Xvnc with RENDER - almost working

[Peter Åstrand]

On Wed, 23 Feb 2005, Peter Åstrand wrote:

> I'm attaching two patches that adds RENDER support to Xvnc in Fedora 3. It 
> works, except that I've found a small glitch when using the menus in 
> OpenOffice: Sometimes, some of the menu choices disappears. See screenshot at 
> http://www.cendio.se/~peter/vnc-render-oo.png.
>
> I've verified this problem both with Fedoras VNC package (with my attached 
> patches), and with the TightVNC 1.5 series (using xorg 6.8.2).
>
> A screenshot in the VNC session displays the menus correctly. Also, doing a 
> "Refresh screen" in the VNC client fixes the problem.

I've been able to reproduce the exact problem by loading vnc.so for my :0 
display. I've tested vnc.so from:

* The original Fedora 3 VNC package

* RealVNCs binary 4.0 package

* RealVNC 4.1, built from source

The problem appears with all these versions. So, this appears to be a very 
generic RENDER-with-VNC problem. My gut feeling is that there's something 
wrong with vncHooks.cc, which leads me to a question for the XOrg 
developers:

  How do you implement RENDER support?

I've noticed that mga_storm.c and others have a RenderCallback function 
and defines a RENDER_DELAY. What's the purpose of these? Are these 
required to properly support RENDER?

The problem seems to be timing related; if I start the VNC client with 
-debugdelay=500, the problem goes away.

Any ideas?

-- 
Peter Åstrand		Chief Developer
Cendio			www.thinlinc.com
Teknikringen 3		www.cendio.se
583 30 Linköping        Phone: +46-13-21 46 00