QRendererSettings::setActiveFrameGraph(): Set surface for new graph

If the old frame graph already has a QRenderSurfaceSelector, use the
surface assigned to this selector for the new frame graph, too.

Task-number: QTBUG-57401
Change-Id: I5a0142d4ca40f5ff0047b7b42ae79fdc48189cf0
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/src/render/frontend/qrendersettings.cpp b/src/render/frontend/qrendersettings.cpp
index aa10a7ef3..4fb348617 100644
--- a/src/render/frontend/qrendersettings.cpp
+++ b/src/render/frontend/qrendersettings.cpp
@@ -40,6 +40,8 @@
 #include "qrendersettings.h"
 #include "qrendersettings_p.h"
 #include "qframegraphnode.h"
+#include "qrendersurfaceselector.h"
+#include "qrendersurfaceselector_p.h"
 
 QT_BEGIN_NAMESPACE
 
@@ -210,6 +212,14 @@ void QRenderSettings::setActiveFrameGraph(QFrameGraphNode *activeFrameGraph)
     if (d->m_activeFrameGraph == activeFrameGraph)
         return;
 
+    // if the old frame graph had a SurfaceSelector, use the given surface for the new framegraph, too.
+    if (d->m_activeFrameGraph && activeFrameGraph) {
+        Qt3DRender::QRenderSurfaceSelector *oldSurfaceSelector = Qt3DRender::QRenderSurfaceSelectorPrivate::find(d->m_activeFrameGraph);
+        Qt3DRender::QRenderSurfaceSelector *newSurfaceSelector = Qt3DRender::QRenderSurfaceSelectorPrivate::find(activeFrameGraph);
+        if (oldSurfaceSelector && newSurfaceSelector && oldSurfaceSelector->surface())
+            newSurfaceSelector->setSurface(oldSurfaceSelector->surface());
+    }
+
     if (d->m_activeFrameGraph)
         d->unregisterDestructionHelper(d->m_activeFrameGraph);