Audio and Labels - Learn SpriteBuilder for iOS Game Development - page 373

The playBg method internally preloads the audio file before playing it. With looping en-
abled, the audio track will loop indefinitely. The drawback of playing audio this way is
that you can't specify a seekTime .
Let's complete the music playback by opening SceneManager.m and locating its
presentGameScene method. In order to play the game music, add the code high-
lighted in Listing 11-3 to the end of the method.
Listing 11-3 . Playing game music when presenting the game scene
-(void) presentGameScene
{
// existing code omitted for brevity ...
OALSimpleAudio* audio = [OALSimpleAudio sharedInstance];
[audio playBg:@"Audio/game-music.m4a" loop:YES];
}
If you play the game now, you should hear music playing in the menu and different music
when you play the game.
You may want to improve this behavior—for instance, to have the game music track start
over if you advance from one level to another or restart the level. One way to fix that is to
extend the presentGameScene method in SceneManager with an additional para-
meter of type BOOL —for instance, presentGameS-
ceneWithMusic:(BOOL)playMusic . You would only pass in YES for
playMusic when presenting the game scene from the main menu; otherwise, you would
pass NO to that parameter. Inside the method, add a condition to play the music only when
playMusic is YES .
Playing Sound Effects
Assuming you'll want to play a sound effect every time a popover layer is closed, you can
do so easily by adding the code highlighted in Listing 11-4 at the end of the
shouldClose method found in CloseButton.m .
Listing 11-4 . Playing a sound effect when closing popovers
-(void) shouldClose