feat(gameplay): implement entity update packets

Add S2CEntityUpdate to sync entity positions from server to client, including update handling in the client entity manager and server-side AI updates.

include/Cubed/gameplay/client_entity_manager.hpp

@@ -10,14 +10,15 @@ namespace Cubed {
 class ClientWorld;
 class ClientEntityManager {
 public:
-    enum class Command { CREATE, DESTORY };
+    enum class Command { CREATE, DESTORY, UPDATE };
 
     ClientEntityManager(ClientWorld& world);
     void update();
     void init();
 
-    void receive_entity_create(S2CEntityCreate& s2c);
+    void receive_entity_create(S2CEntityCreate& msg);
     void receive_entity_destory(EntityID id);
+    void receive_entity_update(S2CEntityUpdate& msg);
 
     void destory(EntityID id);
     void create(std::string_view name, const glm::vec3& pos);
@@ -30,11 +31,17 @@ private:
         std::string name;
         glm::vec3 pos;
     };
+
+    struct UpdateInfo {
+        EntityID id;
+        glm::vec3 pos;
+    };
+
     using EntityMap = tbb::concurrent_hash_map<EntityID, entt::entity>;
     using acc = EntityMap::accessor;
     using cacc = EntityMap::const_accessor;
     using CreateFunc = std::function<void(EntityID id)>;
-    using TaskElement = std::variant<EntityCreateElement, EntityID>;
+    using TaskElement = std::variant<EntityCreateElement, EntityID, UpdateInfo>;
     using TaskPair = std::pair<Command, TaskElement>;
 
     ClientWorld& m_world;
@@ -48,6 +55,7 @@ private:
     // not thread safe
     void handle_entity_create(EntityID id, std::string_view name,
                               const glm::vec3& pos);
+    void handle_entity_update(UpdateInfo& info);
     template <typename... Args>
     void create_entity_in_registry(EntityID id, Args&&... args) {
         {

include/Cubed/gameplay/packet.hpp

@@ -51,10 +51,12 @@ enum class PacketEnum : uint16_t {
     LOGIN_RSP = 1002,
     LOGOUT_REQ = 1003,
     LOGOUT_RSP = 1004,
+
     PLAYER_INFO = 2001,
     C2S_PLAYER_INFO = 2002,
     PLAYER_INFO_RSP = 2003,
     PLAYER_WATER_SOUND = 2004,
+
     CHUNK_DATA_REQ = 3001,
     CHUNK_DATA_RSP = 3002,
     BLOCK_CHANGE_REQ = 3003,
@@ -65,8 +67,11 @@ enum class PacketEnum : uint16_t {
     S2C_ENTITY_DESTORY = 3008,
     C2S_ENTITY_CREATE_REQUEST = 3009,
     C2S_ENTITY_DESTORY_REQUEST = 3010,
+    S2C_ENTITY_UPDATE = 3011,
+
     CHAT_MSG = 4001,
     VOICE_MSG = 4002,
+
     PING = 9001,
     PONG = 9002
 
@@ -145,6 +150,9 @@ template <> constexpr uint16_t get_packet_id<ChatMsg>() {
 template <> constexpr uint16_t get_packet_id<VoiceMsg>() {
     return std::to_underlying(PacketEnum::VOICE_MSG);
 }
+template <> constexpr uint16_t get_packet_id<S2CEntityUpdate>() {
+    return std::to_underlying(PacketEnum::S2C_ENTITY_UPDATE);
+}
 
 template <typename T>
     requires std::derived_from<T, google::protobuf::Message>

include/Cubed/gameplay/server_entity_manager.hpp

@@ -44,6 +44,7 @@ private:
     void handle_entity_destory(EntityID id);
     void handle_task();
     void send_all_entities(std::shared_ptr<Session>& session);
+    void update_ai();
     template <typename... Args>
     EntityID create_entity_in_factory(Args&&... args) {
         auto entity = m_registry.create();