fix: potential data race in m_gen_player_pos

include/Cubed/gameplay/world.hpp

@@ -31,6 +31,7 @@ private:
     std::mutex m_gen_signal_mutex;
     std::mutex m_new_chunk_queue_mutex;
     std::mutex m_delete_vbo_mutex;
+    std::mutex m_gen_player_pos_mutex;
     std::vector<GLuint> m_pending_delete_vbo;
     std::condition_variable m_gen_cv;
     std::atomic<bool> m_gen_running{false};

src/gameplay/world.cpp

@@ -169,8 +169,12 @@ ChunkPos World::chunk_pos(int world_x, int world_z) {
 }
 
 void World::gen_chunks_internal() {
+    glm::vec3 player_pos;
+    {
+        std::lock_guard lk(m_gen_player_pos_mutex);
+        player_pos = m_gen_player_pos;
+    }
     
-    const auto& player_pos = m_gen_player_pos;
 
     int x = std::floor(player_pos.x);
     int z = std::floor(player_pos.z);
@@ -293,7 +297,11 @@ void World::stop_gen_thread() {
 }
 
 void World::need_gen() {
+    {
+        std::lock_guard lk(m_gen_player_pos_mutex);
         m_gen_player_pos = get_player("TestPlayer").get_player_pos();
+    }
+    
     m_need_gen_chunk = true;
     m_gen_cv.notify_one();
 }