Add shape data to area overlap data.

4 files changed, 167 insertions, 192 deletions

diff --git a/modules/bullet/area_bullet.cpp b/modules/bullet/area_bullet.cpp
index 0d4982baba..1c49029570 100644
--- a/modules/bullet/area_bullet.cpp
+++ b/modules/bullet/area_bullet.cpp
@@ -59,8 +59,8 @@ AreaBullet::AreaBullet() :
 
 AreaBullet::~AreaBullet() {
 	// signal are handled by godot, so just clear without notify
-	for (int i = overlappingObjects.size() - 1; 0 <= i; --i) {
-		overlappingObjects[i].object->on_exit_area(this);
+	for (int i = 0; i < overlapping_shapes.size(); i++) {
+		overlapping_shapes[i].other_object->on_exit_area(this);
 	}
 }
 
@@ -70,20 +70,26 @@ void AreaBullet::dispatch_callbacks() {
 	}
 	isScratched = false;
 
-	// Reverse order because I've to remove EXIT objects
-	for (int i = overlappingObjects.size() - 1; 0 <= i; --i) {
-		OverlappingObjectData &otherObj = overlappingObjects.write[i];
+	// Reverse order so items can be removed.
+	for (int i = overlapping_shapes.size() - 1; i >= 0; i--) {
+		OverlappingShapeData &overlapping_shape = overlapping_shapes.write[i];
 
-		switch (otherObj.state) {
+		switch (overlapping_shape.state) {
 			case OVERLAP_STATE_ENTER:
-				otherObj.state = OVERLAP_STATE_INSIDE;
-				call_event(otherObj.object, PhysicsServer3D::AREA_BODY_ADDED);
-				otherObj.object->on_enter_area(this);
+				overlapping_shape.state = OVERLAP_STATE_INSIDE;
+				call_event(overlapping_shape, PhysicsServer3D::AREA_BODY_ADDED);
+				if (_overlapping_shape_count(overlapping_shape.other_object) == 1) {
+					// This object's first shape being added.
+					overlapping_shape.other_object->on_enter_area(this);
+				}
 				break;
 			case OVERLAP_STATE_EXIT:
-				call_event(otherObj.object, PhysicsServer3D::AREA_BODY_REMOVED);
-				otherObj.object->on_exit_area(this);
-				overlappingObjects.remove(i); // Remove after callback
+				call_event(overlapping_shape, PhysicsServer3D::AREA_BODY_REMOVED);
+				if (_overlapping_shape_count(overlapping_shape.other_object) == 1) {
+					// This object's last shape being removed.
+					overlapping_shape.other_object->on_exit_area(this);
+				}
+				overlapping_shapes.remove(i); // Remove after callback
 				break;
 			case OVERLAP_STATE_INSIDE: {
 				if (otherObj.object->getType() == TYPE_RIGID_BODY) {
@@ -98,8 +104,8 @@ void AreaBullet::dispatch_callbacks() {
 	}
 }
 
-void AreaBullet::call_event(CollisionObjectBullet *p_otherObject, PhysicsServer3D::AreaBodyStatus p_status) {
-	InOutEventCallback &event = eventsCallbacks[static_cast<int>(p_otherObject->getType())];
+void AreaBullet::call_event(const OverlappingShapeData &p_overlapping_shape, PhysicsServer3D::AreaBodyStatus p_status) {
+	InOutEventCallback &event = eventsCallbacks[static_cast<int>(p_overlapping_shape.other_object->getType())];
 
 	if (!event.event_callback.is_valid()) {
 		event.event_callback = Callable();
@@ -107,54 +113,92 @@ void AreaBullet::call_event(CollisionObjectBullet *p_otherObject, PhysicsServer3
 	}
 
 	call_event_res[0] = p_status;
-	call_event_res[1] = p_otherObject->get_self(); // Other body
-	call_event_res[2] = p_otherObject->get_instance_id(); // instance ID
-	call_event_res[3] = 0; // other_body_shape ID
-	call_event_res[4] = 0; // self_shape ID
+	call_event_res[1] = p_overlapping_shape.other_object->get_self(); // RID
+	call_event_res[2] = p_overlapping_shape.other_object->get_instance_id(); // Object ID
+	call_event_res[3] = p_overlapping_shape.other_shape_id; // Other object's shape ID
+	call_event_res[4] = p_overlapping_shape.our_shape_id; // This area's shape ID
 
 	Callable::CallError outResp;
 	Variant ret;
 	event.event_callback.call((const Variant **)call_event_res, 5, ret, outResp);
 }
 
-void AreaBullet::scratch() {
-	if (isScratched) {
-		return;
+int AreaBullet::_overlapping_shape_count(CollisionObjectBullet *p_other_object) {
+	int count = 0;
+	for (int i = 0; i < overlapping_shapes.size(); i++) {
+		if (overlapping_shapes[i].other_object == p_other_object) {
+			count++;
+		}
 	}
-	isScratched = true;
+	return count;
 }
 
-void AreaBullet::clear_overlaps(bool p_notify) {
-	for (int i = overlappingObjects.size() - 1; 0 <= i; --i) {
-		if (p_notify) {
-			call_event(overlappingObjects[i].object, PhysicsServer3D::AREA_BODY_REMOVED);
+int AreaBullet::_find_overlapping_shape(CollisionObjectBullet *p_other_object, uint32_t p_other_shape_id, uint32_t p_our_shape_id) {
+	for (int i = 0; i < overlapping_shapes.size(); i++) {
+		const OverlappingShapeData &overlapping_shape = overlapping_shapes[i];
+		if (overlapping_shape.other_object == p_other_object && overlapping_shape.other_shape_id == p_other_shape_id && overlapping_shape.our_shape_id == p_our_shape_id) {
+			return i;
 		}
-		overlappingObjects[i].object->on_exit_area(this);
 	}
-	overlappingObjects.clear();
+	return -1;
 }
 
-void AreaBullet::remove_overlap(CollisionObjectBullet *p_object, bool p_notify) {
-	for (int i = overlappingObjects.size() - 1; 0 <= i; --i) {
-		if (overlappingObjects[i].object == p_object) {
-			if (p_notify) {
-				call_event(overlappingObjects[i].object, PhysicsServer3D::AREA_BODY_REMOVED);
-			}
-			overlappingObjects[i].object->on_exit_area(this);
-			overlappingObjects.remove(i);
-			break;
+void AreaBullet::mark_all_overlaps_dirty() {
+	OverlappingShapeData *overlapping_shapes_w = overlapping_shapes.ptrw();
+	for (int i = 0; i < overlapping_shapes.size(); i++) {
+		// Don't overwrite OVERLAP_STATE_ENTER state.
+		if (overlapping_shapes_w[i].state != OVERLAP_STATE_ENTER) {
+			overlapping_shapes_w[i].state = OVERLAP_STATE_DIRTY;
 		}
 	}
 }
 
-int AreaBullet::find_overlapping_object(CollisionObjectBullet *p_colObj) {
-	const int size = overlappingObjects.size();
-	for (int i = 0; i < size; ++i) {
-		if (overlappingObjects[i].object == p_colObj) {
-			return i;
+void AreaBullet::mark_object_overlaps_inside(CollisionObjectBullet *p_other_object) {
+	OverlappingShapeData *overlapping_shapes_w = overlapping_shapes.ptrw();
+	for (int i = 0; i < overlapping_shapes.size(); i++) {
+		if (overlapping_shapes_w[i].other_object == p_other_object && overlapping_shapes_w[i].state == OVERLAP_STATE_DIRTY) {
+			overlapping_shapes_w[i].state = OVERLAP_STATE_INSIDE;
+		}
+	}
+}
+
+void AreaBullet::set_overlap(CollisionObjectBullet *p_other_object, uint32_t p_other_shape_id, uint32_t p_our_shape_id) {
+	int i = _find_overlapping_shape(p_other_object, p_other_shape_id, p_our_shape_id);
+	if (i == -1) { // Not found, create new one.
+		OverlappingShapeData overlapping_shape(p_other_object, OVERLAP_STATE_ENTER, p_other_shape_id, p_our_shape_id);
+		overlapping_shapes.push_back(overlapping_shape);
+		p_other_object->notify_new_overlap(this);
+		isScratched = true;
+	} else {
+		overlapping_shapes.ptrw()[i].state = OVERLAP_STATE_INSIDE;
+	}
+}
+
+void AreaBullet::mark_all_dirty_overlaps_as_exit() {
+	OverlappingShapeData *overlapping_shapes_w = overlapping_shapes.ptrw();
+	for (int i = 0; i < overlapping_shapes.size(); i++) {
+		if (overlapping_shapes[i].state == OVERLAP_STATE_DIRTY) {
+			overlapping_shapes_w[i].state = OVERLAP_STATE_EXIT;
+			isScratched = true;
+		}
+	}
+}
+
+void AreaBullet::remove_object_overlaps(CollisionObjectBullet *p_object) {
+	// Reverse order so items can be removed.
+	for (int i = overlapping_shapes.size() - 1; i >= 0; i--) {
+		if (overlapping_shapes[i].other_object == p_object) {
+			overlapping_shapes.remove(i);
 		}
 	}
-	return -1;
+}
+
+void AreaBullet::clear_overlaps() {
+	for (int i = 0; i < overlapping_shapes.size(); i++) {
+		call_event(overlapping_shapes[i], PhysicsServer3D::AREA_BODY_REMOVED);
+		overlapping_shapes[i].other_object->on_exit_area(this);
+	}
+	overlapping_shapes.clear();
 }
 
 void AreaBullet::set_monitorable(bool p_monitorable) {
@@ -182,7 +226,7 @@ void AreaBullet::reload_body() {
 void AreaBullet::set_space(SpaceBullet *p_space) {
 	// Clear the old space if there is one
 	if (space) {
-		clear_overlaps(false);
+		clear_overlaps();
 		isScratched = false;
 
 		// Remove this object form the physics world
@@ -203,24 +247,6 @@ void AreaBullet::on_collision_filters_change() {
 	updated = true;
 }
 
-void AreaBullet::add_overlap(CollisionObjectBullet *p_otherObject) {
-	scratch();
-	overlappingObjects.push_back(OverlappingObjectData(p_otherObject, OVERLAP_STATE_ENTER));
-	p_otherObject->notify_new_overlap(this);
-}
-
-void AreaBullet::put_overlap_as_exit(int p_index) {
-	scratch();
-	overlappingObjects.write[p_index].state = OVERLAP_STATE_EXIT;
-}
-
-void AreaBullet::put_overlap_as_inside(int p_index) {
-	// This check is required to be sure this body was inside
-	if (OVERLAP_STATE_DIRTY == overlappingObjects[p_index].state) {
-		overlappingObjects.write[p_index].state = OVERLAP_STATE_INSIDE;
-	}
-}
-
 void AreaBullet::set_param(PhysicsServer3D::AreaParameter p_param, const Variant &p_value) {
 	switch (p_param) {
 		case PhysicsServer3D::AREA_PARAM_GRAVITY:
diff --git a/modules/bullet/area_bullet.h b/modules/bullet/area_bullet.h
index 4d9227c31a..3bff364cc1 100644
--- a/modules/bullet/area_bullet.h
+++ b/modules/bullet/area_bullet.h
@@ -43,8 +43,6 @@
 class btGhostObject;
 
 class AreaBullet : public RigidCollisionObjectBullet {
-	friend void SpaceBullet::check_ghost_overlaps();
-
 public:
 	struct InOutEventCallback {
 		Callable event_callback;
@@ -59,21 +57,19 @@ public:
 		OVERLAP_STATE_EXIT // Mark ended overlaps
 	};
 
-	struct OverlappingObjectData {
-		CollisionObjectBullet *object = nullptr;
-		OverlapState state = OVERLAP_STATE_ENTER;
-
-		OverlappingObjectData() {}
-		OverlappingObjectData(CollisionObjectBullet *p_object, OverlapState p_state) :
-				object(p_object),
-				state(p_state) {}
-		OverlappingObjectData(const OverlappingObjectData &other) {
-			operator=(other);
-		}
-		void operator=(const OverlappingObjectData &other) {
-			object = other.object;
-			state = other.state;
-		}
+	struct OverlappingShapeData {
+		CollisionObjectBullet *other_object = nullptr;
+		OverlapState state = OVERLAP_STATE_DIRTY;
+		uint32_t other_shape_id = 0;
+		uint32_t our_shape_id = 0;
+
+		OverlappingShapeData() {}
+
+		OverlappingShapeData(CollisionObjectBullet *p_other_object, OverlapState p_state, uint32_t p_other_shape_id, uint32_t p_our_shape_id) :
+				other_object(p_other_object),
+				state(p_state),
+				other_shape_id(p_other_shape_id),
+				our_shape_id(p_our_shape_id) {}
 	};
 
 private:
@@ -82,7 +78,9 @@ private:
 	Variant *call_event_res_ptr[5] = {};
 
 	btGhostObject *btGhost = nullptr;
-	Vector<OverlappingObjectData> overlappingObjects;
+	Vector<OverlappingShapeData> overlapping_shapes;
+	int _overlapping_shape_count(CollisionObjectBullet *p_other_object);
+	int _find_overlapping_shape(CollisionObjectBullet *p_other_object, uint32_t p_other_shape_id, uint32_t p_our_shape_id);
 	bool monitorable = true;
 
 	PhysicsServer3D::AreaSpaceOverrideMode spOv_mode = PhysicsServer3D::AREA_SPACE_OVERRIDE_DISABLED;
@@ -104,7 +102,6 @@ public:
 	~AreaBullet();
 
 	_FORCE_INLINE_ btGhostObject *get_bt_ghost() const { return btGhost; }
-	int find_overlapping_object(CollisionObjectBullet *p_colObj);
 
 	void set_monitorable(bool p_monitorable);
 	_FORCE_INLINE_ bool is_monitorable() const { return monitorable; }
@@ -143,20 +140,18 @@ public:
 	virtual void set_space(SpaceBullet *p_space);
 
 	virtual void dispatch_callbacks();
-	void call_event(CollisionObjectBullet *p_otherObject, PhysicsServer3D::AreaBodyStatus p_status);
-	void scratch();
-
-	void clear_overlaps(bool p_notify);
-	// Dispatch the callbacks and removes from overlapping list
-	void remove_overlap(CollisionObjectBullet *p_object, bool p_notify);
+	void call_event(const OverlappingShapeData &p_overlapping_shape, PhysicsServer3D::AreaBodyStatus p_status);
 
 	virtual void on_collision_filters_change();
 	virtual void on_collision_checker_start() {}
 	virtual void on_collision_checker_end() { updated = false; }
 
-	void add_overlap(CollisionObjectBullet *p_otherObject);
-	void put_overlap_as_exit(int p_index);
-	void put_overlap_as_inside(int p_index);
+	void mark_all_overlaps_dirty();
+	void mark_object_overlaps_inside(CollisionObjectBullet *p_other_object);
+	void set_overlap(CollisionObjectBullet *p_other_object, uint32_t p_other_shape_id, uint32_t p_our_shape_id);
+	void mark_all_dirty_overlaps_as_exit();
+	void remove_object_overlaps(CollisionObjectBullet *p_object);
+	void clear_overlaps();
 
 	void set_param(PhysicsServer3D::AreaParameter p_param, const Variant &p_value);
 	Variant get_param(PhysicsServer3D::AreaParameter p_param) const;
diff --git a/modules/bullet/collision_object_bullet.cpp b/modules/bullet/collision_object_bullet.cpp
index afd8cf4bf4..987a45ad5f 100644
--- a/modules/bullet/collision_object_bullet.cpp
+++ b/modules/bullet/collision_object_bullet.cpp
@@ -93,11 +93,9 @@ CollisionObjectBullet::CollisionObjectBullet(Type p_type) :
 		type(p_type) {}
 
 CollisionObjectBullet::~CollisionObjectBullet() {
-	// Remove all overlapping, notify is not required since godot take care of it
-	for (int i = areasOverlapped.size() - 1; 0 <= i; --i) {
-		areasOverlapped[i]->remove_overlap(this, /*Notify*/ false);
+	for (int i = 0; i < areasOverlapped.size(); i++) {
+		areasOverlapped[i]->remove_object_overlaps(this);
 	}
-
 	destroyBulletCollisionObject();
 }
 
@@ -178,7 +176,9 @@ bool CollisionObjectBullet::is_collisions_response_enabled() {
 }
 
 void CollisionObjectBullet::notify_new_overlap(AreaBullet *p_area) {
-	areasOverlapped.push_back(p_area);
+	if (areasOverlapped.find(p_area) == -1) {
+		areasOverlapped.push_back(p_area);
+	}
 }
 
 void CollisionObjectBullet::on_exit_area(AreaBullet *p_area) {
diff --git a/modules/bullet/space_bullet.cpp b/modules/bullet/space_bullet.cpp
index bf47127877..7aa3815c94 100644
--- a/modules/bullet/space_bullet.cpp
+++ b/modules/bullet/space_bullet.cpp
@@ -662,101 +662,77 @@ void SpaceBullet::destroy_world() {
 }
 
 void SpaceBullet::check_ghost_overlaps() {
-	/// Algorithm support variables
-	btCollisionShape *other_body_shape;
-	btConvexShape *area_shape;
-	btGjkPairDetector::ClosestPointInput gjk_input;
-	AreaBullet *area;
-	int x(-1), i(-1), y(-1), z(-1), indexOverlap(-1);
-
-	/// For each areas
-	for (x = areas.size() - 1; 0 <= x; --x) {
-		area = areas[x];
-
-		btVector3 area_scale(area->get_bt_body_scale());
-
+	// For each area
+	for (int area_idx = 0; area_idx < areas.size(); area_idx++) {
+		AreaBullet *area = areas[area_idx];
 		if (!area->is_monitoring()) {
 			continue;
 		}
 
-		/// 1. Reset all states
-		for (i = area->overlappingObjects.size() - 1; 0 <= i; --i) {
-			AreaBullet::OverlappingObjectData &otherObj = area->overlappingObjects.write[i];
-			// This check prevent the overwrite of ENTER state
-			// if this function is called more times before dispatchCallbacks
-			if (otherObj.state != AreaBullet::OVERLAP_STATE_ENTER) {
-				otherObj.state = AreaBullet::OVERLAP_STATE_DIRTY;
-			}
-		}
+		btGhostObject *bt_ghost = area->get_bt_ghost();
+		const btTransform &area_transform = area->get_transform__bullet();
+		const btVector3 &area_scale(area->get_bt_body_scale());
 
-		/// 2. Check all overlapping objects using GJK
+		// Mark all current overlapping shapes dirty.
+		area->mark_all_overlaps_dirty();
 
-		const btAlignedObjectArray<btCollisionObject *> ghostOverlaps = area->get_bt_ghost()->getOverlappingPairs();
+		// Broadphase
+		const btAlignedObjectArray<btCollisionObject *> overlapping_pairs = bt_ghost->getOverlappingPairs();
+		// Narrowphase
+		for (int pair_idx = 0; pair_idx < overlapping_pairs.size(); pair_idx++) {
+			btCollisionObject *other_bt_collision_object = overlapping_pairs[pair_idx];
+			RigidCollisionObjectBullet *other_object = static_cast<RigidCollisionObjectBullet *>(other_bt_collision_object->getUserPointer());
+			const btTransform &other_transform = other_object->get_transform__bullet();
+			const btVector3 &other_scale(other_object->get_bt_body_scale());
 
-		// For each overlapping
-		for (i = ghostOverlaps.size() - 1; 0 <= i; --i) {
-			bool hasOverlap = false;
-			btCollisionObject *overlapped_bt_co = ghostOverlaps[i];
-			RigidCollisionObjectBullet *otherObject = static_cast<RigidCollisionObjectBullet *>(overlapped_bt_co->getUserPointer());
-			btVector3 other_body_scale(otherObject->get_bt_body_scale());
-
-			if (!area->is_updated() && !otherObject->is_updated()) {
-				hasOverlap = -1 != area->find_overlapping_object(otherObject);
-				goto collision_found;
+			if (!area->is_updated() && !other_object->is_updated()) {
+				area->mark_object_overlaps_inside(other_object);
+				continue;
 			}
 
-			if (overlapped_bt_co->getUserIndex() == CollisionObjectBullet::TYPE_AREA) {
-				if (!static_cast<AreaBullet *>(overlapped_bt_co->getUserPointer())->is_monitorable()) {
+			if (other_bt_collision_object->getUserIndex() == CollisionObjectBullet::TYPE_AREA) {
+				if (!static_cast<AreaBullet *>(other_bt_collision_object->getUserPointer())->is_monitorable()) {
 					continue;
 				}
-			} else if (overlapped_bt_co->getUserIndex() != CollisionObjectBullet::TYPE_RIGID_BODY) {
+			} else if (other_bt_collision_object->getUserIndex() != CollisionObjectBullet::TYPE_RIGID_BODY) {
 				continue;
 			}
 
 			// For each area shape
-			for (y = area->get_shape_count() - 1; 0 <= y; --y) {
-				if (!area->get_bt_shape(y)->isConvex()) {
+			for (int our_shape_id = 0; our_shape_id < area->get_shape_count(); our_shape_id++) {
+				btCollisionShape *area_shape = area->get_bt_shape(our_shape_id);
+				if (!area_shape->isConvex()) {
 					continue;
 				}
+				btConvexShape *area_convex_shape = static_cast<btConvexShape *>(area_shape);
 
-				btTransform area_shape_treansform(area->get_bt_shape_transform(y));
-				area_shape_treansform.getOrigin() *= area_scale;
-
-				gjk_input.m_transformA =
-						area->get_transform__bullet() *
-						area_shape_treansform;
-
-				area_shape = static_cast<btConvexShape *>(area->get_bt_shape(y));
+				btTransform area_shape_transform(area->get_bt_shape_transform(our_shape_id));
+				area_shape_transform.getOrigin() *= area_scale;
+				btGjkPairDetector::ClosestPointInput gjk_input;
+				gjk_input.m_transformA = area_transform * area_shape_transform;
 
 				// For each other object shape
-				for (z = otherObject->get_shape_count() - 1; 0 <= z; --z) {
-					other_body_shape = static_cast<btCollisionShape *>(otherObject->get_bt_shape(z));
-
-					btTransform other_shape_transform(otherObject->get_bt_shape_transform(z));
-					other_shape_transform.getOrigin() *= other_body_scale;
-
-					gjk_input.m_transformB =
-							otherObject->get_transform__bullet() *
-							other_shape_transform;
+				for (int other_shape_id = 0; other_shape_id < other_object->get_shape_count(); other_shape_id++) {
+					btCollisionShape *other_shape = other_object->get_bt_shape(other_shape_id);
+					btTransform other_shape_transform(other_object->get_bt_shape_transform(other_shape_id));
+					other_shape_transform.getOrigin() *= other_scale;
+					gjk_input.m_transformB = other_transform * other_shape_transform;
 
-					if (other_body_shape->isConvex()) {
+					if (other_shape->isConvex()) {
 						btPointCollector result;
 						btGjkPairDetector gjk_pair_detector(
-								area_shape,
-								static_cast<btConvexShape *>(other_body_shape),
+								area_convex_shape,
+								static_cast<btConvexShape *>(other_shape),
 								gjk_simplex_solver,
 								gjk_epa_pen_solver);
-						gjk_pair_detector.getClosestPoints(gjk_input, result, nullptr);
 
-						if (0 >= result.m_distance) {
-							hasOverlap = true;
-							goto collision_found;
+						gjk_pair_detector.getClosestPoints(gjk_input, result, nullptr);
+						if (result.m_distance <= 0) {
+							area->set_overlap(other_object, other_shape_id, our_shape_id);
 						}
-
-					} else {
-						btCollisionObjectWrapper obA(nullptr, area_shape, area->get_bt_ghost(), gjk_input.m_transformA, -1, y);
-						btCollisionObjectWrapper obB(nullptr, other_body_shape, otherObject->get_bt_collision_object(), gjk_input.m_transformB, -1, z);
-
+					} else { // Other shape is not convex.
+						btCollisionObjectWrapper obA(nullptr, area_convex_shape, bt_ghost, gjk_input.m_transformA, -1, our_shape_id);
+						btCollisionObjectWrapper obB(nullptr, other_shape, other_bt_collision_object, gjk_input.m_transformB, -1, other_shape_id);
 						btCollisionAlgorithm *algorithm = dispatcher->findAlgorithm(&obA, &obB, nullptr, BT_CONTACT_POINT_ALGORITHMS);
 
 						if (!algorithm) {
@@ -765,42 +741,20 @@ void SpaceBullet::check_ghost_overlaps() {
 
 						GodotDeepPenetrationContactResultCallback contactPointResult(&obA, &obB);
 						algorithm->processCollision(&obA, &obB, dynamicsWorld->getDispatchInfo(), &contactPointResult);
-
 						algorithm->~btCollisionAlgorithm();
 						dispatcher->freeCollisionAlgorithm(algorithm);
 
 						if (contactPointResult.hasHit()) {
-							hasOverlap = true;
-							goto collision_found;
+							area->set_overlap(other_object, our_shape_id, other_shape_id);
 						}
 					}
+				} // End for each other object shape
+			} // End for each area shape
+		} // End for each overlapping pair
 
-				} // ~For each other object shape
-			} // ~For each area shape
-
-		collision_found:
-			if (!hasOverlap) {
-				continue;
-			}
-
-			indexOverlap = area->find_overlapping_object(otherObject);
-			if (-1 == indexOverlap) {
-				// Not found
-				area->add_overlap(otherObject);
-			} else {
-				// Found
-				area->put_overlap_as_inside(indexOverlap);
-			}
-		}
-
-		/// 3. Remove not overlapping
-		for (i = area->overlappingObjects.size() - 1; 0 <= i; --i) {
-			// If the overlap has DIRTY state it means that it's no more overlapping
-			if (area->overlappingObjects[i].state == AreaBullet::OVERLAP_STATE_DIRTY) {
-				area->put_overlap_as_exit(i);
-			}
-		}
-	}
+		// All overlapping shapes still marked dirty must have exited.
+		area->mark_all_dirty_overlaps_as_exit();
+	} // End for each area
 }
 
 void SpaceBullet::check_body_collision() {