Chapter 3 - Essentials
This chapter is a reference about the fundamental classes of cocos2d and how to use them. Nodes, Layers, Scenes, Labels, Sprites, Transitions, Actions, you name it. Also CCDirector, SimpleAudioEngine and other often used singleton classes as well. More advanced concepts will be discussed in a later chapter, Spritesheets for example.
The submission of the first chapter draft is due next Friday, July 16th.
What do you think should be in Chapter 3?
Do you know a cocos2d class or process that you think is essential and should be discussed in this chapter? Let me know!
Summary of working on Chapter 2 - Getting Started
For one I detailed the Hello World sample project and made a simple modification using touch input. At the same time at least some basic level of understanding about cocos2d classes was introduced but the gist of it is done in Chapter 3. In addition, there were a lot of theoretical aspects I wanted to discuss as well, most of all Memory Management and available memory as well as setting expectations on testing on Simulator vs. a device. And of course the devices and their subtle differences. I do hope that those kind of details are appreciated even if they’re not 100% related to cocos2d. I regularly see cocos2d developers struggling with memory issues, with unexpected differences on the device vs the Simulator, or comparing framerates of the Simulator and possibly even Debug builds. That made me want to stray off the beaten path for a moment to hopefully save the readers some misconceptions and the pain associated with them.
I also realized how many steps a new developer has to go through and how much there is to learn in case you’ve never been working with the iPhone SDK before. It starts with registering as iPhone developer and doesn’t end with installing the SDK because you also need the provisioning profiles, a much discussed and troublesome feature. For all of this I refered to existing (and excellent) Apple documentation. Typically the processes change with each new iPhone SDK or may even be under NDA, so discussing how all of this works with iPhone SDK 4 wouldn’t be a good idea since shortly after the book is out iPhone SDK 5 may be coming, introducing changes to the Developer Portal and iTunes Connect with it. It did get me the idea, and I know others have it too, that we need some holding-hands Tutorial which takes one through the steps from registering as iPhone Developer to publishing one’s first App, by referring to the correct official documentation for each step while not forgetting about common pitfalls that are not in the official docs.
I also noticed how easy it can be to overlook how you suddenly introduce a new concept without explaining it first. And then you have to decide how much information is necessary to introduce the concept without straying too far away from what you want to talk about in the first place. It’s especially hard for me because I tend to want to explain everything in detail but some things have to be left for a later discussion. I’m looking forward to editorial feedback now. It has helped tremendeously for the first chapter and I learned a lot from the Apress editorial staff, so I find it exciting that the experts point me to the flaws and make suggestions, I go in to fix them and then see how much better it is. That’s how I like to learn things and it’s going to be one of the core concepts of the book. Show how it’s done, how it shouldn’t be done (if it’s often done wrong) and how it can be done even better if you want to avoid trouble in the long run, while explaining why.
Chapter 2 - Getting Started
This chapter starts with the usual prerequisites. Download and install iPhone SDK and cocos2d. Installing cocos2d Templates. Creating the first project from a cocos2d project template.
From what I already wrote I estimate that will be about one third of the chapter. I think what would be most interesting in this chapter is to talk about general code structure of cocos2d projects. The basic elements like Scenes, Layers and Nodes. How to transition from one screen to another, to see that we’re actually doing something cool with little effort. For that I think the scheduled selectors should also be introduced to time transitions, and one screen might be a Layer which is waiting for touch input to advance to the next screen.
It might also be a good place to discuss cocos2d memory management, like static autorelease initializers, and making sure dealloc gets called when you switch scenes - otherwise you’re obviously having a memory leak.
The goal is to get the reader into a position where he feels comfortable laying out a screen structure in cocos2d. He knows how to initialize objects and how to add and remove them from the scene. The foundation of working with cocos2d if you so will.
What do you think should be in Chapter 2?
Let me know if you think I’m missing anything important. If you don’t have any suggestions then just think about what you would expect from the chapter by reading this description, that might give you some thoughts.
Also I would welcome any tips and the common pitfalls first-time cocos2d developers might trap themselves into. Expert tips are also welcome, those little nasty things or habits which could bite you later on if you don’t consider them from the beginning.
I’m looking forward to your feedback! The earlier the better. Chapter 2 will be submitted next Friday, July 9th.
What’s planned for the Chapter after this one
Just to put Chapter 2 in context, for Chapter 3 I’m planning to talk about essential cocos2d classes and processes. Sprites, Labels, Menus, Actions, etc. It’ll show you how to work with them using small code snippets. The chapter will probably have a “reference” character with various code samples, so that experienced users feel comfortable skipping ahead while beginners still find it easy and encouraging to pick up the details.
