I'm trying to create a video overlay for information display via a video switcher. Using a 'Key' function, the black area on the screen can be replaced with the underlying video image.
Is there a way to just have a black screen, then add elements of graphics and data to that black screen?
Not certain exactly what you are trying to do....
Do you want the full windows desktop to be black (no taskbar, no heading)?
Correct. One of the extended desktops (not the main system one), should be black. No heading or anything else on this extended desktop. But I want to be able to 'print' data and graphics to that extended desktop.
This should get you what you want -- although its set for the primary screen.
begin
for line$ from fin(0,"XYMonitors")
read data from line$,sep="," to *,*,*,wd,hi ! Get Primary monitor size from 1st line
break
next
print 'dialogue'(0,0,80,25,"",opt="F*m"),'SR','_black','white','DF', ! Create the window
print 'option'("AlwaysOnTop","1"), ! Force on top
print 'option'("Frame","none"), ! Remove frame
print 'option'("XYPos","0,0,"+str(wd)+","+str(hi)), ! Set size to full screen size
print 'CS', ! Clear the screen
escape
You code combine all the prints to a single line but it was easier to read by breaking them down.