Develop Reference

SDL2 cross-platform OpenGL 3+ and OpenGL ES 2.0 or 3.0

Is there some super-easy basic hello world cube project (with setup tutorial) for SDL2 that builds and runs easily across (Windows, Linux eg Ubuntu, Mac OS X, Android, iOS), using modern OpenGL as in OpenGL 3.x or 4.x and OpenGLES 2.0 or 3.0?
I downloaded SDL2 and it was pretty easy to get their example testgles.cpp and testgl.cpp to build...
However, the testgl.cpp one is horribly old (gl2 style), so I tried the testgles.cpp. Unfortunately, even this is full of old style fixed function calls like glMatrixMode(GL_MODELVIEW). And it's annoyingly over-integrated with SDLTest_Common code.
Is there a better simple clean hello world project (eg colored cube, textured cube) that I can start from?
Or is there some reason why they don't include such an example starting project or tutorial?
Or should I be using a different library instead of SDL2 that is simpler & cleaner to setup? Basically I want to write OpenGL / OpenGLES (and maybe DirectX) cross-platform C++ code. But setting up SDL2 has been a lot messier and more painful than I expected.
So far I just made an svn repository with SDL2 code and got testgl.cpp and testgles.cpp to build on those five platforms. But that used a lot of old style OpenGL/OpenGLES code, so now I am slowly hacking it to use newer stuff... It's been quite a pain. I don't get why SDL2 doesn't just include a basic hello world cross-platform starting project (eg textured cube) using modern OpenGL/OpenGLES (and DirectX).

SDL2 is a good way to start. I could even say, that SDL is the most popular and yet multiplatform lib for that, especially is you think about using joystics or going steam later on. There is no need to look for any other lib. But please remember, that it's just low level layer for providing media access. It's not their job to provide high quality Opengl 3.0 projects to users. What you need is to learn some modern OGL basics - and you have to do it somewhere else. As simple as that.
A good place to start is http://www.open.gl. There is a couple of very straightforward and simple tutorials written in C++ with some SDL and SFML approach.
Lazy Foo also cover some of the topic http://lazyfoo.net/tutorials/SDL/
http://openme.gl/ is also nice, maybe http://openme.gl/opengl-4-x-example-using-sdl2-and-glm/ is something for you. It seems to be a quite good quality code.
http://www.opengl-tutorial.org/ is also a great place to learn OpenGL 3.3+. It's recomended in many places.
You can always come with some kind of project like this and link to official SDL wiki. ;) SDL community will be greatfull for that.
And by the way. DirectX is "Microsoft's non-opensource SDL" - and it's very non-crossplatform.

If you want to write cross platform OpenGL, you might take a look at GLFW for setting up your OpenGL context. It handles simple window and context creation as well as user input.
I have a method to render a colored cube in some of my example code here. It's pretty enmeshed in my library though as it makes lots of calls out to my wrapper classes. They're also available in the same library, or you can take a look at the latest version of them here.

Android Animations?

I would like to create an android game but one thing I do not understand is what I should use to create the graphics for it,
It is going to be a 2d game with movable images but would I use OpenGL ES or something else?

You should use OpenGl ES to get the best performance. Alternatively you could use Canvas drawing which is the default way of drawing in Android...
But the easiest way of creating an Android game probably by using Unity 3D...
Not Java development thoe :)

Try it via libgdx
it is easy to use.
Thanks

LibGDX is a fast library that is essentially a wrapper around OpenGL, saving you a lot of time. Unfortunately the documentation around it is severely lacking, so there is quite a steep learning curve, but once you are used to the library development is very fast.
It also gives you the option to run your code as a java application instead of the android emulator, which saves a lot of time.
There are a few good tutorials on the wiki to help you get started, but you will ultimately have to rely on the Java Docs and the test code to see how to use the library properly.
There are other options such as AndEngine, which is easier to learn but has less flexbility and runs slower, so ultimately you are better off with LibGDX.

Android 2D framework for Graph Visualisation

I'm going to work in the next weeks on a visualisation project on android tablets and mobile devices. This is a kind of project where there is webservices calls, databases and little processing but a lot of data visualisation and manipulation. Mainly 2D (advanced charts and advanced graphs). Like http://max-planck-research-networks.net/.
And I was wondering if there was some framework on android that could accelerate my devs. I heard about game engine (like AndEnine and cocos) but i'm looking for something more like processing.org. Any idea?

You might be able to use a graphing library like http://code.google.com/p/achartengine/ or http://code.google.com/p/chartdroid/

I am also currently looking for a framwork that could do this. Up to now the best I could find was JUNG (http://jung.sourceforge.net/). JUNG uses swing in its renderer, so to use it with android a new renderer would need to be built.

Open GL 3D library for iOS (and Android)?

Is there some free and easy to use 3D library for iOS (and Android) that simplifies Open GL ES framework. Just like there is cool WebGL library: ThreeJS for javascript.
So far I saw Unity but it's not free and I would like something simplified.
My usage would be setting the scene, meshes, camera, rotating the camera etc...

For Android you can use AndEngine which supports GL ES1 and GL ES2. For IOS you can use Cocos2D.

I decided to go with Cocos3D because it has all the features I need and is similar to JS libraries. It is free and you don't have to use any special engines with it.

Well, there is Sparrow for iOS, and as for Android you can consider AndEngine
(easier) or LibGDX (faster).

One option I believe is SiO2.. And Oolong too.. I once played with blender and SiO2 and it went well..If you are only interested in 2D games only then Cocos2D is best bet for iphone..
For android AndEngine is good,and I believe SiO2 works for android too..

Ahh, Unity did give away the iOS/Android versions back in March/April this year - maybe if you asked them nicely?
OpenSceneGraph has a large and active following in the Vis/Sim community, and is starting to creep into games, here's a couple iOS/game related topics from their forums:
http://forum.openscenegraph.org/viewtopic.php?t=10291
http://forum.openscenegraph.org/viewtopic.php?t=10308 (p.2 of this thread has links to a couple osg-based games in the iTunes store)

For Leaning very basic of open GL for iOs I would suggest to have a look at this http://antonholmquist.com/blog/opengl-es-2-0-ios-tutorial-getting-started/. This gives the basic idea of vertex and fragment shaders. After going through this a beginner can go through other tutorials which explains the detailed concepts of openGL.
I have gone through so many links but this one explains the basic really well.

3D Scene graph toolkits for Android

I was wondering if there is any 3D scene graph toolkit available or at least in development for Android? I could not find anything, assuming that all existing solutions for Java won't run on the Android platform.

I played around with the simple but quite powerful JPCT library that is supported by quite an active forum. The author has ported the libary to Android, and shows some nice demos on his site.
http://www.jpct.net/jpct-ae

You might look into JMonkey Engine. They are working on an Android version:
http://www.jmonkeyengine.com/forum/index.php?topic=13643.0
http://jmonkeyengine.com/blog/blog/2010/02/10/android-support-confirmed-for-jme3/

Have you tried out JavaFX Mobile? http://java.sun.com/javafx/index.jsp

I'm looking for one as well. I came across this today, but I have no idea if its actually any good -- the company site looks kinda sketchy!!
http://www.artfulbits.com/Android/aiCharts.aspx