Fix: rebuild material and layer caches when FrameGraph tree is dirty

This could otherwise result in black screens when the FrameGraph
tree is updated and no other change is sent. Screen would remain
black until some other element with dirty changes triggers a cache
rebuild.

Change-Id: Iac43965f06d1d644de14e6a6c8768e035bed69a6
Reviewed-by: Mike Krus <mike.krus@kdab.com>

2 files changed, 8 insertions, 5 deletions

diff --git a/src/render/renderers/opengl/renderer/renderer.cpp b/src/render/renderers/opengl/renderer/renderer.cpp
index 7ed766f8b..4b70710f2 100644
--- a/src/render/renderers/opengl/renderer/renderer.cpp
+++ b/src/render/renderers/opengl/renderer/renderer.cpp
@@ -1596,7 +1596,6 @@ Renderer::ViewSubmissionResultData Renderer::submitRenderViews(const QVector<Ren
     ViewSubmissionResultData resultData;
     resultData.lastBoundFBOId = lastBoundFBOId;
     resultData.surface = lastUsedSurface;
-
     return resultData;
 }
 
@@ -1720,11 +1719,13 @@ QVector<Qt3DCore::QAspectJobPtr> Renderer::renderBinJobs()
     }
 
 
-    // Layer cache is dependent on layers, layer filters and the enabled flag
-    // on entities
+    // Layer cache is dependent on layers, layer filters (hence FG structure
+    // changes) and the enabled flag on entities
+    const bool frameGraphDirty = dirtyBitsForFrame & AbstractRenderer::FrameGraphDirty;
     const bool layersDirty = dirtyBitsForFrame & AbstractRenderer::LayersDirty;
-    const bool layersCacheNeedsToBeRebuilt = layersDirty || entitiesEnabledDirty;
+    const bool layersCacheNeedsToBeRebuilt = layersDirty || entitiesEnabledDirty || frameGraphDirty;
     const bool materialDirty = dirtyBitsForFrame & AbstractRenderer::MaterialDirty;
+    const bool materialCacheNeedsToBeRebuilt = materialDirty || frameGraphDirty;
 
     // Rebuild Entity Layers list if layers are dirty
     if (layersDirty)
@@ -1751,7 +1752,7 @@ QVector<Qt3DCore::QAspectJobPtr> Renderer::renderBinJobs()
         for (int i = 0; i < fgBranchCount; ++i) {
             RenderViewBuilder builder(fgLeaves.at(i), i, this);
             builder.setLayerCacheNeedsToBeRebuilt(layersCacheNeedsToBeRebuilt);
-            builder.setMaterialGathererCacheNeedsToBeRebuilt(materialDirty);
+            builder.setMaterialGathererCacheNeedsToBeRebuilt(materialCacheNeedsToBeRebuilt);
             builder.prepareJobs();
             renderBinJobs.append(builder.buildJobHierachy());
         }
@@ -1762,6 +1763,7 @@ QVector<Qt3DCore::QAspectJobPtr> Renderer::renderBinJobs()
         // FilterLayerEntityJob is part of the RenderViewBuilder jobs and must be run later
         // if none of those jobs are started this frame
         notCleared |= AbstractRenderer::EntityEnabledDirty;
+        notCleared |= AbstractRenderer::FrameGraphDirty;
         notCleared |= AbstractRenderer::LayersDirty;
     }
 
diff --git a/src/render/renderers/opengl/renderer/renderer_p.h b/src/render/renderers/opengl/renderer/renderer_p.h
index 23708e3e8..b89c1e7c0 100644
--- a/src/render/renderers/opengl/renderer/renderer_p.h
+++ b/src/render/renderers/opengl/renderer/renderer_p.h
@@ -185,6 +185,7 @@ public:
     Entity *sceneRoot() const override { return m_renderSceneRoot; }
 
     FrameGraphNode *frameGraphRoot() const override;
+    RenderQueue *renderQueue() const { return m_renderQueue; }
 
     void markDirty(BackendNodeDirtySet changes, BackendNode *node) override;
     BackendNodeDirtySet dirtyBits() override;