I need information on OpenGL

[Aldragor]

I would like to know:

- The portability of OpenGL between version of Windows (NT, 2000, XP)
- Requirement for OpenGL (memory, video card)
- Where to start (library, sample, ...)

Also if you have good links about the subject it will be great.

Thanx

[Sastraxi]

- Usable on all Windows versions except NT 3.51 (I think), also usable on Linux (but VB isn't )
- OpenGL doesn't require any 3D acceleration; it would run on a P100 with a 2mb graphics card, but it wouldn't run well!
- http://nehe.gamedev.net/

Neon Helium (the link) is for C++ but it has downloadable code that is translated to VB for most of the tutorials. Plus the tutorials just use the functions names so you can pretty much convert it as you read.

[Sastraxi]

Also, www.glsetup.com has an OpenGL setup utility (most video card drivers now come with OpenGL that works best with their card; if you don't have it you can go there). One more thing; OpenGL has two big-name books: The Red and Black Books of OpenGL. You should look into these if you want to do a lot of programming with GL.

[Aldragor]

Thanx Sastraxi,


I will look over that!

[CornedBee]

OpenGL is an open standard. That means you can use it on every platform where an implementation is written. OpenGL implementations exist for every windows version from 95 up and NT4 up, for many UNIX OSs (GNU/Linux, BSD-derivates etc.), Mac (I think) and probably some not-so-common ones.
OpenGL was developed for use with C/C++, so while VB can use OpenGL, it's not the ideal solution. Pascal can use OpenGL too, as can every language that is capable of calling shared C functions.
For speed: OpenGL is just a graphics library. As long as you do only 2D drawing (and not too much of it) it will run smoothly on a P100. Once you do fancy 3D rendering you can bring every machine down (Quake 3 was written with OpenGL).

So OpenGL is the portable equivalent of DirectGraphics. The main advantage of OpenGL is portability: Quake 3 runs on Linux computers. The advantage of Direct3D is that MS works hard to keep it up-to-date with the latest technology. Usually you can use the fanciest tricks of any available 3D card with real Direct3D calls (the Radeon 9700 is an exception: DirectX 9.0 is delayed). In OpenGL you have to use card-specific extensions, which fail to be consistent through all the cards. The general OpenGL standard is only updated every so often (major update ahead!).
But if you have a good graphics engine that hides these details from you the bottom line remains: OpenGL is portable, which might become more and more important in the near future.