/// <summary>
/// Calls directly into our Draw method from the background worker thread,
/// so as to update the load animation in parallel with the actual loading.
/// </summary>
void DrawLoadAnimation(GameTime gameTime)
{
if ((graphicsDevice == null) || graphicsDevice.IsDisposed)
{
return;
}
try
{
graphicsDevice.Clear(Color.Black);
// Draw the loading screen.
Draw(gameTime);
// If we have a message display component, we want to display
// that over the top of the loading screen, too.
if (messageDisplay != null)
{
messageDisplay.Update(gameTime);
messageDisplay.Draw(gameTime);
}
graphicsDevice.Present();
}
catch
{
// If anything went wrong (for instance the graphics device was lost
// or reset) we don't have any good way to recover while running on a
// background thread. Setting the device to null will stop us from
// rendering, so the main game can deal with the problem later on.
graphicsDevice = null;
}
}
/// <summary>
/// Worker thread draws the loading animation and updates the network
/// session while the load is taking place.
/// </summary>
void BackgroundWorkerThread()
{
long lastTime = Stopwatch.GetTimestamp();
// EventWaitHandle.WaitOne will return true if the exit signal has
// been triggered, or false if the timeout has expired. We use the
// timeout to update at regular intervals, then break out of the
// loop when we are signalled to exit.
#if !Windows
while (!backgroundThreadExit.WaitOne(1000/30))
{
#endif
#if Windows
while (!backgroundThreadExit.WaitOne(1000/30,false))
{
#endif
GameTime gameTime = GetGameTime(ref lastTime);
DrawLoadAnimation(gameTime);
UpdateNetworkSession();
}
}
/// <summary>
/// Works out how long it has been since the last background thread update.
/// </summary>
GameTime GetGameTime(ref long lastTime)
{
long currentTime = Stopwatch.GetTimestamp();
long elapsedTicks = currentTime - lastTime;
lastTime = currentTime;
TimeSpan elapsedTime = TimeSpan.FromTicks(elapsedTicks *
TimeSpan.TicksPerSecond /
Stopwatch.Frequency);
return new GameTime(loadStartTime.TotalGameTime + elapsedTime, elapsedTime
);
}
/// <summary>
/// Calls directly into our Draw method from the background worker thread,
/// so as to update the load animation in parallel with the actual loading.
/// </summary>
void DrawLoadAnimation(GameTime gameTime)
{
if ((graphicsDevice == null) || graphicsDevice.IsDisposed)
return;
try
{
graphicsDevice.Clear(Color.Black);
// Draw the loading screen.
Draw(gameTime);
// If we have a message display component, we want to display
// that over the top of the loading screen, too.
if (messageDisplay != null)
{
messageDisplay.Update(gameTime);
messageDisplay.Draw(gameTime);
}
graphicsDevice.Present();
}
catch
{
// If anything went wrong (for instance the graphics device was lost
// or reset) we don't have any good way to recover while running on a
// background thread. Setting the device to null will stop us from
// rendering, so the main game can deal with the problem later on.
graphicsDevice = null;
}
}
/// <summary>
/// Updates the network session from the background worker thread, to avoid
/// disconnecting due to network timeouts even if loading takes a long time.
/// </summary>
void UpdateNetworkSession()
{
if ((networkSession == null) ||
(networkSession.SessionState == NetworkSessionState.Ended))
return;
try
{
networkSession.Update();
}
catch
{
// If anything went wrong, we don't have a good way to report that
// error while running on a background thread. Setting the session to
// null will stop us from updating it, so the main game can deal with
// the problem later on.
networkSession = null;
}
}
#endregion
}
