Sr. Mistu for iPhone - the Great Olive Pursuit


After some time developing with openFrameworks, I decided to show two projects that I have done with it.

The first one is “Sr. Mistu”, an iPhone game that I created a few months ago. It’s my first serious attempt at making a full featured game creating a story, characters, etc.

It’s the hand-drawn story of a little blind man who travels around the world with his dog Gaido to find olives for his pizza. It’s currently available for the iPhone 4 and it will be ready for the iPad in a few days. We’ve been very lucky to be the app of the day in Gizmodo, reach the top 50 in the US App store and get some press

In the technical side, there’s no much to say that most of the people in the oF community don’t know about it. The biggest difficulty was to create some classes in objective-c to make use of Game Center and in-app purchases and to communicate them with the main program. I’ll be happy to share specific parts of the code and techniques if they are of somebody’s interest.

You can get more info in my site: or in
You can get the game here:
oF members: ask me for a code, so you can download it free (in an e-mail or PM, let’s keep this clean)

Illustrations by Cinta Vidal ( )
Music by The Black Atlantic ( )

I hope that you like it!


Wow marc, this quite fantastic. The level of detail in the drawings are really incredible. Huge congrats on the success - what a great achievement!

I’d be curious if you have any tips for using game center and in-app purchases. Did you use the MTStoreKit framework for the IAPs? Do you think it’d be beneficial to create an addon for these things so people could use cpp and not have to do the heavy lifting of repeat actions?

Thank you Seth!

Yes, I used MKStoreKit and it was not as difficult to implement as I previously thought. My main problem when working with objective-C is that I don’t know how to communicate with C++:

From C++ -> ObjC: No problem, use [instanceName Message] or even instanceName->message
From ObjC -> C++: ???

So I essentially used their framework and inserted a variable inside each function indicating the status of the transaction, so I could proceed when everything is OK and remove the class when finished. Example:

- (void) failedTransaction: (SKPaymentTransaction *)transaction{	  
	// Marc's Variables  
	// End of Marc's Variables  
	[[MKStoreManager sharedManager] transactionCanceled:transaction];  
	[[SKPaymentQueue defaultQueue] finishTransaction: transaction];	  

It was more difficult to set up it all in itunesconnect than to make the code work. This goes for Game Center stuff too.

(BTW, I used it in Sr. Mistu - Lite, which is not yet available (and I’m not sure if I’ll make it))

Game Center is easier, as you just have to use a few functions to check if Game Center is available, the user is authenticated and to report scores and achievements. I will clean my code and share it.

I’ll send your comments to Cinta Vidal :slight_smile:


Thanks for the reply Marc.

Yeah, I can see how it gets tricky trying to talk between obj-c and c++.

I haven’t looked into using Game Center yet, but it’s good to hear it’s only a few functions. I can’t wait to take a look at some of the code and I’m sure it’ll be very helpful for the community.

Thanks for sharing and the quick response. :slight_smile:


I cleaned my GameCenter code and published it to GitHub

It’s quite easy to implement, I added some more info in this thread:


Hi Marc,

We would really appreciate some help implementing in app purchases in OF.

We’ve been trying to convert the code from a IAP tutorial in this thread:±for-in-app-purchase/11197/0

Thanks and congrats! Loving the game

Hi Marc,

Congratulations on a lovely game, and thanks so much for sharing your insight and experience with us all.

I’m curious about how you managed all the animation in the game. There must be a lot of art assets! Are they all stored as sprite sheets? Did you use any frameworks or addons to help you manage all the assets and animation?

I’ve been using openFrameworks for a while now, but I’ve only just started iOS programming. Any advice or links to more information would be hugely appreciated.

Thanks so much