I am new to iPhone dev and would like to write a game that involves 2d collisions. Would somebody give me a conceptual overview on how the various frameworks interact in a typical 2d collision game?
The candidates I see mentioned so far are 2d packages such as quartz and cocos2d and physics engines such as chipmunk and box2d. What I am not extremely clear is the relationships among these in my context.
Thanks in advance for answering!
Quartz is a 2D graphics API by Apple. It's usually not used for performance-intensive games, because you can get better performance by using OpenGL directly or by using some thin framework made for games. (Which is what Cocos2D provides.) The collision stuff is independent on this debate, since the collisions are usually calculated without knowing anything about the graphic representation of the colliding objects.
The relationship between collision (or general physics) engines and the graphic layer is exactly the relationship between a model and a view in the MVC pattern. In each frame you move the physical world a bit forward (physics) and then you draw the objects on their new positions (graphics).
In reality the model and view sometimes blend a bit to make things faster, but in principle they are completely separate things. Which means you can pick any of the possible combinations of OpenGL, Quartz or Cocos2D as the graphics engine and Box2D or Chipmunk as the physics engine and get a decent game. I'm not sure how well do the particular combinations work in practice - if that was your question, then I've just wasted a few minutes of your life :-)
zoul got it right, I would just add this :
Cocos2d for iPhone provides samples including Box2D and Chipmunk if you want to try them and see how easy or hard they are to use. So you can go ahead and download Cocos2d, then play with the samples a bit to see if it fits your needs.
Related
I have been looking into Open GL ES, Quartz 2D, a framework called cocos2D and I am not sure what would be the best direction to move forward in when making a 2D game. I am planning on making a pretty simple not to intense game and I am new to game development but not to iphone development.
Which would be the easiest to learn? Which one would give the best performance ?
Thanks
I was in the same position as you and I chose Cocos2D. It's perfect for a beginner. It's basically a wrapper for OpenGL ES, and it's open-source so you can see how it works and modify it to your liking.
Starting with Cocos2D is a good idea because you can make a lot of abstraction from complex low-level functionality, while achieving a good high-level overview of your game. While developing, you will pick up some low-level details as well, so that you'll be more prepared for them in future games.
Plus, Cocos2D has a really nice structure for simple 2D games. If you were to write this yourself in say OpenGL ES, then you would just lose a lot of time that you could be spending actually designing your game :)
But that's just my opinion.
Oh and don't worry too much about performance. Cocos2D is fine in that aspect. Like I said, it works on top of OpenGL ES so the drawing is done very efficiently. It also supports stuff like sprite batching and texture atlasses, which is good for performance.
As the goal of these frameworks is to provide simplified game development, this is definitely the way to go. Of those that you list, two of them are graphics "engines" (Open GL ES, Quartz 2D), and one is a game engine (cocos2D). If you choose graphics, then you'll probably have to write quite a bit of extra code, even for a simple game.
I want to start as a 3d game developer . But I am not getting from where to start.
Should I work on some game engine or should I work to learn openGL which is the core of any game engine.
I am working as an application developer (iPHone) and I have worked on Cocos2d game engine for iPhone.
Any guide lines. Please help.
How about cocos3d?
cocos3d is a significant extension to cocos2d
that adds a full 3D modelling space,
including 3D mesh models, perspective
projection cameras, materials, and
lighting.
Do you want to emphasize the "3D" or the "Game" in "3D Game Developer"?
If you emphasize the 3D, you can dig deep into OpenGL, and all the concepts behind 3D graphics, and develop the low level drawing code for your game. See HG's response for a good start. 3D graphics programming is a huge subject. Just OpenGL ES, which is available in two incompatible versions under iOS, is a huge subject that could take many months to learn. Plus if you're writing the rendering code for your game, you'll probably be writing the rest of the game subsystems code such as AI and physics.
If you want to emphasize the Game, you can learn 3D game engines such as cocos3d (as Kazuki Sakamoto mentions). There are lots of such game engines. In addition to offering rendering code, these engines may offer other game subsystems. You'll be working on your game content more than reinventing the game subsystems.
It just depends upon which is more interesting to you.
I'm looking for is a heuristic for determining which of the primary graphics methods for iPhone/iPad development would be the most appropriate solution for a given problem.
Simple answer:
Quartz 2D
Use Quartz 2D for custom interface elements to give a stylized look to your application.
Core Animation
Easier to use, although used where performance is not critical. Great for quick animation routines. a lot easier to do effect in. Used with UIViews as well. Can be used to create simple fine games. like pong or card games.
OpenGL ES
Great for performance critical games. A bit more complex but once you can get your head around the tutorials available and the frameworks provided you can create high perfomance games. And also port them to other devices other than the iphone very easily which is quite cool.
Long Answer:
Quartz 2D
Quartz 2D is the powerful 2D graphics API for iOS. It offers professional-strength 2D graphics features such as Bézier curves, transformations, and gradients. Use Quartz 2D for custom interface elements to give a stylized look to your application.
Core Animation
Core Animation is likely the appropriate choice for games where performance is not critical such as simon says type games, card games, and trivia games. Some might argue that OpenGL ES is easier to use, and it likely is if you’ve studied say.. DirectX.. but Core Animation (and Quartz 2D for that matter) is much easier to do simple effects in, and can be used with existing UIViews.
Core Animation is fine for games where performance is not critical, and for new programmers will likely be easy to use, OpenGL is needed for anything else.
Core Animation utilizes OpenGL ES, it is high level, and in my testing works fine in situations where performance is critical.
OpenGL ES
is your choice for performance critical games. Which is essentially anything but simple mostly static games like the ones mentioned I above such as first person shooters, flight simulators and the like. You also get the added benefit of potentially being able to port your games to a device other than the iPhone, and there is alot of existing game code in OpenGL that can be converted the other way. OpenGL ES is an open standard that is used on a growing number of devices created by a wide variety of companies, and because CoreAnimation is a higher level framework built atop OpenGL ES it cannot provide nearly the same performance.
http://maniacdev.com/2009/07/iphone-game-programming-coreanimation-vs-opengl-es/
http://developer.apple.com/technologies/ios/graphics-and-animation.html
PK
I am writing a simple game that animates a ball image quickly across a background image.
Would Core Animation/Quartz be sufficient for this scenario?
I don't really want to learn OpenGL ES if it is not going to provide any substantial benefit in this one off project.
This is a commonly asked question. Other questions like this include:
"iPhone board game: OpenGL ES or CoreGraphics?"
"Are most games on the IPhone done with OpenGL ES?"
"Core Animation or OpenGL ES?"
"Does openGL ES have a better performance than Core Animation and UIKit when it comes to highly animated user interfaces?"
OpenGL ES I suppose isnt too hard.
But at the end of the day Core Animation is going to be fine, its super powerful and not to hard to work with. It will also get you up and running so quick that you will release you game "sucks" a bit and you want to change it and you didn't even have to learn OpenGL.
I highly recommend looking at cocos2d. A very simple game engine for 2d stuff.
http://cocos2d.org/
Have a look at that.
Cheers, John
OpenGL ES isn't that hard, there are lot of really good resources in the web and step by step tutorials. Can be hard at first, but once you get the grip of It things will be easy. 71 Squared has very detailed tutorials:
http://www.71squared.co.uk/iphone-tutorials/
About the question, Core Animation Is great for most apps, but in a videogame It's fundamental to draw your game efficiently and have as much control as possible.
Cocos2d Is great and I recommend It If you need to write a good game, but if you're doing It for educational purposes I recommend OpenGL, You will learn a lot with It and gain a lot of experience.
Just jump to something like Cocos2D so that the OpenGL is done for you. OpenGL ES is significantly faster and more adaptable than Quartz, plus it's not any harder. I even think Quartz is a big pain in the butt and difficult to figure out, although I came from an OpenGL background on desktop computers first, so naturally that jump is pretty small. The point is, though, that either with Quartz or with OpenGL ES you're going to need to spend a lot of time with resource management, etc., so you might as well go with Cocos2D.
yes, it will be fine, as long as you're not wanting to do hundreds of balls at once or something else complicated like that.
If your knowledge of Core Animation is good then i recommend you to skip learning OpenGL ES for now, since it won't really help you (if all you want is what you described of course). On the other hand, if you plan to make more games which have more involved graphics, it might be a better idea to start learning the API. OpenGL ES is a simple API and you can use the full graphics features of the iPhone with it.
If all you want to do is just make this game, then i say go with what you know and are productive.
I would say this very much depends on what you want to do with the ball. If you simply want to fire off an animation and forget about it Core Animation will probably be fine. However, if you are trying to interact with the ball, for example by changing the direction of the ball mid-flight based on user interaction, then you probably want to consider OpenGL ES. Of course, you're other option is to use neither Core Animation or OpenGL ES and simply redraw your view on a timer.
If you're a fairly competent C programmer I wouldn't be too put off the OpenGL ES stuff. Apple supply a lot of the framework for hosting OpenGL ES views in their templates. Although OpenGL can get fairly involved, if you're not trying to render huge multi-object 3D scenes then the basics are fairly straightforward and you should be able to get some nice results quite easily. Although it is for OpenGL rather than OpenGL ES, I would recommend this set of video demos as a good starting point:
www.videotutorialsrock.com
OK, I'm still brand new to iPhone development. I have a free game on the app store, Winner Pong, but it's just a Pong clone (who would've guessed) that uses the standard UIImageViews for the sprites. Now I want to do something a little more complicated, and port my game for the Xbox 360, Trippin Alien, to the iPhone. I obviously can't keep using UIImageViews, so I was wondering which would be better to learn: the simpler, but performance-hindering Qurtz2D, or the smooth-running but dauntingly complex OpenGL ES.
My game is basically a copter game, with about 8-10 sprites on screen plus a simple particle system (video here). Not too complicated, but performance does matter. My only prior game programming experience is in Microsoft's XNA and C#, which has a built in SpriteBatch framework that makes it incredibly easy to draw, scale, and rotate pre-rendered sprites on screen. Is it worth it to learn OpenGL ES? How big is the performance gap? Is quartz really that simple?
Also, if anyone knows of any tutorials for either one, please, post them here. I need as much help as I can get.
Look through code samples of each to actually see the complexity. You might find that OpenGL isn't so daunting.
Regarding the performance. Core Animation, which Quartz2d is part of, uses OpenGL behind the covers, so for simple sprite animations, I would expect your game to perform fairly well.
I would also glance over the programming guide for each before making your final decision.
Another alternative is to use something like Unity. I recently just started playing around with the trial version of this development environment and if you're mostly doing game development with graphical objects and sprites, this may be one option to consider. You can script in C#, Javascript, or Boo. The development environment allows you to graphically setup your scenes and levels. You can then attach scripts to graphical objects for animation to handle user events, etc.
One downside for Unity, which I've heard from others is that if you want to use the familiar UI controls from UIKit, it's not so easy to instantiate them...I haven't verified this myself.