Your loadPixmap( false ) isn't really clearing the pixmap, it is simply setting it to a blank pixmap of the same size as the tiles. So, even if you are scrolling tiles out of the view, you really aren't getting rid of the memory they use.

Change the logic in loadPixmap so that if "status" is false, you call setPixmap( QPixmap() ) so it really is empty.

By the way, it is never necessary to call member functions with "this->" when you are inside the class. It is also odd that you use constructor syntax when you define a local variable:

Qt Code: 
  1. bool returnStatus( false );
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is very unusual for native types, and I had to stop and think about that. Of course it is correct, just unusual. For native types, you usually see the more common form of declaration and assignment:

Qt Code: 
  1. bool returnStatus = false;
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Is there some reason why you use the first method?