From: Marcin Romaszewicz (marcin++at++asmodean.engr.sgi.com)
Date: 06/28/2000 17:51:23
You don't have to pass in 23 for depth, what this translates to inside
glXChooseVisual is "all visuals with depth >= 23 bits". What the
glXChooseVisual manpage means is that it will choose a visual that has AT
LEAST as many bits as you specify, but if there are several visuals with
more depth than you ask for, it will pick the one whose depth is closest
to what you've specified.
-- Marcin
On Wed, 28 Jun 2000, John Kelso wrote:
>
> Yes, that was it! Thank you!
>
> I was using this:
>
> static int FBAttrs[] = {
> PFFB_STEREO,
> PFFB_RGBA,
> PFFB_DOUBLEBUFFER,
> None,
> };
>
> I found in an example this:
>
> static int FBAttrs[] = {
> PFFB_RGBA,
> PFFB_DOUBLEBUFFER,
> PFFB_STEREO,
> PFFB_DEPTH_SIZE, 23,
> PFFB_RED_SIZE, 1,
> PFFB_STENCIL_SIZE, 1,
> None,
> };
>
> So I replaced it, and all's well.
>
> But, on a more general note- I have to admit I was a bit stumped about the
> correct values to put in there. How do I know that "23" is a good
> size for all SGIs? What about Linux? The man page for glXChooseVisual, the
> best thing I could find, says:
>
>
> GLX_DEPTH_SIZE Must be followed by a nonnegative minimum size
> specification. If this value is zero, visuals with
> no depth buffer are preferred. Otherwise, the
> largest available depth buffer of at least the
> minimum size is preferred.
>
> Which seemed a bit vague.
>
> Any pointers how to best set these values?
>
> -John
>
> On Wed, 28 Jun 2000, Marcin Romaszewicz wrote:
>
> >
> > It sounds like your Z buffer is disabled or not present in the visual
> > that you are using. Make sure you pass a non zero value for the
> > PFFB_DEPTH_SIZE tokens to pfPipeWindow::setFBConfigAttrs or
> > pfWindow::setFBConfigAttrs.
> >
> > -- Marcin
> >
> > On Wed, 28 Jun 2000, John Kelso wrote:
> >
> > > Hi,
> > >
> > > I have a bug I'm trying to find in a fairly complicated piece of software.
> > >
> > > I'm hoping if I report the symptoms I can get some pointers about where
> > > to look for the problem.
> > >
> > > This problem occurs in both single-processor and multi-processor modes.
> > > Occurs if I use just one pipe or several pipes. Occurs if I use just one
> > > window and channel, or several windows and channels. Occurs if I run on
> > > an Octane or an Onyx. It's always there. Everything is running IRIX
> > > 6.5.7f and Performer 2.2.7.
> > >
> > > In its simplest form I load two objects with pfdLoadFile. No matter how
> > > I orient the two objects or my viewing position, one object is always
> > > displayed in front of the other.
> > >
> > > If I dump the scene and load it in perfly, the objects occlude as
> > > expected.
> > >
> > > I realize that this is sort of vague- all I'm hoping for are some general
> > > pointers about what to look for- what types of things could cause this
> > > behavior.
> > >
> > > Thanks,
> > >
> > > -John
> > >
> > > -----------------------------------------------------------------------
> > > John Kelso www.cave.vt.edu
> > > Research Associate, Virginia Tech CAVE email: kelso++at++vt.edu
> > > 2000 Kraft Drive, Suite 2400, MS 0468 phone: 540/231-2054
> > > Blacksburg, VA 24061 fax: 540/557-6043
> > >
> > > -----------------------------------------------------------------------
> > > List Archives, FAQ, FTP: http://www.sgi.com/software/performer/
> > > Submissions: info-performer++at++sgi.com
> > > Admin. requests: info-performer-request++at++sgi.com
> > >
> >
>
>
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