Round physical dpi when calculating scale factor

(For the QT_USE_PHYSICAL_DPI use case)

The physical DPI is nominally computed from the physical
screen size, however when QT_USE_PHYSICAL_DPI is set
that size has typically been overridden with a fake
size by the user, such that the resulting DPI calculation
will yield some specific integer DPI.

Round this DPI value in order to arrive at a nice scale
factor, e.g. 144/96 = 1.5 instead of 144.01/96 = 1.5001

Change-Id: I665394e98a818b3a8f46408f3193cac4411f458d
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/gui/kernel/qhighdpiscaling.cpp b/src/gui/kernel/qhighdpiscaling.cpp
index 3a70e5acf7..f93ec5fe76 100644
--- a/src/gui/kernel/qhighdpiscaling.cpp
+++ b/src/gui/kernel/qhighdpiscaling.cpp
@@ -293,7 +293,7 @@ qreal QHighDpiScaling::rawScaleFactor(const QPlatformScreen *screen)
         QSize sz = screen->geometry().size();
         QSizeF psz = screen->physicalSize();
         qreal platformPhysicalDpi = ((sz.height() / psz.height()) + (sz.width() / psz.width())) * qreal(25.4 * 0.5);
-        factor = qreal(platformPhysicalDpi) / qreal(platformBaseDpi.first);
+        factor = qRound(platformPhysicalDpi) / qreal(platformBaseDpi.first);
     } else {
         const QDpi platformLogicalDpi = QPlatformScreen::overrideDpi(screen->logicalDpi());
         factor = qreal(platformLogicalDpi.first) / qreal(platformBaseDpi.first);