I have found this problem when I upgraded my OS from 6.20 to 6.21. The
problem is that the background is not cleared when the widget is invalidated
and I end up drawing up top of old drawings. The background is not even
clean when the widget is first realized. It inherits whatever that was on
the screen before application window is shown.
I’m using PtRaw for all my drawing and I use PtDamageWidget() to invalidate
the widget when a complete redraw is needed. It worked fine for QNX4.25, QNX
6.10, and QNX6.20. That stopped working in 6.21. (Initially I thought it
was related to the graphics driver. That was ruled out after many harddrive
swaps and computer swaps. In addition, I get the same problem if I connect
to the machine remote through Phindows.)
May thanks in adance for any help or insight to the problem.