/// <summary>
/// Updates the state of the game.
/// </summary>
public override void Update(GameTime gameTime, bool otherScreenHasFocus,
bool coveredByOtherScreen)
{
base.Update(gameTime, otherScreenHasFocus, false);
// Gradually fade in or out depending on whether we are covered by the pause screen.
if (coveredByOtherScreen)
{
pauseAlpha = Math.Min(pauseAlpha + 1f / 32, 1);
}
else
{
pauseAlpha = Math.Max(pauseAlpha - 1f / 32, 0);
}
if (IsActive)
{
// Apply some random jitter to make the enemy move around.
const float randomization = 10;
enemyPosition.X += (float)(random.NextDouble() - 0.5) * randomization;
enemyPosition.Y += (float)(random.NextDouble() - 0.5) * randomization;
// Apply a stabilizing force to stop the enemy moving off the screen.
Vector2 targetPosition = new Vector2(200, 200);
enemyPosition = Vector2.Lerp(enemyPosition, targetPosition, 0.05f);
// TODO: this game isn't very fun! You could probably improve
// it by inserting something more interesting in this space :-)
}
// If we are in a network game, check if we should return to the lobby.
if ((networkSession != null) && !IsExiting)
{
if (networkSession.SessionState == NetworkSessionState.Lobby)
{
LoadingScreen.Load(ScreenManager, true, null,
new BackgroundScreen(),
new LobbyScreen(networkSession));
}
}
}
/// <summary>
/// Event handler called when the system delivers an invite notification.
/// This can occur when the user accepts an invite that was sent to them by
/// a friend (pull mode), or if they choose the "Join Session In Progress"
/// option in their friends screen (push mode). The handler leaves the
/// current session (if any), then joins the session referred to by the
/// invite. It is not necessary to prompt the user before doing this, as
/// the Guide will already have taken care of the necessary confirmations
/// before the invite was delivered to you.
/// </summary>
public static void InviteAccepted(ScreenManager screenManager,
InviteAcceptedEventArgs e)
{
// If we are already in a network session, leave it now.
NetworkSessionComponent self = FindSessionComponent(screenManager.Game);
if (self != null)
{
self.Dispose();
}
try
{
// Which local profiles should we include in this session?
IEnumerable <SignedInGamer> localGamers =
ChooseGamers(NetworkSessionType.PlayerMatch, e.Gamer.PlayerIndex);
// Begin an asynchronous join-from-invite operation.
IAsyncResult asyncResult = NetworkSession.BeginJoinInvited(localGamers,
null, null);
// Use the loading screen to replace whatever screens were previously
// active. This will completely reset the screen state, regardless of
// whether we were in the menus or playing a game when the invite was
// delivered. When the loading screen finishes, it will activate the
// network busy screen, which displays an animation as it waits for
// the join operation to complete.
NetworkBusyScreen busyScreen = new NetworkBusyScreen(asyncResult);
busyScreen.OperationCompleted += JoinInvitedOperationCompleted;
LoadingScreen.Load(screenManager, false, null, new BackgroundScreen(),
busyScreen);
}
catch (Exception exception)
{
NetworkErrorScreen errorScreen = new NetworkErrorScreen(exception);
LoadingScreen.Load(screenManager, false, null, new BackgroundScreen(),
new MainMenuScreen(),
errorScreen);
}
}
/// <summary>
/// Updates the state of the game.
/// </summary>
public override void Update(GameTime gameTime, bool otherScreenHasFocus,
bool coveredByOtherScreen)
{
// If we are in a network game, check if we should return to the lobby.
if ((networkSession != null) && !IsExiting)
{
if (networkSession.SessionState == NetworkSessionState.Lobby)
{
LoadingScreen.Load(ScreenManager, true, null,
new BackgroundScreen(),
new LobbyScreen(networkSession));
}
}
base.Update(gameTime, otherScreenHasFocus, coveredByOtherScreen);
if (IsExiting)
{
return;
}
gameEngine.Update(gameTime);
}
/// <summary>
/// Updates the lobby screen.
/// </summary>
public override void Update(GameTime gameTime, bool otherScreenHasFocus,
bool coveredByOtherScreen)
{
base.Update(gameTime, otherScreenHasFocus, coveredByOtherScreen);
if (!IsExiting)
{
if (networkSession.SessionState == NetworkSessionState.Playing)
{
// Check if we should leave the lobby and begin gameplay.
// We pass null as the controlling player, because the networked
// gameplay screen accepts input from any local players who
// are in the session, not just a single controlling player.
LoadingScreen.Load(ScreenManager, true, null,
new GameplayScreen(networkSession));
}
else if (networkSession.IsHost && networkSession.IsEveryoneReady)
{
// The host checks whether everyone has marked themselves
// as ready, and starts the game in response.
networkSession.StartGame();
}
}
}
/// <summary>
/// Internal method for leaving the network session. This disposes the
/// session, removes the NetworkSessionComponent, and returns the user
/// to the main menu screen.
/// </summary>
void LeaveSession()
{
// Destroy this NetworkSessionComponent.
Dispose();
// If we have a sessionEndMessage string explaining why the session has
// ended (maybe this was a network disconnect, or perhaps the host kicked
// us out?) create a message box to display this reason to the user.
MessageBoxScreen messageBox;
if (!string.IsNullOrEmpty(sessionEndMessage))
{
messageBox = new MessageBoxScreen(sessionEndMessage, false);
}
else
{
messageBox = null;
}
// At this point we want to return the user all the way to the main
// menu screen. But what if they just joined a session? In that case
// they went through this flow of screens:
//
// - MainMenuScreen
// - CreateOrFindSessionsScreen
// - JoinSessionScreen (if joining, skipped if creating a new session)
// - LobbyScreeen
//
// If we have these previous screens on the history stack, and the user
// backs out of the LobbyScreen, the right thing is just to pop off the
// intermediate screens, returning them to the existing MainMenuScreen
// instance without bothering to reload everything. But if the user is
// in gameplay, or has been in gameplay and then returned to the lobby,
// the screen stack will have been emptied.
//
// To do the right thing in both cases, we scan through the screen history
// stack looking for a MainMenuScreen. If we find one, we pop any
// subsequent screens so as to return back to it, while if we don't
// find it, we just reset everything via the LoadingScreen.
GameScreen[] screens = screenManager.GetScreens();
// Look for the MainMenuScreen.
for (int i = 0; i < screens.Length; i++)
{
if (screens [i] is MainMenuScreen)
{
// If we found one, pop everything since then to return back to it.
for (int j = i + 1; j < screens.Length; j++)
{
screens [j].ExitScreen();
}
// Display the why-did-the-session-end message box.
if (messageBox != null)
{
screenManager.AddScreen(messageBox, null);
}
return;
}
}
// If we didn't find an existing MainMenuScreen, reload everything.
// The why-did-the-session-end message box will be displayed after
// the loading screen has completed.
LoadingScreen.Load(screenManager, false, null, new BackgroundScreen(),
new MainMenuScreen(),
messageBox);
}
/// <summary>
/// Event handler for when the Single Player menu entry is selected.
/// </summary>
void SinglePlayerMenuEntrySelected(object sender, PlayerIndexEventArgs e)
{
LoadingScreen.Load(ScreenManager, true, e.PlayerIndex,
new GameplayScreen(null));
}
/// <summary>
/// Event handler for when the user selects ok on the "are you sure
/// you want to quit" message box. This uses the loading screen to
/// transition from the game back to the main menu screen.
/// </summary>
void ConfirmQuitMessageBoxAccepted(object sender, PlayerIndexEventArgs e)
{
LoadingScreen.Load(ScreenManager, false, null, new BackgroundScreen(),
new MainMenuScreen());
}
