Refactor VisibilityNotifier3D

* This is the 3D counterpart to #49632
* Implemented a bit different as 3D works using instancing

After merged, both 2D and 3D classes will most likely be renamed in a separate PR to DisplayNotifier2D/3D.

9 files changed, 175 insertions, 4 deletions

diff --git a/servers/rendering/rasterizer_dummy.h b/servers/rendering/rasterizer_dummy.h
index b44088e822..d4c25b6253 100644
--- a/servers/rendering/rasterizer_dummy.h
+++ b/servers/rendering/rasterizer_dummy.h
@@ -621,9 +621,18 @@ public:
 	bool particles_collision_is_heightfield(RID p_particles_collision) const override { return false; }
 	RID particles_collision_get_heightfield_framebuffer(RID p_particles_collision) const override { return RID(); }
 
-	RID particles_collision_instance_create(RID p_collision) override { return RID(); };
-	void particles_collision_instance_set_transform(RID p_collision_instance, const Transform3D &p_transform) override{};
-	void particles_collision_instance_set_active(RID p_collision_instance, bool p_active) override{};
+	RID particles_collision_instance_create(RID p_collision) override { return RID(); }
+	void particles_collision_instance_set_transform(RID p_collision_instance, const Transform3D &p_transform) override {}
+	void particles_collision_instance_set_active(RID p_collision_instance, bool p_active) override {}
+
+	/* VISIBILITY NOTIFIER */
+	virtual RID visibility_notifier_allocate() override { return RID(); }
+	virtual void visibility_notifier_initialize(RID p_notifier) override {}
+	virtual void visibility_notifier_set_aabb(RID p_notifier, const AABB &p_aabb) override {}
+	virtual void visibility_notifier_set_callbacks(RID p_notifier, const Callable &p_enter_callbable, const Callable &p_exit_callable) override {}
+
+	virtual AABB visibility_notifier_get_aabb(RID p_notifier) const override { return AABB(); }
+	virtual void visibility_notifier_call(RID p_notifier, bool p_enter, bool p_deferred) override {}
 
 	/* GLOBAL VARIABLES */
 
diff --git a/servers/rendering/renderer_rd/renderer_storage_rd.cpp b/servers/rendering/renderer_rd/renderer_storage_rd.cpp
index 64be54115f..246b5f0e4c 100644
--- a/servers/rendering/renderer_rd/renderer_storage_rd.cpp
+++ b/servers/rendering/renderer_rd/renderer_storage_rd.cpp
@@ -5535,6 +5535,59 @@ void RendererStorageRD::particles_collision_instance_set_active(RID p_collision_
 	pci->active = p_active;
 }
 
+/* VISIBILITY NOTIFIER */
+
+RID RendererStorageRD::visibility_notifier_allocate() {
+	return visibility_notifier_owner.allocate_rid();
+}
+void RendererStorageRD::visibility_notifier_initialize(RID p_notifier) {
+	visibility_notifier_owner.initialize_rid(p_notifier, VisibilityNotifier());
+}
+void RendererStorageRD::visibility_notifier_set_aabb(RID p_notifier, const AABB &p_aabb) {
+	VisibilityNotifier *vn = visibility_notifier_owner.getornull(p_notifier);
+	ERR_FAIL_COND(!vn);
+	vn->aabb = p_aabb;
+	vn->dependency.changed_notify(DEPENDENCY_CHANGED_AABB);
+}
+void RendererStorageRD::visibility_notifier_set_callbacks(RID p_notifier, const Callable &p_enter_callbable, const Callable &p_exit_callable) {
+	VisibilityNotifier *vn = visibility_notifier_owner.getornull(p_notifier);
+	ERR_FAIL_COND(!vn);
+	vn->enter_callback = p_enter_callbable;
+	vn->exit_callback = p_exit_callable;
+}
+
+AABB RendererStorageRD::visibility_notifier_get_aabb(RID p_notifier) const {
+	const VisibilityNotifier *vn = visibility_notifier_owner.getornull(p_notifier);
+	ERR_FAIL_COND_V(!vn, AABB());
+	return vn->aabb;
+}
+void RendererStorageRD::visibility_notifier_call(RID p_notifier, bool p_enter, bool p_deferred) {
+	VisibilityNotifier *vn = visibility_notifier_owner.getornull(p_notifier);
+	ERR_FAIL_COND(!vn);
+
+	if (p_enter) {
+		if (!vn->enter_callback.is_null()) {
+			if (p_deferred) {
+				vn->enter_callback.call_deferred(nullptr, 0);
+			} else {
+				Variant r;
+				Callable::CallError ce;
+				vn->enter_callback.call(nullptr, 0, r, ce);
+			}
+		}
+	} else {
+		if (!vn->exit_callback.is_null()) {
+			if (p_deferred) {
+				vn->exit_callback.call_deferred(nullptr, 0);
+			} else {
+				Variant r;
+				Callable::CallError ce;
+				vn->exit_callback.call(nullptr, 0, r, ce);
+			}
+		}
+	}
+}
+
 /* SKELETON API */
 
 RID RendererStorageRD::skeleton_allocate() {
@@ -7590,6 +7643,9 @@ void RendererStorageRD::base_update_dependency(RID p_base, DependencyTracker *p_
 	} else if (particles_collision_owner.owns(p_base)) {
 		ParticlesCollision *pc = particles_collision_owner.getornull(p_base);
 		p_instance->update_dependency(&pc->dependency);
+	} else if (visibility_notifier_owner.owns(p_base)) {
+		VisibilityNotifier *vn = visibility_notifier_owner.getornull(p_base);
+		p_instance->update_dependency(&vn->dependency);
 	}
 }
 
@@ -7628,6 +7684,9 @@ RS::InstanceType RendererStorageRD::get_base_type(RID p_rid) const {
 	if (particles_collision_owner.owns(p_rid)) {
 		return RS::INSTANCE_PARTICLES_COLLISION;
 	}
+	if (visibility_notifier_owner.owns(p_rid)) {
+		return RS::INSTANCE_VISIBLITY_NOTIFIER;
+	}
 
 	return RS::INSTANCE_NONE;
 }
@@ -8704,6 +8763,10 @@ bool RendererStorageRD::free(RID p_rid) {
 		}
 		particles_collision->dependency.deleted_notify(p_rid);
 		particles_collision_owner.free(p_rid);
+	} else if (visibility_notifier_owner.owns(p_rid)) {
+		VisibilityNotifier *vn = visibility_notifier_owner.getornull(p_rid);
+		vn->dependency.deleted_notify(p_rid);
+		visibility_notifier_owner.free(p_rid);
 	} else if (particles_collision_instance_owner.owns(p_rid)) {
 		particles_collision_instance_owner.free(p_rid);
 	} else if (render_target_owner.owns(p_rid)) {
diff --git a/servers/rendering/renderer_rd/renderer_storage_rd.h b/servers/rendering/renderer_rd/renderer_storage_rd.h
index 28a1044705..ab470cb3a6 100644
--- a/servers/rendering/renderer_rd/renderer_storage_rd.h
+++ b/servers/rendering/renderer_rd/renderer_storage_rd.h
@@ -947,6 +947,17 @@ private:
 
 	mutable RID_Owner<ParticlesCollisionInstance> particles_collision_instance_owner;
 
+	/* visibility_notifier */
+
+	struct VisibilityNotifier {
+		AABB aabb;
+		Callable enter_callback;
+		Callable exit_callback;
+		Dependency dependency;
+	};
+
+	mutable RID_Owner<VisibilityNotifier> visibility_notifier_owner;
+
 	/* Skeleton */
 
 	struct Skeleton {
@@ -2253,6 +2264,14 @@ public:
 	virtual bool particles_collision_is_heightfield(RID p_particles_collision) const;
 	RID particles_collision_get_heightfield_framebuffer(RID p_particles_collision) const;
 
+	virtual RID visibility_notifier_allocate();
+	virtual void visibility_notifier_initialize(RID p_notifier);
+	virtual void visibility_notifier_set_aabb(RID p_notifier, const AABB &p_aabb);
+	virtual void visibility_notifier_set_callbacks(RID p_notifier, const Callable &p_enter_callbable, const Callable &p_exit_callable);
+
+	virtual AABB visibility_notifier_get_aabb(RID p_notifier) const;
+	virtual void visibility_notifier_call(RID p_notifier, bool p_enter, bool p_deferred);
+
 	//used from 2D and 3D
 	virtual RID particles_collision_instance_create(RID p_collision);
 	virtual void particles_collision_instance_set_transform(RID p_collision_instance, const Transform3D &p_transform);
diff --git a/servers/rendering/renderer_scene.h b/servers/rendering/renderer_scene.h
index 3b25498ed8..d71425f465 100644
--- a/servers/rendering/renderer_scene.h
+++ b/servers/rendering/renderer_scene.h
@@ -207,6 +207,7 @@ public:
 
 	virtual void update() = 0;
 	virtual void render_probes() = 0;
+	virtual void update_visibility_notifiers() = 0;
 
 	virtual bool free(RID p_rid) = 0;
 
diff --git a/servers/rendering/renderer_scene_cull.cpp b/servers/rendering/renderer_scene_cull.cpp
index 2c66b22089..60c7dbf3b7 100644
--- a/servers/rendering/renderer_scene_cull.cpp
+++ b/servers/rendering/renderer_scene_cull.cpp
@@ -506,6 +506,9 @@ void RendererSceneCull::instance_set_base(RID p_instance, RID p_base) {
 				InstanceParticlesCollisionData *collision = static_cast<InstanceParticlesCollisionData *>(instance->base_data);
 				RSG::storage->free(collision->instance);
 			} break;
+			case RS::INSTANCE_VISIBLITY_NOTIFIER: {
+				//none
+			} break;
 			case RS::INSTANCE_REFLECTION_PROBE: {
 				InstanceReflectionProbeData *reflection_probe = static_cast<InstanceReflectionProbeData *>(instance->base_data);
 				scene_render->free(reflection_probe->instance);
@@ -615,6 +618,11 @@ void RendererSceneCull::instance_set_base(RID p_instance, RID p_base) {
 				RSG::storage->particles_collision_instance_set_active(collision->instance, instance->visible);
 				instance->base_data = collision;
 			} break;
+			case RS::INSTANCE_VISIBLITY_NOTIFIER: {
+				InstanceVisibilityNotifierData *vnd = memnew(InstanceVisibilityNotifierData);
+				vnd->base = p_base;
+				instance->base_data = vnd;
+			} break;
 			case RS::INSTANCE_REFLECTION_PROBE: {
 				InstanceReflectionProbeData *reflection_probe = memnew(InstanceReflectionProbeData);
 				reflection_probe->owner = instance;
@@ -1549,6 +1557,9 @@ void RendererSceneCull::_update_instance(Instance *p_instance) {
 			case RS::INSTANCE_VOXEL_GI: {
 				idata.instance_data_rid = static_cast<InstanceVoxelGIData *>(p_instance->base_data)->probe_instance.get_id();
 			} break;
+			case RS::INSTANCE_VISIBLITY_NOTIFIER: {
+				idata.visibility_notifier = static_cast<InstanceVisibilityNotifierData *>(p_instance->base_data);
+			} break;
 			default: {
 			}
 		}
@@ -1758,6 +1769,9 @@ void RendererSceneCull::_update_instance_aabb(Instance *p_instance) {
 			new_aabb = RSG::storage->particles_collision_get_aabb(p_instance->base);
 
 		} break;
+		case RenderingServer::INSTANCE_VISIBLITY_NOTIFIER: {
+			new_aabb = RSG::storage->visibility_notifier_get_aabb(p_instance->base);
+		} break;
 		case RenderingServer::INSTANCE_LIGHT: {
 			new_aabb = RSG::storage->light_get_aabb(p_instance->base);
 
@@ -2613,6 +2627,15 @@ void RendererSceneCull::_scene_cull(CullData &cull_data, InstanceCullResult &cul
 
 				} else if (base_type == RS::INSTANCE_LIGHTMAP) {
 					cull_result.lightmaps.push_back(RID::from_uint64(idata.instance_data_rid));
+				} else if (base_type == RS::INSTANCE_VISIBLITY_NOTIFIER) {
+					InstanceVisibilityNotifierData *vnd = idata.visibility_notifier;
+					if (!vnd->list_element.in_list()) {
+						visible_notifier_list_lock.lock();
+						visible_notifier_list.add(&vnd->list_element);
+						visible_notifier_list_lock.unlock();
+						vnd->just_visible = true;
+					}
+					vnd->visible_in_frame = RSG::rasterizer->get_frame_number();
 				} else if (((1 << base_type) & RS::INSTANCE_GEOMETRY_MASK) && !(idata.flags & InstanceData::FLAG_CAST_SHADOWS_ONLY)) {
 					bool keep = true;
 
@@ -3849,6 +3872,28 @@ TypedArray<Image> RendererSceneCull::bake_render_uv2(RID p_base, const Vector<RI
 	return scene_render->bake_render_uv2(p_base, p_material_overrides, p_image_size);
 }
 
+void RendererSceneCull::update_visibility_notifiers() {
+	SelfList<InstanceVisibilityNotifierData> *E = visible_notifier_list.first();
+	while (E) {
+		SelfList<InstanceVisibilityNotifierData> *N = E->next();
+
+		InstanceVisibilityNotifierData *visibility_notifier = E->self();
+		if (visibility_notifier->just_visible) {
+			visibility_notifier->just_visible = false;
+
+			RSG::storage->visibility_notifier_call(visibility_notifier->base, true, RSG::threaded);
+		} else {
+			if (visibility_notifier->visible_in_frame != RSG::rasterizer->get_frame_number()) {
+				visible_notifier_list.remove(E);
+
+				RSG::storage->visibility_notifier_call(visibility_notifier->base, false, RSG::threaded);
+			}
+		}
+
+		E = N;
+	}
+}
+
 /*******************************/
 /* Passthrough to Scene Render */
 /*******************************/
diff --git a/servers/rendering/renderer_scene_cull.h b/servers/rendering/renderer_scene_cull.h
index bdfbea95a2..d9466d8b04 100644
--- a/servers/rendering/renderer_scene_cull.h
+++ b/servers/rendering/renderer_scene_cull.h
@@ -118,6 +118,8 @@ public:
 	virtual void occluder_initialize(RID p_occluder);
 	virtual void occluder_set_mesh(RID p_occluder, const PackedVector3Array &p_vertices, const PackedInt32Array &p_indices);
 
+	/* VISIBILITY NOTIFIER API */
+
 	RendererSceneOcclusionCull *dummy_occlusion_culling;
 
 	/* SCENARIO API */
@@ -243,6 +245,8 @@ public:
 		}
 	};
 
+	struct InstanceVisibilityNotifierData;
+
 	struct InstanceData {
 		// Store instance pointer as well as common instance processing information,
 		// to make processing more cache friendly.
@@ -271,6 +275,7 @@ public:
 		union {
 			uint64_t instance_data_rid;
 			RendererSceneRender::GeometryInstance *instance_geometry;
+			InstanceVisibilityNotifierData *visibility_notifier;
 		};
 		Instance *instance = nullptr;
 		int32_t parent_array_index = -1;
@@ -611,6 +616,18 @@ public:
 		RID instance;
 	};
 
+	struct InstanceVisibilityNotifierData : public InstanceBaseData {
+		bool just_visible = false;
+		uint64_t visible_in_frame = 0;
+		RID base;
+		SelfList<InstanceVisibilityNotifierData> list_element;
+		InstanceVisibilityNotifierData() :
+				list_element(this) {}
+	};
+
+	SpinLock visible_notifier_list_lock;
+	SelfList<InstanceVisibilityNotifierData>::List visible_notifier_list;
+
 	struct InstanceLightData : public InstanceBaseData {
 		RID instance;
 		uint64_t last_version;
@@ -1123,6 +1140,8 @@ public:
 
 	void set_scene_render(RendererSceneRender *p_scene_render);
 
+	virtual void update_visibility_notifiers();
+
 	RendererSceneCull();
 	virtual ~RendererSceneCull();
 };
diff --git a/servers/rendering/renderer_storage.h b/servers/rendering/renderer_storage.h
index e6b9ac15ff..f22c582f48 100644
--- a/servers/rendering/renderer_storage.h
+++ b/servers/rendering/renderer_storage.h
@@ -557,6 +557,14 @@ public:
 	virtual bool particles_collision_is_heightfield(RID p_particles_collision) const = 0;
 	virtual RID particles_collision_get_heightfield_framebuffer(RID p_particles_collision) const = 0;
 
+	virtual RID visibility_notifier_allocate() = 0;
+	virtual void visibility_notifier_initialize(RID p_notifier) = 0;
+	virtual void visibility_notifier_set_aabb(RID p_notifier, const AABB &p_aabb) = 0;
+	virtual void visibility_notifier_set_callbacks(RID p_notifier, const Callable &p_enter_callbable, const Callable &p_exit_callable) = 0;
+
+	virtual AABB visibility_notifier_get_aabb(RID p_notifier) const = 0;
+	virtual void visibility_notifier_call(RID p_notifier, bool p_enter, bool p_deferred) = 0;
+
 	//used from 2D and 3D
 	virtual RID particles_collision_instance_create(RID p_collision) = 0;
 	virtual void particles_collision_instance_set_transform(RID p_collision_instance, const Transform3D &p_transform) = 0;
diff --git a/servers/rendering/rendering_server_default.cpp b/servers/rendering/rendering_server_default.cpp
index 95aa05f6b3..629d212b69 100644
--- a/servers/rendering/rendering_server_default.cpp
+++ b/servers/rendering/rendering_server_default.cpp
@@ -118,6 +118,7 @@ void RenderingServerDefault::_draw(bool p_swap_buffers, double frame_step) {
 	RSG::rasterizer->end_frame(p_swap_buffers);
 
 	RSG::canvas->update_visibility_notifiers();
+	RSG::scene->update_visibility_notifiers();
 
 	while (frame_drawn_callbacks.front()) {
 		Object *obj = ObjectDB::get_instance(frame_drawn_callbacks.front()->get().object);
diff --git a/servers/rendering/rendering_server_default.h b/servers/rendering/rendering_server_default.h
index 73373c97bb..9404374287 100644
--- a/servers/rendering/rendering_server_default.h
+++ b/servers/rendering/rendering_server_default.h
@@ -529,6 +529,12 @@ public:
 	FUNC1(particles_collision_height_field_update, RID)
 	FUNC2(particles_collision_set_height_field_resolution, RID, ParticlesCollisionHeightfieldResolution)
 
+	/* VISIBILITY_NOTIFIER */
+
+	FUNCRIDSPLIT(visibility_notifier)
+	FUNC2(visibility_notifier_set_aabb, RID, const AABB &)
+	FUNC3(visibility_notifier_set_callbacks, RID, const Callable &, const Callable &)
+
 #undef server_name
 #undef ServerName
 //from now on, calls forwarded to this singleton
@@ -549,7 +555,7 @@ public:
 
 	/* OCCLUDER */
 	FUNCRIDSPLIT(occluder)
-	FUNC3(occluder_set_mesh, RID, const PackedVector3Array &, const PackedInt32Array &);
+	FUNC3(occluder_set_mesh, RID, const PackedVector3Array &, const PackedInt32Array &)
 
 #undef server_name
 #undef ServerName