java games with maximum portability - java

i want to program a simple java game, what should i consider to make it maximal portable? i'm pretty new to java, which grafik and rendering libraries should i use to make it easyly portable to mobile java (for mobile phones)?
i can't develop it directly for mobile java, because i also need a pc version.
or should i jast develop strait forward for pc and do a completele new mobile version later?

I'd say do the PC version first (portable across Mac, Linux, Windows if that is a priority for you), and develop a (or even several) completely new version for mobile handsets.
There may be some code (and art work) that you can re-use, but not too much, as a (good) game will have to be very different for a mobile phone than for a PC, not just screen sizes and input methods, but the major changes in game play that those differences probably result in to make it still fun to play.
The code that you can reuse will likely need to be adapted for J2ME or Android, but better to worry about that later than trying to be overly cross-platform from the beginning (which would place limitations on functionality on the PC version, and eat up a lot of time, without being sure if it ever pays off).
Again, if anything, worry about portability within the several desktop environments, and within several handsets, but not too much about portability between the two.
Of course, if your game has a server-side component, it would be ideal to have only one version of the server code that can talk to clients on all platforms.

I think it's feasible to create a game that is portable across a wide range of platforms. While a desktop version of a J2ME game may look primitive, it does enable your users to preview the game before installing it. Check out my project JGame, which enables writing a game that works without changes on J2ME, Android, and PC. I believe the Slick project also has a working Android version.

Related

What is the advantage of using JavaFX for an android project instead of android UI itself other than portability of the code

The reason why most people would ever make their android project in javafx would be to have the same codebase across different platforms (such as ios, desktop, android, maybe even web using Bck2Brwsr/teavm/doppio)
But my question is, is there any advantage in javafx ui framework itself when compared to android ui framework?
I have never ever written even a hello world application for android, but I intend to do it now. So I am wondering if having the code in javafx is worth the effort when I can develop directly on android apart from the benifit of portability.
This type of question might result in a subjective/opinionated answer but I think it is a good question so I will provide my assessment.
Having the same codebase across all those platforms is huge. Do not dismiss this. I'm using Gluon Mobile to port aspects of the Deep Space Trajectory Explorer (DSTE) to Android and iOS. As you can see from the video its extremely complex application. There's no way I would rewrite that in native Android... it would be a no-go from a cost perspective.
Starting development from JavaFX makes it easier to make complex visuals. I don't just mean traditional 2D GUI forms. Again looking at the DSTE you will see we use Canvas to do dense renderings and JavaFX 3D along with the FXyz library to do 3D renders. These things are easy in JavaFX and again using Gluon simply "just work" on Android/iOS. In fact it only took about a day to get those aspects of the DSTE code base to work on a Pixel C tablet, most of which was getting the Gradle build setup properly. Now imagine having to port 3D code from JavaFX to a Native framework? I'm a 3D guy and I still wouldn't try it.
Testing is so much easier on the desktop than a mobile device. This doesn't mean the testing is 100% on desktop. Sometimes something that works on desktop "doesn't work" on the mobile platform and you have to tweak accordingly. However you can save a LOT of time standing up the application using JavaFX knowing that 90% of it will work the same on your mobile device.
Word of advice though... remember that a desktop application is NOT a mobile application. You will be tempted to just "port" your desktop app to your device. I was my first time. You can get into other issues where the interfaces and layouts you design for a desktop "work" on the mobile device but are not appropriate and so the usability goes down. Start slow when you port. Think of what aspects of your desktop workflow should be mobilized. Only port the things you absolutely belong in a mobile workflow. Save yourself some headaches.

Android animation flash vs. HTML5 vs. Android's native animation library?

I am going to be writing a tower defense game for Android phones. I have knowledge of Java and the Android SDK; however, I am new to animation and have a few questions about where to start.
I will be using only 2D graphics (maybe later down the road 3D graphics but for now I will keep it simple), have basic animations (enemies moving along pre-determined paths, stationary towers shooting at moving enemies, and maybe a few explosions here and there), and some sounds that result from different in game actions. Just to give you a rough idea of what I am thinking about, my game would be very similar to bloons tower defense 4.
My question is, based on what I have stated above would you suggest I incorporate Flash, HTML5, or Android's native animation libraries? What are the pros and cons of using each one? If none of these are good options than what is?
I'd suggest using Android's native libraries. Adobe has already said they're not longer going to support flash on Android so you'll slowly users over time. And beside, Android's native libraries are going to give you better performance anyway. In addition, there are some really nice frameworks out there that make developing games on android with OpenGL super easy (see andengine or this Gamers post for more details).
As far as HTML5 goes, I'd say stay away from it. Most users prefer a native app over a web-app and I can almost guarantee you that you're going to get better performance with a native app.
1) If you are going to make games, use definitely the Java. It is fast, there are plenty of game physic libraries, you can use OpenGL and you can even use C ports of some famous game libraries. You are simply not limited.
2) The HTML5 is pretty slow so far and no matter how good it is for mobile web pages, it is not sufficient for more complex games then Tetris or Sudoku. Just try some HTML games on couple of Android devices - nothing is better then own experience.
3) Do not start with Flash - Adobe company closes the Flash support in mobile phones. See there or there. This is releted to the Flash support in browsers.
4) As mentioned in one comment below - the Adobe AIR is other possibility and different story then Flash in web browser. This is Flex based technology (Action script + XML). It allows you creating standalone applications - we have 2 apps with AIR, but the AIR framework is slower then Java, it does not run on certain devices (low-end Androids), you must purchase the Adobe IDE and the developers base is smaller, so it is harder to find answers if you are in troubles. There is no clear advantage over Java, unless you plan to release also for desktop.
Regards,
STeN

What are the portability implications of using the NDK?

I need some operations that are to be performed on large long[]s to be very fast. The only option I can see is to use the Android NDK. Can anyone give a summary on what using the NDK does to my app in terms of which devices can use the app and what the implications are to maintaining my app?
I saw that you need to specify which architecture you want to compile your C code for, like ARM and Intel. What happens when new architectures for Android appear? Will I have to update my app every time a new architecture appears?
Can anyone give a summary on what using the NDK does to my app in terms of which devices can use the app
Only devices running on a CPU for which you have an NDK .so will be able to run your app.
and what the implications are to maintaining my app?
Testing on multiple CPU architectures may require hardware for each architecture. I say "may" because...
What happens when new architectures for Android appear?
...we really have no idea. Other than adding ARM7 support, the NDK has not changed its targets.
Right now, there are two major non-ARM platforms for Android that I can think of:
Intel Atom, being used by Google TV devices. At the time of this writing, the NDK does not support this. However, you can't ship apps for Google TV yet, either. So, it may be that the NDK will be updated by the time we get to write Google TV apps.
MIPS. At the time of this writing, the NDK does not support this. I have no idea what the plans might be in this area.
It is conceivable that emulators will appear to emulate those CPUs. After all, the existing Android emulator emulates ARM5. However, unless and until this happens, you will need test hardware for every architecture you intend to support.
Will I have to update my app every time a new architecture appears?
Only if you want to support the new architecture. Until there is a critical mass of devices for it that can access your app, any new architecture is not going to be terribly important. "Critical mass" could be from general device sales, or it could be because you strike an OEM deal to have your app bundled on somebody's device.
The code is simple though and will work on all archs.
Watch your endian-ness.

Best of both worlds: browser and desktop game?

When considering a platform for a game, I've decided on multi-platform (Win/Lin/Mac) but can't make up my mind as far as browser vs. desktop. As I'm not all too far in development, and now having second thoughts, I'd like your opinion!
Browser-based games using Java applets:
market penetration is reasonably high (for version 6, it's somewhere around 60% I believe?)
using JOGL, 3D performance/quality is decent; certainly good enough to render the crappy 3D graphics that I make
there's the (small?) possibility of porting something to Android
great for an audience of gamers who switch computers often; can sit down at any computer, load a webpage and play it
also great for casual gamers or less knowledgeable gamers who are quite happy with playing games in a browser but don't want to install more things to their computer
written in a high-level language which I am more familiar with than C++ - but at the same time, I would like to improve my skills with C++ as it is probably where I am headed in the game industry once I get out of school...
easier update process: reload the page.
Desktop games using good ol' C++ and OpenGL
100% market penetration, assuming complete cross-platform; however, that number reduces when you consider how many people will go through downloading and installing an executable compared to just browsing to a webpage and hitting "yes" to a security warning.
more trouble to maintain the cross-platform; but again, for learning purposes I would embrace the challenge and the knowledge I would gain
better performance all around
true full screen, whereas browser games often struggle with smooth full screen graphics (especially on Linux, in my experience)
can take advantage of distribution platforms such as Steam
more likely to be considered a "real" game, whereas browser and Java games are often dismissed as not being real games and therefore not played by "hardcore gamers"
installer can be large; don't have to worry so much about download times
Is there a way to have the best of both worlds? I love Java applets, but I also really like the reasons to write a desktop game. I don't want to constantly port everything between a Java applet project and a C++ project; that would be twice the work!
Unity chose to write their own web player plugin. I don't like this, because I am one of the people that will not install their web player for anything, and I don't see myself being able to convince my audience to install a browser plugin.
What are my options? Are there other examples out there besides Unity, of games that have browser and desktop versions? Did I leave out anything in the pro/con lists above?
I'd suggest writing a game first.
It's easy to get caught up in how to make the best game ever,which can run on anything from an abacus to SkyNet, but the reality is that you're going to have plenty of challenges ahead of you just finishing a game that runs on your own PC.
Write a game first, for one platform (whether that platform is "Windows native with DirectX", or "Java applet" or even "pure AJAX in a browser"). If you can do that, then you can start thinking about how to port it to other platforms. But trying to do everything is a sure way to end up achieving nothing.
Or to put it another way:
I've decided on multi-platform (Win/Lin/Mac)
so you've actually decided nothing. Decide on a platform to develop on. Then make the game. Then make it work on other platforms.
Don't worry so much about what your "audience" will find acceptable. If your game is fun, then yes, people will happily install Unity. Just like they'll install your game if it's not browser-based. But the important point is not "what do I have to install to play it", but rather "is it worth it". Your focus should be on making a game that is worth the installation.
And unless you're planning to sell 20 million copies of the game and live off it, your "audience" doesn't really matter that much, does it? What matters is putting the game out there so those who are interested can try it.
But a single-platform game is a lot better than an unfinished cross-platform nothing.
A game that requires me to install Unity is a lot better than something that takes you an additional 3 years to develop because you insisted on reinventing the wheel.
Yes you can have the best of both worlds.
It's perfectly possible to write a Java application that will run in both an applet (for your online users) while also running as a standalone application in downloaded form.
The key technologies are:
JNLP
JOGL for the graphics, which also has some good demos
I'm not so familiar with it but I think jMonkeyEngine looks very promising if you want more of a full-featured game engine
If it's any use, an old game I wrote called Tyrant supported running both as an applet and as a standalone downloaded .jar file, all the source is open if you want to look at it. This used simple AWT rather than 3D graphics.
And finally here's another example of converting an applet into an application with a pretty minimal amount of code.
If you really want that kind of penetration then I suggest HTML 5 + javascript depending on the performance you need.
First of all you start with the wrong question. Your decision for a technology should be driven by the concept behind the game. It seems that you are sure about the idea to write a game - so ask your self what the requirements for the game are. This will lead you to your technologie. If it doesn't get an idea of "what" you want to do.
To your Pro's and Con's:
Don't focus on things you will never need or be able to use. Thinking about the steam platform isn't interesting for a hobby developer. Also android isn't interesting if you are not really want to ship your application for android. This Pro's will actually never be a pro in reality.
To sum it up: Let this decision be driven by your idea, not the technology itself. If you have a clear idea of what you want to do you will get your answer.
(And btw.:
Think about what browsergames imply. Behind a Browsergame there is a huge service-area, only for keeping the game running. Companys working in such areas are basically service-providers.)
You might want to look into Google's Native Client, which allows you to write your application in C or C++ (or anything else that compiles to native code, really). A new feature coming to the SDK is LLVM support, which will (hopefully) allow NaCl software to target any platform that Google's Chrome browser runs on (or any browser that the NaCl plugin works with - currently x86 and ARM are supported, IIRC).
You mentioned Android in your question - have you thought about developing the game purely for Android?
In effect you get the best of both worlds, easy to maintain, easy to release new versions, easy to monetize and get some small income and you don't have write your own installer or update mechanisms either.
Yes. You can make something that will work in both. Basically, make your program work inside a JPanel. The applet can display the JPanel, and the desktop version is just a window with your JPanel in it.
You could also have a full Swing (or whatever) GUI, which the applet launches in a new window when they click the little "start" button you'd have on your applet.
There are a few other differences you'll have to take into account, like possibly loading resources, but I've done it before for simple games I've made.
I don't think you can really compare the two:
In my opinion:
Applet, flash and other browser based games are typically small "toy" games either written for free or supplemented with advertising. For examples, check out the Addicting Games website.
C++ games are more likely to be heavyweight studio-written games relying on dedicated physics engines, graphics engines, etc (particularly true of games distributed on Steam I would have thought). The learning curve is likely to be much steeper, as C++ is inherently a more difficult language than Java / Flash.
If you're unfamiliar with C++ my advice would be to steer towards Java with JOGL. That way you can scale the Open GL learning curve before having to tackle C++.
EDIT
To address the other section of your question regarding implementing a game in both browser and desktop form, you could consider implementing the game in Java and deploying an applet and standalone version, whereby the standalone version can take advantage of Java's full-screen exclusive mode API. You could base both applications on the same codebase. You could also consider shrinking the applet's footprint size by retaining data files (e.g. game levels) on the server-side and retrieving them dynamically when required.
While WebSense won't let me browse directly to the site, for obvious reasons, the first thing that came to mind when reading this question is a game like Wurm Online. It's written in Java with JOGL, implements content streaming and local caches, and seems to have touched on a lot of the points you're interested in. It's a desktop Java application rather than being truly "in-browser" but I think you could still learn quite a bit from its implementation.
The in-browser game is always in peril of having its window closed or refreshed, causing it to abruptly lose state unless everything is being kept server-side. This means you either have very simple games that can maintain synchronization using a call/answer model (such as the myriad of Facebook "Mob Wars" text-based games) or risk an inadvertent bump of F5 catapulting someone back to their last "saved game."
I'm not sure that refusing to use a plugin because you personally don't like it is a sensible choice. This option lets you write you app installable as a desktop app, or a browser plugin (with not much extra work) and you still get to write it in C++/GL. You said you don't think your users will install plugins... why not? If they will install an application then why not a plugin which basically boils down to the same thing?
You could look at Flash too, which is gathering some 3D functionality and can run in-browser or as an AIR dektop app. But then users would need a Flash plugin, which you presumably don't have either.

symbian application as background process

is it possible to create java application that will
work as background process on symbian smartphones?
You can approximate it but J2ME (the version of java on mobile phones) may not be the right technology to do this.
starting a MIDlet (a Java application for mobile phones) when the phone is switched on is tricky at best without coding a small Symbian OS C++ module that will start it for you. If you want to try anyway, look at the PushRegistry class in the MIDP specs
(http://java.sun.com/javame/reference/apis/jsr118/). The Content Handling API might provide some way to do it too (http://java.sun.com/javame/reference/apis/jsr211). When you are ready to give up, do it in C++.
Backgrounding a MIDlet isn't hard. The phone's "menu" key will do it for you. Programatically, Canvas.setCurrent(null) has a good chance of working. Trying to trick the phone by providing a fully transparent GUI and not handling any keypad activity will absolutely not work. Creating and starting a separate Thread in the MIDlet should allow you to keep something running even after your overload of MIDlet.pauseApp() has been called by the application management system.
The real issue is that the MIDlet will not have any Inter Process Communication system unless you make one. The usual way of doing that is a loopback socket connection over which you transfer data. Not a nice or efficient way of simulating IPC. Sharing a RMS record can only be done from within the same MIDlet suite (you can package several MIDlets into the same .jar file), I think. The code to create a provider/consumer data flow over a file connection is even uglier and will raise security issues.
Without any more information about what you want to use it for, my answer is : maybe but you should probably not try.
You will have in-built MIDP support for background MIDlets in MIDP 3.0 (http://jcp.org/en/jsr/detail?id=271). Don't hold your breath for devices to appear, however - might be some time.
(Note that a few Symbian OS devices have more than just MIDP - the S-E p990 for instance, https://developer.sonyericsson.com/site/global/products/phonegallery/p990/p_p990.jsp).
As already pointed out, it might be helpful to have more information on what product functionality you are trying to implement - often more than one way to skin a cat.

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