Question

I’m trying to learn Cocos2D from Learning Cocos2D, A hands-on guide by Rod Strougo & Ray Wenderlich, but it uses Cocos 1, not 2 which is out now. I imagine the book is still relevant later on, but in the first chapter I’m running into an issue telling the director to run a scene, because it seems like that whole process is now different in Cocos2D 2.

I’d rather not have to buy a different book, so I was hoping that changing the way to run a scene is fairly simple.

This is what the book says to do:

find the -applicationDidFinishLaunching method and comment out:

 [[CCDirector sharedDirector]runWithScene: [HelloWorld scene]];

and add:

[[CCDirector sharedDirector]runWithScene:[GameScene node]];

I can’t find anything that looks like that in AppDelegate, instead it looks like this has something to do with the new way:

[director_ pushScene: [IntroLayer scene]]; 

My attempts to adapt what the tutorial says to the new way has so far failed, but maybe it is an easy fix.

Incase it is the GameScene which is outdated:
GameScene.h

#import <Foundation/Foundation.h>
#import "cocos2d.h"
#import "BackgroundLayer.h"
#import "GameplayLayer.h"
#import "CCScene.h"

@interface GameScene : CCScene
{

}
@end

GameScene.m

@implementation GameScene

-(id)init
{
    self = [super init];
    if (self != nil)
    {
        BackgroundLayer *backgroundLayer = [BackgroundLayer node];
        [self addChild:backgroundLayer z:0];
        GameplayLayer *gameplayLayer = [GameplayLayer node];
        [self addChild:gameplayLayer z:5];
    }
    return self;
}
@end

Answer 1

The issue you are having is with the class method +scene. That is used when creating the scene within a layer instead of initializing a scene and having that instance create its own child layers. You will understand the differences later in the book when you get more into the scene -> layer relationship.

Comment out [director_ pushScene: [IntroLayer scene]]; in -applicationDidFinishLaunching and replace it with the following:

[director_ pushScene:[GameScene node]];

That should work just fine for your needs. It will create an instance of GameScene (subclass of CCScene) with your two CCLayer subclass instances as children, those being the backgroundLayer and gameplayLayer you instantiate in the GameScene -init method.

If you are curious as to why calling [GameScene scene] was not working for you, that is because you never declared such a method in your interface. It is a little confusing, but basically you would instead create a Game Layer subclass of CCLayer and in your .h file, declare this class method:

+ (CCScene *)scene;

In your implementation .m file, you would define that method as such:

// Class initializer method
+ (CCScene *)scene {
    CCScene *scene = [CCScene node]; // Create a container scene instance
    GameLayer *gameLayer = [GameLayer node]; // Create an instance of the current layer class
    [scene addChild:gameLayer]; // Add new layer to container scene
    return scene; // Return ready-made scene and layer in one
}

Then when you call [GameLayer scene] that +scene method creates the scene for that layer and adds it as a child. It is quicker, but can be more troublesome with multiple layers in my experience.