Submitted by Anonymous on Tue, 01/16/2001 - 11:39. Developers
Hello Sir,
I am a beginner to X window System programming.Currently i am
working on a project realated to X and i am in desperate need of help from
someone who knows the ins and outs of X and i couldn`t think of a better
person to contact than you.For my project i am following your book on X
Window System Programming.
***************************** PROBLEM **********************************
My problem is a little complicated .............but i will try my best to
explian it properly to you.
PROBLEM SUMMARY
We had a dual head SGI machine with two graphics card............so we
had two different displays(0.0 and 0.1) and accordingly all our windows
and widgets used to come up on different displays.
but now we have dual head with only one graphics card with the x-axis
doubled......
So our problem now is how to distinguish between the two heads to ensure
that the windows come up on the right head.And one major issue which we
have is dragging windows from one head to the other(which should not be
there) and the dependency of the two heads on each other.
In a nut shell to mean that the two heads should work independently to
each other and there should be no dragging between the windows.
Now that the we have only one graphics card for the two monitors ,it is
equivalent to having a single monitor with x-axis expanded to double it`s
previous limit.
We require a generic X solution so that there is backward compatibility
with the previous system.
After a lot of brainstorming done to find solutions to this problem,we
have come up with some solutions(which we don`t know are possible or
not)
SOLUTIONS
----------
1) can we make a copy of the X-server...so that we have two x-servers
running, one for each monitor,so that we can differentiate between the two
heads. Is it possible??????
if yes, will this solve our problem????
2) Is there a way of splitting the screen into two independent
displays(0.0 and 0.1)???????(by setting the screen goemetry or??????
3) can we provide for some utility at the startup of X to set the two
displays(their goemetry,etc) and then use these for latter
applications.....
I don`t know whether these solutions make sense to you or not....but this
is the kind of solution that we need.
To summarize the whole thing in a single line,i would say that......
we need to split one display into two,one for each monitior which
should run independent of each other.
It would be really nice if you could suggest some solution for
this problem and answer my questions.
I have very less time in hand for this,so i need a quick reply.
I would be highly obliged if you could send some sample code or
instructions or functions that could help me in achieving this.
Thanks and Reagrds,
Ritu Singh.
(Design engineer)
Well, I`m neither Doug Young nor an SGI maven, but I may have some answers for you. It sounds as though you used to have a cool system, and now you have a very cool system. Unfortunately, that`s not what you want.
You do identify a few solutions, and there is software that corresponds to those solutions
1) there is software called Xnest, which is basically an X server inside a window. You would then need to recognize the case in which your software is running on a double-wide system and then start up two of these Xnest servers next to each other. However, this is messy, and your application is then connecting to two different displays instead of to two different screens, which is lots easier.
2) ideally, you`d find, and then provide to your users, an X server which understands how this graphics card works, such that it can suspend the treatment of two monitors as one screen. Because this feature is unusual, I suspect that the X server you`re using already handles this, such that additional monitors can become additional screens. If not, consult SGI.
3) practically speaking, this is the same solution as (2).
Of course, it may turn out that your users are OK with having the application work by being stretched onto two monitors -- or that you really need to rewrite the application so that you don`t have a dependence on particular and rare hardware.