Re: 8-bit vs. 24-bit color on Windows

[steinhh(at)ulrik.uio.no (Stein Vidar Hagfors Haugan)]

In article <78avv7$2lg@post.gsfc.nasa.gov> 
thompson@orpheus.nascom.nasa.gov (William Thompson) writes:

>Thank you for that response.  One question, though:  Does loading the color
>table in this way instantly change the colors of already displayed graphics,
>or do you have to redisplay them to make the color table changes?
>
>What I'm really looking for is a way to make already existing code work as it
>did in the past, without recourse to new software, and particularly without
>recourse to redisplaying graphics.  That includes the traditional tools such 
>as LOADCT and XLOADCT, as well as any other color-table manipulation routines
>that have been developed over the years.  Pseudo-color is much more 
>appropriate for the kind of scientific analysis that I do than any kind of 
>24-bit color.  There really should be a way to let IDL use pseudo-color on a
>Windows display, if
>that's what's desired, while other programs can take advantage of the full
>capabilities of 24-bits if appropriate.  This can be done on other platforms,
>why not Windows?

I'm not 100% sure, but I seem to remember that when David F. was here, he
was very surprised to see that our 24-bit alpha displays did indeed
change the on-screen colors automatically in pseudo-8-bit mode. Isn't
that right, David?

I think we agreed that this must be a feature that varies from one X
Window implementation to another, possibly with some hardware dependency
as well. I don't have a 24-bit display myself, so I'm not able to check
exactly which settings that do (do not) produce this effect, but it might
be interesting to have others report whether they're able to reproduce it
on other (X Windows) platforms..

Regards,

Stein Vidar