larry@focsys.UUCP (Larry Williamson) (07/03/88)
A question with respect to Bell Technologies BLIT express card
and their Xwindows driver.
I need help getting more than 4 levels of grey on my display. I
can get 4 levels with no trouble. My primary requirement is 256
levels of grey on a 640x480 display.
My hardware setup is a BLIT express with a Sony Multisync monitor.
This monitor (apparently) uses the same electronics as the NEC
multisync. It is a colour monitor.
I was told by Bell Tech that I should use a multisync monitor.
If I am using the wrong monitor, then please tell me what is the
right one.
The monochrome displays that Bell Tech recommends are not any good for
my application as they do not support grey levels, (at least that is
what I have been lead to believe).
First let me say that as a colour system, this setup works wonderfully.
The colours and the display are quite something to behold. But now, my
troubles...
Assuming that the monitor is okay, I tried a number of things. To
keep the testing simple, I've tried to keep my program simple. I am
displaying a window with a number of squares filled in with each
grey level I want.
First test was to simply write out grey patches with XSetPix() and a
pixel value of from 1 to 256. The grey patches that I am writing
out show up as colour patches.
Then I tried to do a XGetHardwareColor() with a colour cell set with
red, green and blue all the same value. I then displayed the
patches with the pixel value that was returned. This works in that
I get a grey patches, but only 4 levels.
Then I tried to define my own colour cells by calling
XGetColorCells() and XSetColors(), but XGetColorCells() returns
an error if more than 4 levels or more than 4 planes are requested.
Is there a setup option that must be set before I can define more
than 4 levels of colour? or more than 4 levels of grey?
Do I have to bypass the Xwindows software completely to the grey levels
setup?
Any suggestions?
Larry.
--
Larry Williamson Focus Automation Systems
UUCP: watmath!focsys!larry 608 Weber St. N, Waterloo, Ontario N2V 1K4
+1 519 746 4918