OSDev.org

What exactly is OpenGL? Is it a set of routines that a video card has to support in order to be compatible? Or is it an abstraction layer that presents a common interface to a programmer?

If it's an abstraction layer, i'm assuming ATI and NVidea provided drivers to the OpenGL developers under some for of Non Disclosure Agreement?

How would someone code support for OpenGL in an operating system?

OpenGL is "an abstraction layer that presents a common interface to a programmer". I don't know the answers to your other questions, but hopefully someone else can help.

Thermite wrote:What exactly is OpenGL?

As said previously:
it is

Thermite wrote: an abstraction layer that presents a common interface to a programmer?

Thermite wrote: If it's an abstraction layer, i'm assuming ATI and NVidea provided drivers to the OpenGL developers under some for of Non Disclosure Agreement?

What do you mean? Yes, ATI and NVidea provide drivers with the support of OpenGL(and DirectX). Then a developer writes a program using OpenGL API,and then he(/she) links(dynamicly) it to the driver. The "OpenGL developers" are the people at ATI and NVidia-what do you think they get paid for?

Thermite wrote: How would someone code support for OpenGL in an operating system?

You need to implement the OpenGL api.

Anton.

but you will still need drivers -- unless you implement the win32 API (or better yet winNT API) of course you could implement the linux API but theres a reason niether ATI nor nVidea have managed to get good drivers ready dispite huge development teams dedicated to it

do you have a specific preference for OpenGL? you could also use directX (which is better supported although it updates more frequently -- adding new features and capabilities)

for a start you could port mesa.

hey im wondering how much effort is involed in porting mesa. has any one attempted to port this to thier OS?