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Re: Colour table, multiple sessions [message #29839] Thu, 21 March 2002 08:53
Craig Markwardt is currently offline  Craig Markwardt
Messages: 1869
Registered: November 1996
Senior Member
David Fanning <david@dfanning.com> writes:

>
> ... I see
> that by IDL 5.4 these keywords have been removed. Probably
> because they don't seem necessary in a 24-bit world.


Sigh, there are some things about 8-bit and pseudo color that are
actually *nice*, like the ability to intertactively futz the stretch
in real-time and blink between different tables. Oh well, I have
24-bit now too.

Craig

--
------------------------------------------------------------ --------------
Craig B. Markwardt, Ph.D. EMAIL: craigmnet@cow.physics.wisc.edu
Astrophysics, IDL, Finance, Derivatives | Remove "net" for better response
------------------------------------------------------------ --------------
Re: Colour table, multiple sessions [message #29843 is a reply to message #29839] Thu, 21 March 2002 06:37 Go to previous message
Randall Skelton is currently offline  Randall Skelton
Messages: 169
Registered: October 2000
Senior Member
This is probably becuse the first instance of an IDL direct graphics
window is using all of the colors on your 8-bit graphics head. A similar
problem will occur if you run netscape and IDL simultaneously on such a
machine.

In brief, the Xwindow colormap associated with a window is used to display
the contents of the window; each pixel value indexes the colormap to
produce an RGB value that is scaled by the X server to match the display
hardware and these scaled values drive the guns of a monitor. Depending on
hardware limitations, one or more colormaps can be installed at one time
so that windows associated with those maps display with true colors.
Your hardware will only allow one colormap to be displayed, so either
upgrade your video card or live with the limitation.


On Thu, 21 Mar 2002, Reimar Bauer wrote:

> trouble wrote:
>>
>> Yo,
>>
>> When I open 2 IDL sessions on the same workstation and open a window,
>> the colours in the the 2nd window are screwed and the screen flicks
>> into "reverse video"(?) [ie. black->white, white->black] when passing
>> the mouse over it. Is there a remedy? I played with DEVICE for a while
>> but after multiple crashes, concluded that didn't know what I was
>> doing... (oh really?)
>>
>> I was wondering if anyone has a quick fix, something to put in
>> IDL_STARTUP maybe?
>>
>> Currently on Unix Tru64, IDL 5.4.
>>
>> Ciao.
>
> Dear trouble
>
>
> How is your graphics card configured?
> Normally this behaviour is given with 8 bit color mode.
>
>
> Reimar
> --
> Reimar Bauer
>
> Institut fuer Stratosphaerische Chemie (ICG-I)
> Forschungszentrum Juelich
> email: R.Bauer@fz-juelich.de
> ------------------------------------------------------------ -------
> a IDL library at ForschungsZentrum Juelich
> http://www.fz-juelich.de/icg/icg1/idl_icglib/idl_lib_intro.h tml
> ============================================================ =======
>
Re: Colour table, multiple sessions [message #29845 is a reply to message #29843] Thu, 21 March 2002 06:14 Go to previous message
David Fanning is currently offline  David Fanning
Messages: 11724
Registered: August 2001
Senior Member
Craig Markwardt (craigmnet@cow.physics.wisc.edu) writes:

> As Reimar points out, you probably have an 8-bit (pseudo-color)
> display. If that is true, then you are running into a basic
> limitation of your display rather than IDL. For example, Netscape, xv
> (if you are doing Unix), will be starved for colors too, after one
> instance of IDL is started.
>
> One saving possibility is for each IDL session to reserve a fraction
> of the available colors. Usually, you would do this in a call to
> WINDOW with the COLORS keyword. For example, WINDOW, COLORS=100. The
> first time around that should leave about another 100 colors available
> for the second invocation of IDL, or any other color-hungry
> application.
>
> To get around this further you will need a new graphics mode for your
> screen (could be as simple as selecting it). 24-bit is the best
> supported by IDL.

There used to be undocumented Get_X_ID and Set_X_ID keywords
for the DEVICE and WINDOW commands that would allow you to
export and share X window drawables (and their associated
colortables) with other programs. This was one way to
circumvent the limitations of an 8-bit graphics card. I see
that by IDL 5.4 these keywords have been removed. Probably
because they don't seem necessary in a 24-bit world.

Cheers,

David

--
David W. Fanning, Ph.D.
Fanning Software Consulting
Phone: 970-221-0438, E-mail: david@dfanning.com
Coyote's Guide to IDL Programming: http://www.dfanning.com/
Toll-Free IDL Book Orders: 1-888-461-0155
Re: Colour table, multiple sessions [message #29846 is a reply to message #29845] Thu, 21 March 2002 05:25 Go to previous message
Craig Markwardt is currently offline  Craig Markwardt
Messages: 1869
Registered: November 1996
Senior Member
Greetings--

As Reimar points out, you probably have an 8-bit (pseudo-color)
display. If that is true, then you are running into a basic
limitation of your display rather than IDL. For example, Netscape, xv
(if you are doing Unix), will be starved for colors too, after one
instance of IDL is started.

One saving possibility is for each IDL session to reserve a fraction
of the available colors. Usually, you would do this in a call to
WINDOW with the COLORS keyword. For example, WINDOW, COLORS=100. The
first time around that should leave about another 100 colors available
for the second invocation of IDL, or any other color-hungry
application.

To get around this further you will need a new graphics mode for your
screen (could be as simple as selecting it). 24-bit is the best
supported by IDL.

Craig



the_cacc@hotmail.com (trouble) writes:

> Yo,
>
> When I open 2 IDL sessions on the same workstation and open a window,
> the colours in the the 2nd window are screwed and the screen flicks
> into "reverse video"(?) [ie. black->white, white->black] when passing
> the mouse over it. Is there a remedy? I played with DEVICE for a while
> but after multiple crashes, concluded that didn't know what I was
> doing... (oh really?)
>
> I was wondering if anyone has a quick fix, something to put in
> IDL_STARTUP maybe?
>
> Currently on Unix Tru64, IDL 5.4.
>
> Ciao.

--
------------------------------------------------------------ --------------
Craig B. Markwardt, Ph.D. EMAIL: craigmnet@cow.physics.wisc.edu
Astrophysics, IDL, Finance, Derivatives | Remove "net" for better response
------------------------------------------------------------ --------------
Re: Colour table, multiple sessions [message #29847 is a reply to message #29846] Thu, 21 March 2002 04:28 Go to previous message
R.Bauer is currently offline  R.Bauer
Messages: 1424
Registered: November 1998
Senior Member
trouble wrote:
>
> Yo,
>
> When I open 2 IDL sessions on the same workstation and open a window,
> the colours in the the 2nd window are screwed and the screen flicks
> into "reverse video"(?) [ie. black->white, white->black] when passing
> the mouse over it. Is there a remedy? I played with DEVICE for a while
> but after multiple crashes, concluded that didn't know what I was
> doing... (oh really?)
>
> I was wondering if anyone has a quick fix, something to put in
> IDL_STARTUP maybe?
>
> Currently on Unix Tru64, IDL 5.4.
>
> Ciao.

Dear trouble


How is your graphics card configured?
Normally this behaviour is given with 8 bit color mode.


Reimar
--
Reimar Bauer

Institut fuer Stratosphaerische Chemie (ICG-I)
Forschungszentrum Juelich
email: R.Bauer@fz-juelich.de
------------------------------------------------------------ -------
a IDL library at ForschungsZentrum Juelich
http://www.fz-juelich.de/icg/icg1/idl_icglib/idl_lib_intro.h tml
============================================================ =======
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