[vtk-developers] swap interval and mouse input problems

[Clinton Stimpson]

On Monday, November 30, 2015 01:26:05 PM Ben Boeckel wrote:
> On Mon, Nov 30, 2015 at 10:38:57 -0700, Clinton Stimpson wrote:
> > On certain platforms with certain Xlib or OpenGL implementations, I'm
> > seeing interaction lags when using VTK in Qt applications.  I see this
> > with both QVTKWidget and QVTKWidget2.
> 
> This is a Qt bug; they don't collapse mouse events as they used to. The
> patch with the fix is in 5.6 (I asked about getting it into 5.5.1, but
> it was pushed to 5.6.0 anyways).
> 
>     https://codereview.qt-project.org/#/c/115531/
>     https://codereview.qt-project.org/#/c/126136/

Thanks!  I had first expected a compression of mouse events, and was confused 
when I saw this problem.  A fix in Qt would be nice.

> 
> Though if the fix is as simple as tis makes it seem to be…
> 
>    
> https://codereview.qt-project.org/#/c/90873/4/examples/opengl/hellogl/glwid
> get.cpp

That fix to hellogl is basically equivalent to what I did in an experiment.
Putting a formal fix into VTK is what I'm proposing here.

In the past, I expected compression to be a normal thing (and done by the X 
server), but now I understand this is not how it works on the X level.  
Compression is implemented by the client, and in this case, compression is 
being expected of Qt.

Here is a request to *not* compress X events.
https://bugreports.qt.io/browse/QTBUG-44964

Are we still interested in putting a fix into VTK for this?

Clint