Renderer/QRenderTargetSurfaceSelector: implement proper synchronization

This is needed to avoid rendering on a surface that has been destroyed.

Change-Id: Iadc2a32e2e0113704ca4df48df6bcdd1a0d8256c
Reviewed-by: Paul Lemire <paul.lemire@kdab.com>

4 files changed, 74 insertions, 0 deletions

diff --git a/src/render/framegraph/qrendersurfaceselector.cpp b/src/render/framegraph/qrendersurfaceselector.cpp
index a0d7e3a47..8bd31ac12 100644
--- a/src/render/framegraph/qrendersurfaceselector.cpp
+++ b/src/render/framegraph/qrendersurfaceselector.cpp
@@ -86,6 +86,7 @@ namespace Qt3DRender {
 QRenderSurfaceSelectorPrivate::QRenderSurfaceSelectorPrivate()
     : Qt3DRender::QFrameGraphNodePrivate()
     , m_surface(Q_NULLPTR)
+    , m_surfaceEventFilter(new Qt3DRender::Render::PlatformSurfaceFilter())
 {
 }
 
@@ -143,6 +144,23 @@ void QRenderSurfaceSelector::setSurface(QSurface *surface)
         return;
 
     d->m_surface = surface;
+    // The platform surface filter only deals with QObject
+    // We assume therefore that our surface is actually a QObject underneath
+    if (d->m_surface) {
+        switch (d->m_surface->surfaceClass()) {
+        case QSurface::Window:
+            d->m_surfaceEventFilter->setSurface(static_cast<QWindow *>(d->m_surface));
+            break;
+        case QSurface::Offscreen:
+            d->m_surfaceEventFilter->setSurface(static_cast<QOffscreenSurface *>(d->m_surface));
+            break;
+        default:
+            break;
+        }
+    } else {
+        QWindow *nullWindow = Q_NULLPTR;
+        d->m_surfaceEventFilter->setSurface(nullWindow);
+    }
     emit surfaceChanged(surface);
 }
 
@@ -177,6 +195,37 @@ void QRenderSurfaceSelector::setWindow(QWindow *window)
         return;
 
     d->m_surface = window;
+    d->m_surfaceEventFilter->setSurface(window);
+
+    if (window) {
+        QObject::connect(window, &QWindow::widthChanged, [=] (int width) {
+            if (d->m_changeArbiter != Q_NULLPTR) {
+                Qt3DCore::QScenePropertyChangePtr change(
+                            new Qt3DCore::QScenePropertyChange(
+                                Qt3DCore::NodeUpdated,
+                                Qt3DCore::QSceneChange::Node,
+                                id()));
+
+                change->setPropertyName("width");
+                change->setValue(QVariant::fromValue(width));
+                d->notifyObservers(change);
+            }
+        });
+        QObject::connect(window, &QWindow::heightChanged, [=] (int height) {
+            if (d->m_changeArbiter != Q_NULLPTR) {
+                Qt3DCore::QScenePropertyChangePtr change(
+                            new Qt3DCore::QScenePropertyChange(
+                                Qt3DCore::NodeUpdated,
+                                Qt3DCore::QSceneChange::Node,
+                                id()));
+
+                change->setPropertyName("height");
+                change->setValue(QVariant::fromValue(height));
+                d->notifyObservers(change);
+            }
+        });
+    }
+
     emit windowChanged(window);
     emit surfaceChanged(d->m_surface);
 }
diff --git a/src/render/framegraph/qrendersurfaceselector_p.h b/src/render/framegraph/qrendersurfaceselector_p.h
index 136ad0991..33e9eab96 100644
--- a/src/render/framegraph/qrendersurfaceselector_p.h
+++ b/src/render/framegraph/qrendersurfaceselector_p.h
@@ -52,6 +52,7 @@
 //
 
 #include <Qt3DRender/private/qframegraphnode_p.h>
+#include <Qt3DRender/private/platformsurfacefilter_p.h>
 #include <QtGui/qsurface.h>
 #include <QtGui/qwindow.h>
 
@@ -69,6 +70,7 @@ public:
 
     QSurface *m_surface;
     QSize m_externalRenderTargetSize;
+    QScopedPointer<Qt3DRender::Render::PlatformSurfaceFilter> m_surfaceEventFilter;
 };
 
 } // namespace Qt3DRender
diff --git a/src/render/framegraph/rendersurfaceselector.cpp b/src/render/framegraph/rendersurfaceselector.cpp
index 738e1f231..838b03c57 100644
--- a/src/render/framegraph/rendersurfaceselector.cpp
+++ b/src/render/framegraph/rendersurfaceselector.cpp
@@ -43,6 +43,7 @@
 #include <Qt3DCore/qscenepropertychange.h>
 
 #include <QtGui/qwindow.h>
+#include <QtGui/qscreen.h>
 #include <QtGui/qoffscreensurface.h>
 
 QT_BEGIN_NAMESPACE
@@ -55,6 +56,9 @@ namespace Render {
 RenderSurfaceSelector::RenderSurfaceSelector()
     : FrameGraphNode(FrameGraphNode::Surface)
     , m_surface(Q_NULLPTR)
+    , m_width(0)
+    , m_height(0)
+    , m_devicePixelRatio(0.0f)
 {
 }
 
@@ -64,6 +68,15 @@ void RenderSurfaceSelector::updateFromPeer(Qt3DCore::QNode *peer)
     m_surface = selector->surface();
     setEnabled(selector->isEnabled());
     setRenderTargetSize(selector->externalRenderTargetSize());
+    if (m_surface) {
+        if (m_surface->surfaceClass() == QSurface::Window) {
+            QWindow *window = static_cast<QWindow *>(m_surface);
+            m_width = window->width();
+            m_height = window->height();
+            if (window->screen())
+                m_devicePixelRatio = window->screen()->devicePixelRatio();
+        }
+    }
 }
 
 void RenderSurfaceSelector::sceneChangeEvent(const Qt3DCore::QSceneChangePtr &e)
@@ -77,6 +90,10 @@ void RenderSurfaceSelector::sceneChangeEvent(const Qt3DCore::QSceneChangePtr &e)
             setEnabled(propertyChange->value().toBool());
         else if (propertyChange->propertyName() == QByteArrayLiteral("externalRenderTargetSize"))
             setRenderTargetSize(propertyChange->value().toSize());
+        else if (propertyChange->propertyName() == QByteArrayLiteral("width"))
+            m_width = propertyChange->value().toInt();
+        else if (propertyChange->propertyName() == QByteArrayLiteral("height"))
+            m_height = propertyChange->value().toInt();
         markDirty(AbstractRenderer::AllDirty);
     }
 }
diff --git a/src/render/framegraph/rendersurfaceselector_p.h b/src/render/framegraph/rendersurfaceselector_p.h
index 114a52a31..8c84695a8 100644
--- a/src/render/framegraph/rendersurfaceselector_p.h
+++ b/src/render/framegraph/rendersurfaceselector_p.h
@@ -72,10 +72,16 @@ public:
     void sceneChangeEvent(const Qt3DCore::QSceneChangePtr &e) Q_DECL_OVERRIDE;
 
     QSurface *surface() const { return m_surface; }
+    inline int width() const Q_DECL_NOEXCEPT { return m_width; }
+    inline int height() const Q_DECL_NOEXCEPT { return m_height; }
+    inline float devicePixelRatio() const Q_DECL_NOEXCEPT { return m_devicePixelRatio; }
 
 private:
     QSurface *m_surface;
     QSize m_renderTargetSize;
+    int m_width;
+    int m_height;
+    float m_devicePixelRatio;
 };
 
 } // namespace Render