So, you’ve heard about Objective-C automatic reference counting (ARC). And you’ve read about it here and there and every where. But you’re not using it.
Guess what? You’re not alone. There are developers out there who refuse to use ARC, who delay using it, who believe they just can’t use it or expressly decided against using ARC for the time being. They all have their reasons.
Most of them are wrong.
Here’s a summary of reasons I’ve heard (repeatedly) in the past months from developers who aren’t using ARC, or have tried it but gave up using it. And I’ll tell you why these rationalizations are wrong, or at least over-inflated. Continue reading »
While Cocos2D is compatible with ARC, simply enabling ARC in the project’s Build Setting will throw several hundreds of errors in your face. Cocos2D doesn’t provide ARC-enabled project templates. Thus this tutorial about how to enable ARC in a newly created Cocos2D Xcode Project.
While none of these steps are overly difficult, you’ll notice there’s plenty of steps to perform. Unavoidably, and on the off chance you don’t already know, I’d like to recommend Kobold2D to you if you want to write ARC enabled Cocos2D apps. Because none of the steps below, really zero, zilch, nada, niente, keine are necessary to enable ARC in Kobold2D. That’s because it ships with 15 template projects all of which have ARC enabled out of the box. And Kobold2D 2.0 with cocos2d-iphone 2.0 is just around the corner.
Self-advertisment aside, these steps are tested with cocos2d-iphone v2.0 but should also work with cocos2d-iphone v1.1 - but admittedly I haven’t tested the process with the v1.1 version. If you find anything that’s not quite working with v1.1 please leave a comment. Preferably with the solution, that’ll be awesome!
UPDATE: I released a video version of this tutorial: Continue reading »
This quick comparison sheet gives you all the info to decide whether to use Cocos2D 1.x or Cocos2D 2.x. Contrary to most programs, a higher version number doesn’t infer “better” or “more”. There are pros and cons for both versions.
At the time of this writing the decision really only boils down to whether you want to use shaders and whether you must be able to deploy your app to 1st & 2nd generation devices. See for yourself, it’s that simple:
Cocos2D v1.x(+) compatible with all iOS devices |
Cocos2D v2.x(+) OpenGL ES 2.0 shader programs |
All other differences to this day are minor, and most new features and bugfixes have been migrated back and forth between versions. For beginners I strongly recommend using v1.x as there’s a lot more documentation available for this version. Those who have no interest in writing shader programs can also safely use the v1.x branch without missing out.
I have no doubt that automatic reference counting (ARC) is the next big leap forward for Objective-C since the introduction of Objective-C 2.0. ARC allows you to put the burden of memory management on the (Apple LLVM 3.0) compiler, and never think about retain, release and autorelease ever again.
Since many user’s first experiences with ARC will be trying to convert an existing app, they will learn the hard way that converting existing code to ARC is not a fire & forget operation. And since this is the Internet, there’s also a lot of assumptions, false statements and other myths revolving around ARC going around.
So here’s just about everything you need to know about ARC, and some ARC-mythbusting too.
- Development Requirements for ARC apps
- Minimum Deployment Targets for ARC apps
- Required Deployment Targets with zeroing weak references
- How to enable ARC in your project
- Compile errors after switching to LLVM 3.0
- Getting third party libraries to build with ARC
- Converting an existing app to ARC
- “Cannot Convert to Objective-C ARC”
- Fixing pointer types in C structs
- Fixing C/C++ pointer transfers with bridged casts
- Fixing NSAutoreleasePool with @autoreleasepool
- Methods you can’t call (or override) anymore
- You can still override -(void) dealloc {}
- Property naming restriction
- New Property keywords: strong and weak
- ARC forbids synthesizing a readonly property without ownership qualifier
- For experts: detecting at compile-time if ARC is enabled
- For experts: allow use of ARC keywords with ARC disabled
- Myth: ARC has not been proven reliable
- Myth: ARC takes away control over Memory Management
- ARC Reference Documentation
Whaaaaaat?
You heard right: if you want to forget about using retain, release and autorelease in your code, then the newly introduced automatic reference counting (ARC) mechanism (aka “automatic memory management”) is the way to go. And guess what?
Kobold2D Preview 6 fully supports ARC out of the box!
You may have heard that Cocos2D is incompatible with ARC at this time, and you’re right. However, the Cocos2D version in Kobold2D Preview 6 released just now has been improved to work with ARC. This post explains the most important changes to make Cocos2D compatible with ARC. All 15 Kobold2D example projects compile with and without ARC, just like the other libraries Kobold2D makes use of!
The Ultimate Cocos2D Project is: Kobold2D!
Put simply: Kobold2D is designed to make Cocos2D developers more productive.
Original Post
Last week I wrote that I’m Building The Ultimate Cocos2D Xcode Project. In today’s weekly update I wanted to give you some more details on the use of libraries in that project.
Cocos3D included
So there happens to be a Cocos3D now. Rather than being part of the Cocos2D distribution, it’s an extension project. Guess what that means? Right, installing Cocos3D means fumbling with the dreaded install-templates.sh script (see this Cocos3D tutorial). Of course the first user reactions were: how do I install it? Installation failed, what am I doing wrong? And so on …
The Ultimate Cocos2D Project wouldn’t be ultimate if it didn’t include Cocos3D out of the box. And unmodified of course, as with all included libraries I want to make it as simple as possible to replace one library version with another. Once you get to half a dozen of included libraries, maintaining them all can become a hassle, so the very least I can do is to make it easy for everyone to upgrade specific libraries.
Obviously: Cocos2D included
Of course Cocos2D is also included as a static library as opposed to cluttering your project with all of its source files. Xcode project references make it very convenient to add external code and keeping it seperate. I’ve described the process in detail in my Cocos2D Xcode Project tutorial but since then I’ve learned a couple more things about how to make this even better.
For example, I no longer include cocos2d-iphone directly, instead there’s a seperate Xcode project in between so that I have full control over build settings (using XCConfig files) and make it possible to build both iOS and Mac OS targets in the same Xcode project. I will also include the current version of Cocos2D in the download because my goal is to make everything work out of the box.
No fumbling with install scripts, no additional downloads necessary, no need to modify any Xcode build settings - including developer certificates and header search paths. Build configurations for Ad Hoc and App Store release builds are also included, which will create .IPA and .ZIP files for you ready for Ad Hoc distribution respectively upload on iTunes Connect.
Popular libraries included
Now let’s get to the juicy part. Early on I realized that Cocos2D users often needed (or wanted) to include other libraries. Some of them have become so popular among the Cocos2D crowd that they could as well be part of the official distribution. Alas, they’re not. That’s a service I want to provide.
Often those libraries require special and non-obvious steps to successfully add them to an existing project. All too often those steps are either undocumented, untested, hard to follow, refer to outdated versions of Xcode, iOS SDK, etc. and generally require technical expertise of project configuration and compiler settings.
This is all taken care of for you. Here’s the list of libraries that are already included in the Ultimate Cocos2D Xcode Project:
- Cocos2D (iOS & Mac OS in the same project)
- Cocos3D (ready to use of course)
- Wax & Lua (Wax is enabled and setup, essential Lua functions have an ObjC interface)
- ObjectAL - “iOS Audio, minus the headache” (has excellent documentation!)
- iSimulate - lib included with permission, requires separate iSimulate Lite App or full version
- Cocos2D Gems: GameKitHelper, ClippingNode, Multiple Update Selectors, FrameOrFile, more…
- iAd (already setup in RootViewController, just enable it)
- Chipmunk SpaceManager (ObjC interface for Chipmunk physics)
- SneakyInput (or alternative Joypad library if there is one)
- Objective-C Optimized Singleton Macro (gets rid of @synchronized to improve speed)
- LOG_EXPR (logs any statement, no format strings needed: LOG_EXPR([self contentSize]) )
- … did I miss an essential library? Please leave a comment!
That is quite a list. All you need to do to use these libraries is to either enable them in code or merely include the header file and start using them. If you worry that all these libraries will bloat your App, rest assured that Xcode is very clever: if you don’t actually make use of a static library (eg don’t include any of its header files), it will not be linked with your App and not waste any space or performance. I verified that.
Update policy
These are a lot of libraries to keep up to date. I plan to make about 4-8 point releases each year, usually triggered by a major (speak: non-beta) release of Cocos2D. If updating other libraries justifies an update depends on the library’s importance and the significance of the update.
Your libraries
Adding your own libraries to the project will be easy and the process will be documented. This will encourage code-sharing because your library will just work with other user’s project, it only needs to follow a few simple guidelines to become plugin-capable. This opens the door for better and tighter integration of 3rd party code into your projects. Even if you don’t intend to share your code, you’ll still benefit because your code will be easier to re-use and maintain.
Also, if you like you can make a request for a specific library or additional source code that should be included in the project, please leave a comment. I’ll see what I can do. 
