Implement game mutex for thread safety

src/Game.cpp

@@ -10,18 +10,24 @@ using namespace std::literals::chrono_literals;
 void Game::update(std::stop_token stop_token)
 {
     while (!stop_token.stop_requested()) {
+        game_mutex.lock();
+
         player.update();
 
         renderer.redraw();
 
         map.check_bounds(player.x, player.y);
 
+        game_mutex.unlock();
+
         std::this_thread::sleep_for(16666us);
     }
 }
 
-void Game::draw() const
+void Game::draw()
 {
+    const std::lock_guard lock(game_mutex);
+
     renderer.clear_screen(0x80, 0x40, 0xFF, 0xFF);
 
     map.draw(player.x, player.y);

src/Game.hpp

@@ -14,6 +14,7 @@ private:
     Map map;
 
     std::jthread update_thread;
+    std::mutex game_mutex;
 
     void update(std::stop_token stop_token);
 
@@ -24,7 +25,7 @@ public:
 
     void run();
 
-    void draw() const;
+    void draw();
 };
 
 #endif