Go Back   nV News Forums > Linux Support Forums > NVIDIA Linux

Newegg Daily Deals

Reply
 
Thread Tools
Old 06-28-03, 01:05 PM   #1
samh
Registered User
 
Join Date: Jun 2003
Location: Philadelphia
Posts: 6
Default dual monitors and openGL programming

Hello,

With two monitors configured under XWindows, and an OpenGL application which is going to do our rendering in full screen exclusive mode, what is the access method for writing to each monitor. Are there separate buffers? Is this possible?

Target application is _again_ stereoscopic rendering on a hmd with twin vga inputs. Though if anyone has any info on just accessing the two different display pipelines from OGL, I would be very interested.

Sam
samh is offline   Reply With Quote
Old 06-28-03, 01:38 PM   #2
Thunderbird
 
Join Date: Jul 2002
Location: Netherlands, Europe
Posts: 2,105
Default

I don't think you have to do much specific things to get opengl on two screens. For example games list "2048x768" which runs a game accross two screens...

So you need to request that mode I think.
Thunderbird is offline   Reply With Quote
Old 06-28-03, 02:03 PM   #3
samh
Registered User
 
Join Date: Jun 2003
Location: Philadelphia
Posts: 6
Default

So you are saying that if I enable twinview in my XF86Config file and set the screen resolution to twice the width of my actual screen, the left half of the image will be displayed on the left monitor, and the right half of the image will be displayed on the right monitor?

Any more details?

Thanks
Sam
samh is offline   Reply With Quote
Old 06-28-03, 02:31 PM   #4
samh
Registered User
 
Join Date: Jun 2003
Location: Philadelphia
Posts: 6
Default slightly off topic OpenGL nvidia twinview side by side rendering

Ok, I did some research about nvidia and twinview. I found the readme.txt appendix 1 configuring twinview document at the nvidia ftp site.

Here is my question:
If I have two 640x480 monitors side by side, configured for twinview on a quadro 4 card, x now sees a 1280x480 monitor.
What is the OpenGL syntax, or just some info for me to look up for having two seperate viewpionts, IE a birdseye view and a isometric view of a scene, or a left eye and a right eye, rendered side by side in a single buffer?

This is really an openGL question, but I thought someone might be able to answer it.

Sam
samh is offline   Reply With Quote
Old 06-28-03, 04:08 PM   #5
bwkaz
Registered User
 
Join Date: Sep 2002
Posts: 2,262
Default Re: slightly off topic OpenGL nvidia twinview side by side rendering

Quote:
Originally posted by samh
What is the OpenGL syntax, or just some info for me to look up for having two seperate viewpionts, IE a birdseye view and a isometric view of a scene, or a left eye and a right eye, rendered side by side in a single buffer?
I am not positive (I don't do much OpenGL), but I don't believe this issue is in the domain of the OpenGL spec. Plus, I've never seen anything addressing how to do it (which definitely doesn't mean it doesn't exist, though).

I would think, however, that it would be quite simple. All you'd have to do is look at Appendix R in the README, then set up two GLX contexts (one for each screen). Then render to each context from a slightly different viewpoint.

The problem with trying to do it all in one GLX context is that, AFAIK, you cannot change your viewpoint for only half of any given update. Plus, you would not want to set up two different world models inside your program (which is about the only thing you'd be able to do -- with a single GLX context, you can't just "offset" the pixels by a certain amount, I don't believe), one for each eye. You'd end up doing all the rendering twice anyway, so you might as well just set up two GLX contexts.
__________________
Registered Linux User #219692
bwkaz is offline   Reply With Quote
Old 06-28-03, 04:19 PM   #6
samh
Registered User
 
Join Date: Jun 2003
Location: Philadelphia
Posts: 6
Default

The problem with that approach is that, according to appendix R you cannot hardware accelerate on 2 screens set up as individual displays.. You can accelerate one display across multiple screens with twinview.

Thinking about CAD programs or modellers written in opengl, they often have multi window displays with different viewpoints. It doesn't seem to me to be a far cry to just have a sort of two pane display, with one image on the left and the other on the right. Twinview would figure out where to split the display and put the correct half on the correct monitor.

Sam
samh is offline   Reply With Quote
Reply


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


Similar Threads
Thread Thread Starter Forum Replies Last Post
A question of acelloration, openGL and anti-aliasing stootles NVIDIA Linux 1 08-12-02 03:24 AM
Dual Monitor cards GF2 or GF4 Geoinfo SRL NVIDIA Linux 15 08-06-02 04:48 AM

All times are GMT -5. The time now is 02:33 PM.


Powered by vBulletin® Version 3.7.1
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright 1998 - 2014, nV News.