Fix issue with multiple View3D + stereoscopic

Stereoscopic QParameter is per-layer.
Also move some logic from engine into scenemanager side.

Task-number: QT3DS-2561
Change-Id: I2c426a8511edc0cdbaae8760578651915a05dd28
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>

4 files changed, 29 insertions, 27 deletions

diff --git a/src/runtime/q3dsengine.cpp b/src/runtime/q3dsengine.cpp
index b05c911..6bb87b5 100644
--- a/src/runtime/q3dsengine.cpp
+++ b/src/runtime/q3dsengine.cpp
@@ -1249,13 +1249,7 @@ void Q3DSEngine::setViewportSettings(Q3DSViewportSettings *viewportSettings)
 
     connect(m_viewportSettings, &Q3DSViewportSettings::stereoModeChanged, [this] {
         if (!m_uipPresentations.isEmpty()) {
-            m_uipPresentations[0].sceneManager->updateViewportRects();
-
-            if (isStereoscopic() != m_wasStereoscopic)
-                emit stereoscopicChanged();
-
-            m_wasStereoscopic = isStereoscopic();
-
+            emit stereoModeChanged();
             // Force a refresh
             resize(m_size, m_dpr);
         }
diff --git a/src/runtime/q3dsengine_p.h b/src/runtime/q3dsengine_p.h
index d349dec..162c205 100644
--- a/src/runtime/q3dsengine_p.h
+++ b/src/runtime/q3dsengine_p.h
@@ -230,7 +230,7 @@ Q_SIGNALS:
     void slideExited(Q3DSGraphObject *context, int index, const QString &name);
     void layerResized(Q3DSLayerNode *layer3DS);
     void layerTextureNodeChanged(Q3DSLayerNode *layer3DS);
-    void stereoscopicChanged();
+    void stereoModeChanged();
 
 private:
     Q_DISABLE_COPY(Q3DSEngine)
@@ -315,7 +315,6 @@ private:
     QMutex m_renderLoopStatsMutex;
     float m_quickDeltaSum = 0;
     int m_quickDeltaCount = 0;
-    bool m_wasStereoscopic = false;
 };
 
 Q_DECLARE_OPERATORS_FOR_FLAGS(Q3DSEngine::Flags)
diff --git a/src/runtime/q3dsscenemanager.cpp b/src/runtime/q3dsscenemanager.cpp
index 80ea720..a43084c 100644
--- a/src/runtime/q3dsscenemanager.cpp
+++ b/src/runtime/q3dsscenemanager.cpp
@@ -726,7 +726,7 @@ Q3DSSceneManager::Scene Q3DSSceneManager::buildScene(Q3DSUipPresentation *presen
                        this, std::placeholders::_1, std::placeholders::_2, std::placeholders::_3));
     }
 
-    QObject::disconnect(m_engine, &Q3DSEngine::stereoscopicChanged, 0, 0);
+    QObject::disconnect(m_engine, &Q3DSEngine::stereoModeChanged, 0, 0);
 
     // Kick off the Qt3D scene.
     m_rootEntity = new Qt3DCore::QEntity;
@@ -1166,9 +1166,6 @@ void Q3DSSceneManager::updateViewportRects()
             break;
         }
     }
-
-    // Update mode into shader parameter
-    m_stereoMode->setValue(m_engine->viewportSettings()->stereoMode());
 }
 
 void Q3DSSceneManager::updateStereoRenderTree(Q3DSLayerAttached *layerData)
@@ -1410,8 +1407,10 @@ void Q3DSSceneManager::buildLayer(Q3DSLayerNode *layer3DS,
     // Enable/disable correct selectors depending on mode
     updateStereoRenderTree(layerData);
 
-    m_stereoMode = new Qt3DRender::QParameter(QLatin1String("stereoMode"),
-                                              m_engine->viewportSettings()->stereoMode());
+    layerData->stereoModeParam
+            = new Qt3DRender::QParameter(QLatin1String("stereoMode"),
+                                         m_engine->viewportSettings()->stereoMode());
+    layerData->wasStereoscopic = m_engine->isStereoscopic();
 
     // The effective texture for the layer can change over time (for example
     // when a postproc effect or progaa becomes active or inactive). Keep the
@@ -1437,20 +1436,29 @@ void Q3DSSceneManager::buildLayer(Q3DSLayerNode *layer3DS,
             emit m_engine->layerTextureNodeChanged(layer3DS);
     });
 
-    QObject::connect(m_engine, &Q3DSEngine::stereoscopicChanged,
+    QObject::connect(m_engine, &Q3DSEngine::stereoModeChanged,
                      [this, layer3DS, layerData]()
     {
-        // When switching between stereo <-> non-stereo, update used shader
-        // TODO: Here we disable effects when rendering stereo as msaa+effect currently doesn't work for stereo
-        int activeEffectCount = layerData->eyeMono->effectData.activeEffectCount;
-        layerData->effectActive = m_engine->isStereoscopic() ? false : activeEffectCount > 0;
+        if (m_engine->isStereoscopic() != layerData->wasStereoscopic) {
+            // When switching between stereo <-> non-stereo do extra initialization
+            // TODO: Here we disable effects when rendering stereo as msaa+effect currently doesn't work for stereo
+            int activeEffectCount = layerData->eyeMono->effectData.activeEffectCount;
+            layerData->effectActive = m_engine->isStereoscopic() ? false : activeEffectCount > 0;
 
-        // If any layer uses advanced blending, let them update shaders
-        updateAdvancedBlendLayers();
+            // If any layer uses advanced blending, let them update shaders
+            updateAdvancedBlendLayers();
+
+            updateLayerCompositorProgram(layer3DS);
+            // And enable/disable related selectors
+            updateStereoRenderTree(layerData);
+
+            layerData->wasStereoscopic = m_engine->isStereoscopic();
+        }
+
+        // Update mode into shader parameter
+        if (m_engine->isStereoscopic())
+            layerData->stereoModeParam->setValue(m_engine->viewportSettings()->stereoMode());
 
-        updateLayerCompositorProgram(layer3DS);
-        // And enable/disable related selectors
-        updateStereoRenderTree(layerData);
     });
 
     layer3DS->setAttached(layerData);
@@ -3807,7 +3815,7 @@ void Q3DSSceneManager::buildLayerQuadEntity(Q3DSLayerNode *layer3DS, Qt3DCore::Q
         renderPass->addParameter(data->eyeRight->compositorSourceParam);
 
         // Add stereo parameter
-        renderPass->addParameter(m_stereoMode);
+        renderPass->addParameter(data->stereoModeParam);
     }
 
     technique->addRenderPass(renderPass);
diff --git a/src/runtime/q3dsscenemanager_p.h b/src/runtime/q3dsscenemanager_p.h
index 8607789..507b2cc 100644
--- a/src/runtime/q3dsscenemanager_p.h
+++ b/src/runtime/q3dsscenemanager_p.h
@@ -321,9 +321,11 @@ public:
     bool usesDefaultCompositorProgram = true;
     bool effectActive = false;
     bool wasDirty = false;
+    bool wasStereoscopic = false;
     bool rayCasterBusy = false;
     Qt3DRender::QParameter *cameraPropertiesParam = nullptr;
     Qt3DRender::QRayCaster *layerRayCaster = nullptr;
+    Qt3DRender::QParameter *stereoModeParam = nullptr;
 
     struct RayCastQueueEntry {
         QVector3D direction;
@@ -1003,7 +1005,6 @@ private:
     QVector<Qt3DCore::QEntity *> m_compositorEntities;
     bool m_compositorEnabled = true;
     QVector<ViewportSet> m_viewports;
-    Qt3DRender::QParameter *m_stereoMode;
     friend class Q3DSFrameUpdater;
     friend class Q3DSProfiler;
     friend class Q3DSSlidePlayer;