Add 'mouse_entered', 'mouse_exited' and 'mouse_pressed' to Sprite2D and Polygon2D

doc/classes/CanvasItem.xml

@@ -556,6 +556,14 @@
 				Usually, this is the same as this node's viewport (see [method Node.get_viewport] and [method Viewport.find_world_2d]).
 			</description>
 		</method>
+		<method name="has_point" qualifiers="const">
+			<return type="bool" />
+			<param index="0" name="point" type="Vector2" />
+			<description>
+				Returns [code]true[/code] if the given [param point] (in local coordinates) is inside the visible area of this [CanvasItem]. The visible area is only calculated in [Sprite2D] and [Polygon2D].
+				This method is used internally for mouse picking when mouse picking is enabled.
+			</description>
+		</method>
 		<method name="hide">
 			<return type="void" />
 			<description>
@@ -568,6 +576,12 @@
 				Returns [code]true[/code] if the node receives [constant NOTIFICATION_LOCAL_TRANSFORM_CHANGED] whenever its local transform changes. This is enabled with [method set_notify_local_transform].
 			</description>
 		</method>
+		<method name="is_mouse_picking_enabled" qualifiers="const">
+			<return type="bool" />
+			<description>
+				Returns [code]true[/code] if mouse picking is enabled for this [CanvasItem].
+			</description>
+		</method>
 		<method name="is_transform_notification_enabled" qualifiers="const">
 			<return type="bool" />
 			<description>
@@ -622,6 +636,13 @@
 				[b]Note:[/b] [param name] is case-sensitive and must match the name of the uniform in the code exactly (not the capitalized name in the inspector).
 			</description>
 		</method>
+		<method name="set_mouse_picking_enabled">
+			<return type="void" />
+			<param index="0" name="enabled" type="bool" />
+			<description>
+				Enables or disables mouse picking for this [CanvasItem].
+			</description>
+		</method>
 		<method name="set_notify_local_transform">
 			<return type="void" />
 			<param index="0" name="enable" type="bool" />
@@ -727,6 +748,22 @@
 				Emitted when the [CanvasItem]'s boundaries (position or size) change, or when an action took place that may have affected these boundaries (e.g. changing [member Sprite2D.texture]).
 			</description>
 		</signal>
+		<signal name="mouse_entered_node">
+			<description>
+				Emitted when the mouse cursor enters the CanvasItem boundaries. Requires input processing enabled to be emitted.
+			</description>
+		</signal>
+		<signal name="mouse_exited_node">
+			<description>
+				Emitted when the mouse cursor exits the CanvasItem boundaries. Requires input processing enabled to be emitted.
+			</description>
+		</signal>
+		<signal name="mouse_pressed_node">
+			<param index="0" name="button_index" type="int" />
+			<description>
+				Emitted when a mouse button is pressed while the cursor is over the CanvasItem boundaries. The [param button_index] indicates which button was pressed. Requires input processing enabled to be emitted.
+			</description>
+		</signal>
 		<signal name="visibility_changed">
 			<description>
 				Emitted when the [CanvasItem]'s visibility changes, either because its own [member visible] property changed or because its visibility in the tree changed (see [method is_visible_in_tree]).

scene/2d/polygon_2d.cpp

@@ -105,6 +105,11 @@ void Polygon2D::_skeleton_bone_setup_changed() {
 	queue_redraw();
 }
 
+bool Polygon2D::has_point(const Vector2 &p_point) const {
+	Vector2 local = to_local(p_point);
+	return Geometry2D::is_point_in_polygon(local, polygon);
+}
+
 void Polygon2D::_notification(int p_what) {
 	if (p_what == NOTIFICATION_TRANSFORM_CHANGED && !Engine::get_singleton()->is_editor_hint()) {
 		return; // Mesh recreation for NOTIFICATION_TRANSFORM_CHANGED is only needed in editor.

scene/2d/polygon_2d.h

@@ -150,6 +150,8 @@ class Polygon2D : public Node2D {
 	void set_skeleton(const NodePath &p_skeleton);
 	NodePath get_skeleton() const;
 
+	bool has_point(const Vector2 &p_point) const override;
+
 #ifndef NAVIGATION_2D_DISABLED
 private:
 	static Callable _navmesh_source_geometry_parsing_callback;

scene/2d/sprite_2d.cpp

@@ -475,6 +475,21 @@ void Sprite2D::_validate_property(PropertyInfo &p_property) const {
 	}
 }
 
+bool Sprite2D::has_point(const Vector2 &p_point) const {
+	if (!texture.is_valid()) {
+		return false;
+	}
+	Vector2 local = to_local(p_point);
+	Rect2 rect = get_rect();
+	if (!rect.has_point(local)) {
+		return false;
+	}
+	Vector2 uv = (local - rect.position) / rect.size;
+	uv *= texture->get_size();
+	Color c = texture->get_image()->get_pixelv(uv);
+	return c.a > 0.01;
+}
+
 void Sprite2D::_texture_changed() {
 	// Changes to the texture need to trigger an update to make
 	// the editor redraw the sprite with the updated texture.
@@ -532,7 +547,6 @@ void Sprite2D::_bind_methods() {
 
 	ADD_SIGNAL(MethodInfo("frame_changed"));
 	ADD_SIGNAL(MethodInfo("texture_changed"));
-
 	ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "texture", PROPERTY_HINT_RESOURCE_TYPE, "Texture2D"), "set_texture", "get_texture");
 	ADD_GROUP("Offset", "");
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "centered"), "set_centered", "is_centered");

scene/2d/sprite_2d.h

@@ -135,5 +135,7 @@ class Sprite2D : public Node2D {
 	Rect2 get_rect() const;
 	virtual Rect2 get_anchorable_rect() const override;
 
+	bool has_point(const Vector2 &p_point) const override;
+
 	Sprite2D();
 };

scene/gui/control.h

@@ -566,7 +566,7 @@ class Control : public CanvasItem {
 	virtual void gui_input(const Ref<InputEvent> &p_event);
 	void accept_event();
 
-	virtual bool has_point(const Point2 &p_point) const;
+	bool has_point(const Point2 &p_point) const override;
 
 	void set_mouse_filter(MouseFilter p_filter);
 	MouseFilter get_mouse_filter() const;

scene/main/canvas_item.cpp

@@ -1122,6 +1122,19 @@ void CanvasItem::set_canvas_item_use_identity_transform(bool p_enable) {
 	}
 }
 
+bool CanvasItem::has_point(const Vector2 &p_point) const { //We'll override this in Sprite2D and Polygon2D
+	return false;
+}
+
+void CanvasItem::input(const Ref<InputEvent> &p_event) { //It needs to be enabled by setting set_process_input(true);
+	Ref<InputEventMouse> mouse_event = p_event;
+	Ref<InputEventMouseButton> mouse_button_event = mouse_event;
+	if (mouse_button_event.is_valid() && mouse_button_event->is_pressed()) { //If the mouse is over the item and a button is pressed, emit signal
+		emit_signal("mouse_pressed_node", mouse_button_event->get_button_index());
+	}
+	get_viewport()->set_input_as_handled(); //We mark the event as handled to avoid propagating it to other nodes
+}
+
 Rect2 CanvasItem::get_viewport_rect() const {
 	ERR_READ_THREAD_GUARD_V(Rect2());
 	ERR_FAIL_COND_V(!is_inside_tree(), Rect2());
@@ -1278,6 +1291,14 @@ Vector2 CanvasItem::get_local_mouse_position() const {
 	return get_global_transform().affine_inverse().xform(get_global_mouse_position());
 }
 
+void CanvasItem::set_mouse_picking_enabled(bool p_enabled) {
+	mouse_picking = p_enabled;
+}
+
+bool CanvasItem::is_mouse_picking_enabled() const {
+	return mouse_picking;
+}
+
 void CanvasItem::force_update_transform() {
 	ERR_THREAD_GUARD;
 	ERR_FAIL_COND(!is_inside_tree());
@@ -1465,6 +1486,11 @@ void CanvasItem::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("set_clip_children_mode", "mode"), &CanvasItem::set_clip_children_mode);
 	ClassDB::bind_method(D_METHOD("get_clip_children_mode"), &CanvasItem::get_clip_children_mode);
 
+	ClassDB::bind_method(D_METHOD("is_mouse_picking_enabled"), &CanvasItem::is_mouse_picking_enabled);
+	ClassDB::bind_method(D_METHOD("set_mouse_picking_enabled", "enabled"), &CanvasItem::set_mouse_picking_enabled);
+
+	ClassDB::bind_method(D_METHOD("has_point", "point"), &CanvasItem::has_point);
+
 	GDVIRTUAL_BIND(_draw);
 
 	ADD_GROUP("Visibility", "");
@@ -1498,6 +1524,9 @@ void CanvasItem::_bind_methods() {
 	ADD_SIGNAL(MethodInfo("visibility_changed"));
 	ADD_SIGNAL(MethodInfo("hidden"));
 	ADD_SIGNAL(MethodInfo("item_rect_changed"));
+	ADD_SIGNAL(MethodInfo("mouse_entered_node"));
+	ADD_SIGNAL(MethodInfo("mouse_exited_node"));
+	ADD_SIGNAL(MethodInfo("mouse_pressed_node", PropertyInfo(Variant::INT, "button_index")));
 
 	BIND_CONSTANT(NOTIFICATION_TRANSFORM_CHANGED);
 	BIND_CONSTANT(NOTIFICATION_LOCAL_TRANSFORM_CHANGED);

scene/main/canvas_item.h

@@ -115,6 +115,8 @@ class CanvasItem : public Node {
 	bool notify_local_transform = false;
 	bool notify_transform = false;
 	bool hide_clip_children = false;
+	bool mouse_inside = false;
+	bool mouse_picking = false;
 
 	ClipChildrenMode clip_children_mode = CLIP_CHILDREN_DISABLED;
 
@@ -180,7 +182,7 @@ class CanvasItem : public Node {
 	void item_rect_changed(bool p_size_changed = true);
 
 	void set_canvas_item_use_identity_transform(bool p_enable);
-
+	virtual void input(const Ref<InputEvent> &p_event) override;
 	void _notification(int p_what);
 	static void _bind_methods();
 
@@ -393,6 +395,9 @@ class CanvasItem : public Node {
 	Vector2 get_global_mouse_position() const;
 	Vector2 get_local_mouse_position() const;
 
+	void set_mouse_picking_enabled(bool p_enable);
+	bool is_mouse_picking_enabled() const;
+
 	void set_notify_local_transform(bool p_enable);
 	bool is_local_transform_notification_enabled() const;
 
@@ -417,6 +422,7 @@ class CanvasItem : public Node {
 	CanvasLayer *get_canvas_layer_node() const;
 
 	virtual PackedStringArray get_configuration_warnings() const override;
+	bool virtual has_point(const Vector2 &p_point) const;
 
 	CanvasItem();
 	~CanvasItem();

scene/main/scene_tree.cpp

@@ -1447,9 +1447,32 @@ void SceneTree::_call_input_pause(const StringName &p_group, CallInputType p_cal
 		}
 
 		switch (p_call_type) {
-			case CALL_INPUT_TYPE_INPUT:
-				n->_call_input(p_input);
+			case CALL_INPUT_TYPE_INPUT: {
+				CanvasItem *ci = Object::cast_to<CanvasItem>(n);
+				if (ci) {
+					if (!ci->is_mouse_picking_enabled()) {
+						continue;
+					}
+					if (!ci->is_visible_in_tree()) {
+						continue;
+					}
+					Ref<InputEventMouse> mouse_event = p_input;
+					if (mouse_event.is_valid()) {
+						if (ci->has_point(mouse_event->get_position())) {
+							_change_mouse_over_node(ci);
+							n->_call_input(p_input);
+							break;
+						}
+					}
+				} else {
+					n->_call_input(p_input);
+					break;
+				}
+				if (i == 0) {
+					_change_mouse_over_node(nullptr);
+				}
 				break;
+			}
 			case CALL_INPUT_TYPE_SHORTCUT_INPUT: {
 				const Control *c = Object::cast_to<Control>(n);
 				if (c) {
@@ -1861,6 +1884,24 @@ bool SceneTree::is_multiplayer_poll_enabled() const {
 	return multiplayer_poll;
 }
 
+void SceneTree::_change_mouse_over_node(Node *p_node) {
+	if (mouse_over == p_node) { // No change
+		return;
+	}
+	if (p_node == nullptr) { //Mouse exited node
+		if (mouse_over) {
+			mouse_over->emit_signal(SNAME("mouse_exited_node"));
+		}
+	} else {
+		if (mouse_over) { //Mouse entered new node, so we exit the previous one
+			mouse_over->emit_signal(SNAME("mouse_exited_node"));
+		}
+		mouse_over = p_node;
+		p_node->emit_signal(SNAME("mouse_entered_node"));
+	}
+	mouse_over = p_node;
+}
+
 void SceneTree::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("get_root"), &SceneTree::get_root);
 	ClassDB::bind_method(D_METHOD("has_group", "name"), &SceneTree::has_group);

scene/main/scene_tree.h

@@ -213,6 +213,7 @@ class SceneTree : public MainLoop {
 	Ref<Material> debug_paths_material;
 	Ref<Material> collision_material;
 	int collision_debug_contacts;
+	Node *mouse_over = nullptr;
 
 	void _flush_scene_change();
 
@@ -287,6 +288,7 @@ class SceneTree : public MainLoop {
 protected:
 	void _notification(int p_notification);
 	static void _bind_methods();
+	void _change_mouse_over_node(Node *p_node);
 
 public:
 	enum {