feat: add emergent world foundations

simulation/state/WorldEntityRef.gd

@@ -0,0 +1,63 @@
+class_name WorldEntityRef
+extends RefCounted
+
+const SCHEMA_VERSION := 1
+
+var _entity_type: StringName
+var _entity_id: StringName
+
+
+func _init(entity_type: StringName = &"", entity_id: StringName = &"") -> void:
+	_entity_type = entity_type
+	_entity_id = entity_id
+
+
+static func create(entity_type: StringName, entity_id: StringName) -> WorldEntityRef:
+	var entity_ref := WorldEntityRef.new(entity_type, entity_id)
+	return entity_ref if entity_ref.is_valid() else null
+
+
+static func from_dictionary(record_data: Dictionary) -> WorldEntityRef:
+	if int(record_data.get("schema_version", -1)) != SCHEMA_VERSION:
+		return null
+	if not record_data.has_all(["entity_type", "entity_id"]):
+		return null
+	return create(StringName(record_data["entity_type"]), StringName(record_data["entity_id"]))
+
+
+func is_valid() -> bool:
+	return not _entity_type.is_empty() and not _entity_id.is_empty()
+
+
+func get_entity_type() -> StringName:
+	return _entity_type
+
+
+func get_entity_id() -> StringName:
+	return _entity_id
+
+
+func index_key() -> String:
+	var type_text := String(_entity_type)
+	var id_text := String(_entity_id)
+	return "%d:%s%d:%s" % [type_text.length(), type_text, id_text.length(), id_text]
+
+
+func equals(other: WorldEntityRef) -> bool:
+	return (
+		other != null
+		and _entity_type == other.get_entity_type()
+		and _entity_id == other.get_entity_id()
+	)
+
+
+func duplicate_ref() -> WorldEntityRef:
+	return WorldEntityRef.new(_entity_type, _entity_id)
+
+
+func to_dictionary() -> Dictionary:
+	return {
+		"schema_version": SCHEMA_VERSION,
+		"entity_type": String(_entity_type),
+		"entity_id": String(_entity_id),
+	}