WPF Text blurry

Question

Hi,

I'm wondering if this is a known problem:
I have a multi monitor setup and whenever I move a WPF window from one screen to the other the text becomes totally blurred. Also, moving the window across to the other screens is very slow. Sometimes, this blurry text effect also appears on the main monitor, for example when I expand a combo box, etc.
Anybody knows what's going on there?

Thanks,

Tom

Answer 1

Try setting SnapsToDevicePixels="True" on the UIElement that looks blurry.

This has been discussed before here http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=168948&SiteID=1 and here http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=391349&SiteID=1 Some people on some hardware seem to find WPF (and cleartype in general) to be too blurry for them.

Answer 2

This happens with every WPF application, so if this is not fixed by default this is a huge problem. Also, as soon as I move the application to another screen it seems as the hardware drawing support is missing and everything is way laggy?

Answer 3

Here is a screenshot that shows a WPF control halfway on anoter screen: http://www.kingvest.de/blur.png

Answer 4

anyone? I think this is a real big problem

Answer 5

Hi Tom,

This problem has not reported before (the aforementioned SnapsToDevicePixels property does not affect Text).

I wonder if your second monitor is actually set to its optimal resolution setting. Does non-Avalon text show up clearly on both monitors?

-Seema

Answer 6

yes, everything but WPF apps is perfectly fine

Answer 7

here some proof: http://www.kingvest.de/blur2.png

Answer 8

RE: performance of multi-adapter, multi-monitor system
Tom and I followed up offline, I have been unable to repro the performance issue with a similar multi-monitor-multi-adapter-multi-IHV configuration. If other folks watching this thread have seen similar issues, please mail me.

RE: WPF Text blurry
Followup: In the linked jpg, all of WPF is shifted an odd amount (by 1-2 pixels). As WPF text is rendered via an algorithm handling subpixel placement, a slight shift in rendering causes the text to be very blurry. The issue does not repro when WPF hardware acceleration is disabled; without being able to reproduce the issue on my own machines, I am guessing that the shifting might be due to the interactions between the two video drivers.

-SeemaR@Microsoft
http://blogs.msdn.com/seema

Answer 9

Hi,

I was expecting this to be fixed by release, but it hasn't been.

I'm running the first release of .NET 3.0 on a Radeon 9600 with multiple monitors on Windows XP SP2.

When I move the window from one monitor to the other, the text blurs, in the exact same way that the text blurs when it is being animated. However, when the text is animated, on the second monitor, rather than blurring more, it becomes clear -- extremely bizarre. I thought the blurring during animation was intentional, but evidently it's not. SnapsToDevicePixels has no effect.

Furthermore, I have the same problem with the whole window contents being skewed when the window is moved. On the other hand, I can minimize it and restore it on the second monitor, which fixes the skewing, but doesn't fix the blurry text. It's most likely a separate bug altogether.

 

This is a crucial problem affecting not just aesthetics but also legibility and usability; it must be fixed ASAP. Please contact me if you need more repro information.

 

Thanks,

Rei