Do you follow me on Twitter? You don't? Well you should! If you do though you know how much pain the iPhone SDK has brought me in the last three or four months. I'm very close to being done with a very cool app, but some Apple bugs are making it quite difficult to get it done. Care to read my story and learn about the iPhone application I'm making? Okay...
The Street Ceelo App
I'm working on a dice game – a street dice game called Ceelo. The application itself is essentially a 3D dice rolling simulation. You can play with one phone, passing it back and forth, or you can connect using iOS's GameKit over bluetooth or wi-fi and play with multiple "iDevices". It features custom UI design and elements, networking, peer to peer gameplay, animation, navigation and tab controllers...basically "the works" of the iOS kit. I used this application as a learning exercise and it's turned into an application I'm very proud of.
Pretty cool huh? Well, it was cool until iOS 4.0 came out. You see, 4.0 introduced some new classes called GameCenter that expand on GameKit. It also broke the hell out of the original GameKit classes. So my application runs "flawlessly" (it's essentially complete) on devices running the iOS versions 3.0–3.1.3, but on 4.0.X there are numerous issues with the GameKit in Apple's underlying SDK and in certain places it crashes. This is not acceptable to me so I am working to rewrite much of the code and some of the user experience itself to accommodate the issues.
So, what broke when 4.0 was released? Here's an example. In Ceelo, there's a custom peer to peer table display. One player (server) says they are going to start a game and others (clients) join her. Now, if a client quits at any time, a "message" is send to their peers that they disconnected. No problem; we simply remove them from the list of players (if in the game lobby) or the game ends. This works fantastically in 3.x iOS. Now, in 4.0.x, instead of a quick notification, there's a lengthy delay when a player disconnects or cancels a connection request. When the message is finally "sent" (it isn't really), it crashes the server:
Thread 3 Crashed:
0 GameKitServices 0x06352f90 gckSessionChangeStateCList + 411
1 GameKitServices 0x0635b49c gckSessionRecvProc + 1474
2 libSystem.B.dylib 0x981c181d _pthread_start + 345
3 libSystem.B.dylib 0x981c16a2 thread_start + 34
For more information on this crash check out my StackOverflow question on the topic or poke into the developer forums. Radar IDs for these issues include 8095838 & 8203566, 8174249 & 8094858.
So I filed a bug with Apple and it's been confirmed as a "known issue". The great thing is that the recent betas of the SDK fix the crashing. Unfortunately the long delays remain. I'm continuing to file a bug with each release of the beta. I'm really shocked that this hasn't been addressed yet as the 4.1 release is supposed to be the GameCenter/GameKit release. Classic Apple though to release broken product to get it to market. It is what it is and I've learned to be patient with them in becoming an "Objective-C developer". Also, from what I understand, the 3.0 release was very much the same way.
At this point I'm changing some of the connection logic to remove some of the opportunities for players to quit the game. I've also changed the peer to peer game selection interface to just auto-accept incoming connection requests. This was thanks to a brilliant suggestion by Avi Itskovich who diagnosed a similar GameKit bug via my Stackoverflow post on the topic. It seems to work much better if you connect people up first.
If the game ever gets to the store, it'll be interesting to see how I'll word the required iOS version. You see, this game will work on *all* iDevices, even those without Bluetooth (I wrote it so there's wifi fallbacks). It works on iPhone, 3G, 3GS, Touches, etc. From iOS 3.0–3.1.3. It'll probably run very well on iPhone4 with 4.1 when that is released (already upscaled all the graphics for the retina display!). The only OS it won't run well on is 4.0. How should I word that? "We don't support 4.0 at all but everything else is grand". Just seems odd to have support for everything all the way back to 3.0, but here in the middle is this turd. Such is life.
So what's the point of all this? Well, I'm worried that GameKit may be phased out. It doesn't seem like Apple is putting priority on fixing it and is focusing more on the Xbox Live-like GameCenter (which obviously is much more lucrative prospect than peer-to-peer gaming). So, I wanted to share my experience as an introduction to Typeoneerror Studios offering iOS development one of our new services. As frustrating as this has been, I absolutely love the Apple development kits, tools and the overall process.
Want to beta test at some point?
Send an email to ceelo at typeonerror with your device ID. How do you get that? Use this fantastic video that Sam Vermette hosts at http://whatsmyudid.com/.