Re: Why are my graph colors wrong with 24 bitplanes but not with 8?

["Liam Gumley" <Liam.Gumley(at)ssec.wisc.edu>]

Charlie Zender <zender@uci.edu> wrote in message
news:37F99C3D.F3286338@uci.edu...
> I have a bunch of graphics procedures which use colormaps that work
> fine under IDL 5.2.1l when I run the X server at 8 bit planes.
> I would really like to use the full graphics potential of this high
> end card, and use all 24 bit planes. Unfortunately, all of my IDL
procedures
> give unexpected, weird colors on 24 bit plane screens.
> The graphics still print correctly, but printing and viewing the files
> with, e.g. ghostscript is time-consuming and I want the graphics to
> show up in the window with the right colors. Any ideas what is going
> on?
>
> I would very much appreciate receiving a sample of a simple plotting
> procedure, e.g., a horizontal green line crossing a vertical red line
> in an xyplot, that shows up on 24 bit plane graphics the same as on
> 8 bit plane graphics.

(1) Grab the COLORS procedure from:
http://cimss.ssec.wisc.edu/~gumley/colortools.html

(2) Start a new IDL session and type the following:
device, true=24
window, /free
device, decomposed=0, retain=2

(3) Create your sample plot:
colors
plot, indgen(10), /nodata
oplot, replicate(5, 10), color=4
oplot, [5, 5], [0, 10], color=5

The key here is the commands issued in (2) immediately after IDL startup. I
suggest that you put these commands in a startup file (e.g.
$HOME/idl_startup.pro), and then point to the startup file as shown below:
setenv IDL_STARTUP $HOME/idl_startup.pro (csh)
export IDL_STARTUP=$HOME/idl_startup.pro (ksh)

Cheers,
Liam.