max root area what is its size is there a limit

Harold L Hunt II
Mon Mar 8 22:58:00 GMT 2004

Bonert Brigitte wrote:

> Hello,
> I am still struggling with this. Find attached the Xwin log file.
> I am using a root area of 6400x2048
> I am getting this error in my X application:
> BadWindow (invalid Windowparameter) 
> Mayor Op Code of failed request: 20(X_GetProperty)
> And the picture I want to display never comes up.
> It works with a smaller root area of 2560x2048 
> 4 1280x1024 projectors arranged in 2 rows.

Yes, it sounds like your remote application has a problem trying to draw 
to a window that is larger than a certain size.  That is, it has not 
problem with 2560x2048, but it just won't work with widths greater than 
some amount.

Assuming your application respects the standard "-geometry 
WIDTHxHEIGHT+X_OFFSET+Y_OFFSET", then you should be able to run a test 
with your twenty monitors (or whatever the full number was) with a 
window size restricted like the following:

my_app_name -geometry 2560x2048+0+0

If it runs, then try bumping the width value until you figure out that 
it has a problem; if it eventually has a problem, then you have found a 
bug or limitation in your application that will have to be fixed, there 
is nothing we can do to fix this for you.

If your application does not run, then it is because it does not like 
the size of the root window being too large; this means that once you 
have a display area larger than a certain amount then the application 
will fail to run.  You could always run it within an "Xnest" server that 
was restricted to a specified size, but this would not help you get it 
working on 20 monitors.

I hope that helps.  Is the application that you are using open source or 
closed source?  If it is open source, then perhaps we could take a peek 
at it; if it is closed source there is nothing we can do. :)

> What does the multiplemonitors option do?

It tells XWin.exe to use the space on all monitors instead of just on 
the primary monitor.  In other words, without -multiplemonitors you can 
only display applications on the primary monitor.


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