GRASS monitor on 24 bit display

[Kenn Gardels (CEDR-REGIS)]

> 
> 
> On 16 Feb 1995, hsuan wrote:
> 
> > Hi,
> > 
> > Has anyone successfully run GRASS monitors on 24 bit display ?
> > I tried to hack the code for XDRIVER but still failed.  Currently
> > GRASS monitors don't run on anything but 8-bit display.
> > 
> > Thanks for any help or comments.
> > 
> > --
> > --------------------------------------------------------------
> > Hsuan-Chih Lu
> > 
> > Department of Urban Planning
> > University of Illinois at Urbana-Champaign
> > 
> 
> Are you attempting to get the grass monitor to user 24-bit color, or do 
> you need to get your 24-bit monitor to display 8-bit graphics?  I haven't 
> looked at the grass monitor code much, but if you need to do the latter, you
> might need to change the program's visual, if the program doesn't do this 
> already.
> 
> Randy Hills, National Operational Hydrologic Remote Sensing Center (NOHRSC)
> National Weather Service
> Minneapolis,  MN
> 
> 

A quick solution is simply to restart your X server in psuedo-color mode (the
exact method for doing this depends on your particular OS).  But of course
you then lose any 24bit capabilities for other software.

We have modified the GRASS code to work on a 24bit display directly, by checking
first for a psuedocolor or truecolor visual.  It works fine on DEC Alpha, but
we havn't tested it on other platforms.  Note that it is still standard
grass color map display - ie it doesn't magically give GRASS real 24-bit display
capabilities.  You also lose the colormode float capability, since the visual
is read-only.  If you're interested in this, mail me directly.

-kenn

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