[vlc-commits] [Git][videolan/vlc][master] 3 commits: Revert "qt: fix video surface being displaced when extended margin changes"

[Steve Lhomme (@robUx4)]

Steve Lhomme pushed to branch master at VideoLAN / VLC


Commits:
afe64921 by Fatih Uzunoglu at 2025-03-06T15:55:35+00:00
Revert "qt: fix video surface being displaced when extended margin changes"

This reverts commit af27693dc2755064c55da76301412b47cccd6711.

- - - - -
d155ffa5 by Fatih Uzunoglu at 2025-03-06T15:55:35+00:00
qt: introduce `MatrixChangeObserverNode` and use it to signal `ViewBlockingRectangle::scenePositionHasChanged()`

- - - - -
29793d55 by Fatih Uzunoglu at 2025-03-06T15:55:35+00:00
qt: use `scenePositionHasChanged()` signal to update surface position in `VideoSurface`

- - - - -


4 changed files:

- modules/gui/qt/maininterface/videosurface.cpp
- modules/gui/qt/maininterface/videosurface.hpp
- modules/gui/qt/widgets/native/viewblockingrectangle.cpp
- modules/gui/qt/widgets/native/viewblockingrectangle.hpp


Changes:

=====================================
modules/gui/qt/maininterface/videosurface.cpp
=====================================
@@ -214,8 +214,9 @@ VideoSurface::VideoSurface(QQuickItem* parent)
 
         connect(this, &QQuickItem::xChanged, this, &VideoSurface::updateSurfacePosition);
         connect(this, &QQuickItem::yChanged, this, &VideoSurface::updateSurfacePosition);
-        connect(this, &QQuickItem::parentChanged, this, &VideoSurface::updateParentChanged);
-        updateParentChanged();
+
+        // This is for the case when the item's parent-relative position stays the same, but ancestors change position:
+        connect(this, &ViewBlockingRectangle::scenePositionHasChanged, this, &VideoSurface::updateSurfacePosition, Qt::QueuedConnection);
     }
 }
 
@@ -420,27 +421,3 @@ void VideoSurface::setVideoSurfaceProvider(VideoSurfaceProvider *newVideoSurface
 
     emit videoSurfaceProviderChanged();
 }
-
-void VideoSurface::updateParentChanged()
-{
-    //we need to track the global position of the VideoSurface within the scene
-    //it depends on the position of the VideoSurface itself and all its parents
-
-    for (const QPointer<QQuickItem>& p : m_parentList)
-    {
-        if (!p)
-            continue;
-        disconnect(p, &QQuickItem::xChanged, this, &VideoSurface::updateSurfacePosition);
-        disconnect(p, &QQuickItem::yChanged, this, &VideoSurface::updateSurfacePosition);
-        disconnect(p, &QQuickItem::parentChanged, this, &VideoSurface::updateParentChanged);
-    }
-    m_parentList.clear();
-
-    for (QQuickItem* p = parentItem(); p != nullptr; p = p->parentItem())
-    {
-        connect(p, &QQuickItem::xChanged, this, &VideoSurface::updateSurfacePosition);
-        connect(p, &QQuickItem::yChanged, this, &VideoSurface::updateSurfacePosition);
-        connect(p, &QQuickItem::parentChanged, this, &VideoSurface::updateParentChanged);
-        m_parentList.push_back(p);
-    }
-}


=====================================
modules/gui/qt/maininterface/videosurface.hpp
=====================================
@@ -148,8 +148,6 @@ protected slots:
     void updateSurfaceScale();
     void updateSurface();
 
-    void updateParentChanged();
-
 private:
     QPointF m_oldHoverPos;
 
@@ -157,8 +155,6 @@ private:
 
     QPointer<VideoSurfaceProvider> m_provider;
 
-    std::vector<QPointer<QQuickItem>> m_parentList;
-
     bool m_sizeDirty = false;
     bool m_positionDirty = false;
     bool m_scaleDirty = false;


=====================================
modules/gui/qt/widgets/native/viewblockingrectangle.cpp
=====================================
@@ -122,15 +122,23 @@ QSGNode *ViewBlockingRectangle::updatePaintNode(QSGNode *oldNode, UpdatePaintNod
 
     if (!oldNode)
     {
+        const auto observerNode = new MatrixChangeObserverNode([p = QPointer(this)]() {
+            if (Q_LIKELY(p))
+                emit p->scenePositionHasChanged();
+        });
+        observerNode->setFlag(QSGNode::OwnedByParent);
+
         if (softwareMode)
         {
             softwareRenderNode = new SoftwareRenderNode;
             softwareRenderNode->setWindow(window());
+            softwareRenderNode->appendChildNode(observerNode);
         }
         else
         {
             rectangleNode = window()->createRectangleNode();
             assert(rectangleNode);
+            rectangleNode->appendChildNode(observerNode);
 
             const auto material = rectangleNode->material();
             if (!material ||


=====================================
modules/gui/qt/widgets/native/viewblockingrectangle.hpp
=====================================
@@ -21,6 +21,37 @@
 
 #include <QQuickItem>
 #include <QColor>
+#include <QMatrix4x4>
+#include <QSGRenderNode>
+
+// WARNING: Do not use QSGTransformNode here with preprocess, Qt does not
+//          necessarily call preprocess when the combined matrix changes!
+class MatrixChangeObserverNode : public QSGRenderNode
+{
+public:
+    explicit MatrixChangeObserverNode(const std::function<void()>& callback)
+        : m_callback(callback) { }
+
+    void render(const RenderState *) override
+    {
+        assert(matrix());
+        const QMatrix4x4 m = *matrix(); // matrix() is the combined matrix here
+        if (m_lastCombinedMatrix != m)
+        {
+            m_callback();
+            m_lastCombinedMatrix = m;
+        }
+    }
+
+    RenderingFlags flags() const override
+    {
+        // Enable all optimizations, as we are not actually rendering anything in this node:
+        return static_cast<RenderingFlags>(BoundedRectRendering | DepthAwareRendering | OpaqueRendering | NoExternalRendering);
+    }
+private:
+    std::function<void()> m_callback;
+    QMatrix4x4 m_lastCombinedMatrix;
+};
 
 class ViewBlockingRectangle : public QQuickItem
 {
@@ -29,7 +60,7 @@ class ViewBlockingRectangle : public QQuickItem
     Q_PROPERTY(QColor color MEMBER m_color NOTIFY colorChanged FINAL)
 
 public:
-    ViewBlockingRectangle(QQuickItem *parent = nullptr);
+    explicit ViewBlockingRectangle(QQuickItem *parent = nullptr);
 
 protected:
     QSGNode *updatePaintNode(QSGNode *, UpdatePaintNodeData *) override;
@@ -39,6 +70,9 @@ private:
     bool m_windowChanged = false;
 
 signals:
+    // NOTE: `scenePositionHasChanged()` signal is emitted from the render thread,
+    //       and NOT during synchronization (meaning, GUI thread is not blocked):
+    void scenePositionHasChanged();
     void colorChanged();
 };
 



View it on GitLab: https://code.videolan.org/videolan/vlc/-/compare/484506e3cd39c6e5551eed440fbb25a174791cca...29793d55e1bbe9f2be97ae77bde48522164d8d7c

-- 
View it on GitLab: https://code.videolan.org/videolan/vlc/-/compare/484506e3cd39c6e5551eed440fbb25a174791cca...29793d55e1bbe9f2be97ae77bde48522164d8d7c
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