[quote name='Aliii' timestamp='1335024671' post='4933540']
Ive written a few little apps for android, but now I know that java is definitely not for me. I know that the best selling apps are usually 2D and all that, but Im mostly intrested in 3D or 2D physics, ...and to write that in java would be horror(for me at least).

I know there are tools for including native parts in the java code, but I dont know anything else about them. Is it hard to implement such tools or APIs? Do they produce more overhead than the speed I gain by writing in CPP? What parts of the application can I write in native?
Thanks very much!
[/quote]Java is JIT compiled to take best advantage of the hardware running it. It has been shown by quite a few major studies that Java is either on-par with C++ or better performing than C++. The only very rare exception is when you need to take advantage of some hardware-specific benefit that has no bytecode equivalent and the JIT compiler just cannot access. But Android doesn't have that problem since all the hardware out there runs java-accelerated chipsets.

Every device I'm aware of has chips that run Java bytecode directly. That means Java *IS* native code.

You can write whatever you want in whatever language you can find Android compilers for. There are quite a few languages to chose from. But don't expect to get better performance since Java *IS* the hardware native instruction set.
[/quote]

While Java performance on android is pretty rock solid its not necessarily native (as android runs on standard x86 hardware aswell), the JIT compiler however does make that distinction pretty irrelevant and Google does recommend against using the native SDK for performance reasons (usually it results in a slowdown due to JNI overhead unless you write very large chunks as native code).

There is however a few very good reason to use C++ for Android apps and those are:
iOS portability (iOS doesn't run Java bytecode) (Allthough using something like Unity is a better option for this)
Memory limitations on older Android devices, (Older android versions have a 16MB per process limit for the managed heap) (Allthough since memory used by the GPU isn't counted towards that limit its rarely an issue for games and devices running those old android versions usually don't have all that much ram to play with anyway)

Thanks for your answers!

"

[background=rgb(250, 251, 252)]You can (especially if you're using openGL) basically write almost your whole app in C(or C++, but beware of no STL) fairly easily.[/background]

"

...Its good to hear that. Yes Im just getting started with opengl ES2. Do you mean NDK? It seems like it doesnt really support ARMv6 processors, which my phone uses:S

"

[color=#282828][font=helvetica, arial, verdana, tahoma, sans-serif]

[background=rgb(250, 251, 252)]Why? Because you don't like Java? As a programmer you should write for the best tool for the job; databases mean SQL, build scripts mean python and perl, and Android programming means Java[/background][/font]

"

Im OK with Java, I know its much better when it comes to portability or when you have to write little apps fast, ...but to write complex games in Java it sounds like a joke.
Under the VM is C and CPP, ....as far as I know openGL functions also run native. ....there must be a reason for that.

[color=#282828][font=helvetica, arial, verdana, tahoma, sans-serif]

[background=rgb(250, 251, 252)]"Every device I'm aware of has chips that run Java bytecode directly. That means Java *IS* native code."[/background][/font]

I didnt know that. Im not an expert, I dont know much about the hardware, how the VM executes the native parts, how and when exactly the JIT compiling happens. I need to read a lot about that.

I want to learn some Java but I would prefer juggling with pointers:) My longterm goal is to develop games for PC but android seems like a really good starter.(Maybe if I find a job at an android-dev company this will change)

"

[color=#282828][font=helvetica, arial, verdana, tahoma, sans-serif]

[background=rgb(250, 251, 252)]While Java performance on android is pretty rock solid its not necessarily native (as android runs on standard x86 hardware aswell), the JIT compiler however does make that distinction pretty irrelevant and Google does recommend against using the native SDK for performance reasons (usually it results in a slowdown due to JNI overhead unless you write very large chunks as native code).[/background][/font]

"

Its hard to imagine that lets say a physics algorithm can have the same performance without using pointers and references. And what about the garbage collector? Wont it "pop up" every few seconds and noticeably affect the FPS?
Thanks!

Thanks for your answers!

"

[background=rgb(250, 251, 252)]You can (especially if you're using openGL) basically write almost your whole app in C(or C++, but beware of no STL) fairly easily.[/background]

"

...Its good to hear that. Yes Im just getting started with opengl ES2. Do you mean NDK? It seems like it doesnt really support ARMv6 processors, which my phone uses:S