OpenGL versions and flavors should I be using

Question

I have some OpenGL Questions.

I know OGL is an early 90s SGI API.. Back in the 90s I developed a couple apps using OGL for the DEC Alpha platform but haven't used the API since.

With SGI long gone, it seems a bit different. My questions:

1. Is OpenGL open source now?
2. I notice a lot of different versions and what appears to be different APIs from different developers. is this true?
3. What is the preferred version/flavor for CAD and Graphics? What should I download? I will be using WINAPI and VS6 VS2003 and VS 2010 etc...

Answer 1

1. OpenGL is an open specification. Some of the implementations are open source, like Mesa3D. Usually implementations come with your graphics drivers.

2. There are many standards like OpenGL, OpenGL ES (for mobile) and soon glNext (not named yet).

3. Most modern implementations/drivers support OpenGL 3.3 Core Profile and using older fixed-function pipeline (glBegin, glVertex, glMatrix* etc.) is considered deprecated.

Answer 2

The two main strands of OpenGL are OpenGL, mostly for desktop/laptop computers; and OpenGL ES, for embedded and other 'small' systems. For example, Macintosh computers use OpenGL, iPhones and iPads are OpenGL ES.

There were major changes in the API when OpenGL 3 came out, not backward compatible. If you see people discussing core vs compatibility profiles, this is usually what they are talking about.

Since you are doing CAD style graphics with MS Windows, you'll be using OpenGL, not ES. I recommend:

• Get a copy of the OpenGL SuperBible, preferably the current 6th edition but the older 5th would do in a pinch. Also download all the example code from the web site: http://www.openglsuperbible.com/

Most of the OpenGL you learned in the 1990s just doesn't apply any more :-( But the newer versions do allow you to do some really amazing stuff. It's worth the pain.

• Download the ATI or NVIDIA OpenGL drivers and SDK from the appropriate web site. If you're using Intel, erm, good luck.

• On MS Windows, you need an OpenGL loader to use anything more recent than OpenGL 1.1, due to MS being extremely unhelpful to anyone who wants to use OpenGL instead of DirectX. Details here:

https://www.opengl.org/wiki/OpenGL_Loading_Library

I personally am very pleased with glLoadGen on MS Windows, but the others presumably work.

Hope this helps.