On Thu, 28 Oct 2004, Jonathan Osuch wrote:
On Wednesday 27 October 2004 2:07 pm, SherLok Merfy wrote:
<a href="http://www.starlink.rl.ac.uk/star/docs/sun239.htx/node19.html"
LUTTWEAK - Tweaks a colour table of an image-display device </a>
Unless you can rewrite a jeneralized subroutine like the above for your own purposes or use it from a library.
Yes, that would be the best approach. However, the code is essentially already in place. It just doesn't work. The problem could be any one of:
1. The detected visual class is incorrect for changing the palette because the palette is read-only in that visual class. It should be possible to change the visual class to one that allows read-write palettes
I think that what you describe would cause a fault and _could_ raise a fault handler. LUTTWEAK is relevant to the National Centre for Supercomputing Applications, BTW, so you might find some really nifty tools among their pages. NCSA is Al Gore, taken at face value when he said he invented PPPd, Telnetd, FTPd, and HTTPd, among about thirty other utilities that are lies in the mouth of a politician.
2. The colors may be allocated read-only. This is different from #1 because the colors could be allocated read-write or read-only with a visual class that allows read-write.
If the address works out to be within memory that is read-only (in the local or global descriptor tables), then there should be a way to diagnose the problem with a fault handler for the XFractint task.
3. Forcing an expose event that tells the xwindow server to redraw (repaint not recalculate) the window may not be sent to the server correctly and may not be handled correctly by the Xfractint code (in unixscr.c).
I've obviously missed something. Any help you can provide would be appreciated.
You're welcome to ask questions that I might be able to provide keywords for in your requests to a search enjin. You have perhaps run accross the likelihood that source that compiles cleanly with -Wall is likely to run nicely, too (to some point of complexity, anyway). _______ fault handler diagnostic xwindows