graphic problem in win 7

BlitzMax Forums/BlitzMax Programming/graphic problem in win 7

allos(Posted 2011) [#1]
A part of my applications runs in graphics, full screen; I easily solved screen resolution problems on diffrrent machines (via desktopwidth(), desktopheight() and viewport setting).
The app runs properly under winXP, but when it comes to win7 there is a strong annoying flickering outside the viewport; I think it may be a directx driver problem.
A quick way to get out of troubles? ( I feel there are no quick ways...)
allos


xlsior(Posted 2011) [#2]
What video card are you using in the win7 machine?

e.g. Is it a low-end built-in Intel graphics adapter, or a plug-in ATI or NVidia adapter?

One possibility: Many video cards have multiple backbuffers, and cycle through them. When you first initialize your background, do you immediately start using the viewport? If so, it's possible that your second / third / fourth / whatever backbuffer still has random junk on it, and when you use flip that may come by every few frames.

Instead of drawing the area outside of your viewport just once, try drawing the same thing a couple of times and see if that changes anything.


BlitzSupport(Posted 2011) [#3]
Try calling Cls and Flip twice in a row (clearing both front and back buffers) while the viewport is still full-size, then set the viewport.

I had a similar problem here and that's how I solved it.


xlsior(Posted 2011) [#4]
Try calling Cls and Flip twice in a row (clearing both front and back buffers) while the viewport is still full-size, then set the viewport.


You may need to do it 3-4 times, depending on the video card. My old ATI X1650XT alternated between 4 different backbuffers, just to name one.


allos(Posted 2011) [#5]
Thank you for your tips; I have solved the problem avoiding viewport use; is it sensitive to different graphics environments?