24-bit color with XWindows ??

GRASS GRASS user
1

I succesfully have Grass up and running on our DEC mips machines using
XWindows and with the display going to screens with 8-bit color boards.

When I switch to a 24-bit color board, I get an error when I try to execute

> d.mon start=x0
  Request Major code 78 ()
  Error Serial #266
  Current Serial #267

Does anyone have Grass running successfully on a 24-bit color display with
XWindows? And are you getting full use out of the 24-bits?

GRASS expects (and can use) only a PseudoColor visual, and 24bits is
TrueColor. There are two fixes available that we have adopted:

1. The quick solution is restart the Xserver with PseudoColor as the
default (this can be added to the /etc/ttys file). Other applications
can explicitly still request TrueColor, but most just use the default.

2. As part of our port to Alpha, we modified XDRIVER to operate on
24bit displays correctly. However, due to fundamental design issues
in GRASS, it still only uses standard 8bit display parameters. Also,
since there is no color map in TrueColor, GRASS can't do tricks with
color table toggling - changes in color require redrawing the image
(we achieved this by making GRASS believe the color table was
readonly).

The revised code can be found at ohlone.ced.berkeley.edu:/pub/grass.

--
Ramsey Haddad <haddad@pa.dec.com>
speaking for myself.

Hope this helps - let me know.

-kenn

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