Round values, don't just truncate.

svn path=/branches/work/kwin_composite/; revision=656976

effects/desktopgrid.cpp

@@ -10,6 +10,8 @@ License. See the file "COPYING" for the exact licensing terms.
 
 #include "desktopgrid.h"
 
+#include <math.h>
+
 #include <kaction.h>
 #include <kactioncollection.h>
 #include <klocale.h>
@@ -276,10 +278,10 @@ QRect DesktopGridEffect::desktopRect( int desktop, bool scaled ) const
     if( !scaled )
         return rect;
     QRect current = desktopRect( effects->currentDesktop(), false );
-    rect = QRect( int( interpolate( rect.x() - current.x(), rect.x() / float( x ), progress )),
-        int( interpolate( rect.y() - current.y(), rect.y() / float( y ), progress )),
-        int( interpolate( rect.width(), displayWidth() / float( x ), progress )),
-        int( interpolate( rect.height(), displayHeight() / float( y ), progress )));
+    rect = QRect( lround( interpolate( rect.x() - current.x(), rect.x() / float( x ), progress )),
+        lround( interpolate( rect.y() - current.y(), rect.y() / float( y ), progress )),
+        lround( interpolate( rect.width(), displayWidth() / float( x ), progress )),
+        lround( interpolate( rect.height(), displayHeight() / float( y ), progress )));
     return rect;
     }