Fix rendering of intersecting quads

Split intersecting quads using a BSP tree in the same manner as Chromium's
rendering algorithm. Note that these split quads still will not be correctly
rendered in software mode as Qt Quick's software renderer is not at all aware of
non-rectangular QSGClipNodes.

Task-number: QTBUG-62112
Change-Id: Ibfb72b9220817baebf828bc6183af7bd9c25d050
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>

1 files changed, 24 insertions, 0 deletions

diff --git a/src/core/delegated_frame_node.h b/src/core/delegated_frame_node.h
index 40aca23b1..cc682988d 100644
--- a/src/core/delegated_frame_node.h
+++ b/src/core/delegated_frame_node.h
@@ -61,6 +61,11 @@ QT_END_NAMESPACE
 namespace cc {
 class DelegatedFrameData;
 class DrawQuad;
+class DrawPolygon;
+}
+
+namespace gfx {
+class QuadF;
 }
 
 namespace QtWebEngineCore {
@@ -88,6 +93,25 @@ public:
     void commit(ChromiumCompositorData *chromiumCompositorData, cc::ReturnedResourceArray *resourcesToRelease, RenderWidgetHostViewQtDelegate *apiDelegate);
 
 private:
+    void flushPolygons(
+        std::deque<std::unique_ptr<cc::DrawPolygon>> *polygonQueue,
+        QSGNode *renderPassChain,
+        DelegatedNodeTreeHandler *nodeHandler,
+        QHash<unsigned, QSharedPointer<ResourceHolder> > &resourceCandidates,
+        RenderWidgetHostViewQtDelegate *apiDelegate);
+    void handlePolygon(
+        const cc::DrawPolygon *polygon,
+        QSGNode *currentLayerChain,
+        DelegatedNodeTreeHandler *nodeHandler,
+        QHash<unsigned, QSharedPointer<ResourceHolder> > &resourceCandidates,
+        RenderWidgetHostViewQtDelegate *apiDelegate);
+    void handleClippedQuad(
+        const cc::DrawQuad *quad,
+        const gfx::QuadF &clipRegion,
+        QSGNode *currentLayerChain,
+        DelegatedNodeTreeHandler *nodeHandler,
+        QHash<unsigned, QSharedPointer<ResourceHolder> > &resourceCandidates,
+        RenderWidgetHostViewQtDelegate *apiDelegate);
     void handleQuad(
         const cc::DrawQuad *quad,
         QSGNode *currentLayerChain,