Fix hidpi support for opengl window grabbing

Now set the QImage devicePixelRatio so the content is correct on all
screens.

Task-number: QTBUG-53795
Change-Id: If94edf901da1285afe9bb847b8973d568a2b7082
Reviewed-by: Morten Johan Sørvig <morten.sorvig@qt.io>
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>

6 files changed, 7 insertions, 4 deletions

diff --git a/src/quick/items/qquickrendercontrol.cpp b/src/quick/items/qquickrendercontrol.cpp
index 03d96aea1f..e2a20f9e7e 100644
--- a/src/quick/items/qquickrendercontrol.cpp
+++ b/src/quick/items/qquickrendercontrol.cpp
@@ -385,6 +385,9 @@ QImage QQuickRenderControl::grab()
         cd->syncSceneGraph();
         render();
         grabContent = qt_gl_read_framebuffer(d->window->size() * d->window->effectiveDevicePixelRatio(), false, false);
+        if (QQuickRenderControl::renderWindowFor(d->window)) {
+            grabContent.setDevicePixelRatio(d->window->effectiveDevicePixelRatio());
+        }
 #endif
     } else if (d->window->rendererInterface()->graphicsApi() == QSGRendererInterface::Software) {
         QQuickWindowPrivate *cd = QQuickWindowPrivate::get(d->window);
diff --git a/src/quick/items/qquickwindow.cpp b/src/quick/items/qquickwindow.cpp
index e9108b7bda..46af829f79 100644
--- a/src/quick/items/qquickwindow.cpp
+++ b/src/quick/items/qquickwindow.cpp
@@ -3491,6 +3491,7 @@ QImage QQuickWindow::grabWindow()
 
             bool alpha = format().alphaBufferSize() > 0 && color().alpha() < 255;
             QImage image = qt_gl_read_framebuffer(size() * effectiveDevicePixelRatio(), alpha, alpha);
+            image.setDevicePixelRatio(effectiveDevicePixelRatio());
             d->cleanupNodesOnShutdown();
             d->context->invalidate();
             context.doneCurrent();
diff --git a/src/quick/scenegraph/qsgrenderloop.cpp b/src/quick/scenegraph/qsgrenderloop.cpp
index ec874f6ff0..64f920e417 100644
--- a/src/quick/scenegraph/qsgrenderloop.cpp
+++ b/src/quick/scenegraph/qsgrenderloop.cpp
@@ -423,6 +423,7 @@ void QSGGuiThreadRenderLoop::renderWindow(QQuickWindow *window)
     if (data.grabOnly) {
         bool alpha = window->format().alphaBufferSize() > 0 && window->color().alpha() != 255;
         grabContent = qt_gl_read_framebuffer(window->size() * window->effectiveDevicePixelRatio(), alpha, alpha);
+        grabContent.setDevicePixelRatio(window->effectiveDevicePixelRatio());
         data.grabOnly = false;
     }
 
diff --git a/src/quick/scenegraph/qsgthreadedrenderloop.cpp b/src/quick/scenegraph/qsgthreadedrenderloop.cpp
index 4543782d5b..41347cf868 100644
--- a/src/quick/scenegraph/qsgthreadedrenderloop.cpp
+++ b/src/quick/scenegraph/qsgthreadedrenderloop.cpp
@@ -432,6 +432,7 @@ bool QSGRenderThread::event(QEvent *e)
             qCDebug(QSG_LOG_RENDERLOOP) << QSG_RT_PAD << "- grabbing result";
             bool alpha = ce->window->format().alphaBufferSize() > 0 && ce->window->color().alpha() != 255;
             *ce->image = qt_gl_read_framebuffer(windowSize * ce->window->effectiveDevicePixelRatio(), alpha, alpha);
+            ce->image->setDevicePixelRatio(ce->window->effectiveDevicePixelRatio());
         }
         qCDebug(QSG_LOG_RENDERLOOP) << QSG_RT_PAD << "- waking gui to handle result";
         waitCondition.wakeOne();
diff --git a/src/quick/scenegraph/qsgwindowsrenderloop.cpp b/src/quick/scenegraph/qsgwindowsrenderloop.cpp
index 13388c0841..209715fff6 100644
--- a/src/quick/scenegraph/qsgwindowsrenderloop.cpp
+++ b/src/quick/scenegraph/qsgwindowsrenderloop.cpp
@@ -326,6 +326,7 @@ QImage QSGWindowsRenderLoop::grab(QQuickWindow *window)
 
     bool alpha = window->format().alphaBufferSize() > 0 && window->color().alpha() != 255;
     QImage image = qt_gl_read_framebuffer(window->size() * window->effectiveDevicePixelRatio(), alpha, alpha);
+    image.setDevicePixelRatio(window->effectiveDevicePixelRatio());
     return image;
 }
 
diff --git a/src/quickwidgets/qquickwidget.cpp b/src/quickwidgets/qquickwidget.cpp
index 4ed41a0c6c..c6dce6bf71 100644
--- a/src/quickwidgets/qquickwidget.cpp
+++ b/src/quickwidgets/qquickwidget.cpp
@@ -76,10 +76,6 @@
 
 QT_BEGIN_NAMESPACE
 
-#if QT_CONFIG(opengl)
-extern Q_GUI_EXPORT QImage qt_gl_read_framebuffer(const QSize &size, bool alpha_format, bool include_alpha);
-#endif
-
 class QQuickWidgetRenderControl : public QQuickRenderControl
 {
 public: