->set_emulate_mouse_from_touch(bool(GLOBAL_DEF("display/window/handheld/emulate_mouse_from_touch", true)));
 	}
 
 	MAIN_PRINT("Main: Load Remaps");
diff --git a/platform/android/os_android.cpp b/platform/android/os_android.cpp
index 67ce79627..2b076da17 100644
--- a/platform/android/os_android.cpp
+++ b/platform/android/os_android.cpp
@@ -332,17 +332,6 @@ void OS_Android::process_touch(int p_what, int p_pointer, const Vector<TouchPos>
 
 			if (touch.size()) {
 				//end all if exist
-				{
-					Ref<InputEventMouseButton> ev;
-					ev.instance();
-					ev->set_button_index(BUTTON_LEFT);
-					ev->set_button_mask(BUTTON_MASK_LEFT);
-					ev->set_pressed(false);
-					ev->set_position(touch[0].pos);
-					ev->set_global_position(touch[0].pos);
-					input->parse_input_event(ev);
-				}
-
 				for (int i = 0; i < touch.size(); i++) {
 
 					Ref<InputEventScreenTouch> ev;
@@ -360,21 +349,6 @@ void OS_Android::process_touch(int p_what, int p_pointer, const Vector<TouchPos>
 				touch[i].pos = p_points[i].pos;
 			}
 
-			{
-				//send mouse
-				Ref<InputEventMouseButton> ev;
-				ev.instance();
-				// ev.type = Ref<InputEvent>::MOUSE_BUTTON;
-				ev->set_button_index(BUTTON_LEFT);
-				ev->set_button_mask(BUTTON_MASK_LEFT);
-				ev->set_pressed(true);
-				ev->set_position(touch[0].pos);
-				ev->set_global_position(touch[0].pos);
-				input->set_mouse_position(Point2(touch[0].pos.x, touch[0].pos.y));
-				last_mouse = touch[0].pos;
-				input->parse_input_event(ev);
-			}
-
 			//send touch
 			for (int i = 0; i < touch.size(); i++) {
 
@@ -389,19 +363,6 @@ void OS_Android::process_touch(int p_what, int p_pointer, const Vector<TouchPos>
 		} break;
 		case 1: { //motion
 
-			if (p_points.size()) {
-				//send mouse, should look for point 0?
-				Ref<InputEventMouseMotion> ev;
-				ev.instance();
-				ev->set_button_mask(BUTTON_MASK_LEFT);
-				ev->set_position(p_points[0].pos);
-				input->set_mouse_position(Point2(ev->get_position().x, ev->get_position().y));
-				ev->set_speed(input->get_last_mouse_speed());
-				ev->set_relative(p_points[0].pos - last_mouse);
-				last_mouse = p_points[0].pos;
-				input->parse_input_event(ev);
-			}
-
 			ERR_FAIL_COND(touch.size() != p_points.size());
 
 			for (int i = 0; i < touch.size(); i++) {
@@ -434,16 +395,6 @@ void OS_Android::process_touch(int p_what, int p_pointer, const Vector<TouchPos>
 
 			if (touch.size()) {
 				//end all if exist
-				Ref<InputEventMouseButton> ev;
-				ev.instance();
-				ev->set_button_index(BUTTON_LEFT);
-				ev->set_button_mask(BUTTON_MASK_LEFT);
-				ev->set_pressed(false);
-				ev->set_position(touch[0].pos);
-				ev->set_global_position(touch[0].pos);
-				input->set_mouse_position(Point2(touch[0].pos.x, touch[0].pos.y));
-				input->parse_input_event(ev);
-
 				for (int i = 0; i < touch.size(); i++) {
 
 					Ref<InputEventScreenTouch> ev;
diff --git a/platform/android/os_android.h b/platform/android/os_android.h
index 12181b368..d2457e538 100644
--- a/platform/android/os_android.h
+++ b/platform/android/os_android.h
@@ -93,7 +93,6 @@ public:
 private:
 	Vector<TouchPos> touch;
 
-	Point2 last_mouse;
 	GFXInitFunc gfx_init_func;
 	void *gfx_init_ud;
 
diff --git a/platform/iphone/gl_view.mm b/platform/iphone/gl_view.mm
index 69116c64c..ab02822d7 100644
--- a/platform/iphone/gl_view.mm
+++ b/platform/iphone/gl_view.mm
@@ -489,7 +489,7 @@ static void clear_touches() {
 			int tid = get_touch_id(touch);
 			ERR_FAIL_COND(tid == -1);
 			CGPoint touchPoint = [touch locationInView:self];
-			OSIPhone::get_singleton()->mouse_button(tid, touchPoint.x * self.contentScaleFactor, touchPoint.y * self.contentScaleFactor, true, touch.tapCount > 1, tid == 0);
+			OSIPhone::get_singleton()->touch_press(tid, touchPoint.x * self.contentScaleFactor, touchPoint.y * self.contentScaleFactor, true, touch.tapCount > 1);
 		};
 	};
 }
@@ -506,10 +506,9 @@ static void clear_touches() {
 				continue;
 			int tid = get_touch_id(touch);
 			ERR_FAIL_COND(tid == -1);
-			int first = get_first_id(touch);
 			CGPoint touchPoint = [touch locationInView:self];
 			CGPoint prev_point = [touch previousLocationInView:self];
-			OSIPhone::get_singleton()->mouse_move(tid, prev_point.x * self.contentScaleFactor, prev_point.y * self.contentScaleFactor, touchPoint.x * self.contentScaleFactor, touchPoint.y * self.contentScaleFactor, first == tid);
+			OSIPhone::get_singleton()->touch_drag(tid, prev_point.x * self.contentScaleFactor, prev_point.y * self.contentScaleFactor, touchPoint.x * self.contentScaleFactor, touchPoint.y * self.contentScaleFactor);
 		};
 	};
 }
@@ -525,9 +524,9 @@ static void clear_touches() {
 				continue;
 			int tid = get_touch_id(touch);
 			ERR_FAIL_COND(tid == -1);
-			int rem = remove_touch(touch);
+			remove_touch(touch);
 			CGPoint touchPoint = [touch locationInView:self];
-			OSIPhone::get_singleton()->mouse_button(tid, touchPoint.x * self.contentScaleFactor, touchPoint.y * self.contentScaleFactor, false, false, rem == 0);
+			OSIPhone::get_singleton()->touch_press(tid, touchPoint.x * self.contentScaleFactor, touchPoint.y * self.contentScaleFactor, false, false);
 		};
 	};
 }
diff --git a/platform/iphone/os_iphone.cpp b/platform/iphone/os_iphone.cpp
index c284ab690..5f643de73 100644
--- a/platform/iphone/os_iphone.cpp
+++ b/platform/iphone/os_iphone.cpp
@@ -191,7 +191,7 @@ void OSIPhone::key(uint32_t p_key, bool p_pressed) {
 	queue_event(ev);
 };
 
-void OSIPhone::mouse_button(int p_idx, int p_x, int p_y, bool p_pressed, bool p_doubleclick, bool p_use_as_mouse) {
+void OSIPhone::touch_press(int p_idx, int p_x, int p_y, bool p_pressed, bool p_doubleclick) {
 
 	if (!GLOBAL_DEF("debug/disable_touch", false)) {
 		Ref<InputEventScreenTouch> ev;
@@ -203,28 +203,10 @@ void OSIPhone::mouse_button(int p_idx, int p_x, int p_y, bool p_pressed, bool p_
 		queue_event(ev);
 	};
 
-	mouse_list.pressed[p_idx] = p_pressed;
-
-	if (p_use_as_mouse) {
-
-		Ref<InputEventMouseButton> ev;
-		ev.instance();
-
-		ev->set_position(Vector2(p_x, p_y));
-		ev->set_global_position(Vector2(p_x, p_y));
-
-		//mouse_list.pressed[p_idx] = p_pressed;
-
-		input->set_mouse_position(ev->get_position());
-		ev->set_button_index(BUTTON_LEFT);
-		ev->set_doubleclick(p_doubleclick);
-		ev->set_pressed(p_pressed);
-
-		queue_event(ev);
-	};
+	touch_list.pressed[p_idx] = p_pressed;
 };
 
-void OSIPhone::mouse_move(int p_idx, int p_prev_x, int p_prev_y, int p_x, int p_y, bool p_use_as_mouse) {
+void OSIPhone::touch_drag(int p_idx, int p_prev_x, int p_prev_y, int p_x, int p_y) {
 
 	if (!GLOBAL_DEF("debug/disable_touch", false)) {
 
@@ -235,21 +217,6 @@ void OSIPhone::mouse_move(int p_idx, int p_prev_x, int p_prev_y, int p_x, int p_
 		ev->set_relative(Vector2(p_x - p_prev_x, p_y - p_prev_y));
 		queue_event(ev);
 	};
-
-	if (p_use_as_mouse) {
-		Ref<InputEventMouseMotion> ev;
-		ev.instance();
-
-		ev->set_position(Vector2(p_x, p_y));
-		ev->set_global_position(Vector2(p_x, p_y));
-		ev->set_relative(Vector2(p_x - p_prev_x, p_y - p_prev_y));
-
-		input->set_mouse_position(ev->get_position());
-		ev->set_speed(input->get_last_mouse_speed());
-		ev->set_button_mask(BUTTON_LEFT); // pressed
-
-		queue_event(ev);
-	};
 };
 
 void OSIPhone::queue_event(const Ref<InputEvent> &p_event) {
@@ -263,10 +230,10 @@ void OSIPhone::touches_cancelled() {
 
 	for (int i = 0; i < MAX_MOUSE_COUNT; i++) {
 
-		if (mouse_list.pressed[i]) {
+		if (touch_list.pressed[i]) {
 
 			// send a mouse_up outside the screen
-			mouse_button(i, -1, -1, false, false, false);
+			touch_press(i, -1, -1, false, false);
 		};
 	};
 };
@@ -377,7 +344,7 @@ Point2 OSIPhone::get_mouse_position() const {
 
 int OSIPhone::get_mouse_button_state() const {
 
-	return mouse_list.pressed[0];
+	return false;
 };
 
 void OSIPhone::set_window_title(const String &p_title){};
diff --git a/platform/iphone/os_iphone.h b/platform/iphone/os_iphone.h
index 2e4458aee..994762725 100644
--- a/platform/iphone/os_iphone.h
+++ b/platform/iphone/os_iphone.h
@@ -106,7 +106,7 @@ private:
 		};
 	};
 
-	MouseList mouse_list;
+	MouseList touch_list;
 
 	Vector3 last_accel;
 
@@ -127,8 +127,8 @@ public:
 
 	uint8_t get_orientations() const;
 
-	void mouse_button(int p_idx, int p_x, int p_y, bool p_pressed, bool p_doubleclick, bool p_use_as_mouse);
-	void mouse_move(int p_idx, int p_prev_x, int p_prev_y, int p_x, int p_y, bool p_use_as_mouse);
+	void touch_press(int p_idx, int p_x, int p_y, bool p_pressed, bool p_doubleclick);
+	void touch_drag(int p_idx, int p_prev_x, int p_prev_y, int p_x, int p_y);
 	void touches_cancelled();
 	void key(uint32_t p_key, bool p_pressed);
 	void set_virtual_keyboard_height(int p_height);
@@ -151,7 +151,6 @@ public:
 	virtual void set_mouse_grab(bool p_grab);
 	virtual bool is_mouse_grab_enabled() const;
 	virtual Point2 get_mouse_position() const;
-	virtual int get_mouse_button_state() const;
 	virtual void set_window_title(const String &p_title);
 
 	virtual void alert(const String &p_alert, const String &p_title = "ALERT!");
diff --git a/platform/javascript/os_javascript.cpp b/platform/javascript/os_javascript.cpp
index e226ab633..0f057d929 100644
--- a/platform/javascript/os_javascript.cpp
+++ b/platform/javascript/os_javascript.cpp
@@ -277,23 +277,6 @@ static EM_BOOL _touchpress_callback(int event_type, const EmscriptenTouchEvent *
 
 		_input->parse_input_event(ev);
 	}
-
-	if (touch_event->touches[lowest_id_index].isChanged) {
-
-		Ref<InputEventMouseButton> ev_mouse;
-		ev_mouse.instance();
-		ev_mouse->set_button_mask(_input->get_mouse_button_mask());
-		dom2godot_mod(touch_event, ev_mouse);
-
-		const EmscriptenTouchPoint &first_touch = touch_event->touches[lowest_id_index];
-		ev_mouse->set_position(Point2(first_touch.canvasX, first_touch.canvasY));
-		ev_mouse->set_global_position(ev_mouse->get_position());
-
-		ev_mouse->set_button_index(BUTTON_LEFT);
-		ev_mouse->set_pressed(event_type == EMSCRIPTEN_EVENT_TOUCHSTART);
-
-		_input->parse_input_event(ev_mouse);
-	}
 	return true;
 }
 
@@ -319,24 +302,6 @@ static EM_BOOL _touchmove_callback(int event_type, const EmscriptenTouchEvent *t
 
 		_input->parse_input_event(ev);
 	}
-
-	if (touch_event->touches[lowest_id_index].isChanged) {
-
-		Ref<InputEventMouseMotion> ev_mouse;
-		ev_mouse.instance();
-		dom2godot_mod(touch_event, ev_mouse);
-		ev_mouse->set_button_mask(_input->get_mouse_button_mask());
-
-		const EmscriptenTouchPoint &first_touch = touch_event->touches[lowest_id_index];
-		ev_mouse->set_position(Point2(first_touch.canvasX, first_touch.canvasY));
-		ev_mouse->set_global_position(ev_mouse->get_position());
-
-		ev_mouse->set_relative(ev_mouse->get_position() - _input->get_mouse_position());
-		_input->set_mouse_position(ev_mouse->get_position());
-		ev_mouse->set_speed(_input->get_last_mouse_speed());
-
-		_input->parse_input_event(ev_mouse);
-	}
 	return true;
 }
 
diff --git a/platform/uwp/app.cpp b/platform/uwp/app.cpp
index 5ff62b38f..c18aa3640 100644
--- a/platform/uwp/app.cpp
+++ b/platform/uwp/app.cpp
@@ -85,8 +85,7 @@ App::App() :
 		mWindowHeight(0),
 		mEglDisplay(EGL_NO_DISPLAY),
 		mEglContext(EGL_NO_CONTEXT),
-		mEglSurface(EGL_NO_SURFACE),
-		number_of_contacts(0) {
+		mEglSurface(EGL_NO_SURFACE) {
 }
 
 // The first method called when the IFrameworkView is being created.
@@ -271,48 +270,44 @@ void App::pointer_event(Windows::UI::Core::CoreWindow ^ sender, Windows::UI::Cor
 		last_touch_y[screen_touch->get_index()] = pos.Y;
 
 		os->input_event(screen_touch);
-		if (number_of_contacts > 1)
-			return;
-
-	}; // fallthrought of sorts
+	} else {
 
-	Ref<InputEventMouseButton> mouse_button;
-	mouse_button.instance();
-	mouse_button->set_device(0);
-	mouse_button->set_pressed(p_pressed);
-	mouse_button->set_button_index(but);
-	mouse_button->set_position(Vector2(pos.X, pos.Y));
-	mouse_button->set_global_position(Vector2(pos.X, pos.Y));
+		Ref<InputEventMouseButton> mouse_button;
+		mouse_button.instance();
+		mouse_button->set_device(0);
+		mouse_button->set_pressed(p_pressed);
+		mouse_button->set_button_index(but);
+		mouse_button->set_position(Vector2(pos.X, pos.Y));
+		mouse_button->set_global_position(Vector2(pos.X, pos.Y));
 
-	if (p_is_wheel) {
-		if (point->Properties->MouseWheelDelta > 0) {
-			mouse_button->set_button_index(point->Properties->IsHorizontalMouseWheel ? BUTTON_WHEEL_RIGHT : BUTTON_WHEEL_UP);
-		} else if (point->Properties->MouseWheelDelta < 0) {
-			mouse_button->set_button_index(point->Properties->IsHorizontalMouseWheel ? BUTTON_WHEEL_LEFT : BUTTON_WHEEL_DOWN);
+		if (p_is_wheel) {
+			if (point->Properties->MouseWheelDelta > 0) {
+				mouse_button->set_button_index(point->Properties->IsHorizontalMouseWheel ? BUTTON_WHEEL_RIGHT : BUTTON_WHEEL_UP);
+			} else if (point->Properties->MouseWheelDelta < 0) {
+				mouse_button->set_button_index(point->Properties->IsHorizontalMouseWheel ? BUTTON_WHEEL_LEFT : BUTTON_WHEEL_DOWN);
+			}
 		}
-	}
-
-	last_touch_x[31] = pos.X;
-	last_touch_y[31] = pos.Y;
 
-	os->input_event(mouse_button);
+		last_touch_x[31] = pos.X;
+		last_touch_y[31] = pos.Y;
 
-	if (p_is_wheel) {
-		// Send release for mouse wheel
-		mouse_button->set_pressed(false);
 		os->input_event(mouse_button);
+
+		if (p_is_wheel) {
+			// Send release for mouse wheel
+			mouse_button->set_pressed(false);
+			os->input_event(mouse_button);
+		}
 	}
 };
 
 void App::OnPointerPressed(Windows::UI::Core::CoreWindow ^ sender, Windows::UI::Core::PointerEventArgs ^ args) {
 
-	number_of_contacts++;
 	pointer_event(sender, args, true);
 };
 
 void App::OnPointerReleased(Windows::UI::Core::CoreWindow ^ sender, Windows::UI::Core::PointerEventArgs ^ args) {
 
-	number_of_contacts--;
 	pointer_event(sender, args, false);
 };
 
@@ -351,7 +346,7 @@ void App::OnPointerMoved(Windows::UI::Core::CoreWindow ^ sender, Windows::UI::Co
 	Windows::UI::Input::PointerPoint ^ point = args->CurrentPoint;
 	Windows::Foundation::Point pos = _get_pixel_position(window, point->Position, os);
 
-	if (point->IsInContact && _is_touch(point)) {
+	if (_is_touch(point)) {
 
 		Ref<InputEventScreenDrag> screen_drag;
 		screen_drag.instance();
@@ -361,25 +356,23 @@ void App::OnPointerMoved(Windows::UI::Core::CoreWindow ^ sender, Windows::UI::Co
 		screen_drag->set_relative(Vector2(screen_drag->get_position().x - last_touch_x[screen_drag->get_index()], screen_drag->get_position().y - last_touch_y[screen_drag->get_index()]));
 
 		os->input_event(screen_drag);
-		if (number_of_contacts > 1)
-			return;
-
-	}; // fallthrought of sorts
+	} else {
 
-	// In case the mouse grabbed, MouseMoved will handle this
-	if (os->get_mouse_mode() == OS::MouseMode::MOUSE_MODE_CAPTURED)
-		return;
+		// In case the mouse grabbed, MouseMoved will handle this
+		if (os->get_mouse_mode() == OS::MouseMode::MOUSE_MODE_CAPTURED)
+			return;
 
-	Ref<InputEventMouseMotion> mouse_motion;
-	mouse_motion.instance();
-	mouse_motion->set_device(0);
-	mouse_motion->set_position(Vector2(pos.X, pos.Y));
-	mouse_motion->set_global_position(Vector2(pos.X, pos.Y));
-	mouse_motion->set_relative(Vector2(pos.X - last_touch_x[31], pos.Y - last_touch_y[31]));
+		Ref<InputEventMouseMotion> mouse_motion;
+		mouse_motion.instance();
+		mouse_motion->set_device(0);
+		mouse_motion->set_position(Vector2(pos.X, pos.Y));
+		mouse_motion->set_global_position(Vector2(pos.X, pos.Y));
+		mouse_motion->set_relative(Vector2(pos.X - last_touch_x[31], pos.Y - last_touch_y[31]));
 
-	last_mouse_pos = pos;
+		last_mouse_pos = pos;
 
-	os->input_event(mouse_motion);
+		os->input_event(mouse_motion);
+	}
 }
 
 void App::OnMouseMoved(MouseDevice ^ mouse_device, MouseEventArgs ^ args) {
diff --git a/platform/uwp/app.h b/platform/uwp/app.h
index c23270b8b..5f69f2cb0 100644
--- a/platform/uwp/app.h
+++ b/platform/uwp/app.h
@@ -107,7 +107,6 @@ namespace GodotUWP
 
 		int last_touch_x[32]; // 20 fingers, index 31 reserved for the mouse
 		int last_touch_y[32];
-		int number_of_contacts;
 		Windows::Foundation::Point last_mouse_pos;
 	};
 }
diff --git a/platform/windows/os_windows.cpp b/platform/windows/os_windows.cpp
index ee86a594b..b2670af01 100644
--- a/platform/windows/os_windows.cpp
+++ b/platform/windows/os_windows.cpp
@@ -361,6 +361,14 @@ LRESULT OS_Windows::WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
 		} break;
 		case WM_MOUSEMOVE: {
 
+			if (input->is_emulating_mouse_from_touch()) {
+				// Universal translation enabled; ignore OS translation
+				LPARAM extra = GetMessageExtraInfo();
+				if (IsPenEvent(extra)) {
+					break;
+				}
+			}
+
 			if (outside) {
 				//mouse enter
 
@@ -386,18 +394,6 @@ LRESULT OS_Windows::WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
 			// Don't calculate relative mouse movement if we don't have focus in CAPTURED mode.
 			if (!window_has_focus && mouse_mode == MOUSE_MODE_CAPTURED)
 				break;
-			/*
-			LPARAM extra = GetMessageExtraInfo();
-			if (IsPenEvent(extra)) {
-
-				int idx = extra & 0x7f;
-				_drag_event(idx, uMsg, wParam, lParam);
-				if (idx != 0) {
-					return 0;
-				};
-				// fallthrough for mouse event
-			};
-			*/
 
 			Ref<InputEventMouseMotion> mm;
 			mm.instance();
@@ -467,18 +463,13 @@ LRESULT OS_Windows::WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
 			/*case WM_XBUTTONDOWN:
 		case WM_XBUTTONUP: */ {
 
-				/*
-			LPARAM extra = GetMessageExtraInfo();
-			if (IsPenEvent(extra)) {
-
-				int idx = extra & 0x7f;
-				_touch_event(idx, uMsg, wParam, lParam);
-				if (idx != 0) {
-					return 0;
-				};
-				// fallthrough for mouse event
-			};
-			*/
+				if (input->is_emulating_mouse_from_touch()) {
+					// Universal translation enabled; ignore OS translation
+					LPARAM extra = GetMessageExtraInfo();
+					if (IsPenEvent(extra)) {
+						break;
+					}
+				}
 
 				Ref<InputEventMouseButton> mb;
 				mb.instance();
diff --git a/platform/x11/os_x11.cpp b/platform/x11/os_x11.cpp
index 448a1d583..e153dba88 100644
--- a/platform/x11/os_x11.cpp
+++ b/platform/x11/os_x11.cpp
@@ -1626,6 +1626,11 @@ void OS_X11::process_xevents() {
 							if (touch.state.has(index)) // Defensive
 								break;
 							touch.state[index] = pos;
+							if (touch.state.size() == 1) {
+								// X11 may send a motion event when a touch gesture begins, that would result
+								// in a spurious mouse motion event being sent to Godot; remember it to be able to filter it out
+								touch.mouse_pos_to_filter = pos;
+							}
 							input->parse_input_event(st);
 						} else {
 							if (!touch.state.has(index)) // Defensive
@@ -1832,6 +1837,18 @@ void OS_X11::process_xevents() {
 				// to be able to send relative motion events.
 				Point2i pos(event.xmotion.x, event.xmotion.y);
 
+				// Avoidance of spurious mouse motion (see handling of touch)
+				bool filter = false;
+				// Adding some tolerance to match better Point2i to Vector2
+				if (touch.state.size() && Vector2(pos).distance_squared_to(touch.mouse_pos_to_filter) < 2) {
+					filter = true;
+				}
+				// Invalidate to avoid filtering a possible legitimate similar event coming later
+				touch.mouse_pos_to_filter = Vector2(1e10, 1e10);
+				if (filter) {
+					break;
+				}
+
 				if (mouse_mode == MOUSE_MODE_CAPTURED) {
 
 					if (pos == Point2i(current_videomode.width / 2, current_videomode.height / 2)) {
diff --git a/platform/x11/os_x11.h b/platform/x11/os_x11.h
index 3347b37f4..26f3c7ff2 100644
--- a/platform/x11/os_x11.h
+++ b/platform/x11/os_x11.h
@@ -127,6 +127,7 @@ class OS_X11 : public OS_Unix {
 		Vector<int> devices;
 		XIEventMask event_mask;
 		Map<int, Vector2> state;
+		Vector2 mouse_pos_to_filter;
 	} touch;
 #endif
 
diff --git a/scene/main/scene_tree.cpp b/scene/main/scene_tree.cpp
index 136fd4cfd..f1a08f23e 100644
--- a/scene/main/scene_tree.cpp
+++ b/scene/main/scene_tree.cpp
@@ -33,6 +33,7 @@
 #include "editor/editor_node.h"
 #include "io/marshalls.h"
 #include "io/resource_loader.h"
+#include "main/input_default.h"
 #include "message_queue.h"
 #include "node.h"
 #include "os/keyboard.h"
@@ -618,6 +619,13 @@ void SceneTree::_notification(int p_notification) {
 		case NOTIFICATION_WM_FOCUS_IN:
 		case NOTIFICATION_WM_FOCUS_OUT: {
 
+			if (p_notification == NOTIFICATION_WM_FOCUS_IN) {
+				InputDefault *id = Object::cast_to<InputDefault>(Input::get_singleton());
+				if (id) {
+					id->ensure_touch_mouse_raised();
+				}
+			}
+
 			get_root()->propagate_notification(p_notification);
 		} break;
 		case NOTIFICATION_TRANSLATION_CHANGED: {