Previously, the backing store and default framebuffer were created with
the logical screen resolution (in device-independent pixels), not the
the physical screen resolution. This lead to blurry text on high-DPI
devices. This change fixes this by creating those at full size, and
setting the device pixel ratio appropriately. Windows are still reported
in device-independent pixels, but text and images are now rendered
sharply for Qt Quick applications.
As QPainter does not support non-integer scaling, the backing store is
still drawn in DIPs and scaled by OpenGL.
Task-number: QTBUG-38464
Change-Id: I7377d4c734126825d670b8ebb65fd0dd1ef705f2
Reviewed-by: Oliver Wolff <oliver.wolff@digia.com>
eea02ff10d