UIKit; do you use it? « cocos2d for iPhone

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UIKit; do you use it?

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Started 1 year ago by robodude666
Latest reply from robodude666

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robodude666
Member

Hey guys,

For those who may not know recently Apple gave access to all registered ADC members the WWDC2010 session videos. Amongst these videos were a number related to the making of the Quest tech demo Apple showed off during the State of the Union Design & Media session. This demo is a dungeon crawler that features an OpenGL 2.0 w/ shader-based world and a beautiful UIKit-based interface atop of it. It looks absolutely beautiful, and runs at a wonderful ~45 FPS on both the iPhone and iPad.

I was blown away by these demos and have spent the past few days attempting to seamlessly integrate UIKit and Cocos2D... with various degrees of success, which got me thinking:

How many of you use UIKit with Cocos2D?

Am I pointlessly wasting time because I saw something shiny, or is there a true benefit here?

Personally, I'm attempting this because it makes using Model-View-Controller easier. It also makes integration with iAd and Game Center so much easier. It allows access to Core Animation and provides many UI elements currently not available in Cocos2D natively (though yes.. they can be reproduced).

So, do you use UIKit? Why or why not?

-robodude666

Posted 1 year ago #
jordo
Member

I use it for the TableViewController....

Posted 1 year ago #
saim80
Member

I'm also impressed by the session video. However, I expect fps to drop greatly in actual, production-level games. See... there were only 1 character, 1 monster, and 1 map. They clipped the entire scene statically so that any kinds of camera wasn't really possible in the game. (Users could see the clipped space) It all depends on the game requirements set at design time though. :) Anyway, I liked the video! Lesson learnt: cut out anything unnecessary. minimize draw() calls. :P

Hmm, one of old Apple's tech videos says that "do not update overlay UIView (especially, animations) on top of OpenGL view. that will hurt performance." I think this still holds. If you have a paused scene and run UIKit instances, there shouldn't be a problem though.

I use UIKit only for non-game apps. For games, I want pure cocos2d. I tried once to mix UIKit and cocos2d. I tried my best to separate those worlds to maintain the code better, but it wasn't neat enough. (just on my own perspective.) Anyway, there's nothing wrong with UIKit + Cocos2D mix if you like it, if that saves time, etc etc.

Posted 1 year ago #
robodude666
Member

saim80,

Yeah.. Is quite interesting, really.

While searching about other attempts to do OpenGL + UIKit I ran into a number of comments quoting apple saying to not overlay things on top of OpenGL, and especially don't use core animation when OpenGL is running. Yet.. The Quest tech demo was just screaming out "Use UIKit with OpenGL! Look at these cool Core Animation effects!" I suppose it might be due to the fact that the hardware is faster now, I guess? The 3GS and iPhone 4 are leaps and bounds faster than the original iPhone and 3G. I haven't done any hardware testing, but the simulator seems to be okay with OpenGL and UIKit.. Though, that means nothing lol.

What sort of issues did you run into when attempting to make OpenGL and UIKit get along? I can't speak for performance, as I can't test on a device yet, but from a technical side I have been going through a few leaps and dances trying to get the two to work together nicely. I finally have a class that can somewhat orchestrate everything, though not quite how I originally planned for it. Spent the last two days attempting to get multiple EAGLViews to play nice... I'll just leave that at that and say it wasn't successful. Finally managed to get it working somewhat similar to what I originally wanted... and now I'm starting to doubt if the effort is worth it (hence this thread).

Anyone else tried to combine the two? I can get marshmallows and a campfire. Have some good ol' programming horror story telling time if you want.

-robodude666

Posted 1 year ago #
ShempLock
Member

You've got to remember a couple things:

1) One of the overlays was for a character info panel. When this panel is up, performance does not matter because it is not up while playing, only while viewing and setting character options. The same can be said for an inventory screen!

2) Did you notice that the buttons on the bottom bar were not transparent? This is just a simple clip and will not effect performance.

The only time you will get a performance hit is when you are not opaque, OR if you have OGL layers on top of UIKit. Remeber that the whole iPhone GUI is completely OpenGL ES, so of course you can overlap the two layer types, just avoid transparancy and try to keep UIKit on top of OpenGL, not the other way around.

Posted 1 year ago #
robodude666
Member

Yeah. None of the UI elements in Quest were transparent, and that's one of the things that they kept going over in the performance related sessions. It makes sense of course. Draw less pixels. No point in having OpenGL render your flashy animation stuff if that pixel will be drawn over by a static UI element.

But, that's not really where I had trouble. It seems rather difficult to have OpenGL "exist" in multiple places at once. I mean, the EAGLView class shares a context it seems, and it would require some modifications to make multiple instances possible. As-is, if a new instance is created all previous ones go blank.

I did end up getting OpenGL to play with UIKit, though it ended up being more of a hassle than it's worth I think.. it also didn't work exactly the way I wanted it, which made it worse, so I said screw it. Right now I'm rewriting the entire app to be Cocos2D only. Working out pretty well.

I had an epiphany this morning while taking a nice cold shower and thought of a way I can make the MVC design pattern make a bit more sense with Cocos2D. We'll see how it goes...

-robodude666

Posted 1 year ago #

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