Brian Paul wrote:
>
> Michael wrote:
> >
> > On Mon, Apr 29, 2002 at 12:53:15AM -0600, Jens Owen wrote:
> > > Is there any compelling reason to report single buffer visuals?
> >
> > Dunno, you tell me ;o)
> >
> > Here's how I noticed, some of the Mesa demos use single buffer (or
> > either as an option). The existing (commented out) page flipping code
> > checks for a double buffered visual before enabling page flipping, the
> > result is your sb mesa demo is using a db visual and doesn't call swap
> > buffers so you don't see anything.
> >
> > Admittedly the page flipping doesn't exist yet, what I did to get it
> > working is a kludge but something here has it wrong - either the mesa
> > demo isn't checking the visual it gets from glut or glut doesn't tell
> > you this kind of thing, or we need sb visuals for apps that ask for
> > them. I've not really looked far enough to see which.
Page flipping vs. regular blitting should be transparent to the
application. If this works without page flipping, then it sounds like
page flipping is broken. Perhaps the glDrawBuffer(GL_FRONT) isn't
working properly--anyway, that explains why the code isn't enabled.
> > It's obviously not an issue until page flipping is back, but I think an
> > extra loop to add an SB visual for each visual we currently do would be
> > all that's needed...
>
> OpenGL doesn't require any single-buffered visuals.
>
> If you request a single-buffered visual with GLUT but only double-
> buffered visuals are available, GLUT will use a double-buffered visual
> and call glDraw/ReadBuffer(GL_FRONT) during initializations. glutSwap-
> Buffers() will just do a glFlush or glFinish.
That make's sense. Thanks for the explanation, Brian.
> I don't see a compelling argument for single-buffered visuals but it
> would be easy to do if someone really needed it.
Doesn't sound like it's necessary. However, I would avoid spelling out
"No Single Buffer Visual" in a feature checklist if that functionality
is indeed present. The first thing I thought of when I saw this was "is
front buffer rendering broken?".
-- /\
Jens Owen / \/\ _
[EMAIL PROTECTED] / \ \ \ Steamboat Springs, Colorado
_______________________________________________
Dri-devel mailing list
[EMAIL PROTECTED]
https://lists.sourceforge.net/lists/listinfo/dri-devel
