deferred-renderer-cpp: properly handle window size changes

Change-Id: I8e89a6c0adc2b99e5fe2af61629df2f2a6ae3ccd
Task-number: QTBUG-55163
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>

2 files changed, 31 insertions, 8 deletions

diff --git a/tests/manual/deferred-renderer-cpp/deferredrenderer.cpp b/tests/manual/deferred-renderer-cpp/deferredrenderer.cpp
index fe0c168e4..48f8ad3fe 100644
--- a/tests/manual/deferred-renderer-cpp/deferredrenderer.cpp
+++ b/tests/manual/deferred-renderer-cpp/deferredrenderer.cpp
@@ -64,7 +64,9 @@ DeferredRenderer::DeferredRenderer(Qt3DCore::QNode *parent)
     , m_geometryPassFilter(new Qt3DRender::QRenderPassFilter(m_clearGBuffer))
     , m_finalPassFilter(new Qt3DRender::QRenderPassFilter(m_clearScreenQuad))
     , m_sceneCameraSelector(new Qt3DRender::QCameraSelector(m_geometryPassFilter))
+    , m_winSize(new Qt3DRender::QParameter(QStringLiteral("winSize"), QSizeF(1024.0f, 768.0f)))
     , m_gBuffer(new GBuffer(this))
+    , m_window(nullptr)
 {
     m_clearGBuffer->setBuffers(Qt3DRender::QClearBuffers::ColorDepthBuffer);
     m_clearScreenQuad->setBuffers(Qt3DRender::QClearBuffers::ColorDepthBuffer);
@@ -73,13 +75,7 @@ DeferredRenderer::DeferredRenderer(Qt3DCore::QNode *parent)
     m_finalPassFilter->addParameter(new Qt3DRender::QParameter(QStringLiteral("position"), m_gBuffer->positionTexture()));
     m_finalPassFilter->addParameter(new Qt3DRender::QParameter(QStringLiteral("normal"), m_gBuffer->normalTexture()));
     m_finalPassFilter->addParameter(new Qt3DRender::QParameter(QStringLiteral("color"), m_gBuffer->colorTexture()));
-
-    Qt3DRender::QParameter *winSize = new Qt3DRender::QParameter(QStringLiteral("winSize"), QSizeF(1024.0f, 768.0f));
-    QObject::connect(m_surfaceSelector, &Qt3DRender::QRenderSurfaceSelector::externalRenderTargetSizeChanged,
-                     [=] (const QSize &viewSize) {
-       winSize->setValue(QSizeF(viewSize));
-    });
-    m_finalPassFilter->addParameter(winSize);
+    m_finalPassFilter->addParameter(m_winSize);
 }
 
 void DeferredRenderer::setSceneCamera(Qt3DCore::QEntity *camera)
@@ -111,5 +107,27 @@ void DeferredRenderer::setScreenQuadLayer(Qt3DRender::QLayer *layer)
 
 void DeferredRenderer::setSurface(QWindow *surface)
 {
-    m_surfaceSelector->setSurface(surface);
+    if (surface != m_window) {
+
+        // Disconnect old window's signals
+        if (m_window != nullptr) {
+            QObject::disconnect(m_widthChangedConnection);
+            QObject::disconnect(m_heightChangedConnection);
+        }
+
+        m_window = surface;
+        m_surfaceSelector->setSurface(surface);
+
+        if (m_window != nullptr) {
+            // Store connections
+            m_widthChangedConnection = QObject::connect(surface, &QWindow::widthChanged,
+                                                        [this] (int width) {
+                m_winSize->setValue(QSizeF(float(width), m_winSize->value().toSizeF().height()));
+            });
+            m_heightChangedConnection = QObject::connect(surface, &QWindow::heightChanged,
+                                                         [this] (int height) {
+                m_winSize->setValue(QSizeF(m_winSize->value().toSizeF().width(), float(height)));
+            });
+        }
+    }
 }
diff --git a/tests/manual/deferred-renderer-cpp/deferredrenderer.h b/tests/manual/deferred-renderer-cpp/deferredrenderer.h
index 4483afb07..0d22c1e81 100644
--- a/tests/manual/deferred-renderer-cpp/deferredrenderer.h
+++ b/tests/manual/deferred-renderer-cpp/deferredrenderer.h
@@ -85,7 +85,12 @@ private:
     Qt3DRender::QRenderPassFilter *m_geometryPassFilter;
     Qt3DRender::QRenderPassFilter *m_finalPassFilter;
     Qt3DRender::QCameraSelector *m_sceneCameraSelector;
+    Qt3DRender::QParameter *m_winSize;
     GBuffer *m_gBuffer;
+    QWindow *m_window;
+
+    QMetaObject::Connection m_widthChangedConnection;
+    QMetaObject::Connection m_heightChangedConnection;
 };
 
 #endif // DEFERREDRENDERER_H