Sparrow Framework – The Open Source Game Engine for iOS

I just wanted to inform you that we added a documentation section that teaches you all you need to know to get started with Sparrow. You will learn all about the most important features of Sparrow:

• Display Objects
• Events
• Displaying Text
• Animations
• Extending Sparrow

Dive into it here.

If any part of the documentation is not as clear as it could be, or you are missing something crucial, don’t hesitate to inform us about that by adding a comment below this post. Thanks in advance!

As I wrote in the last post, we decided to write our next games in Objective C, with a framework that was designed with games in mind.

This, of course, limited the choice of suitable game libraries. There are several C++ frameworks and even one that uses C# (Unity). I did not want to use those for the reasons stated in the last post.

The only thing left was Cocos2D. Unfortunately, at that time (early 2009), Cocos2D was not as far evolved as we liked it to be, and we were unsure about the commitment of the developers to keep the project up and running. Furthermore, there were some things I did not like about the architecture. That said, it’s a great library and has evolved a lot since then, so I really recommend to anyone having a look at it!

Anyway, we were sure that having a Flash-like API would be something other developers would enjoy just as much as we do. There is room for several iPhone gaming frameworks — choice is always a good thing!

In addition, I have to admit that the challenge of creating such a library was very appealing to me.

Nearly one year later, I could not be happier about that decision. We are proud that our little bird has hatched. It might not be as feature rich as some other game engines — but in exchange, it’s extremely lightweight and easy to learn. At funworld, I have created quite a number of games, and all of them could easily be rewritten with Sparrow, without the need for any additional libraries. And in case I do need something more, Sparrow can be easily extended.

Another thing I think we can be proud about is the stability of Sparrow. At the time I am writing these lines, PenguFlip has been played over 180.000 times, and less than 0.09 percent of all games created an error. Frankly, with this error rate, I am inclined to lay the blame on hardware problems, not Sparrow.

Now, that’s it! I hope some of you will find the time to have a look at Sparrow and tell us what you think about it! We are happy about any feedback we can get.

Last time, I described our first iPhone game, Find it!. As I said, that’s a game that was relatively straight forward to implement, as there’s not too much movement involved. For that reason, we created the game directly with Cocoa (and learned Cocoa by doing so).

But some things are really cumbersome to do in Cocoa; that’s understandable, as it was developed with user interfaces in mind, not games. So we had to look for specialized game engines.

Or should we develop the game directly using OpenGL? I am against that, because having OpenGL calls (a C-API, after all) all over the source code would make the code confusing and difficult to read. To program a game, you need a framework that was designed with games in mind.

As I wrote in the last post, I am employee at funworld. My job at funworld is — yep, you guessed right — to create games. A few years ago, the games that are running on our PHOTO PLAY touch screen terminals were developed in C++, later we switched to C# with an in-house engine. And since about 2 years, we have been using ActionScript 3 (Flash) for game development, as this allows our games to be played over the internet, as well (just visit funwin.com). Contrary to common believe, the Flash API is really elegant and powerful, and you can program games just like you would in C# or Java: by writing well structured code. There’s no need to even open the Flash authoring application if you don’t want to.

You can read between the lines of the last paragraph that I really love the API that Adobe created for ActionScript 3. It’s clean, simple and very concise. I really longed to have something like that when developing for the iPhone. And I wanted to program in Objective C.

Not that I was a particular big fan of that language (at that time), but one thing that I have learned in my programming career is that it’s always best to stick with the fewest possible number of technologies in a project. Mixing different languages is a guarantee for nasty, hard to find bugs that are created by tiny incompatibilities. Furthermore, you are often forced you to violate the DRY principle, since you have to code some things twice.

Granted, sometimes there is no other choice. But if I have the choice, and I felt I had in this project, I’d rather avoid that and stick with one technology only. That technology had to be Objective C, as that’s the native language of the iPhone API.

To be continued in the final chapter!

Hi folks! I’m Daniel, and I am responsible for most of the source code that makes up the Sparrow framework. Some of you might be interested in how the sparrow came to life, so I thought I drop a few words at this place.

We started development of Sparrow quite a while ago, in early spring 2009. In January of the same year, my friend Holger and me had finished and launched our first iPhone game: PHOTO PLAY: Find it!.

That project was more or less an experiment — we wanted to get to know the iPhone platform, and we wanted to see if we could execute such a project successfully — not just create a prototype, but finish the game and release it on the AppStore. (We had worked on several small projects in our spare time before, but — as it is often with such projects — they were never finished for one reason or the other.)

“Find it!” was perfect for that experiment. It’s a very simple game that many people know. You are presented two images that seem to be identical on first glance, but have tiny differences. The player, of course, has to find those differences. That’s a game that’s easy to create in terms of programming skills: it’s relatively static and slow-paced. And since I work for the company funworld that creates touch screen game terminals (among other things), we could even make a deal with them to get an official brand (in Europe, PHOTO PLAY and Find it! are relatively well-known) and a lot of images.

What should I say: we were just blown away by the success of the project. Especially in the Netherlands, traditionally a country where PHOTO PLAY is very popular, we found a solid fan base that was interested in the game — even more so than in Austria, where we live. (A big thanks for all who downloaded the game, no matter if you’re Dutch or not!)

You can imagine that this success was a big boost for our motivation. So we looked out for another game we could create for the iPhone – this time, a game with a little more action

For that, of course, we needed a good framework.
And the quest for that framework is the part of the next blog entry!

Hello again,

as you probably already know: the Sparrow website went online yesterday. Today we added the Sparrow framework download in version 0.7.

Give it a try!

http://www.sparrow-framework.org/download