Set dummy surface for renderer

This works around the crash reporeted in QTBUG-54318.

Using a dummy surface instead of the proper one appears
to have no negative side effects, probably because we
draw to offscreen FBO anyway.

Change-Id: I54e8c467cac8a6cf403a7aab1da17ba2141f83b8
Reviewed-by: Titta Heikkala <titta.heikkala@qt.io>

2 files changed, 29 insertions, 3 deletions

diff --git a/editorlib/src/editorviewportitem.cpp b/editorlib/src/editorviewportitem.cpp
index ae1c025..b6582af 100644
--- a/editorlib/src/editorviewportitem.cpp
+++ b/editorlib/src/editorviewportitem.cpp
@@ -79,15 +79,19 @@ public:
                               Qt3DCore::QAspectEngine *aspectEngine,
                               Qt3DRender::QRenderAspect *renderAspect,
                               Qt3DInput::QInputAspect *inputAspect,
-                              Qt3DLogic::QLogicAspect *logicAspect)
+                              Qt3DLogic::QLogicAspect *logicAspect,
+                              QOffscreenSurface *surface)
         : m_item(item)
         , m_aspectEngine(aspectEngine)
         , m_renderAspect(renderAspect)
         , m_inputAspect(inputAspect)
         , m_logicAspect(logicAspect)
+        , m_surface(surface)
     {
         ContextSaver saver;
-        m_item->scene()->renderer()->setSurface(reinterpret_cast<QObject *>(saver.surface()));
+        // HACK: Use dummy surface for renderer to work around crash when running in creator
+        // TODO: Remove hack when QTBUG-54318 is fixed
+        m_item->scene()->renderer()->setSurface(reinterpret_cast<QObject *>(m_surface));
         static_cast<Qt3DRender::QRenderAspectPrivate *>(
                     Qt3DRender::QRenderAspectPrivate::get(m_renderAspect))
                 ->renderInitialize(saver.context());
@@ -134,6 +138,7 @@ public:
     Qt3DRender::QRenderAspect *m_renderAspect;
     Qt3DInput::QInputAspect *m_inputAspect;
     Qt3DLogic::QLogicAspect *m_logicAspect;
+    QOffscreenSurface *m_surface;
 };
 
 EditorViewportItem::EditorViewportItem(QQuickItem *parent)
@@ -145,6 +150,7 @@ EditorViewportItem::EditorViewportItem(QQuickItem *parent)
     , m_logicAspect(new Qt3DLogic::QLogicAspect)
     , m_cameraController(nullptr)
     , m_inputEnabled(true)
+    , m_surface(nullptr)
 {
     setFlag(ItemHasContents, true);
     m_aspectEngine->registerAspect(m_renderAspect);
@@ -153,6 +159,8 @@ EditorViewportItem::EditorViewportItem(QQuickItem *parent)
 
     setAcceptHoverEvents(true);
     setAcceptedMouseButtons(Qt::AllButtons);
+
+    connect(this, &QQuickItem::windowChanged, this, &EditorViewportItem::handleWindowChanged);
 }
 
 EditorViewportItem::~EditorViewportItem()
@@ -161,6 +169,9 @@ EditorViewportItem::~EditorViewportItem()
         static_cast<Qt3DRender::QRenderAspectPrivate *>
             (Qt3DRender::QRenderAspectPrivate::get(m_renderAspect))->renderShutdown();
     }
+
+    if (m_surface)
+        m_surface->deleteLater();
 }
 
 EditorScene *EditorViewportItem::scene() const
@@ -182,6 +193,17 @@ void EditorViewportItem::setInputEnabled(bool enable)
     }
 }
 
+void EditorViewportItem::handleWindowChanged(QQuickWindow *win)
+{
+    if (!m_surface && win) {
+        m_surface = new QOffscreenSurface;
+        QSurfaceFormat format = win->format();
+        format.setSamples(4);
+        m_surface->setFormat(format);
+        m_surface->create();
+    }
+}
+
 void EditorViewportItem::setScene(EditorScene *scene)
 {
     if (m_scene == scene)
@@ -224,7 +246,7 @@ QQuickFramebufferObject::Renderer *EditorViewportItem::createRenderer() const
 {
     EditorViewportItem *self = const_cast<EditorViewportItem*>(this);
     return new FrameBufferObjectRenderer(self, m_aspectEngine, m_renderAspect,
-                                         m_inputAspect, m_logicAspect);
+                                         m_inputAspect, m_logicAspect, m_surface);
 }
 
 QSGNode *EditorViewportItem::updatePaintNode(QSGNode *node,
diff --git a/editorlib/src/editorviewportitem.h b/editorlib/src/editorviewportitem.h
index 43c7c88..7c31f93 100644
--- a/editorlib/src/editorviewportitem.h
+++ b/editorlib/src/editorviewportitem.h
@@ -33,6 +33,8 @@
 class EditorScene;
 class EditorCameraController;
 
+class QOffscreenSurface;
+
 namespace Qt3DCore
 {
 class QAspectEngine;
@@ -66,6 +68,7 @@ public:
 
     bool inputEnabled() const;
     void setInputEnabled(bool enable);
+    void handleWindowChanged(QQuickWindow *win);
 
 public slots:
     void setScene(EditorScene* scene);
@@ -97,6 +100,7 @@ private:
     EditorCameraController *m_cameraController;
 
     bool m_inputEnabled;
+    QOffscreenSurface *m_surface;
 };
 
 #endif // EDITORVIEWPORTITEM_H