crossplatform & extentions

Hi all,

I’m new to OpenGL and got a few questions:

I’m creating a application that should run on windows ubuntu & mac
so far so good…

but i want to use the “best” of the current pc its running on.
so I’m getting the version and extension list
from glGetString(…)

On the windows platform im could use the wglGetProcAddress function
and if NULL, the extension is not there.
So no need to use the extension list.
but how to get the functionPointer on a linux/mac machine?
on linux im guessing its glXGetProcAddress or glXGetProcAddressARB

a example where i could the use of “fall-back code” is
“glGenTextures” to “glGenLists” (yea i admit: i found it on the net :whistle: )
but i also found “glGenTexturesEXT”
Wat’s story about that one? glGenTextures is there form vers 1.1
is glGenTexturesEXT a optimised version or just a extension for vers1.0?

are there other good examples for fall-back code ?