Re: 24-bit color with writable color maps

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

David Fanning wrote:

> This is an interesting article, because I just taught an IDL
> class this week on 8 SGI 24-bit color machines. The default
> visual class for these machines was DirectColor, 24-bits just
> like Ken's machine. But, on about half of these machines
> the private color table caused severe color flashing and
> the colors were only correct when the cursor was in the
> IDL graphics window. On the other half, the colors worked
> exactly as Ken describes. 

We may have seen some of the same behaviour here with the
8bit PseudoColor visual. On some machines (with one specific
graphics card with hardware acceleration), the colors are
messed up when going from inside a draw window out to the
"widget area" surrounding it. 

We did find a temporary fix: Move outside the widget and
back in again -- this restores the correct color table for
the draw windows again!! This has to be repeated every time
the cursor has been inside a draw window... We suspect a bug
in the graphics drivers, or in the way IDL communicates with
them.

This was on Digital Alphas - uh, I mean, Compaq XPS 1000's,
as they're called now, after Compaq bought Digital....
I don't have the details on the graphics cards, though.

Regards,

Stein Vidar