Irrlicht Engine

ok. so i know that there are different versions of open gl ex(2.1, 3.3 , 4.0) .
and i know that when you code just open gl you can use either one..

but how does that work in a game engine like in irrlicht?
how does it know what version to use? what about the code? wouldn't 90% of most things just not be supported if it was written in
4.0+? i don't really know how this works. what version would the engines opengl run? and i hope this makes sense. just trying to get an understanding.

First off Irrlicht is a Rendering Engine not a Game Engine ;)

As you should know by now when you setup your IrrlichtDevice you choose which driver to use, be it D3D or OGL that's the first step to telling the engine which driver it should use.

Behind the scenes Irrlicht takes care of the rendering for you and uses the appropriate raw DirectX or OpenGL functions to actually display stuff on screen.

As a side note when you move up versions, for example going from OGL 3 to OGL 4, yes there will be some new functions and some removed functions and some changed functions, however normally features will not be dropped in newer versions unless they become depreciated by some newer features.

In other words, Irrlicht knows which version to use because it was programmed to use it ;)

We don't support OpenGL 3 and 4 yet. They will likely need new drivers (and we might deprecate the old ones). OpenGL 3 is in the works. So basically - it will use the driver version you tell it to use.