Mark changed regions dirty instead of bounding box of changes

This helps a bit with LinuxFB on low end devices.

Change-Id: I16fcce23e7073272d1d1c6bc660c255163b96c30
Fixes: QTBUG-88174
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>

1 files changed, 3 insertions, 3 deletions

diff --git a/src/platformsupport/fbconvenience/qfbwindow.cpp b/src/platformsupport/fbconvenience/qfbwindow.cpp
index 9f5f87d9d6..f02721dce4 100644
--- a/src/platformsupport/fbconvenience/qfbwindow.cpp
+++ b/src/platformsupport/fbconvenience/qfbwindow.cpp
@@ -138,14 +138,14 @@ void QFbWindow::lower()
 void QFbWindow::repaint(const QRegion &region)
 {
     const QRect currentGeometry = geometry();
-    const QRect dirtyClient = region.boundingRect();
-    const QRect dirtyRegion = dirtyClient.translated(currentGeometry.topLeft());
     const QRect oldGeometryLocal = mOldGeometry;
     mOldGeometry = currentGeometry;
     // If this is a move, redraw the previous location
     if (oldGeometryLocal != currentGeometry)
         platformScreen()->setDirty(oldGeometryLocal);
-    platformScreen()->setDirty(dirtyRegion);
+    auto topLeft = currentGeometry.topLeft();
+    for (auto rect : region)
+        platformScreen()->setDirty(rect.translated(topLeft));
 }
 
 QT_END_NAMESPACE