[CentOS] Re: dragging windows leaves traces -- running older GeForce drivers on newer cards

Mon Jun 6 16:59:18 UTC 2005
Bryan J. Smith <b.j.smith@ieee.org> <thebs413 at earthlink.net>

From: Sukru TIKVES <sukru at cs.hacettepe.edu.tr>
> NVidia has its own desktop utility for Windows. It works fine. It also 
> has a "keystone" function which allows you transform (stretch, skew, 
> resize, etc) your "entire desktop" freely.

Actually, there is a GUI management program in the nVidia driver suite.
Unfortunately, by the way X works, some of these things the Win32 GDI
allows is not always possible in X, for a variety of reasons.

> There is a new X extension called RENDER. It comes disabled with xorg 
> server, however once you enable the extension and install necessary user 
> level tools, you'll have hardware accelerated (ie: true) transparent 
> windows.

Unfortunately, it's a hack.  It uses unused video memory as a faster,
local store than main memory, but still doesn't address the reality that
you should be using your GPU functions instead of memory tricks.

I.e., a window is simply a set of vectors and/or bitmaps on a plane.  It
doesn't matter if it looks like 3D to a user, or is perfectly perpendiular
and appears to be 2D (but is still using 3D in the GPU, even if no Z
buffer).

>From simple concepts to the Xgl server to FreeDesktop Cario which
brings full aliasing, vector graphics on planes as well as traditional
bitmaps on planes, it is the X11/GLX's equivalent to QuartzExtreme.

IMHO, I think Sun's got the right idea.  Go 3D everything, solve the
inconsistency, hacks upon hacks and overall inefficiency of layers
upon layers with Looking Glass.  What really sold me that Sun is
"thinking ahead" is that even the input is 3D.

The "technology demo" of Looking Glass doesn't do their innovative
approach an ounce of justice.  It's not eye candy, it's efficiency.

> See my previous post. I've tried the setup on a gentoo installation
> and it works very well.

On nVidia cards with the nVidia driver, but that's about all right now.
It largely has to do with the fact that nVidia driver has that
proprietary memory management module in the kernel that is tied
to the X11/GLX driver/libraries.

nVidia knows what it's doing, because they solved the problem 5+
years ago.


--
Bryan J. Smith   mailto:b.j.smith at ieee.org