VirtualSurfaceImageSource too slow.


  • VirtualSurfaceImageSource does not update its content fast enough if it is scrolled quickly, even if the simplest things are drawn (like some rectangles). The issue can be seen in the magazine sample app (http://code.msdn.microsoft.com/windowsapps/Magazine-Sample-2a657289) by increasing the amount of text displayed, and scrolling quickly, the area scrolled to will be empty for a little bit of time before the text gets displayed. What is the reason for this? Is this some inner limitation of the VirtualSurfaceImageSource?

    I though about using a large SurfaceImageSource instead of the virtual one. What is the size limit of a SurfaceImageSource? Is it depending on the memory available on the video card?

    Tuesday, July 31, 2012 12:05 PM

All replies

  • Yes, in general the size limit of a SIS is dependent on available memory (similar to allocating a DX surface).

    We've made some changes to VSIS since Release Preview which could hopefully improve the experience here when rapidly scrolling.

    Tuesday, July 31, 2012 4:30 PM
  • Another piece of information: it seems that the problem only happens if scrolling with a mouse which has fast-scroll (that kind of scroll wheel which freely spins when spinned and let go, like http://www.gizmag.com/go/6060/, or some other Logitech mice).

    The issue does not occur when the scroll bar of the ScrollViewer is dragged, regardless of how fast.

    Wednesday, August 08, 2012 11:12 AM