What's the best language for real-time graphics programming on Android?

Question

Some googling has led me to believe that C++ is the best language for real-time 2D graphics programming, but since the Android is Java-based, is that still the best option? Or u

Answer 1

Android applications are written Java, yes - however the Android NDK allows you to write performance-critical sections of your program in C or C++. From the Android NDK website,

The Android NDK is a companion tool to the Android SDK that lets you build performance-critical portions of your apps in native code. It provides headers and libraries that allow you to build activities, handle user input, use hardware sensors, access application resources, and more, when programming in C or C++.

That said, using the NDK appropriately will most likely not slow your program down.

OpenGL works for 3D and 2D graphics - if you're only interested in 2D you will want to look at using an Orthographic Projection - see glOrtho for more information. The Android Canvas, on the other hand, is the Java method for drawing raster graphics to the screen. It will let you render 2D graphics, but at a slower rate (and with frequent interruptions from the Android Garbage Collector).

Keep in mind that if you want to use C++, as of writing, there is no STL implementation available. There are, however unofficial ports that provide most of the functionality. STLPort is one that I have tried with some success. The biggest reason to move code to C/C++ is because of interruptions from the Android Java Garbage Collector - if you're not overly careful with your code, it will interrupt your program frequently to clean up objects you've left lying around. In practice this can limit game or simulation framerates drastically.

All that said, I would strongly recommend you look into one of the few open source android game engines that are cropping up. The best one I've tried is libGDX. It takes care of all the messy NDK details and lets you code your game / simulation purely in Java. It automatically runs the performance-heavy parts of the game engine in native code to get the fastest possible performance with the ease of coding in Java. Best of all, you can write your application code once and have it automatically run on Windows, Linux, OSX and Android - which makes testing your applications much, much easier than using the Android Emulator.

If you really want to look into the NDK yourself, or need to have really fine control on what OpenGL is doing, I would recommend you download the Android SDK and NDK, get eclipse set up, and then start with the NDK samples. There is an OpenGL demo there that shows you how to get everything set up. Another good starting point would be the SpinningCube google project.

EDIT: I'm not really sure if what you mean by 'GPU-like capabilities', but With libGDX, you can compile vertex and fragment shaders under OpenGL ES 2.0 - you could use this to run embarrassingly parallel code using the device's GPU.