[osg-users] glew and graphics contexts

Wills Alan AWILLS at qinetiq.com
Fri Oct 19 01:07:24 PDT 2007


Hi Robert,

Thanks for the reply. To answer your question, glew is being used by a 3rd-party library which I can't modify and which I'm integrating with my OSG stuff so I have to accommmodate it.

Thanks,
Alan.

-----Original Message-----
From: osg-users-bounces at lists.openscenegraph.org [mailto:osg-users-bounces at lists.openscenegraph.org] On Behalf Of Robert Osfield
Sent: 18 October 2007 19:14
To: OpenSceneGraph Users
Subject: Re: [osg-users] glew and graphics contexts

Hi Wills,

Since osgViewer by default will multi-thread the main thread calling
the realize() won't be the graphics thread so your glew call will
fail.

If you want to init glew then do it in a realize operation - see
osgshaderterrain for an example of this.

I have to ask way are you trying to use glew?  The OSG manages
extensions checking all itself and in a way that is thread safe and
robust w.r.t multiple graphics contexts.

Robert.

On 10/18/07, Wills Alan <AWILLS at qinetiq.com> wrote:
>
>
> If I have the following ...
>
> // ..create traits ...
> osg::GraphicsContext* gc =
> osg::GraphicsContext::createGraphicsContext(traits);
> gc->realize();
> gc->makeCurrent();
>
> GLenum err = glewInit();
>
> if (err != GL_OK)
>     // error msg.
> else
>     // ok
>
> ... then all is well.  But if I do ...
>
> osgViewer::Viewer viewer.
> viewer.setUpViewOnSingleScreen(0);
> viewer.realize();
>
>
> GLenum err = glewInit();
>
> if (err != GL_OK)
>     // error msg.
> else
>     // ok
>
> I get an error:  "Missing GL version"
>
> I'm checking the viewer's graphics context by doing
>
> std::vector<osg::GraphicsContext*> contexts;
> viewer->getContexts(contexts);
>
> with results:
> contexts.size() = 1;
> contexts[0]->isRealized() = 1;
> contexts[0]->isCurrent() = 1;
>
> but glewInit() returns an error.  What have I missed?
>
> Thanks,
> Alan.
>
>
> The information contained in this E-Mail and any subsequent
> correspondence is private and is intended solely for the intended
> recipient(s).  The information in this communication may be
> confidential and/or legally privileged.  Nothing in this e-mail is
> intended to conclude a contract on behalf of QinetiQ or make QinetiQ
> subject to any other legally binding commitments, unless the e-mail
> contains an express statement to the contrary or incorporates a formal
> Purchase Order.
>
> For those other than the recipient any disclosure, copying,
> distribution, or any action taken or omitted to be taken in reliance
> on such information is prohibited and may be unlawful.
>
> Emails and other electronic communication with QinetiQ may be
> monitored and recorded for business purposes including security, audit
> and archival purposes.  Any response to this email indicates consent
> to this.
>
> Telephone calls to QinetiQ may be monitored or recorded for quality
> control, security and other business purposes.
>
> QinetiQ Limited
> Registered in England & Wales: Company Number:3796233
> Registered office: 85 Buckingham Gate, London SW1E 6PD, United Kingdom
> Trading address: Cody Technology Park, Cody Building, Ively Road,
> Farnborough, Hampshire, GU14 0LX, United Kingdom
> http://www.QinetiQ.com/home/legal.html
> _______________________________________________
> osg-users mailing list
> osg-users at lists.openscenegraph.org
> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
>
>
_______________________________________________
osg-users mailing list
osg-users at lists.openscenegraph.org
http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org

The information contained in this E-Mail and any subsequent 
correspondence is private and is intended solely for the intended 
recipient(s).  The information in this communication may be 
confidential and/or legally privileged.  Nothing in this e-mail is 
intended to conclude a contract on behalf of QinetiQ or make QinetiQ 
subject to any other legally binding commitments, unless the e-mail 
contains an express statement to the contrary or incorporates a formal Purchase Order.

For those other than the recipient any disclosure, copying, 
distribution, or any action taken or omitted to be taken in reliance 
on such information is prohibited and may be unlawful.

Emails and other electronic communication with QinetiQ may be 
monitored and recorded for business purposes including security, audit 
and archival purposes.  Any response to this email indicates consent 
to this.

Telephone calls to QinetiQ may be monitored or recorded for quality 
control, security and other business purposes.

QinetiQ Limited
Registered in England & Wales: Company Number:3796233
Registered office: 85 Buckingham Gate, London SW1E 6PD, United Kingdom
Trading address: Cody Technology Park, Cody Building, Ively Road, Farnborough, Hampshire, GU14 0LX, United Kingdom 
http://www.QinetiQ.com/home/legal.html



More information about the osg-users mailing list