Pausing a Game

Demonstrates how to add pause functionality to a game.

Pausing a Game

Typically, there are two circumstances when you want to pause your game: to respond to a user request such as a launch menu or the user entering a specific keystroke, or when the Guide appears on the screen and obscures the playing field. In addition, there are different scenarios for ending a pause. A user requested pause should end when the user takes an action, however, a Guide pause should end when the Guide is dismissed.

Query the Guide.IsVisible property to check for the presence of the Guide.

Pausing your game often means more than just halting your simulation. It could also require pausing or muting sounds, halting controller vibrations, sending a network message, and so on. To handle those tasks, you need to declare a BeginPause and EndPause method. EndPause resumes anything that was halted by BeginPause.

Pausing a game

1. Add a variable to track the pause state.

2. Add a variable to track the state of the pause key.

3. Add a variable to track if the pause is due to user action or the Guide.

   private bool paused = false;
   private bool pauseKeyDown = false;
   private bool pausedForGuide = false;
   

4. Add a BeginPause method to initiate a pause, setting the variables appropriately.

   private void BeginPause(bool UserInitiated)
   {
       paused = true;
       pausedForGuide = !UserInitiated;
       //TODO: Pause audio playback
       //TODO: Pause controller vibration
   }
   

5. Add an EndPause method to resume from a paused state, resetting variables appropriately.

   private void EndPause()
   {
       //TODO: Resume audio
       //TODO: Resume controller vibration
       pausedForGuide = false;
       paused = false;
   }
   

6. Add a function to poll the state of the pause key with Keyboard.GetState and KeyboardState.IsKeyDown.

   If the key has changed from down to up, toggle the pause state using BeginPause or EndPause.

   private void checkPauseKey(KeyboardState keyboardState,
       GamePadState gamePadState)
   {
       bool pauseKeyDownThisFrame = (keyboardState.IsKeyDown(Keys.P) ||
           (gamePadState.Buttons.Y == ButtonState.Pressed));
       // If key was not down before, but is down now, we toggle the
       // pause setting
       if (!pauseKeyDown && pauseKeyDownThisFrame)
       {
           if (!paused)
               BeginPause(true);
           else
               EndPause();
       }
       pauseKeyDown = pauseKeyDownThisFrame;
   }
   

7. During Update, check to see if the user paused, or if the Guide is active.

   Add a conditional around any update code so it is called only if the game is not paused. Be sure to call base.Update even if the simulation is paused.

   // Check to see if the user has paused or unpaused
   checkPauseKey(keyboardState, gamePadState);
   
   checkPauseGuide();
   
   // If the user hasn't paused, Update normally
   if (!paused)
   {
       Simulate(gameTime);
   }
   

8. Add a function to poll the state of the Guide.

   If the Guide is newly visible, call BeginPause.

   If the Guide is not visible, but the game was paused for the guide, call EndPause.

   private void checkPauseGuide()
   {
       // Pause if the Guide is up
       if (!paused && Guide.IsVisible)
           BeginPause(false);
       // If we paused for the guide, unpause if the guide
       // went away
       else if (paused && pausedForGuide && !Guide.IsVisible)
           EndPause();
   }
   

Remarks

Best Practice

You could implement a menu of options to display when a game is paused, such as those listed below.

• Guide.IsVisible is true, as the guide blocks user inputs from reaching the game.
• Game.IsActive is false, indicating that trial mode may have ended for the game.
• GamePadState.IsConnected is false, indicating that the game controller is disconnected.

For a multiplayer game, a pause usually disables local input without pausing the game for remote players.