Object Order in CCLayer ( cocos2d-iphone ) - cocos2d-iphone

Question

I initialize my CCLayer using the following init code:
- (id)init {
if((self=[super init])) {
UIImagePickerController *picker = [[UIImagePickerController alloc] init];
picker.delegate = self;
picker.sourceType = UIImagePickerControllerSourceTypeCamera;
picker.wantsFullScreenLayout = YES;
picker.allowsEditing = NO;
picker.showsCameraControls = NO;
picker.navigationBarHidden = YES;
picker.toolbarHidden = YES;
picker.cameraViewTransform= CGAffineTransformMakeScale(1.3, 1.33);
[[[CCDirector sharedDirector] openGLView] addSubview:picker.view];
CCSprite *gold = [CCSprite sprite];
gold.position = ccp(150, 150);
[self addChild:gold];
}
return self;
}
The CCSprite was above the camera view before the camera shutter opens, but when the shutter opens, the CCSprite is overlapped by the camera.
Can I rearrange the order of these 2 objects / put the camera view to the back ?

Answer 1

Not without some extra work.
To understand this you have to consider that you're adding the camera view to the openGLView by Cocos2D. This makes the camera view a "child" view of the Cocos2D view. This is similar to adding a child node to a CCScene or CCLayer, and then wanting to have that node drawn behind the scene or layer. You can't do this without changing the way the view hierarchy is setup.
So you will have to modify Cocos2D's startup so that the openGLView is not added to the UIWindow directly, but to another UIView.
UIView* dummyView = [[UIView alloc] initWithFrame:[window bounds]];
[dummyView autorelease];
[dummyView addSubview:[CCDirector sharedDirector].openGLView];
rootViewController.view = dummyView;
You can then add the camera view to the dummyView (not the openGLView or you'll have the same problem as before) and perform sendSubviewToBack on it so that it is in the background.
You will also have to initialize the OpenGL view of Cocos2D with kEAGLColorFormatRGBA8 pixelFormat in order to provide an alpha channel.
EAGLView* glView = [EAGLView viewWithFrame:[window bounds]
pixelFormat:kEAGLColorFormatRGBA8
depthFormat:0
preserveBackbuffer:NO
sharegroup:nil
multiSampling:NO
numberOfSamples:0];
You also need to make the openGLView transparent:
[CCDirector sharedDirector].openGLView.opaque = NO;
Of course this only works if you don't render anything fullscreen on the cocos2d view. For example, if you provide a fullscreen background image for your Cocos2D view, nothing will show up because the background image is rendered on top of the camera view.
You can find a more detailed explanation in the second edition of my book. You can also download the book's source code from that link and see the examples of chapter 15. Or download Kobold2D and use the provided Cocos2D-With-UIKit-Views template project.