I don't know if this is possible, but I would like to create one big texture atlas and use it on all classes of the application.
Can one CCSpriteBatchNode be used for multiple classes?
Suppose I create this on the main class
[[CCSpriteFrameCache sharedSpriteFrameCache] addSpriteFramesWithFile:#"atlasGeral.plist"];
self.batchNodeGeneral = [CCSpriteBatchNode batchNodeWithFile:#"atlasGeral.png"];
[self addChild:self.batchNodeGeneral];
and I have another class creating CCLayers on the main class, that is initialized, before using CCSpriteBatchNode, like this:
-(id) init
{
if( (self=[super init])) {
self.bg = [CCSprite spriteWithFile: #"cCircularBG.png"];
[self addChild:self.bg];
self.dr = [CCSprite spriteWithFile: #"cCircularDR.png"];
[self addChild:self.dr];
}
return self; // self is a CCLayer
}
can this be optimized using the self.batchNodeGeneral from the main class? My idea is to replace these two sprites and others with something like [CCSprite spriteWithSpriteFrameName:...
thanks
I'm not entirely sure I follow, but I'm pretty sure the answer is yes.
CCSpriteBatchNode doesn't have anything to do with classes, it has to do with assets. The important restriction on the use of batch nodes is that every sprite in the batch needs to reference the same texture atlas. So it is perfectly fine to have one batch node for your entire application and have every gameplay class add its own sprites to that batch. This can turn into a practical issue if your texture atlas becomes larger than the maximum texture size on your target hardware (see iOS device specs for details), but if you still want to have global batches and lots of assets it's not too hard to create a batch pool indexed by texture ID, create one batch node per atlas, and whenever you create a new sprite add it to the appropriate batch.
Honestly, I feel like the whole batch node thing is a terrible kludge on Cocos2D's part that could be made almost completely transparent to developers while still retaining its efficiency, but maybe this opinion is not entirely fair since I haven't dug around in the rendering code to understand their motivations. I guess it would mess with expectations of how depth sorting works, etc., but still I don't understand why batching objects for render is made the programmer's responsibility, it should be done by the engine.
Edit to add possible solution:
-(id) initWithMainClass:(MainClass*)mc
{
if( (self=[super init])) {
self.bg = [CCSprite spriteWithSpriteFrameName: #"cCircularBG.png"];
[mc.batchNodeGeneral addChild:self.bg];
self.dr = [CCSprite spriteWithSpriteFrameName: #"cCircularDR.png"];
[mc.batchNodeGeneral addChild:self.dr];
}
return self; // self is a CCLayer
}
`
So when you initialize one of the other classes, you pass the main class instance as a parameter so you can access its fields. Or make the main/manager class a singleton or find another architecture suitable to your needs.
Related
I need to create an object that contains several sprites (2 for simplicity: the game object and its' shadow).
I need to compose them into the same class, so having the following questions:
what is the best ancestor class to the described one?
I used CCNode for this purpose. I overridden its draw method in the following way:
- (void)draw {
[super draw];
[_item draw];
[_itemShadow draw];
}
and suddenly found that need to change all other CCNode methods in the same way. For ex. change position, visible, etc. in order to change these properties in both Sprites my custom container aggregates:
#interface NBChecker : CCNode {
CCSprite *_item;
CCSprite *_itemShadow;
}
#end
There is the other way I see - to make both sprites parent property pointing to self. This should synchronise positions, visibility, etc. for these sprites.
Who has better ideas?
Would like to use aggregation and not sure I'm right in my thoughts.
Thanks!
Scrap the draw code. All you need to do is to add the two sprites as children of the CCNode subclass. Write your logic code in the CCNode subclass and have two ivars for each sprite for easier access (like you already have).
You don't need to draw the sprites yourself as long as they are part of the scene graph.
The sprites will move and rotate relative to their parent automatically. Move the node to move the sprites in unison, etc.
I have 2 CCLayers that needs to communicate with each other in separate .m files
Level1.m (CCScene with Level1 CCLayer) - Holds tiled map and player sprite
HUDLayer.m (links to top of Level1.m) - Holds all buttons
How can I get the following code in HUDLayer.m to talk to player sprite in Level1.m?
- (void)MoveUpSelected {
CCMoveTo* moveup = [CCMoveBy actionWithDuration:1 position:ccp(0,-100)];
CCSequence* sequence = [CCSequence actions: moveup, nil];
[Player runAction:sequence];
}
Please help I've been stuck on this for days. At least if someone can point me in the right direction. Thanks!
I would advice you to use you scene object to control communication between its layers.
You can create a HUD protocol and set the scene as its delegate. And for each HUD event the scene will react accordingly by accessing the proper layer (stored as its member).
This way you won't have to make this layer coupling.
To access another layer, you need a reference to it. There are many ways to do that. In your case just add one property for each layer to the CCScene class. The layers can then access the scene via their parent:
CCLayer* otherLayer = [(YourActualSceneClass*)self.parent otherLayer];
It is very important that you do not store a reference to the other layer in either layer, or if you do, make sure to make it a weak reference, or nil them in the cleanup method. Otherwise you created a retain cycle.
You'll find more info on accessing other nodes here.
I'm currently developing a game with cocos2d and box2d on iPhone.
I read a lot of articles concerning game code organization, game objects structure etc.
I first started developing my game objects by inheriting from a base class itself inheriting from CCSprite.
I had a CCSpriteBatchNode to draw all the game items, which the player can interact with, in one draw call. This was easy because my Item class indirectly inherit from CCSprite so I could easily add my items to the CCSpriteBatchNode. And on top of that I could rely on cocos2d to retain my objects.
After I read the articles, I understood the need to refactor my code with a more composition oriented style rather than the inheritance style.
So I went with a GameObject base class inherited from NSObject and having properties such as one or more CCSprite, one b2Body etc.
The problem I'm facing now is that I can't directly add my GameObject to the CCSpriteBatchNode anymore. I first thought I could easily fix the problem by adding the sprite property of the GameObject to the CCSpriteBatchNode. It's ok but who retains the object owning the CCSprite ? How can I easily access the original object from the CCSprite (are userData/Object ok) ?
Should I create an array retaining my items ?
I'd like to know how you would use a CCSpriteBatchNode with such a game object structure ?
There is already a thread about that which is unanswered and I'd really like to hear about the subject. Not a straight answer but some elements to go further.
Thanks.
Personally I don't recommend using NSObject as the base class for cocos2d classes anymore. Simply because you lose some cocos2d convenience features such as scheduling and you can easily shoot yourself in the foot, memory-management wise.
What you want is a setup where the scene has one or more sprite batch nodes. You can consider them layers for your sprites. Your actual game objects (consider them to be MVC controllers) deriving from CCNode can be added anywhere, typically directly to the scene.
scene
+ batch node 1
+ sprite 1
+ sprite 2
+ sprite n
+ batch node 2
+ sprite 1
+ sprite 2
+ sprite n
+ game node 1
+ game node 2
+ game node 3
+ game node n
The thing to keep in mind is that each game node has one or more sprites as instance variables, but they're not childs of the node. So for example the game node 1 class might look like this:
game node 1 class
CCSprite* sprite1; // instance variable
CCSprite* sprite2; // instance variable
Now when you init game node 1 and its sprites, you add the sprites to the appropriate sprite batch node. Typically you will want to access your scene like a singleton to get access to its sprite batch properties.
sprite1 = [CCSprite spriteWithSpriteFrameName:#"doodle.png"];
[[scene sharedScene].batchNode1 addChild:sprite1];
sprite2 = [CCSprite spriteWithSpriteFrameName:#"splash.png"];
[[scene sharedScene].batchNode2 addChild:sprite2];
Note that you do not need to retain the sprites as long as they are children of the sprite batch node. The addChild method retains it for you. Actually, it just adds it into an array which does the retaining. Also, if you're still thinking about "retain", by all means start using ARC.
You do not need to figure out how to access the sprite in the sprite batch. It's available as an instance variable of your game node class, and if you wish, you can also make it publicly available to other classes as a property.
The game node class obviously runs all the object's game logic, including positioning and otherwise modifying the sprite's properties. The only thing you need to take care of in the game node class is that you remove the sprites from the batch node, otherwise it may be leaking. To do so, override the cleanup method:
-(void) cleanup
{
[sprite1 removeFromParentAndCleanup:YES];
sprite1 = nil;
[sprite2 removeFromParentAndCleanup:YES];
sprite2 = nil;
[super cleanup];
}
It's important to set the variables to nil because there may be code running after cleanup, including the code in the dealloc method. You could also remove the sprites in dealloc but depending on your setup, dealloc may not even get called because of the references to the sprite the game node class is still holding. Therefore it is generally safer to use the cleanup method if the sprites are not children (or grandchildren) of the game node class itself.
I was playing around with a Joystick moving a Sprite around in one layer. Now, according to best practice, the Joystick and the Sprite have to be in different Layers of the same scene. I have managed to separate these, yet I am now completely stuck having absolutely no clue whatsoever how to pass joystick commands from one layer to another? What is the recommended way to do this?
Scene
Game Play Layer
Sprite
Game Control Layer
Joystick
When the joystick is manipulated I need to pass this info to the GamePlayLayer to control the sprite.
Well, I got a great Cocos2d book, written by Rod Strougo and Ray Wenderlich, by the name "Learning Cocos2d". In their book, they implement a game, which has a joystick implemented and all, using your initial setup. The GamePlayLayer contains both the joyStick and the hero sprite. (See book page 40).
I don't believe they would use bad practices in their book, given they are very talented!
...
With that being said, I have possible solutions, if you wish to implement them on separate layers:
GameScene
|
|__>GameLayer
|
|__>ControlLayer
That's your basic setup. But, intuitively, what is the purpose of the control layer? Control the game layer's content! So, I would suggest you hold a (weak) reference to the GameLayer within the ControlLayer. That way, using a simple:
#property (nonatomic, assign) CCSprite* hero;
you now have access to the hero from the ControlLayer!
Extra (if needed):
//GameScene init:
- (id)init {
....
gameLayer = [GameLayer node];
controlLayer = [ControlLayer node];
[controlLayer setGameLayerRef:gameLayer];
...
}
// Control layer:
#property (nonatomic, assign) GameLayer* gameLayerRef;
Even though I just suggested that way, I don't use it in my games :)
What I normally do is:
Make the GameScene class a "Semi-Singleton". (I learned this method from "Learn iPhone and iPad Game Dev" By Itterheim (aka gaming horror, Kobold2d publisher ... etc).
Then, inside the control layer, I would call the GameScene object:
[[GameScene sharedScene] doSomethingToTheGameLayer];
Yeah, the gameScene has simplistic methods that just relies what the control need to update in the game layer.
Edit:
Implementing the Semi-singleton pattern, as described by Itterheim in his book.
But, what is semi-singleton?
It has the singleton pattern's property: you can access the object instance from anywhere using a static call.
[GameScene sharedScene];
However, singleton objects are usually retained, after being created for the first time, till the end of the application's life. In the Semi-singleton pattern, this is not the case.
Once you create the instance, you cannot create another instance before destroying the old one, BUT once you are done with the instance, you destroy it (dealloc). Creating another one when necessary.
Recap:
Semi-Singleton: Create many object from it, but only one at any given time. Only recreate after destroying the old.
Implementation:
Of course, as you do with any singleton class, you first declare a static variable of the same type of the class:
//In GameScene.m
static GameScene* instance = nil;
#implementation
//Here we have the static method to access the instance:
+(GameScene*)sharedScene {
//you must have created one before trying to access it "Globally".
///Typically, created where you transition the GameScene using CCDirector's replaceScene.
NSAssert(instance != nil, #"GameScene not instantiated!!");
return instance;
}
-(id)init {
if((self = [super init])) {
//Make sure you don't have another instance of the class created
//NOTE: Possible race condition that I wouldn't worry about, since it should never happen.
NSAssert(instance == nil, #"Another instance is already created!!");
instance = self;
...
}
return self;
}
//Don't forget!! Dealloc!!
- (void)dealloc {
//the only instance we had is dealloc'd! We are back to zero. Can create a new one later! :D
instance = nil;
[super dealloc];
}
Edit2:
So, the timeline:
CCScene* scene = [GameScene node];
[[CCDirector sharedDirector] replaceScene:scene];
...
[[GameScene sharedScene] doSomething];
...
[[CCDirector sharedDirector] replaceScene:otherScene];
//After the new scene replaces GameScene, dealloc will be called, implicitly. Making instance = nil;
instance = nil;
[super dealloc];
...
//Loop again
CCScene* scene = [GameScene node];
[[CCDirector sharedDirector] replaceScene:scene];
...
I wonder what's the best approach to combine several CCSprites dynamically into one grouped object using cocos2d.
I have to dynamically create characters from a set of multiple CCSprites. The elements can't move relative to each other after combined - and are never separated again.
When combined they should behave just like one CCSprite in terms of moving and turning etc.
I couldn't find anything in cocos2d, or do I have to use a physics engine just to achieve this? I am afraid, using Box2d (without experience) creates a lot of additional coding overhead and effort.
Many thanks
Create an empty CCSprite and add the body parts from different sprites. Example:
CCSprite *body = [CCSprite node];
CCSprite *arm = [CCSprite spriteWithSpriteFrameName:#"arm.png"];
[arm setPosition:CGPointMake(10,10)];
[body addChild:arm];
And so on. This way you can rotate the sprite named body and all body parts will adjust accordingly.