cocos2d for iPhone

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

1. 

   twinkle
   Member

   I have two sequences that need to run sequentially. They are triggered by different parts of the code, so I can't embed the second sequence in the first sequence. Here's the reduced scenario.

   CGPoint deltaPos = {-150,0};
   	id shootArrow = [CCMoveBy actionWithDuration:3 position:deltaPos];
   	id seq1 = [CCSequence actions:shootArrow, nil];
   	[sprite1 runAction:seq1];
   
   	CGPoint deltaPos2 = {150,0};
   	id moveSprite = [CCMoveBy actionWithDuration:3 position:deltaPos2];
   	id seq2 = [CCSequence actions:  moveSprite, nil];
   	[sprite2 runAction:seq2];

   I've tried various approaches to no avail -- the sequences either start simultaneously, or I get deadlock.

   Approach 1:

   Create instance variable NSLock* mLock, and embed at the start and end of the CCSequence calls to acquire and release the locks.

   Resulting problem:

   Attempt to acquire the lock within seq2 results in deadlock.

   Approach 2:

   Repeat approach 1, but now run seq2 with [NSThread detachNewThreadSelector]

   Resulting problem:

   Same deadlock.

   Would someone point me in the right direction? Muchos gracias.

   Posted 1 year ago #
2. 

   jd
   Member

   A few things:
   1. You don't need to use CCSequence for these actions, you can do runAction:shootArrow directly and save yourself another action call for each.
   2. You can check when the first action is finished (or if it's running) and only run the second when the first is done.
   3. I'm not knocking the built in actions in cocos2d, but I find it easier to update positions of sprites in schedulers when I want full control and don't feel like maintaining actions. It's also more convenient in some cases because your actionWithDuration:3 takes 3 seconds whether you are 5 pixels away or 200 pixels away leading to inconsistent movement speeds.

   Posted 1 year ago #
3. 

   slycrel
   Member

   You could also make a function that does the second half and use a CCCallFunc action to queue the second action at the end of the first event.

   jd, in response to #3 I've thought about this some as well. I decided that it wouldn't be a big deal to simply to some extra math on the time up front based on where the start and end destination was, but your idea is a bit more appealing if possibly less efficient, because it's simpler.

   On that note it would be really cool to have a function in cocos2d to get a rate of time based on the current cocos event loop speed and a start/end destination to be able to use with actions to get the constant speed rather than doing it every time by hand.

   Posted 1 year ago #
4. 

   twinkle
   Member

   This is just a really reduced example -- the actual CCSequence do much more complicated set of actions + CCCallFunc. Because an action can keep triggering a subsequent action, I can't keep appending the actions to the end of a CCSequence as some actions need to be submitted but running some of those actions (that calls other methods) result in additional actions.

   Since logical processing goes much faster than a sequence of animation with delays embedded delay, it is absolutely necessary to be able to queue separate CCSequence. Does anyone know how to do that?

   @jd, on #2 in your response, how does one check when the first CCSequence is finished (or if it's running)?
   @slycrel, how does one "use a CCCallFunc action to queue the second action at the end of the first event" other than simply adding the CCCallFunc before submitting the sequence?

   Thanks.

   Posted 1 year ago #
5. 

   slycrel
   Member

   hi twinkle,

   I think I need to know more background before being more specific. I was thinking you could take care of this with a CCCallFunc appended originally. You could still do this and conditionally start a new event as needed, but it sounds like that's not going to be a good fit.

   if in your case can have repercussions all along the way, you can stop the sequence and then re-queue the unfinished sequence pieces using CCSequence's actionOne: actionTwo: method, though I'm not sure that is optimal either.

   So really it all depends on what kind of thing you're trying to accomplish. If you have a complex string of actions you could also inherit from the actions and include custom code in their update functions. You could also manage the actions individually by running an action and then checking via some other mechanism on if you wanted to continue running the actions or do something different on an action by action basis. Kind of a lot of work on that one though. =)

   Posted 1 year ago #

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