feat(gameplay): optimize chunk request with player chunk tracking

Add `update_player_chunk()` method to `ClientPlayer` that triggers a chunk request when the player moves more than 2 chunks away from the last recorded chunk. Introduce an atomic `m_requesting_chunk` flag in `ClientWorld` to prevent concurrent requests. Rename `m_player_chunk_pos` to `m_last_chunk_pos` for clarity.

include/Cubed/gameplay/client_player.hpp

@@ -86,7 +86,7 @@ private:
     // player is tow block tall, the pos is the lower pos
 
     glm::vec3 m_player_pos{0.0f, 255.0f, 0.0f};
-    ChunkPos m_player_chunk_pos{0, 0};
+    ChunkPos m_last_chunk_pos{0, 0};
 
     glm::vec3 m_front{0, 0, -1};
     glm::vec3 m_right{0, 0, 0};
@@ -112,5 +112,6 @@ private:
     void update_x_move(glm::vec3& player_pos);
     void update_y_move(glm::vec3& player_pos);
     void update_z_move(glm::vec3& player_pos);
+    void update_player_chunk();
 };
 } // namespace Cubed

include/Cubed/gameplay/client_world.hpp

@@ -40,7 +40,7 @@ public:
     void stop_client_thread();
 
     void hot_reload();
-
+    void request_chunk();
     std::vector<glm::vec4>& planes();
     std::vector<ChunkRenderSnapshot>& render_snapshots();
     glm::vec3 sunlight_dir() const;
@@ -76,6 +76,7 @@ private:
     std::atomic<int> m_rendering_distance{24};
     std::atomic<TickType> m_game_ticks{0};
     std::atomic<TickType> m_day_tick{6000};
+    std::atomic<bool> m_requesting_chunk{false};
     std::shared_ptr<NetworkClient> m_client;
     void client_run(std::stop_token token);
 
@@ -83,7 +84,6 @@ private:
 
     void report_player_pos();
 
-    void request_chunk();
     void set_block(const glm::ivec3& pos, unsigned id);
 };
 } // namespace Cubed