Understanding cocos2d scenes, how they works really? - replace

Question

I'm stuck on something about the scenes creation and replacement in cocos2d, so I'm going to ask precisely what seems to be misunderstood by me. I have a game (fully working except for scene swapping, sadly) with some little-games, now, if I had to do this starting with a cocos2d scene as menu I wouldn't have any problem, but since I did it starting with UIKit I truly need to know better how the scenes are working to fix it.
Firstly, is it required to start a scene in the appDelegate? since I'm starting with UIkit and the scene must be shown after you choice the game (say, out of 3 choices), which scene should I put in the appDelegate? and where exactly? I'm putting the scene in this method:
-(void) directorDidReshapeProjection:(CCDirector*)director
{
if(director.runningScene == nil)
//start scene
}
If I put the FIRST scene, the UIKit part works good and when I start the "game number TWO" as first choice (say we play this game for first) I got the Open GL 0x0506 error, then the scene start.
If I put the first scene, I choice the first game, and then quit and choice the second game, the scene is replaced properly without that error.
If I put the first scene, and I start the "game number 1" it works (obviously) because he has the scene loaded, but I cannot know which game will start as first the user.
I tried with an "intro scene" loaded at the appDelegate but I got the same problem. the problem basically is "how to start scene if you have more than one scene and don't know which will be called as first"...

Answer 1

The 'getting started with iOS' documentation will really clear up a lot of these questions. You can find it at developer.apple.com - https://developer.apple.com/library/ios/#documentation/iPhone/Conceptual/iPhoneOSProgrammingGuide/Introduction/Introduction.html#//apple_ref/doc/uid/TP40007072
It explains just what an AppDelegate actually is, as well as how to use one properly. It is not immediately clear how to mix UIKit and cocos2d, but the above link cleared a lot up for me. Another very helpful resource is a tutorial by Ray Wenderlich -
http://www.raywenderlich.com/4817/how-to-integrate-cocos2d-and-uikit
From a bird's eye view, the CCDirector inherits from a UIWindow. Mixing UIKit and cocos2d is as simple as building your interface with UIKit, then at some point opening a UIWindow and allowing the CCDirector to start cocos2d. In a sense, the components act as almost two entirely separate entities.