IDL -> X-terminal -> Windows using Xwin32, "backing store"? - Idl-pvwave

On Sun, 7 Jan 2007, Ed Hyer wrote:

> Because of memory and because it's better, I now do most of my IDL work
> on a Linux machine (IDL6.2, at this writing). I access this machine,
> which I have never physically seen, from my Windows box using Xwin32.
> When I draw a graphics window, it shows symptoms just like the "backing
> store" problems in the manual: that is, any part of the graphics window
> that is not "on top" is blank.
>
> I have tried the solutions in the IDL manual for this problem, so I
> suspect this is an Xwin32 problem rather than an IDL problem, and
> therefore inappropriate to this group . But I also suspect I am not
> the only person reading this group who uses this setup, and you guys
> are just so darn _helpful_!
>
> Any ideas?

Lots of ideas. Can you run demanding native apps such as Google Earth? It
took me a couple driver updates from ATI before GE worked properly. Not
surprisingly, the improvements carried over to X. We have Hummingbird
Exceed at work, and find that new machines often need updates of graphihcs
drivers and or Exceed to work properly, so 1) check your app and drivers
for updates/bug fixes, 2) try Xming (free) -- works for me and even
supports SGI's gr_osview, 3) run a recent linux in a VMware appliance on
your desktop, 4) try a different video card (some models just never work
properly on demanding apps although they are fine when running MS Office),
and 5) watch out for overheating and power supply problems if you have a
recent high-end graphics card.

It seems to take 6 months to a year before all the bugs are worked out for
a new graphics card/drivers, so for reliability you want to shop for old
stock from name-brand companies being sold at a discount rather than one
based on last week's chipset.

--
George N. White III <aa056@chebucto.ns.ca>

Ed Hyer wrote:

> Because of memory and because it's better, I now do most of my IDL work
> on a Linux machine (IDL6.2, at this writing). I access this machine,
> which I have never physically seen, from my Windows box using Xwin32.
> When I draw a graphics window, it shows symptoms just like the "backing
> store" problems in the manual: that is, any part of the graphics window
> that is not "on top" is blank.
>
> I have tried the solutions in the IDL manual for this problem, so I
> suspect this is an Xwin32 problem rather than an IDL problem, and
> therefore inappropriate to this group . But I also suspect I am not
> the only person reading this group who uses this setup, and you guys
> are just so darn _helpful_!
>
> Any ideas?
>
> --Edward H.

What you should require is device,retain=2. This works with freenx client which,
although it claims it does, does not support the X backing store. I've never
used Xwin32, but the same solution within IDL ought to work.

This command must be issued before you do *anything* which even queries the X
display, never mind produces any output. Once the X display is open this
command will make no difference.

Try this:

$ idl
IDL> device,retain=2
IDL> plot,[1,2,3,4],[1,2,3,4]

it should produce a very simple plot. If you cover it then expose it again the
plot ought to be reproduced correctly.

If this doesn't work then it very probably is an Xwin32 problem. This
instruction tells IDL to keep a copy of the window and redraw it when
requested, so it might be that the X window manager is not handing out redraw
requests to clients properly.

You might want to try using freenx server and nx client. It's free, and it does
work pretty well (provided there's a freenx server for your Linux distro.). We
prefer it to commercial offerings such as Exceed because it works over ADSL
lines, where Exceed is painfully slow to the extent it's unusable.

--
Nigel Wade, System Administrator, Space Plasma Physics Group,
University of Leicester, Leicester, LE1 7RH, UK
E-mail : nmw@ion.le.ac.uk
Phone : +44 (0)116 2523548, Fax : +44 (0)116 2523555

Ed,
I recall having trouble with Xwin32 a few years ago although I do not
remember details. I switched to Exceed back then and do not have the trouble
you report. The Linux installation of IDL did not need modifications to make
the windows refresh right.

Cheers,
Haje


"Ed Hyer" <ejhyer@gmail.com> wrote in message
news:1168194454.459277.209870@s80g2000cwa.googlegroups.com...
> Because of memory and because it's better, I now do most of my IDL work
> on a Linux machine (IDL6.2, at this writing). I access this machine,
> which I have never physically seen, from my Windows box using Xwin32.
> When I draw a graphics window, it shows symptoms just like the "backing
> store" problems in the manual: that is, any part of the graphics window
> that is not "on top" is blank.
>
> I have tried the solutions in the IDL manual for this problem, so I
> suspect this is an Xwin32 problem rather than an IDL problem, and
> therefore inappropriate to this group . But I also suspect I am not
> the only person reading this group who uses this setup, and you guys
> are just so darn _helpful_!
>
> Any ideas?
>
> --Edward H.
>