WIP: Add PdmDevicePixelRatioScaled.

Work around QPainDevice::metric's int return type
by adding a new metric that returns a scaled devicePixelRatio.
Choose a scale factor that gives us more than enough
range.

The QPainDevice::devicePixelRatio() convenience accessor
is public API and can unfortunately not be changed
to return a qreal. Add devicePixelRatioF() which
returns the (unscaled) devicePixelRatio.

Change all call sites of QPainDevice::devicePixelRatio()
to use QPainDevice::devicePixelRatioF().

Task-number: QTBUG-38858
Change-Id: Ia97c24e1c7b10241d6425fab2fa513702bb750b8

1 files changed, 2 insertions, 2 deletions

diff --git a/src/widgets/kernel/qopenglwidget.cpp b/src/widgets/kernel/qopenglwidget.cpp
index 8faa9f8681..8c60818819 100644
--- a/src/widgets/kernel/qopenglwidget.cpp
+++ b/src/widgets/kernel/qopenglwidget.cpp
@@ -671,7 +671,7 @@ void QOpenGLWidgetPrivate::recreateFbo()
     format.setAttachment(QOpenGLFramebufferObject::CombinedDepthStencil);
     format.setSamples(samples);
 
-    const QSize deviceSize = q->size() * q->devicePixelRatio();
+    const QSize deviceSize = q->size() * q->devicePixelRatioF();
     fbo = new QOpenGLFramebufferObject(deviceSize, format);
     if (samples > 0)
         resolvedFbo = new QOpenGLFramebufferObject(deviceSize);
@@ -680,7 +680,7 @@ void QOpenGLWidgetPrivate::recreateFbo()
     context->functions()->glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
 
     paintDevice->setSize(deviceSize);
-    paintDevice->setDevicePixelRatio(q->devicePixelRatio());
+    paintDevice->setDevicePixelRatio(q->devicePixelRatioF());
 
     emit q->resized();
 }