Cocos 2D and Me

There are a few classes in Cocos2d that you are likely to come across over and over again. Since you’ll be seeing them so frequently, getting to know them right away seems like a good place to start.

CCDirector – The CCDirector class is in charge of running the show. If you want to pause your game for some reason (eg. a phone call comes in), it’s as simple as telling the CCDirector to pause – and another one line call will allow you to resume your game exactly where it left off.

CCScene – In a typical game, as well as the gameplay itself, there are also high scores to view, settings to change, a tutorial to read, and so on. Cocos2D handles all the movements between these different parts of your game by representing each as a CCScene. So, you might have a GameScene, a HighScoresScene, a SettingsScene, and a TutorialScene. Cocos2D then allows you to transition between these scenes at the appropriate time with ease.

CCLayer – Each scene is usually made up of one or more layers. If we are in the GameScene, then you might have a BackgroundLayer which simply displays the background, a PlayerLayer which holds your spaceship or character, and an EnemiesLayer, which holds all of the things you’re trying to kill. This allows for a good object orientated design, and allows each layer to handle input, collisions, and so on, as appropriate.

CCSprite – A CCSprite represents a graphic object. This is what you’ll use to represent your game characters, weapons, enemies, and so on. CCSprite offers a very simple means to load in graphics, move them around and do all other sorts of things to them.

CCLabel – As you might expect, this class allows you to render text on screen.

CCNode – The CCNode class is the simplest object type in the game, which everything is derived from. If it’s drawn on screen, moves around, or contains things that are drawn on screen, then it’s a type of CCNode. CCScene is a CCNode, CCLayer is a CCNode, etc. Think of CCNode as bit like the NSObject of Cocos2d.

One thing to note is that v0.9 of Cocos2d introduced the CC namespace. This means that a lot of the examples you find on the net no longer work, but it’s a fairly simple fix – just prefix any of the Cocos2d class references with “CC”. If you’re after a little bit more on the key classes, have a read of this great introduction. Just remember that the article is a bit outdated, and doesn’t include the CC namespace.