cocos2d for iPhone

A fast, easy to use, free, and community supported 2D game engine

1. 

   DaveRC
   Member

   My brain has leaked out my ears trying to figure this out and I can't seem to find a good example to base my code off of.

   I'm simply trying to fade down one piece of background music before i start another one, so that I don't end up with a "hard" stop. I found a topic that posted an example like:

   [CDXPropertyModifierAction fadeBackgroundMusic:2.0f finalVolume:0.0f curveType:kIT_Exponential shouldStop:YES];

   to fade one piece of music out, and that works fine. The issue is that when I go to start a new piece of music, I'm first fading the current music down, then starting the new one. What happens is the first one fades, but the action doesn't finish running before the next one starts, so the next one "clicks" and then never starts. Watching the log confirmed that the action is still running before the second starts.

   I've tried everything I can think of to "wait" before starting the second piece, but nothing seems to work. I've tried watching IsBackgroundMusicPlaying, but that seems to register "YES" even after the first piece has stopped and is in "loaded" state. I tried doing a manual wait, but that froze everything up and causes other issues in the game.

   Does anyone have any suggestions, or a real code sample somewhere that shows how to do a proper crossfade between two background music files?

   Thanks
   Dave

   Posted 1 year ago #
2. 

   Steve Oldmeadow
   Administrator

   What you are describing isn't really a crossfade, for a cross fade you need two audio sources with one fading out while the other is fading in. If that is what you want to do then search for the thread where I explained to Marcotronic how you can do that.

   If you just want to kick off some other background music when the background music has faded out then use the standard pattern of a CCSequence with a CCCallFuncN at the end e.g this works for me:

   -(void) actionComplete:(id)node {
   	CDLOG(@">> Background music has faded out");
   	CDLongAudioSource *player = [[CDAudioManager sharedManager] audioSourceForChannel:kASC_Left];
   	[player load:@"808_120bpm.caf"];
   	player.volume = 1.0f;
   	[player setNumberOfLoops:5];
   	[player play];
   }	
   
   /**
    Test fading out of background music. The test toggles between starting the music with no fade and fading it out.
    */
   -(void) testFive:(id) sender {
   
   	CDLOG(@">>Test five");
   	if (![sae isBackgroundMusicPlaying]) {
   		CDLOG(@">> Background music is not playing");
   		[sae setBackgroundMusicVolume:1.0f];
   		[sae rewindBackgroundMusic];
   		[sae playBackgroundMusic:@"bgm.mp3"];
   	} else {
   		//Fade out
   		CDLongAudioSource *player = [[CDAudioManager sharedManager] audioSourceForChannel:kASC_Left];
   		CDLongAudioSourceFader* fader = [[CDLongAudioSourceFader alloc] init:player interpolationType:kIT_Exponential startVal:player.volume endVal:0.0];
   		[fader setStopTargetWhenComplete:YES];
   		//Create a property modifier action to wrap the fader
   		CDXPropertyModifierAction* action = [CDXPropertyModifierAction actionWithDuration:2.0 modifier:fader];
   		[fader release];//Action will retain
   		id actionCallFuncN = [CCCallFuncN actionWithTarget:self selector:@selector(actionComplete:)];
   		[[CCActionManager sharedManager] addAction:[CCSequence actions:action, actionCallFuncN, nil] target:player paused:NO];
   	}
   }

   Posted 1 year ago #

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