Re: X Windows Visual Error

[Nigel Wade <nmw(at)ion.le.ac.uk>]

Ed Wright wrote:
> 
> I run 5.3 IDL on an SGI Indigo, but connect via telnet
> to my Linux box.
> 
> I added a plot command:
> 
>    plot, state[0,*], state[1,*], PSym = -4
> 
> Instead of a nice plot window popping up on my Linux box,
> I saw the annoying result:
> 
> % Unsupported X Windows visual (class: StaticGray, depth: 0).
>   Substituting default (class: <UndefinedVisual>, Depth: 0).
> 
> What settings do I need to see the plot?
> 

What colour depth are you running your X server at, 16 bit?
You can use the xdpyinfo command to list what X visuals are available.
IDL will only use 8 bit PseudoColor and 24 bit TrueColor, if one of
those isn't available IDL goes away and sulks in the corner.

You have several alternatives to get IDL graphics working.

First, you can run X on your Linux box with a different colour
depth which would match what IDL wants, either 8 or 24 bit. 

Second, XFree86 4.0 can use X overlays on some graphics cards which can
handle it, if your card is one of the supported ones you could try that 
(check out the XFree web site, http://www.xfree86.orf, for more info). 
This would allow you to have applications running in either 8 or 24 bit.

Third, you could start a second X server running at a colour depth which 
IDL can use and direct IDL graphics at that display. You switch between
displays by using ctrl-alt-F7 and ctrl-alt-F8.

-- 
-----------------------------------------------------------
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 2523568, Fax : +44 (0)116 2523555