Which version of OpenGL to use?

Question

I currently run a machine that allows me to program in OpenGL 2.1. If I were to make a program, should I use the power of the current OpenGL versions like 3.x/4.x or use 2.1

Answer 1

In order to use OpenGL 3.x you need a card that supports DirectX10 and proper drivers that have support for it. The advantage in opposite to DirectX is, that you can also use OpenGL3 and 4 on WindowsXP. No need for 7 or Vista. Which version you should use depends on your audience. If your audience are gamers, go ahead, use 3. Won't do 4 exclusive yet. DX11 are still rare. For a first look on how Gamers use their computers and what hardware they have, steam is a good source:

http://store.steampowered.com/hwsurvey

You can determine the version by running:

glGetString(GL_VERSION);

A good OpenGL3 Tutorial:

http://arcsynthesis.org/gltut/

The OpenGL 3.3 SDK Reference:

http://www.opengl.org/sdk/docs/man3/

Hope this helps a bit :).

Answer 2

Lots of embedded Intel graphics are limited to 1.4 or 1.5.

Mac OSX is stuck on 2.1 I hear.

All Radeon and GeForce cards can do 3+ (may need a driver update).

And you can program with any version, but if your hardware doesn't support it, you'll end up testing under a software renderer (slow!).

Answer 3

OpenGL versions (for AMD and NVIDIA GPUs) roughly correspond to levels of hardware. 2.x OpenGL versions are for DX9-level hardware. 3.x represents DX10-level, and 4.x represents DX11-class hardware. So the version you pick restricts you can run your code.

In general, any AMD or NVIDIA GPU you can actually buy new from a store will be 3.x or better (more than likely, 4.x). Even integrated GPUs, motherboard or CPU, from AMD are 3.x or better. I do some home development work on an HD 3300 motherboard GPU, and it works reasonably well.

Intel is a problem. Intel's OpenGL driver quality is pretty poor. Many old Intel machines can only support GL 1.4, which is pre-DX9 class functionality. They do support some higher-level extensions (shaders, but only vertex shaders, since they run them in software).

More recent Intel GPUs are a bit better, but their GL drivers are still rather buggy.

The above describes the situation for Windows. Linux is a bit fuzzier, because there are drivers from NVIDIA/AMD, and open-source community written drivers. The latter are generally not as good, but they are improving. These tend to be for 3.x-class hardware.

The MacOSX world is a bit different. Mac OSX Lion (10.7), recently released, adds support for OpenGL 3.2 (sadly, not 3.3, for some reason). Apple rigidly controls how OpenGL works on their platform, but hopefully they will be updating GL versions more frequently than they have been recently.

So on Macs, you really have two choices: 2.1 or 3.2. Note that Lion's 3.2 support only exposes core OpenGL functionality. See this page for details on what that means.

You cannot tell what the highest version your particular computer is capable of. There is simply the version you get when you create a context. In general, unless you specifically ask for a version (and even then, usually not), you will get the highest version your hardware and drivers can handle.

Oh, and yes: the OpenGL version is controlled by your video card's capabilities (and installed drivers).

The following advise assumes that you're developing a serious application that you intend for others to use. This isn't for little demo apps or whatever.

In general, I would advise against explicitly restricting your code to 4.x. While 4.x adoption increases every day (there are 2 hardware generations from both NVIDIA and AMD with 4.x support, and a third likely will be out by years end from AMD. Also, AMD is starting to embed 4.x capable GPUs in their CPUs now), there is still a lot of 3.x hardware. 4.x doesn't buy you a whole lot, and you can easily add code paths to conditionally support 4.x features if they are available.

Answer 4

On a side question: How can I tell what's the highest version of OpenGL my computer can run?

I answer for the above question. I come across to the tool below, it's really complete in itself and let me see all OpenGL version that my system currently support (from 1.0 up to what it actually support). As well for extensions available for my system to use. Not only for ARB though, it ranges from NV, ATI, OES, etc.

http://www.realtech-vr.com/glview/download.html