Sorry for the late summary.
The original question was regarding a problem with displaying images
from the RSI IDL application on a PXG+ 24 bit graphics accelerator on a
300/600 AXP system running OSF/1 v3.2A. It looked like there was
abacking store problem, as when pieces of the image was obscured by
another window, it would not be refreshed when the window was removed.
And, when the image is too big to be displayed on the screen, the
application provided scroll bars to move around the image. Again,
pieces that were scrolled onto the window from the non-visible parts
were black (like those obscured by the other windows). However, this
problem did not exist with any display that has only 8 bits of color per
pixel. (By the way, we found this problem on a SGI Indy workstation
with 24 bit color display as well.) Appearantly, this problem was also
tied to some color mapping feature, so that the IDL application could
not use psuedocolor pixel maps.
Thanks to Mark Lembree and others for their various suggestions and
ideas on this. I first tried to restart our X server with backing
store disabled (-bs and -su options), so that the application should
take car of backing store. I also tried the -wm option to force backing
store on all windows. These did not help. The IDL application has flags
that directly relate to backing store, and changing them did nothing as
well. Further investigation with RSI tech support indicated that IDL
also supports a private pixmap feature. When this was enabled, the
backing store problem went away. For now, it is sufficient to satisfy
the users, so we'll be leaving it this way until the next problem comes up.
Again, thanks for all the helpful responses. (Sorry, I don't have time
to list all of them.)
eugene chu
Received on Thu Aug 17 1995 - 02:19:36 NZST