Tate74's picture

Flickering Mouse Pointer on GameWindow , and Stable Pointer (cursur) on DeskTop?

hi developers

I have just started today developing with OpenTK,
Started just like the manual say with "QuickStart.sln".

my OS is Ubuntu 8.1 with ManoDevelop 1.91 IDE C#.

when I launch the QuickStart Application I notice that
the cursor is blinking when above my QuickStart Window.
but when above the rest of the screen (the desktop wall paper)
the cursor is fine.

Is there a way to prevent these mouse flickering?



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the Fiddler's picture

Which video card and drivers are you using? Do you have compiz enabled?

Flickering of this kind is generally a driver issue.

Tate74's picture

Sorry I don't know anything about compiz?
can you please teach me what should I do?

the Fiddler's picture

Compiz is a compositing window manager that provides advanced visual effects to the linux desktop (you may have heard of the "desktop cube" for example). To check whether compiz is enabled, open System -> Preferences -> Appearance and click on the last tab ("Visual Effects"). You will find 3 options there, "None", "Normal" and "Extra". "None" means that compiz is disabled. "Normal" and "Advanced" mean that it is enabled.

Older video drivers used to have problems running compiz and OpenGL apps at the same time. This is a driver limitation, there's nothing OpenTK can do about this - you'll either have to disable compiz or upgrade to a more recent distribution (e.g. this issue should be completely fixed in Ubuntu 9.10).To disable compiz, simply select Visual Effects = None, as outlined above.

Of course, if you are still getting this issue with compiz disabled, please say so and we'll look investigate the issue further.

Tate74's picture

I looked on Compiz it was set correctly to "Non". apparently
it is not the problem (or not the complete solution).

However I have another bit of important information I mentiond.
When the mouse is on the OpenTK window it will blink every rendering
step (if I disable rendering using a flag so- only when there is input,
the window will be rendered - it blink only when I enter inputs).
Pay tension, It will not blink when the mouse is on the rest of
the desktop. only on the OpenTK window.

With MFC there was an option to use NULL on Update rendering
or UpdateData (for text)so th window will not blink. is there something
in OpenTK to prevent blinking?

the Fiddler's picture

The best advice I can offer is to run glxgears from a terminal and see if the mouse flickers there, too. If it does, this indicates a driver/OS issue (maybe the mouse pointer is hardware accelerated and doesn't play well with OpenGL?) If the mouse doesn't flicker on top of glxgears, this might indicate some problem in OpenTK (no idea what, though).

This information might help diagnose the issue:

  • the make of the video card (Intel, Ati, Nvidia, ...) Run glxinfo > info.txt on a terminal and attach info.txt here.
  • the mouse pointer you are using (is it the default one that comes with Ubuntu? If not, what is the name of the pointer? You can get the name under System -> Preferences -> Appearance -> Themes -> Customize (button) -> Pointers)