public GameplayManager(ContentManager content, GameScreen screen)
        {
            this.gameMode = GameMode.REALTIME;
            this.parentScreen = screen;
            this.missionRunning = true;

            dayCount = 1;

            ConstructReal();

            StartDay();
        }
        /// <summary>
        /// The constructor is private: loading screens should
        /// be activated via the static Load method instead.
        /// </summary>
        private LoadingScreen(ScreenManager screenManager, bool loadingIsSlow, bool loadIndicator,
                              GameScreen[] screensToLoad)
        {
            this.loadingIsSlow = loadingIsSlow;
            this.screensToLoad = screensToLoad;
            this.progressBar = new ProgressBar(screenManager.Game.GraphicsDevice, 75, 360, 700, 50);
            this.progressBar.minimum = 0;
            this.progressBar.maximum = 100;

            this.loadIndicator = loadIndicator;

            loadThread = new Thread(Load);

            loadProgress = 0;

            TransitionOnTime = TimeSpan.FromSeconds(0.5);
        }
        /// <summary>
        /// Removes a screen from the screen manager. You should normally
        /// use GameScreen.ExitScreen instead of calling this directly, so
        /// the screen can gradually transition off rather than just being
        /// instantly removed.
        /// </summary>
        public void RemoveScreen(GameScreen screen)
        {
            // If we have a graphics device, tell the screen to unload content.
            if (isInitialized)
            {
                screen.UnloadContent();
            }

            screens.Remove(screen);
            screensToUpdate.Remove(screen);
        }
        /// <summary>
        /// Adds a new screen to the screen manager.
        /// </summary>
        public void AddScreen(GameScreen screen, PlayerIndex? controllingPlayer)
        {
            screen.ControllingPlayer = controllingPlayer;
            screen.ScreenManager = this;
            screen.IsExiting = false;

            // If we have a graphics device, tell the screen to load content.
            if (isInitialized)
            {
                screen.LoadContent();
            }

            screens.Add(screen);
        }