title: When does DXGI Desktop Duplication API identify a region as a moved region?
body: <p>I have a program to capture the desktop screen using DXGI Desktop Duplication API.</p>
  
  <p>I get frames with <code>IDXGIOutputDuplication::AcquireNextFrame</code> and I am able to capture my desktop frame by frame fine.</p>
  
  <p>To move forward, I try to optimize my program and try to manage <em>dirty</em> and <em>moved</em> rectangle. The API provides both <code>IDXGIOutputDuplication::GetFrameDirtyRects</code> and <code>IDXGIOutputDuplication::GetFrameMoveRects</code> to obtain these informations.</p>
  
  <p>However, it seems like there are never any rectangles identified as being moved. The documentation says moved rectangle are :</p>
  
  <blockquote>
    <p>rectangles of pixels in the desktop image that the operating system
    moved to another location within the same image</p>
  </blockquote>
  
  <p>What does this mean exactly ? Can DXGI identify arbitrary portion of the screen to have been moved ? Or maybe this only applies to desktop window being moved ?</p>