I don't know if I'm lazy or not, but the fact that I have to commit to downloading and running it before I can see what exactly it does is pretty off putting to me.
Wouldn't drawing with UIKit be less efficient than using an OpenGL backend?<p>SDL[1] on Windows for instance, falls back to GDL when proper DirectX support isn't available. GDI is what most GUI apps use to draw their elements on Windows. It is akin to UIKit on iOS. But GDI is horribly slow as all the computation is done on the CPU.<p>In fact, realizing this fact, Microsoft has recently developed Direct2D, which does the computation on the GPU and which regular GUI apps can use to achieve better performance. (BTW, I believe Direct2D is somewhat similar to Cairo 2D.)<p>[1] Simple DirectMedia Layer -- used by plenty of games to achieve cross-platform compatibility. Most games in the Humble Indie Bundle use this.
This is an admirable effort, but I would not recommend ever using this in practice. I am saying this from experience: I wrote a game engine on top of UIKit, which I spent months trying to fine-tune before finally ditching it and re-writing everything to use Cocos2d.<p>The performance aspect is just not there. Once you get to a game with a large number of sprites and animations, animations will jitter and glitch. You're really going to be stretching what Core Animation can handle.<p>What I usually recommend these days is to use Cocos2d for your main game view, but using UIKit for the rest of the interface (menus, score screens, etc.).