Screen Flashing

[PiperPilotJohn]

I'm using the latest version (3.7.5) and am noticing a lot of screen flashing just within the canvas as I move the cursor around. The flashing doesn't seem to be causing any other problems, and I don't see items such as the menu or toolbars flashing. I'm running this on a late 2009 27-inch iMac running the latest version of the OS (10.10.1). This computer has a 2.8 GHz Intel Core i7 chip with 12 GB of 1067 MHz DDR3 ram. It uses the ATI Radeon HD 4850 video chipset with 512 MB of onboard vram.

Any ideas?

John

[andrew]

Is this the case with a new, empty drawing or with a particular drawing?
In the latter case, could you attach or mail the drawing file please? Thanks.

[PiperPilotJohn]

It seems to flash with any drawing Andrew. With that said I am using the same template for all of these drawings so that may have an effect on the problem. I'm attaching a copy of one of the drawings that flashes. Thanks for looking into this.

John

[andrew]

I wasn't able to reproduce that problem here on Mac OS X 10.1. I have almost identical hardware here.

Can you give an indication of how 'bad' that flashing is? Am I looking for something very obvious or more subtile? To what color does the graphics view change and is it only the graphics view that flashes? Thanks.

[PiperPilotJohn]

Hi Andrew - I guess I'm not surprised that you weren't able to reproduce it - that always happens to me when someone asks me to come help troubleshoot something that ALWAYS happens to them! Anyway, I thought I'd do a screen capture to show you the problem. See the attached file. In this case I just loaded the same drawing that I sent you and started moving the cursor around on the screen. You can see the white flashing within the drawing area window. The rest of the screen does not flash. It's pretty obvious. Hope this capture helps you to see the problem. Thanks.

John

[Clive]

Hi
Are you getting this problem whilst using any other programs?

[PiperPilotJohn]

No I'm not Clive. I do use a lot of other graphically intensive programs, such as Final Cut Pro X and Aperture and have never seen the flashing there.

John

[Clive]

So presumably this is only happening when you move the cursor around/zooming/panning etc. and doesn't happen when you do nothing ?

Sounds like it may be a video card issue ?

Also -are you using any hardware acceleration ?

[PiperPilotJohn]

Clive - yes, it only happens when I move the cursor around. I can't honestly say that it flashes while zooming and panning though. I've never seen it happen while actually executing any drawing commands and it never flashes if the screen is just sitting there without anything happening. Since this computer is an iMac there is no "video card" per se. See an earlier post for the video chip system integrated into the system. And again, since it's an iMac, there's no way to add any kind of hardware acceleration. And because I don't see this with any other graphically intensive programs, I doubt that I have a video system problem with the computer itself. Remember too that only the drawing canvas flashes - the window elements and menus, etc, do not flash.

Is there any kind of way that I can activate a debug mode to try to capture data on what might be happening? Are there some system settings I can adjust to more closely match the program to the video system in the Mac? The ATi Radeon video chip includes 512 MB of VRAM. Is it possible that the program is looking for more VRAM than that which is causing the flashing during screen updates? Although the flashing doesn't seem to affect anything, it is somewhat annoying which is why I'd like to come up with a solution!

John

[andrew]

One thing you could try is to reset QCAD to its default configuration by deleting the file /Users/your name/.config/QCAD/QCAD3.ini
Another thing I would try is to rule out individual tool bars and dock widgets as possible cause by hiding one after another and check if the problem persists (you can afterwards reset QCAD to its default configuration again by deleting the QCAD3.ini file).

Unfortunately, it's very difficult to fix problems that cannot be reproduced here, so it's very difficult to guess at this point what might be going on.

[Clive]

Hi John

I'm not a mac user sorry for my ignorance here about the hardware etc. it was just a wild guess from my side.

Maybe try Andrews suggestions.

[PiperPilotJohn]

Clive and Andrew,

I do appreciate your suggestions and will try them out as time permits. As I've mentioned before, other than being a tad annoying, the flashing doesn't cause any problems with the functionality of the program. I will try your suggestions and play around a bit myself to see if I can eliminate the problem. I may also try running the program in a new, clean account on the Mac just to make sure that there isn't some sort of conflict with my current account. If I do come up with a solution I'll let you know.

John