How to support dual monitor in my OpenGL app?

Hi guys, I asked this question in the beginners forum but got no satisfactory answer. Let see if you can help. Some friend tested my app, and told me all he was seing was a white screen. He has dual monitors. I don’t know what to do in order to be able to support dual monitors in fullscreen, any idea? (Im talking about a Windows app, with OpenGL).
Thx in advance. Rob.

Unless you have a multi-head card (like a GF4), you’ll only get hardware-accelerated OpenGL on the primary display device. This is a restriction of the OpenGL ICD mechanism used in Windows.

But the problem with your friend getting a white screen is probably something else, because you don’t have to do anything special to get your app running on a dual-monitor system.

I’m using a GF4 now with two monitors, but before that I had a GF2 and an old Matrox Millenium running together in my machine, and as long as the OpenGL windows remained on the first monitor (which was connected to the GF2), everything worked like a charm.

Its ok if my app can only run in one monitor…So, Im not supposed to do any kind of special configuration in the case of findind a user using dual monitors?
If you have dual monitors maybe you can test my app and tell me if it worked fine or not.
Thx. www.robals.com/files/game.zip

Originally posted by rob_als:
So, Im not supposed to do any kind of special configuration in the case of findind a user using dual monitors?

Correct.

Originally posted by rob_als:
If you have dual monitors maybe you can test my app and tell me if it worked fine or not.

Works fine on my dual-head GF4. Nice game.

If you have a nVidia card, you can install the drivers 40.41. These drivers support (by default) hardware acceleration on several monitor/card (for example, I have a GeForce 3 AGP and a GeForce2 PCI, I have ICD OpenGL on both cards, but only with the capabilities of the lowest card).
You can enable or disable that option in the driver settings (if you can’t access the driver settings because it crashes, delete all the nvrs*.dll files in the system folder)

Like rob_als, I use dual monitor (three sometimes) and I would like to know if it’s easy to get Hardware-accelerated on one selected monitor and software on the others (since you can get only one Hw-Accelerated monitor with OpenGl ICD).
My question is simply: how to select hardware-accelerated Monitor by implementation (without replacing .DLL or something like that)?

Windows 98 can’t do OpenGL dual mons. HOWEVER, upgrade to WinXP and it will be able to. You’ll need to go to the advanced options in the Display Properties and find something called ‘Advanced OpenGL for Multiple Monitors’. Not sure about this for non-NVidia cards tho…