Area2D can now detect overlap with other areas

this should make everything simpler, specially for newcomers to Godot

scene/2d/area_2d.cpp

@@ -216,6 +216,119 @@ void Area2D::_body_inout(int p_status,const RID& p_body, int p_instance, int p_b
 }
 
 
+
+void Area2D::_area_enter_tree(ObjectID p_id) {
+
+	Object *obj = ObjectDB::get_instance(p_id);
+	Node *node = obj ? obj->cast_to<Node>() : NULL;
+	ERR_FAIL_COND(!node);
+
+	Map<ObjectID,AreaState>::Element *E=area_map.find(p_id);
+	ERR_FAIL_COND(!E);
+	ERR_FAIL_COND(E->get().in_tree);
+
+	E->get().in_tree=true;
+	emit_signal(SceneStringNames::get_singleton()->area_enter,node);
+	for(int i=0;i<E->get().shapes.size();i++) {
+
+		emit_signal(SceneStringNames::get_singleton()->area_enter_shape,p_id,node,E->get().shapes[i].area_shape,E->get().shapes[i].self_shape);
+	}
+
+}
+
+void Area2D::_area_exit_tree(ObjectID p_id) {
+
+	Object *obj = ObjectDB::get_instance(p_id);
+	Node *node = obj ? obj->cast_to<Node>() : NULL;
+	ERR_FAIL_COND(!node);
+	Map<ObjectID,AreaState>::Element *E=area_map.find(p_id);
+	ERR_FAIL_COND(!E);
+	ERR_FAIL_COND(!E->get().in_tree);
+	E->get().in_tree=false;
+	emit_signal(SceneStringNames::get_singleton()->area_exit,node);
+	for(int i=0;i<E->get().shapes.size();i++) {
+
+		emit_signal(SceneStringNames::get_singleton()->area_exit_shape,p_id,node,E->get().shapes[i].area_shape,E->get().shapes[i].self_shape);
+	}
+
+}
+
+void Area2D::_area_inout(int p_status,const RID& p_area, int p_instance, int p_area_shape,int p_self_shape) {
+
+	bool area_in = p_status==Physics2DServer::AREA_BODY_ADDED;
+	ObjectID objid=p_instance;
+
+	Object *obj = ObjectDB::get_instance(objid);
+	Node *node = obj ? obj->cast_to<Node>() : NULL;
+
+	Map<ObjectID,AreaState>::Element *E=area_map.find(objid);
+
+	ERR_FAIL_COND(!area_in && !E);
+
+	locked=true;
+
+	if (area_in) {
+		if (!E) {
+
+			E = area_map.insert(objid,AreaState());
+			E->get().rc=0;
+			E->get().in_tree=node && node->is_inside_tree();
+			if (node) {
+				node->connect(SceneStringNames::get_singleton()->enter_tree,this,SceneStringNames::get_singleton()->_area_enter_tree,make_binds(objid));
+				node->connect(SceneStringNames::get_singleton()->exit_tree,this,SceneStringNames::get_singleton()->_area_exit_tree,make_binds(objid));
+				if (E->get().in_tree) {
+					emit_signal(SceneStringNames::get_singleton()->area_enter,node);
+				}
+			}
+
+		}
+		E->get().rc++;
+		if (node)
+			E->get().shapes.insert(AreaShapePair(p_area_shape,p_self_shape));
+
+
+		if (!node || E->get().in_tree) {
+			emit_signal(SceneStringNames::get_singleton()->area_enter_shape,objid,node,p_area_shape,p_self_shape);
+		}
+
+	} else {
+
+		E->get().rc--;
+
+		if (node)
+			E->get().shapes.erase(AreaShapePair(p_area_shape,p_self_shape));
+
+		bool eraseit=false;
+
+		if (E->get().rc==0) {
+
+			if (node) {
+				node->disconnect(SceneStringNames::get_singleton()->enter_tree,this,SceneStringNames::get_singleton()->_area_enter_tree);
+				node->disconnect(SceneStringNames::get_singleton()->exit_tree,this,SceneStringNames::get_singleton()->_area_exit_tree);
+				if (E->get().in_tree)
+					emit_signal(SceneStringNames::get_singleton()->area_exit,obj);
+
+			}
+
+			eraseit=true;
+
+		}
+		if (!node || E->get().in_tree) {
+			emit_signal(SceneStringNames::get_singleton()->area_exit_shape,objid,obj,p_area_shape,p_self_shape);
+		}
+
+		if (eraseit)
+			area_map.erase(E);
+
+	}
+
+	locked=false;
+
+
+}
+
+
+
 void Area2D::_clear_monitoring() {
 
 	if (locked) {
@@ -223,27 +336,56 @@ void Area2D::_clear_monitoring() {
 	}
 	ERR_FAIL_COND(locked);
 
-	Map<ObjectID,BodyState> bmcopy = body_map;
-	body_map.clear();
-	//disconnect all monitored stuff
+	{
+		Map<ObjectID,BodyState> bmcopy = body_map;
+		body_map.clear();
+		//disconnect all monitored stuff
 
-	for (Map<ObjectID,BodyState>::Element *E=bmcopy.front();E;E=E->next()) {
+		for (Map<ObjectID,BodyState>::Element *E=bmcopy.front();E;E=E->next()) {
 
-		Object *obj = ObjectDB::get_instance(E->key());
-		Node *node = obj ? obj->cast_to<Node>() : NULL;
-		ERR_CONTINUE(!node);
-		if (!E->get().in_tree)
-			continue;
+			Object *obj = ObjectDB::get_instance(E->key());
+			Node *node = obj ? obj->cast_to<Node>() : NULL;
+			ERR_CONTINUE(!node);
+			if (!E->get().in_tree)
+				continue;
 
-		for(int i=0;i<E->get().shapes.size();i++) {
+			for(int i=0;i<E->get().shapes.size();i++) {
 
-			emit_signal(SceneStringNames::get_singleton()->body_exit_shape,E->key(),node,E->get().shapes[i].body_shape,E->get().shapes[i].area_shape);
+				emit_signal(SceneStringNames::get_singleton()->body_exit_shape,E->key(),node,E->get().shapes[i].body_shape,E->get().shapes[i].area_shape);
+			}
+
+			emit_signal(SceneStringNames::get_singleton()->body_exit,obj);
+
+			node->disconnect(SceneStringNames::get_singleton()->enter_tree,this,SceneStringNames::get_singleton()->_body_enter_tree);
+			node->disconnect(SceneStringNames::get_singleton()->exit_tree,this,SceneStringNames::get_singleton()->_body_exit_tree);
 		}
 
-		emit_signal(SceneStringNames::get_singleton()->body_exit,obj);
+	}
+
+	{
 
-		node->disconnect(SceneStringNames::get_singleton()->enter_tree,this,SceneStringNames::get_singleton()->_body_enter_tree);
-		node->disconnect(SceneStringNames::get_singleton()->exit_tree,this,SceneStringNames::get_singleton()->_body_exit_tree);
+		Map<ObjectID,AreaState> bmcopy = area_map;
+		area_map.clear();
+		//disconnect all monitored stuff
+
+		for (Map<ObjectID,AreaState>::Element *E=bmcopy.front();E;E=E->next()) {
+
+			Object *obj = ObjectDB::get_instance(E->key());
+			Node *node = obj ? obj->cast_to<Node>() : NULL;
+			ERR_CONTINUE(!node);
+			if (!E->get().in_tree)
+				continue;
+
+			for(int i=0;i<E->get().shapes.size();i++) {
+
+				emit_signal(SceneStringNames::get_singleton()->area_exit_shape,E->key(),node,E->get().shapes[i].area_shape,E->get().shapes[i].self_shape);
+			}
+
+			emit_signal(SceneStringNames::get_singleton()->area_exit,obj);
+
+			node->disconnect(SceneStringNames::get_singleton()->enter_tree,this,SceneStringNames::get_singleton()->_area_enter_tree);
+			node->disconnect(SceneStringNames::get_singleton()->exit_tree,this,SceneStringNames::get_singleton()->_area_exit_tree);
+		}
 	}
 
 }
@@ -276,8 +418,10 @@ void Area2D::set_enable_monitoring(bool p_enable) {
 	if (monitoring) {
 
 		Physics2DServer::get_singleton()->area_set_monitor_callback(get_rid(),this,"_body_inout");
+		Physics2DServer::get_singleton()->area_set_area_monitor_callback(get_rid(),this,"_area_inout");
 	} else {
 		Physics2DServer::get_singleton()->area_set_monitor_callback(get_rid(),NULL,StringName());
+		Physics2DServer::get_singleton()->area_set_area_monitor_callback(get_rid(),NULL,StringName());
 		_clear_monitoring();
 
 	}
@@ -288,6 +432,26 @@ bool Area2D::is_monitoring_enabled() const {
 	return monitoring;
 }
 
+void Area2D::set_monitorable(bool p_enable) {
+
+	if (locked) {
+		ERR_EXPLAIN("This function can't be used during the in/out signal.");
+	}
+	ERR_FAIL_COND(locked);
+
+	if (p_enable==monitorable)
+		return;
+
+	monitorable=p_enable;
+
+	Physics2DServer::get_singleton()->area_set_monitorable(get_rid(),monitorable);
+}
+
+bool Area2D::is_monitorable() const {
+
+	return monitorable;
+}
+
 Array Area2D::get_overlapping_bodies() const {
 
 	ERR_FAIL_COND_V(!monitoring,Array());
@@ -307,12 +471,33 @@ Array Area2D::get_overlapping_bodies() const {
 	return ret;
 }
 
+Array Area2D::get_overlapping_areas() const {
+
+	ERR_FAIL_COND_V(!monitoring,Array());
+	Array ret;
+	ret.resize(area_map.size());
+	int idx=0;
+	for (const Map<ObjectID,AreaState>::Element *E=area_map.front();E;E=E->next()) {
+		Object *obj = ObjectDB::get_instance(E->key());
+		if (!obj) {
+			ret.resize( ret.size() -1 ); //ops
+		} else {
+			ret[idx++]=obj;
+		}
+
+	}
+
+	return ret;
+}
 
 void Area2D::_bind_methods() {
 
 	ObjectTypeDB::bind_method(_MD("_body_enter_tree","id"),&Area2D::_body_enter_tree);
 	ObjectTypeDB::bind_method(_MD("_body_exit_tree","id"),&Area2D::_body_exit_tree);
 
+	ObjectTypeDB::bind_method(_MD("_area_enter_tree","id"),&Area2D::_area_enter_tree);
+	ObjectTypeDB::bind_method(_MD("_area_exit_tree","id"),&Area2D::_area_exit_tree);
+
 	ObjectTypeDB::bind_method(_MD("set_space_override_mode","enable"),&Area2D::set_space_override_mode);
 	ObjectTypeDB::bind_method(_MD("get_space_override_mode"),&Area2D::get_space_override_mode);
 
@@ -337,15 +522,26 @@ void Area2D::_bind_methods() {
 	ObjectTypeDB::bind_method(_MD("set_enable_monitoring","enable"),&Area2D::set_enable_monitoring);
 	ObjectTypeDB::bind_method(_MD("is_monitoring_enabled"),&Area2D::is_monitoring_enabled);
 
+	ObjectTypeDB::bind_method(_MD("set_monitorable","enable"),&Area2D::set_monitorable);
+	ObjectTypeDB::bind_method(_MD("is_monitorable"),&Area2D::is_monitorable);
+
 	ObjectTypeDB::bind_method(_MD("get_overlapping_bodies"),&Area2D::get_overlapping_bodies);
+	ObjectTypeDB::bind_method(_MD("get_overlapping_areas"),&Area2D::get_overlapping_areas);
 
 	ObjectTypeDB::bind_method(_MD("_body_inout"),&Area2D::_body_inout);
+	ObjectTypeDB::bind_method(_MD("_area_inout"),&Area2D::_area_inout);
+
+
+	ADD_SIGNAL( MethodInfo("body_enter_shape",PropertyInfo(Variant::INT,"body_id"),PropertyInfo(Variant::OBJECT,"body",PROPERTY_HINT_RESOURCE_TYPE,"PhysicsBody2D"),PropertyInfo(Variant::INT,"body_shape"),PropertyInfo(Variant::INT,"area_shape")));
+	ADD_SIGNAL( MethodInfo("body_exit_shape",PropertyInfo(Variant::INT,"body_id"),PropertyInfo(Variant::OBJECT,"body",PROPERTY_HINT_RESOURCE_TYPE,"PhysicsBody2D"),PropertyInfo(Variant::INT,"body_shape"),PropertyInfo(Variant::INT,"area_shape")));
+	ADD_SIGNAL( MethodInfo("body_enter:",PropertyInfo(Variant::OBJECT,"body",PROPERTY_HINT_RESOURCE_TYPE,"PhysicsBody2D")));
+	ADD_SIGNAL( MethodInfo("body_exit",PropertyInfo(Variant::OBJECT,"body",PROPERTY_HINT_RESOURCE_TYPE,"PhysicsBody2D")));
 
+	ADD_SIGNAL( MethodInfo("area_enter_shape",PropertyInfo(Variant::INT,"area_id"),PropertyInfo(Variant::OBJECT,"area",PROPERTY_HINT_RESOURCE_TYPE,"Area2D"),PropertyInfo(Variant::INT,"area_shape"),PropertyInfo(Variant::INT,"area_shape")));
+	ADD_SIGNAL( MethodInfo("area_exit_shape",PropertyInfo(Variant::INT,"area_id"),PropertyInfo(Variant::OBJECT,"area",PROPERTY_HINT_RESOURCE_TYPE,"Area2D"),PropertyInfo(Variant::INT,"area_shape"),PropertyInfo(Variant::INT,"area_shape")));
+	ADD_SIGNAL( MethodInfo("area_enter",PropertyInfo(Variant::OBJECT,"area",PROPERTY_HINT_RESOURCE_TYPE,"Area2D")));
+	ADD_SIGNAL( MethodInfo("area_exit",PropertyInfo(Variant::OBJECT,"area",PROPERTY_HINT_RESOURCE_TYPE,"Area2D")));
 
-	ADD_SIGNAL( MethodInfo("body_enter_shape",PropertyInfo(Variant::INT,"body_id"),PropertyInfo(Variant::OBJECT,"body"),PropertyInfo(Variant::INT,"body_shape"),PropertyInfo(Variant::INT,"area_shape")));
-	ADD_SIGNAL( MethodInfo("body_exit_shape",PropertyInfo(Variant::INT,"body_id"),PropertyInfo(Variant::OBJECT,"body"),PropertyInfo(Variant::INT,"body_shape"),PropertyInfo(Variant::INT,"area_shape")));
-	ADD_SIGNAL( MethodInfo("body_enter",PropertyInfo(Variant::OBJECT,"body")));
-	ADD_SIGNAL( MethodInfo("body_exit",PropertyInfo(Variant::OBJECT,"body")));
 
 	ADD_PROPERTYNZ( PropertyInfo(Variant::INT,"space_override",PROPERTY_HINT_ENUM,"Disabled,Combine,Replace"),_SCS("set_space_override_mode"),_SCS("get_space_override_mode"));
 	ADD_PROPERTY( PropertyInfo(Variant::BOOL,"gravity_point"),_SCS("set_gravity_is_point"),_SCS("is_gravity_a_point"));
@@ -355,6 +551,7 @@ void Area2D::_bind_methods() {
 	ADD_PROPERTY( PropertyInfo(Variant::REAL,"angular_damp",PROPERTY_HINT_RANGE,"0,1024,0.001"),_SCS("set_angular_damp"),_SCS("get_angular_damp"));
 	ADD_PROPERTYNZ( PropertyInfo(Variant::INT,"priority",PROPERTY_HINT_RANGE,"0,128,1"),_SCS("set_priority"),_SCS("get_priority"));
 	ADD_PROPERTY( PropertyInfo(Variant::BOOL,"monitoring"),_SCS("set_enable_monitoring"),_SCS("is_monitoring_enabled"));
+	ADD_PROPERTY( PropertyInfo(Variant::BOOL,"monitorable"),_SCS("set_monitorable"),_SCS("is_monitorable"));
 
 }
 
@@ -369,7 +566,9 @@ Area2D::Area2D() : CollisionObject2D(Physics2DServer::get_singleton()->area_crea
 	locked=false;
 	priority=0;
 	monitoring=false;
+	monitorable=false;
 	set_enable_monitoring(true);
+	set_monitorable(true);
 
 }
 

scene/2d/area_2d.h

@@ -53,6 +53,7 @@ private:
 	real_t angular_damp;
 	int priority;
 	bool monitoring;
+	bool monitorable;
 	bool locked;
 
 	void _body_inout(int p_status,const RID& p_body, int p_instance, int p_body_shape,int p_area_shape);
@@ -84,6 +85,36 @@ private:
 
 	Map<ObjectID,BodyState> body_map;
 
+
+
+	void _area_inout(int p_status,const RID& p_area, int p_instance, int p_area_shape,int p_self_shape);
+
+	void _area_enter_tree(ObjectID p_id);
+	void _area_exit_tree(ObjectID p_id);
+
+	struct AreaShapePair {
+
+		int area_shape;
+		int self_shape;
+		bool operator<(const AreaShapePair& p_sp) const {
+			if (area_shape==p_sp.area_shape)
+				return self_shape < p_sp.self_shape;
+			else
+				return area_shape < p_sp.area_shape;
+		}
+
+		AreaShapePair() {}
+		AreaShapePair(int p_bs, int p_as) { area_shape=p_bs; self_shape=p_as; }
+	};
+
+	struct AreaState {
+
+		int rc;
+		bool in_tree;
+		VSet<AreaShapePair> shapes;
+	};
+
+	Map<ObjectID,AreaState> area_map;
 	void _clear_monitoring();
 
 
@@ -117,7 +148,11 @@ public:
 	void set_enable_monitoring(bool p_enable);
 	bool is_monitoring_enabled() const;
 
+	void set_monitorable(bool p_enable);
+	bool is_monitorable() const;
+
 	Array get_overlapping_bodies() const; //function for script
+	Array get_overlapping_areas() const; //function for script
 
 
 	Area2D();

scene/scene_string_names.cpp

@@ -64,6 +64,9 @@ SceneStringNames::SceneStringNames() {
 	body_exit_shape = StaticCString::create("body_exit_shape");
 	body_exit = StaticCString::create("body_exit");
 
+	area_enter_shape = StaticCString::create("area_enter_shape");
+	area_exit_shape = StaticCString::create("area_exit_shape");
+
 
 	idle=StaticCString::create("idle");
 	iteration=StaticCString::create("iteration");
@@ -103,6 +106,9 @@ SceneStringNames::SceneStringNames() {
 	_body_enter_tree = StaticCString::create("_body_enter_tree");
 	_body_exit_tree = StaticCString::create("_body_exit_tree");
 
+	_area_enter_tree = StaticCString::create("_area_enter_tree");
+	_area_exit_tree = StaticCString::create("_area_exit_tree");
+
 	_input_event=StaticCString::create("_input_event");
 
 	changed=StaticCString::create("changed");

scene/scene_string_names.h

@@ -83,6 +83,10 @@ public:
 	StringName body_exit_shape;
 	StringName body_exit;
 
+	StringName area_enter_shape;
+	StringName area_exit_shape;
+
+
 
 	StringName _get_gizmo_geometry;
 	StringName _can_gizmo_scale;
@@ -124,6 +128,9 @@ public:
 	StringName _body_enter_tree;
 	StringName _body_exit_tree;
 
+	StringName _area_enter_tree;
+	StringName _area_exit_tree;
+
 	StringName changed;
 	StringName _shader_changed;
 

servers/physics_2d/area_2d_sw.cpp

@@ -31,6 +31,7 @@
 #include "body_2d_sw.h"
 
 Area2DSW::BodyKey::BodyKey(Body2DSW *p_body, uint32_t p_body_shape,uint32_t p_area_shape) { rid=p_body->get_self(); instance_id=p_body->get_instance_id(); body_shape=p_body_shape; area_shape=p_area_shape; }
+Area2DSW::BodyKey::BodyKey(Area2DSW *p_body, uint32_t p_body_shape,uint32_t p_area_shape) { rid=p_body->get_self(); instance_id=p_body->get_instance_id(); body_shape=p_body_shape; area_shape=p_area_shape; }
 
 void Area2DSW::_shapes_changed() {
 
@@ -57,6 +58,7 @@ void Area2DSW::set_space(Space2DSW *p_space) {
 	}
 
 	monitored_bodies.clear();
+	monitored_areas.clear();
 
 	_set_space(p_space);
 }
@@ -76,11 +78,31 @@ void Area2DSW::set_monitor_callback(ObjectID p_id, const StringName& p_method) {
 	monitor_callback_method=p_method;
 
 	monitored_bodies.clear();
+	monitored_areas.clear();
 
 	_shape_changed();
 
 }
 
+void Area2DSW::set_area_monitor_callback(ObjectID p_id, const StringName& p_method) {
+
+
+	if (p_id==area_monitor_callback_id) {
+		area_monitor_callback_method=p_method;
+		return;
+	}
+
+	_unregister_shapes();
+
+	area_monitor_callback_id=p_id;
+	area_monitor_callback_method=p_method;
+
+	monitored_bodies.clear();
+	monitored_areas.clear();
+
+	_shape_changed();
+
+}
 
 
 void Area2DSW::set_space_override_mode(Physics2DServer::AreaSpaceOverrideMode p_mode) {
@@ -134,6 +156,15 @@ void Area2DSW::_queue_monitor_update() {
 
 }
 
+void Area2DSW::set_monitorable(bool p_monitorable) {
+
+	if (monitorable==p_monitorable)
+		return;
+
+	monitorable=p_monitorable;
+	_set_static(!monitorable);
+}
+
 void Area2DSW::call_queries() {
 
 	if (monitor_callback_id && !monitored_bodies.empty()) {
@@ -170,13 +201,49 @@ void Area2DSW::call_queries() {
 
 	monitored_bodies.clear();
 
+	if (area_monitor_callback_id && !monitored_areas.empty()) {
+
+
+		Variant res[5];
+		Variant *resptr[5];
+		for(int i=0;i<5;i++)
+			resptr[i]=&res[i];
+
+		Object *obj = ObjectDB::get_instance(area_monitor_callback_id);
+		if (!obj) {
+			monitored_areas.clear();
+			area_monitor_callback_id=0;
+			return;
+		}
+
+
+
+		for (Map<BodyKey,BodyState>::Element *E=monitored_areas.front();E;E=E->next()) {
+
+			if (E->get().state==0)
+				continue; //nothing happened
+
+			res[0]=E->get().state>0 ? Physics2DServer::AREA_BODY_ADDED : Physics2DServer::AREA_BODY_REMOVED;
+			res[1]=E->key().rid;
+			res[2]=E->key().instance_id;
+			res[3]=E->key().body_shape;
+			res[4]=E->key().area_shape;
+
+
+			Variant::CallError ce;
+			obj->call(area_monitor_callback_method,(const Variant**)resptr,5,ce);
+		}
+	}
+
+	monitored_areas.clear();
+
 	//get_space()->area_remove_from_monitor_query_list(&monitor_query_list);
 
 }
 
 Area2DSW::Area2DSW() : CollisionObject2DSW(TYPE_AREA), monitor_query_list(this), moved_list(this)  {
 
-	_set_static(true); //areas are never active
+	_set_static(true); //areas are not active by default
 	space_override_mode=Physics2DServer::AREA_SPACE_OVERRIDE_DISABLED;
 	gravity=9.80665;
 	gravity_vector=Vector2(0,-1);
@@ -187,6 +254,8 @@ Area2DSW::Area2DSW() : CollisionObject2DSW(TYPE_AREA), monitor_query_list(this),
 	linear_damp=0.1;
 	priority=0;
 	monitor_callback_id=0;
+	area_monitor_callback_id=0;
+	monitorable=false;
 
 
 }

servers/physics_2d/area_2d_sw.h

@@ -50,10 +50,14 @@ class Area2DSW : public CollisionObject2DSW{
 	float linear_damp;
 	float angular_damp;
 	int priority;
+	bool monitorable;
 
 	ObjectID monitor_callback_id;
 	StringName monitor_callback_method;
 
+	ObjectID area_monitor_callback_id;
+	StringName area_monitor_callback_method;
+
 	SelfList<Area2DSW> monitor_query_list;
 	SelfList<Area2DSW> moved_list;
 
@@ -80,6 +84,7 @@ class Area2DSW : public CollisionObject2DSW{
 
 		_FORCE_INLINE_ BodyKey() {}
 		BodyKey(Body2DSW *p_body, uint32_t p_body_shape,uint32_t p_area_shape);
+		BodyKey(Area2DSW *p_body, uint32_t p_body_shape,uint32_t p_area_shape);
 	};
 
 	struct BodyState {
@@ -91,6 +96,7 @@ class Area2DSW : public CollisionObject2DSW{
 	};
 
 	Map<BodyKey,BodyState> monitored_bodies;
+	Map<BodyKey,BodyState> monitored_areas;
 
 	//virtual void shape_changed_notify(Shape2DSW *p_shape);
 	//virtual void shape_deleted_notify(Shape2DSW *p_shape);
@@ -108,9 +114,16 @@ public:
 	void set_monitor_callback(ObjectID p_id, const StringName& p_method);
 	_FORCE_INLINE_ bool has_monitor_callback() const { return monitor_callback_id; }
 
+	void set_area_monitor_callback(ObjectID p_id, const StringName& p_method);
+	_FORCE_INLINE_ bool has_area_monitor_callback() const { return area_monitor_callback_id; }
+
+
 	_FORCE_INLINE_ void add_body_to_query(Body2DSW *p_body, uint32_t p_body_shape,uint32_t p_area_shape);
 	_FORCE_INLINE_ void remove_body_from_query(Body2DSW *p_body, uint32_t p_body_shape,uint32_t p_area_shape);
 
+	_FORCE_INLINE_ void add_area_to_query(Area2DSW *p_area, uint32_t p_area_shape,uint32_t p_self_shape);
+	_FORCE_INLINE_ void remove_area_from_query(Area2DSW *p_area, uint32_t p_area_shape,uint32_t p_self_shape);
+
 	void set_param(Physics2DServer::AreaParameter p_param, const Variant& p_value);
 	Variant get_param(Physics2DServer::AreaParameter p_param) const;
 
@@ -142,6 +155,9 @@ public:
 	_FORCE_INLINE_ void remove_constraint( Constraint2DSW* p_constraint) { constraints.erase(p_constraint); }
 	_FORCE_INLINE_ const Set<Constraint2DSW*>& get_constraints() const { return constraints; }
 
+	void set_monitorable(bool p_monitorable);
+	_FORCE_INLINE_ bool is_monitorable() const { return monitorable; }
+
 	void set_transform(const Matrix32& p_transform);
 
 	void set_space(Space2DSW *p_space);
@@ -168,6 +184,24 @@ void Area2DSW::remove_body_from_query(Body2DSW *p_body, uint32_t p_body_shape,ui
 		_queue_monitor_update();
 }
 
+void Area2DSW::add_area_to_query(Area2DSW *p_area, uint32_t p_area_shape,uint32_t p_self_shape) {
+
+
+	BodyKey bk(p_area,p_area_shape,p_self_shape);
+	monitored_areas[bk].inc();
+	if (!monitor_query_list.in_list())
+		_queue_monitor_update();
+
+
+}
+void Area2DSW::remove_area_from_query(Area2DSW *p_area, uint32_t p_area_shape,uint32_t p_self_shape) {
+
+
+	BodyKey bk(p_area,p_area_shape,p_self_shape);
+	monitored_areas[bk].dec();
+	if (!monitor_query_list.in_list())
+		_queue_monitor_update();
+}
 
 
 

servers/physics_2d/area_pair_2d_sw.cpp

@@ -94,3 +94,72 @@ AreaPair2DSW::~AreaPair2DSW() {
 	body->remove_constraint(this);
 	area->remove_constraint(this);
 }
+
+
+//////////////////////////////////
+
+
+
+bool Area2Pair2DSW::setup(float p_step) {
+
+	bool result = CollisionSolver2DSW::solve(area_a->get_shape(shape_a),area_a->get_transform() * area_a->get_shape_transform(shape_a),Vector2(),area_b->get_shape(shape_b),area_b->get_transform() * area_b->get_shape_transform(shape_b),Vector2(),NULL,this);
+
+	if (result!=colliding) {
+
+		if (result) {
+
+			if (area_b->has_area_monitor_callback() && area_a->is_monitorable())
+				area_b->add_area_to_query(area_a,shape_a,shape_b);
+
+			if (area_a->has_area_monitor_callback() && area_b->is_monitorable())
+				area_a->add_area_to_query(area_b,shape_b,shape_a);
+
+		} else {
+
+			if (area_b->has_area_monitor_callback() && area_a->is_monitorable())
+				area_b->remove_area_from_query(area_a,shape_a,shape_b);
+
+			if (area_a->has_area_monitor_callback() && area_b->is_monitorable())
+				area_a->remove_area_from_query(area_b,shape_b,shape_a);
+		}
+
+		colliding=result;
+
+	}
+
+	return false; //never do any post solving
+}
+
+void Area2Pair2DSW::solve(float p_step) {
+
+
+}
+
+
+Area2Pair2DSW::Area2Pair2DSW(Area2DSW *p_area_a,int p_shape_a, Area2DSW *p_area_b,int p_shape_b) {
+
+
+	area_a=p_area_a;
+	area_b=p_area_b;
+	shape_a=p_shape_a;
+	shape_b=p_shape_b;
+	colliding=false;
+	area_a->add_constraint(this);
+	area_b->add_constraint(this);
+
+}
+
+Area2Pair2DSW::~Area2Pair2DSW() {
+
+	if (colliding) {
+
+		if (area_b->has_area_monitor_callback() && area_a->is_monitorable())
+			area_b->remove_area_from_query(area_a,shape_a,shape_b);
+
+		if (area_a->has_area_monitor_callback() && area_b->is_monitorable())
+			area_a->remove_area_from_query(area_b,shape_b,shape_a);
+	}
+
+	area_a->remove_constraint(this);
+	area_b->remove_constraint(this);
+}

servers/physics_2d/area_pair_2d_sw.h

@@ -49,5 +49,23 @@ public:
 	~AreaPair2DSW();
 };
 
+
+class Area2Pair2DSW : public Constraint2DSW {
+
+	Area2DSW *area_a;
+	Area2DSW *area_b;
+	int shape_a;
+	int shape_b;
+	bool colliding;
+public:
+
+	bool setup(float p_step);
+	void solve(float p_step);
+
+	Area2Pair2DSW(Area2DSW *p_area_a,int p_shape_a, Area2DSW *p_area_b,int p_shape_b);
+	~Area2Pair2DSW();
+};
+
+
 #endif // AREA_PAIR_2D_SW_H
 

servers/physics_2d/physics_2d_server_sw.cpp

@@ -463,6 +463,16 @@ Matrix32 Physics2DServerSW::area_get_transform(RID p_area) const {
 	return area->get_transform();
 };
 
+void Physics2DServerSW::area_set_monitorable(RID p_area,bool p_monitorable) {
+
+	Area2DSW *area = area_owner.get(p_area);
+	ERR_FAIL_COND(!area);
+
+	area->set_monitorable(p_monitorable);
+
+}
+
+
 void Physics2DServerSW::area_set_monitor_callback(RID p_area,Object *p_receiver,const StringName& p_method) {
 
 	Area2DSW *area = area_owner.get(p_area);
@@ -473,6 +483,14 @@ void Physics2DServerSW::area_set_monitor_callback(RID p_area,Object *p_receiver,
 
 }
 
+void Physics2DServerSW::area_set_area_monitor_callback(RID p_area,Object *p_receiver,const StringName& p_method) {
+
+
+	Area2DSW *area = area_owner.get(p_area);
+	ERR_FAIL_COND(!area);
+
+	area->set_area_monitor_callback(p_receiver?p_receiver->get_instance_ID():0,p_method);
+}
 
 /* BODY API */
 

servers/physics_2d/physics_2d_server_sw.h

@@ -133,9 +133,10 @@ public:
 
 	virtual Variant area_get_param(RID p_parea,AreaParameter p_param) const;
 	virtual Matrix32 area_get_transform(RID p_area) const;
+	virtual void area_set_monitorable(RID p_area,bool p_monitorable);
 
 	virtual void area_set_monitor_callback(RID p_area,Object *p_receiver,const StringName& p_method);
-
+	virtual void area_set_area_monitor_callback(RID p_area,Object *p_receiver,const StringName& p_method);
 
 	/* BODY API */
 

servers/physics_2d/space_2d_sw.cpp

@@ -527,13 +527,20 @@ void* Space2DSW::_broadphase_pair(CollisionObject2DSW *A,int p_subindex_A,Collis
 
 	if (type_A==CollisionObject2DSW::TYPE_AREA) {
 
-		ERR_FAIL_COND_V(type_B!=CollisionObject2DSW::TYPE_BODY,NULL);
 		Area2DSW *area=static_cast<Area2DSW*>(A);
-		Body2DSW *body=static_cast<Body2DSW*>(B);
+		if (type_B==CollisionObject2DSW::TYPE_AREA) {
+
+			Area2DSW *area_b=static_cast<Area2DSW*>(B);
+			Area2Pair2DSW *area2_pair = memnew(Area2Pair2DSW(area_b,p_subindex_B,area,p_subindex_A) );
+			return area2_pair;
+		} else {
+
+			Body2DSW *body=static_cast<Body2DSW*>(B);
+			AreaPair2DSW *area_pair = memnew(AreaPair2DSW(body,p_subindex_B,area,p_subindex_A) );
+			return area_pair;
+		}
 
-		AreaPair2DSW *area_pair = memnew(AreaPair2DSW(body,p_subindex_B,area,p_subindex_A) );
 
-		return area_pair;
 	} else {
 
 

servers/physics_2d_server.h

@@ -341,7 +341,10 @@ public:
 	virtual Variant area_get_param(RID p_parea,AreaParameter p_param) const=0;
 	virtual Matrix32 area_get_transform(RID p_area) const=0;
 
+	virtual void area_set_monitorable(RID p_area,bool p_monitorable)=0;
+
 	virtual void area_set_monitor_callback(RID p_area,Object *p_receiver,const StringName& p_method)=0;
+	virtual void area_set_area_monitor_callback(RID p_area,Object *p_receiver,const StringName& p_method)=0;
 
 	/* BODY API */
 

tools/editor/connections_dialog.cpp

@@ -607,6 +607,14 @@ void ConnectionsDialog::_remove_confirm() {
 
 }
 */
+
+struct _ConnectionsDialogMethodInfoSort {
+
+	_FORCE_INLINE_ bool operator()(const MethodInfo& a, const MethodInfo& b) const {
+		return a.name < b.name;
+	}
+};
+
 void ConnectionsDialog::update_tree() {
 	
 	if (!is_visible())
@@ -623,7 +631,8 @@ void ConnectionsDialog::update_tree() {
 
 	node->get_signal_list(&node_signals);
 
-	
+	//node_signals.sort_custom<_ConnectionsDialogMethodInfoSort>();
+
 	for(List<MethodInfo>::Element *E=node_signals.front();E;E=E->next()) {