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List:       vnc-list
Subject:    Re: DGA extension
From:       joe () XFree86 ! org
Date:       1999-08-27 19:50:49
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> Xvnc v3.3.3
> XFree86 v3.3.3.1
> RedHat Linux v6.0 ix86
> 
> Running Xvnc :1 and then launching VMware -display :1.0 gives the following
> warning from VMware:
> "Your X server does not support the XFree86 DGA extension for
> direct-to-frame-buffer graphics."
> 
> Can someone explain what the DGA extension is and why it is in XFree86 and
> not in Xvnc? Is there any way around this? Thanks.
> 
> Mike Gehl
> Cognition Inc.

The D(irect) G(raphics) A(ccess) extension allows an X client to talk
directly to the video hardware, instead of going through the X server.
It enables the client to render directly into the framebuffer.  That
client gains exclusive control of the display and all other clients
are essentially suspended.

I suppose Xvnc could fake the extension and provide a pointer to the
"framebuffer" that was really its own area and not the actual
memory on the video card.  It would suffer performance-wise though,
especially since it wouldn't know when the "screen" changed anymore,
except in the case of apps that do lots of page-flipping for animation
purposes, the page-flip would be an indicator.  I certainly would
expect smooth animations via vnc though...


> 
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