Implement Animation Libraries

* Instead of containing single animations, AnimationPlayer now contains libraries.
* Libraries, in turn, contain the animations.

This paves the way for implementing the possibility of importing scenes as animation libraries, finally allowing to import animations separate from the 3D models.

Missing (will be done on separate PRs):

* Make it possible to import scenes (dae/fbx/gltf) as animation libraries.
* Make it possible for AnimationTree to import animation libraries on its own, so it does not rely on AnimationPlayer for everything.

1 files changed, 309 insertions, 57 deletions

diff --git a/scene/animation/animation_player.cpp b/scene/animation/animation_player.cpp
index 1ab2e2419e..6949e3681c 100644
--- a/scene/animation/animation_player.cpp
+++ b/scene/animation/animation_player.cpp
@@ -83,8 +83,31 @@ bool AnimationPlayer::_set(const StringName &p_name, const Variant &p_value) {
 		set_current_animation(p_value);
 
 	} else if (name.begins_with("anims/")) {
+		// Backwards compatibility with 3.x, add them to "default" library.
 		String which = name.get_slicec('/', 1);
-		add_animation(which, p_value);
+
+		Ref<Animation> anim = p_value;
+		Ref<AnimationLibrary> al;
+		if (!has_animation_library(StringName())) {
+			al.instantiate();
+			add_animation_library(StringName(), al);
+		} else {
+			al = get_animation_library(StringName());
+		}
+		al->add_animation(which, anim);
+
+	} else if (name.begins_with("libraries")) {
+		Dictionary d = p_value;
+		while (animation_libraries.size()) {
+			remove_animation_library(animation_libraries[0].name);
+		}
+		List<Variant> keys;
+		d.get_key_list(&keys);
+		for (const Variant &K : keys) {
+			StringName lib_name = K;
+			Ref<AnimationLibrary> lib = d[lib_name];
+			add_animation_library(lib_name, lib);
+		}
 
 	} else if (name.begins_with("next/")) {
 		String which = name.get_slicec('/', 1);
@@ -117,9 +140,13 @@ bool AnimationPlayer::_get(const StringName &p_name, Variant &r_ret) const {
 
 		r_ret = get_current_animation();
 
-	} else if (name.begins_with("anims/")) {
-		String which = name.get_slicec('/', 1);
-		r_ret = get_animation(which);
+	} else if (name.begins_with("libraries")) {
+		Dictionary d;
+		for (uint32_t i = 0; i < animation_libraries.size(); i++) {
+			d[animation_libraries[i].name] = animation_libraries[i].library;
+		}
+
+		r_ret = d;
 
 	} else if (name.begins_with("next/")) {
 		String which = name.get_slicec('/', 1);
@@ -173,8 +200,9 @@ void AnimationPlayer::_validate_property(PropertyInfo &property) const {
 void AnimationPlayer::_get_property_list(List<PropertyInfo> *p_list) const {
 	List<PropertyInfo> anim_names;
 
+	anim_names.push_back(PropertyInfo(Variant::DICTIONARY, "libraries"));
+
 	for (const KeyValue<StringName, AnimationData> &E : animation_set) {
-		anim_names.push_back(PropertyInfo(Variant::OBJECT, "anims/" + String(E.key), PROPERTY_HINT_RESOURCE_TYPE, "Animation", PROPERTY_USAGE_NO_EDITOR | PROPERTY_USAGE_INTERNAL | PROPERTY_USAGE_DO_NOT_SHARE_ON_DUPLICATE));
 		if (E.value.next != StringName()) {
 			anim_names.push_back(PropertyInfo(Variant::STRING, "next/" + String(E.key), PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NO_EDITOR | PROPERTY_USAGE_INTERNAL));
 		}
@@ -1155,71 +1183,106 @@ void AnimationPlayer::_animation_process(double p_delta) {
 	}
 }
 
-Error AnimationPlayer::add_animation(const StringName &p_name, const Ref<Animation> &p_animation) {
-#ifdef DEBUG_ENABLED
-	ERR_FAIL_COND_V_MSG(String(p_name).contains("/") || String(p_name).contains(":") || String(p_name).contains(",") || String(p_name).contains("["), ERR_INVALID_PARAMETER, "Invalid animation name: " + String(p_name) + ".");
-#endif
+void AnimationPlayer::_animation_set_cache_update() {
+	// Relatively fast function to update all animations.
 
-	ERR_FAIL_COND_V(p_animation.is_null(), ERR_INVALID_PARAMETER);
+	animation_set_update_pass++;
+	bool clear_cache_needed = false;
 
-	if (animation_set.has(p_name)) {
-		_unref_anim(animation_set[p_name].animation);
-		animation_set[p_name].animation = p_animation;
-		clear_caches();
-	} else {
-		AnimationData ad;
-		ad.animation = p_animation;
-		ad.name = p_name;
-		animation_set[p_name] = ad;
-	}
+	// Update changed and add otherwise
+	for (uint32_t i = 0; i < animation_libraries.size(); i++) {
+		for (const KeyValue<StringName, Ref<Animation>> &K : animation_libraries[i].library->animations) {
+			StringName key = animation_libraries[i].name == StringName() ? K.key : StringName(String(animation_libraries[i].name) + "/" + String(K.key));
+			if (!animation_set.has(key)) {
+				AnimationData ad;
+				ad.animation = K.value;
+				ad.animation_library = animation_libraries[i].name;
+				ad.name = key;
+				ad.last_update = animation_set_update_pass;
+				animation_set.insert(ad.name, ad);
+			} else {
+				AnimationData &ad = animation_set[key];
+				if (ad.last_update != animation_set_update_pass) {
+					// Was not updated, update. If the animation is duplicated, the second one will be ignored.
+					if (ad.animation != K.value || ad.animation_library != animation_libraries[i].name) {
+						// Animation changed, update and clear caches.
+						clear_cache_needed = true;
+						ad.animation = K.value;
+						ad.animation_library = animation_libraries[i].name;
+					}
 
-	_ref_anim(p_animation);
-	notify_property_list_changed();
-	return OK;
-}
+					ad.last_update = animation_set_update_pass;
+				}
+			}
+		}
+	}
 
-void AnimationPlayer::remove_animation(const StringName &p_name) {
-	ERR_FAIL_COND(!animation_set.has(p_name));
+	// Check removed
+	List<StringName> to_erase;
+	for (const KeyValue<StringName, AnimationData> &E : animation_set) {
+		if (E.value.last_update != animation_set_update_pass) {
+			// Was not updated, must be erased
+			to_erase.push_back(E.key);
+			clear_cache_needed = true;
+		}
+	}
 
-	stop();
-	_unref_anim(animation_set[p_name].animation);
-	animation_set.erase(p_name);
+	while (to_erase.size()) {
+		animation_set.erase(to_erase.front()->get());
+		to_erase.pop_front();
+	}
 
-	clear_caches();
-	notify_property_list_changed();
+	if (clear_cache_needed) {
+		// If something was modified or removed, caches need to be cleared
+		clear_caches();
+	}
 }
 
-void AnimationPlayer::_ref_anim(const Ref<Animation> &p_anim) {
-	Ref<Animation>(p_anim)->connect(SceneStringNames::get_singleton()->tracks_changed, callable_mp(this, &AnimationPlayer::_animation_changed), varray(), CONNECT_REFERENCE_COUNTED);
-}
+void AnimationPlayer::_animation_added(const StringName &p_name, const StringName &p_library) {
+	_animation_set_cache_update();
 
-void AnimationPlayer::_unref_anim(const Ref<Animation> &p_anim) {
-	Ref<Animation>(p_anim)->disconnect(SceneStringNames::get_singleton()->tracks_changed, callable_mp(this, &AnimationPlayer::_animation_changed));
+	update_configuration_warnings();
 }
 
-void AnimationPlayer::rename_animation(const StringName &p_name, const StringName &p_new_name) {
-	ERR_FAIL_COND(!animation_set.has(p_name));
-	ERR_FAIL_COND(String(p_new_name).contains("/") || String(p_new_name).contains(":"));
-	ERR_FAIL_COND(animation_set.has(p_new_name));
+void AnimationPlayer::_animation_removed(const StringName &p_name, const StringName &p_library) {
+	StringName name = p_library == StringName() ? p_name : StringName(String(p_library) + "/" + String(p_name));
 
-	stop();
-	AnimationData ad = animation_set[p_name];
-	ad.name = p_new_name;
-	animation_set.erase(p_name);
-	animation_set[p_new_name] = ad;
+	if (!animation_set.has(name)) {
+		return; // No need to update because not the one from the library being used.
+	}
+	_animation_set_cache_update();
+
+	// Erase blends if needed
+	List<BlendKey> to_erase;
+	for (const KeyValue<BlendKey, float> &E : blend_times) {
+		BlendKey bk = E.key;
+		if (bk.from == name || bk.to == name) {
+			to_erase.push_back(bk);
+		}
+	}
+
+	while (to_erase.size()) {
+		blend_times.erase(to_erase.front()->get());
+		to_erase.pop_front();
+	}
+
+	update_configuration_warnings();
+}
 
+void AnimationPlayer::_rename_animation(const StringName &p_from_name, const StringName &p_to_name) {
+	// Rename autoplay or blends if needed.
 	List<BlendKey> to_erase;
 	Map<BlendKey, float> to_insert;
 	for (const KeyValue<BlendKey, float> &E : blend_times) {
 		BlendKey bk = E.key;
 		BlendKey new_bk = bk;
 		bool erase = false;
-		if (bk.from == p_name) {
-			new_bk.from = p_new_name;
+		if (bk.from == p_from_name) {
+			new_bk.from = p_to_name;
 			erase = true;
 		}
-		if (bk.to == p_name) {
-			new_bk.to = p_new_name;
+		if (bk.to == p_from_name) {
+			new_bk.to = p_to_name;
 			erase = true;
 		}
 
@@ -1239,12 +1302,184 @@ void AnimationPlayer::rename_animation(const StringName &p_name, const StringNam
 		to_insert.erase(to_insert.front());
 	}
 
-	if (autoplay == p_name) {
-		autoplay = p_new_name;
+	if (autoplay == p_from_name) {
+		autoplay = p_to_name;
 	}
+}
+
+void AnimationPlayer::_animation_renamed(const StringName &p_name, const StringName &p_to_name, const StringName &p_library) {
+	StringName from_name = p_library == StringName() ? p_name : StringName(String(p_library) + "/" + String(p_name));
+	StringName to_name = p_library == StringName() ? p_to_name : StringName(String(p_library) + "/" + String(p_to_name));
+
+	if (!animation_set.has(from_name)) {
+		return; // No need to update because not the one from the library being used.
+	}
+	_animation_set_cache_update();
+
+	_rename_animation(from_name, to_name);
+	update_configuration_warnings();
+}
+
+Error AnimationPlayer::add_animation_library(const StringName &p_name, const Ref<AnimationLibrary> &p_animation_library) {
+	ERR_FAIL_COND_V(p_animation_library.is_null(), ERR_INVALID_PARAMETER);
+#ifdef DEBUG_ENABLED
+	ERR_FAIL_COND_V_MSG(String(p_name).contains("/") || String(p_name).contains(":") || String(p_name).contains(",") || String(p_name).contains("["), ERR_INVALID_PARAMETER, "Invalid animation name: " + String(p_name) + ".");
+#endif
+
+	int insert_pos = 0;
+
+	for (uint32_t i = 0; i < animation_libraries.size(); i++) {
+		ERR_FAIL_COND_V_MSG(animation_libraries[i].name == p_name, ERR_ALREADY_EXISTS, "Can't add animation library twice with name: " + String(p_name));
+		ERR_FAIL_COND_V_MSG(animation_libraries[i].library == p_animation_library, ERR_ALREADY_EXISTS, "Can't add animation library twice (adding as '" + p_name.operator String() + "', exists as '" + animation_libraries[i].name.operator String() + "'.");
+
+		if (animation_libraries[i].name.operator String() >= p_name.operator String()) {
+			break;
+		}
+
+		insert_pos++;
+	}
+
+	AnimationLibraryData ald;
+	ald.name = p_name;
+	ald.library = p_animation_library;
+
+	animation_libraries.insert(insert_pos, ald);
+
+	ald.library->connect(SNAME("animation_added"), callable_mp(this, &AnimationPlayer::_animation_added), varray(p_name));
+	ald.library->connect(SNAME("animation_removed"), callable_mp(this, &AnimationPlayer::_animation_added), varray(p_name));
+	ald.library->connect(SNAME("animation_renamed"), callable_mp(this, &AnimationPlayer::_animation_renamed), varray(p_name));
+
+	_animation_set_cache_update();
+
+	notify_property_list_changed();
+
+	update_configuration_warnings();
+	return OK;
+}
+
+void AnimationPlayer::remove_animation_library(const StringName &p_name) {
+	int at_pos = -1;
+
+	for (uint32_t i = 0; i < animation_libraries.size(); i++) {
+		if (animation_libraries[i].name == p_name) {
+			at_pos = i;
+			break;
+		}
+	}
+
+	ERR_FAIL_COND(at_pos == -1);
+
+	animation_libraries[at_pos].library->disconnect(SNAME("animation_added"), callable_mp(this, &AnimationPlayer::_animation_added));
+	animation_libraries[at_pos].library->disconnect(SNAME("animation_removed"), callable_mp(this, &AnimationPlayer::_animation_added));
+	animation_libraries[at_pos].library->disconnect(SNAME("animation_renamed"), callable_mp(this, &AnimationPlayer::_animation_renamed));
+
+	stop();
+
+	for (const KeyValue<StringName, Ref<Animation>> &K : animation_libraries[at_pos].library->animations) {
+		_unref_anim(K.value);
+	}
+
+	animation_libraries.remove_at(at_pos);
+	_animation_set_cache_update();
 
-	clear_caches();
 	notify_property_list_changed();
+	update_configuration_warnings();
+}
+
+void AnimationPlayer::_ref_anim(const Ref<Animation> &p_anim) {
+	Ref<Animation>(p_anim)->connect(SceneStringNames::get_singleton()->tracks_changed, callable_mp(this, &AnimationPlayer::_animation_changed), varray(), CONNECT_REFERENCE_COUNTED);
+}
+
+void AnimationPlayer::_unref_anim(const Ref<Animation> &p_anim) {
+	Ref<Animation>(p_anim)->disconnect(SceneStringNames::get_singleton()->tracks_changed, callable_mp(this, &AnimationPlayer::_animation_changed));
+}
+
+void AnimationPlayer::rename_animation_library(const StringName &p_name, const StringName &p_new_name) {
+	if (p_name == p_new_name) {
+		return;
+	}
+#ifdef DEBUG_ENABLED
+	ERR_FAIL_COND_MSG(String(p_new_name).contains("/") || String(p_new_name).contains(":") || String(p_new_name).contains(",") || String(p_new_name).contains("["), "Invalid animation library name: " + String(p_new_name) + ".");
+#endif
+
+	bool found = false;
+	for (uint32_t i = 0; i < animation_libraries.size(); i++) {
+		ERR_FAIL_COND_MSG(animation_libraries[i].name == p_new_name, "Can't rename animation library to another existing name: " + String(p_new_name));
+		if (animation_libraries[i].name == p_name) {
+			found = true;
+			animation_libraries[i].name = p_new_name;
+			// rename connections
+			animation_libraries[i].library->disconnect(SNAME("animation_added"), callable_mp(this, &AnimationPlayer::_animation_added));
+			animation_libraries[i].library->disconnect(SNAME("animation_removed"), callable_mp(this, &AnimationPlayer::_animation_added));
+			animation_libraries[i].library->disconnect(SNAME("animation_renamed"), callable_mp(this, &AnimationPlayer::_animation_renamed));
+
+			animation_libraries[i].library->connect(SNAME("animation_added"), callable_mp(this, &AnimationPlayer::_animation_added), varray(p_new_name));
+			animation_libraries[i].library->connect(SNAME("animation_removed"), callable_mp(this, &AnimationPlayer::_animation_added), varray(p_new_name));
+			animation_libraries[i].library->connect(SNAME("animation_renamed"), callable_mp(this, &AnimationPlayer::_animation_renamed), varray(p_new_name));
+
+			for (const KeyValue<StringName, Ref<Animation>> &K : animation_libraries[i].library->animations) {
+				StringName old_name = p_name == StringName() ? K.key : StringName(String(p_name) + "/" + String(K.key));
+				StringName new_name = p_new_name == StringName() ? K.key : StringName(String(p_new_name) + "/" + String(K.key));
+				_rename_animation(old_name, new_name);
+			}
+		}
+	}
+
+	ERR_FAIL_COND(!found);
+
+	stop();
+
+	animation_libraries.sort(); // Must keep alphabetical order.
+
+	_animation_set_cache_update(); // Update cache.
+
+	notify_property_list_changed();
+}
+
+bool AnimationPlayer::has_animation_library(const StringName &p_name) const {
+	for (uint32_t i = 0; i < animation_libraries.size(); i++) {
+		if (animation_libraries[i].name == p_name) {
+			return true;
+		}
+	}
+
+	return false;
+}
+
+Ref<AnimationLibrary> AnimationPlayer::get_animation_library(const StringName &p_name) const {
+	for (uint32_t i = 0; i < animation_libraries.size(); i++) {
+		if (animation_libraries[i].name == p_name) {
+			return animation_libraries[i].library;
+		}
+	}
+	ERR_FAIL_V(Ref<AnimationLibrary>());
+}
+
+TypedArray<StringName> AnimationPlayer::_get_animation_library_list() const {
+	TypedArray<StringName> ret;
+	for (uint32_t i = 0; i < animation_libraries.size(); i++) {
+		ret.push_back(animation_libraries[i].name);
+	}
+	return ret;
+}
+
+void AnimationPlayer::get_animation_library_list(List<StringName> *p_libraries) const {
+	for (uint32_t i = 0; i < animation_libraries.size(); i++) {
+		p_libraries->push_back(animation_libraries[i].name);
+	}
+}
+
+TypedArray<String> AnimationPlayer::get_configuration_warnings() const {
+	TypedArray<String> warnings = Node::get_configuration_warnings();
+
+	for (uint32_t i = 0; i < animation_libraries.size(); i++) {
+		for (const KeyValue<StringName, Ref<Animation>> &K : animation_libraries[i].library->animations) {
+			if (animation_set.has(K.key) && animation_set[K.key].animation_library != animation_libraries[i].name) {
+				warnings.push_back(vformat(RTR("Animation '%s' in library '%s' is unused because another animation with the same name exists in library '%s'."), K.key, animation_libraries[i].name, animation_set[K.key].animation_library));
+			}
+		}
+	}
+	return warnings;
 }
 
 bool AnimationPlayer::has_animation(const StringName &p_name) const {
@@ -1585,7 +1820,16 @@ StringName AnimationPlayer::find_animation(const Ref<Animation> &p_animation) co
 		}
 	}
 
-	return "";
+	return StringName();
+}
+
+StringName AnimationPlayer::find_animation_library(const Ref<Animation> &p_animation) const {
+	for (const KeyValue<StringName, AnimationData> &E : animation_set) {
+		if (E.value.animation == p_animation) {
+			return E.value.animation_library;
+		}
+	}
+	return StringName();
 }
 
 void AnimationPlayer::set_autoplay(const String &p_name) {
@@ -1764,7 +2008,10 @@ Ref<AnimatedValuesBackup> AnimationPlayer::apply_reset(bool p_user_initiated) {
 
 	AnimationPlayer *aux_player = memnew(AnimationPlayer);
 	EditorNode::get_singleton()->add_child(aux_player);
-	aux_player->add_animation(SceneStringNames::get_singleton()->RESET, reset_anim);
+	Ref<AnimationLibrary> al;
+	al.instantiate();
+	al->add_animation(SceneStringNames::get_singleton()->RESET, reset_anim);
+	aux_player->add_animation_library("default", al);
 	aux_player->set_assigned_animation(SceneStringNames::get_singleton()->RESET);
 	// Forcing the use of the original root because the scene where original player belongs may be not the active one
 	Node *root = get_node(get_root());
@@ -1792,9 +2039,13 @@ bool AnimationPlayer::can_apply_reset() const {
 #endif // TOOLS_ENABLED
 
 void AnimationPlayer::_bind_methods() {
-	ClassDB::bind_method(D_METHOD("add_animation", "name", "animation"), &AnimationPlayer::add_animation);
-	ClassDB::bind_method(D_METHOD("remove_animation", "name"), &AnimationPlayer::remove_animation);
-	ClassDB::bind_method(D_METHOD("rename_animation", "name", "newname"), &AnimationPlayer::rename_animation);
+	ClassDB::bind_method(D_METHOD("add_animation_library", "name", "library"), &AnimationPlayer::add_animation_library);
+	ClassDB::bind_method(D_METHOD("remove_animation_library", "name"), &AnimationPlayer::remove_animation_library);
+	ClassDB::bind_method(D_METHOD("rename_animation_library", "name", "newname"), &AnimationPlayer::rename_animation_library);
+	ClassDB::bind_method(D_METHOD("has_animation_library", "name"), &AnimationPlayer::has_animation_library);
+	ClassDB::bind_method(D_METHOD("get_animation_library", "name"), &AnimationPlayer::get_animation_library);
+	ClassDB::bind_method(D_METHOD("get_animation_library_list"), &AnimationPlayer::_get_animation_library_list);
+
 	ClassDB::bind_method(D_METHOD("has_animation", "name"), &AnimationPlayer::has_animation);
 	ClassDB::bind_method(D_METHOD("get_animation", "name"), &AnimationPlayer::get_animation);
 	ClassDB::bind_method(D_METHOD("get_animation_list"), &AnimationPlayer::_get_animation_list);
@@ -1838,6 +2089,7 @@ void AnimationPlayer::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("get_root"), &AnimationPlayer::get_root);
 
 	ClassDB::bind_method(D_METHOD("find_animation", "animation"), &AnimationPlayer::find_animation);
+	ClassDB::bind_method(D_METHOD("find_animation_library", "animation"), &AnimationPlayer::find_animation_library);
 
 	ClassDB::bind_method(D_METHOD("clear_caches"), &AnimationPlayer::clear_caches);