Create sub OpenGLWindowPixmap for sub-surfaces

scene_opengl.cpp

@@ -1655,6 +1655,14 @@ void SceneOpenGL2Window::performPaint(int mask, QRegion region, WindowPaintData
 OpenGLWindowPixmap::OpenGLWindowPixmap(Scene::Window *window, SceneOpenGL* scene)
     : WindowPixmap(window)
     , m_texture(scene->createTexture())
+    , m_scene(scene)
+{
+}
+
+OpenGLWindowPixmap::OpenGLWindowPixmap(const QPointer<KWayland::Server::SubSurfaceInterface> &subSurface, WindowPixmap *parent, SceneOpenGL *scene)
+    : WindowPixmap(subSurface, parent)
+    , m_texture(scene->createTexture())
+    , m_scene(scene)
 {
 }
 
@@ -1665,28 +1673,53 @@ OpenGLWindowPixmap::~OpenGLWindowPixmap()
 bool OpenGLWindowPixmap::bind()
 {
     if (!m_texture->isNull()) {
-        if (!toplevel()->damage().isEmpty()) {
+        // always call updateBuffer to get the sub-surface tree updated
+        if (subSurface().isNull() && !toplevel()->damage().isEmpty()) {
             updateBuffer();
+        }
+        auto s = surface();
+        if (s && !s->trackedDamage().isEmpty()) {
             m_texture->updateFromPixmap(this);
             // mipmaps need to be updated
             m_texture->setDirty();
+        }
+        if (subSurface().isNull()) {
             toplevel()->resetDamage();
         }
+        // also bind all children
+        for (auto it = children().constBegin(); it != children().constEnd(); ++it) {
+            static_cast<OpenGLWindowPixmap*>(*it)->bind();
+        }
         return true;
     }
+    // also bind all children, needs to be done before checking isValid
+    // as there might be valid children to render, see https://bugreports.qt.io/browse/QTBUG-52192
+    if (subSurface().isNull()) {
+        updateBuffer();
+    }
+    for (auto it = children().constBegin(); it != children().constEnd(); ++it) {
+        static_cast<OpenGLWindowPixmap*>(*it)->bind();
+    }
     if (!isValid()) {
         return false;
     }
 
     bool success = m_texture->load(this);
 
-    if (success)
-        toplevel()->resetDamage();
-    else
+    if (success) {
+        if (subSurface().isNull()) {
+            toplevel()->resetDamage();
+        }
+    } else
         qCDebug(KWIN_CORE) << "Failed to bind window";
     return success;
 }
 
+WindowPixmap *OpenGLWindowPixmap::createChild(const QPointer<KWayland::Server::SubSurfaceInterface> &subSurface)
+{
+    return new OpenGLWindowPixmap(subSurface, this, m_scene);
+}
+
 //****************************************
 // SceneOpenGL::EffectFrame
 //****************************************

scene_opengl.h

@@ -274,8 +274,12 @@ public:
     virtual ~OpenGLWindowPixmap();
     SceneOpenGL::Texture *texture() const;
     bool bind();
+protected:
+    WindowPixmap *createChild(const QPointer<KWayland::Server::SubSurfaceInterface> &subSurface) override;
 private:
+    explicit OpenGLWindowPixmap(const QPointer<KWayland::Server::SubSurfaceInterface> &subSurface, WindowPixmap *parent, SceneOpenGL *scene);
     QScopedPointer<SceneOpenGL::Texture> m_texture;
+    SceneOpenGL *m_scene;
 };
 
 class SceneOpenGL::EffectFrame

scene_qpainter.cpp

@@ -265,7 +265,7 @@ void SceneQPainter::Window::performPaint(int mask, QRegion region, WindowPaintDa
         return;
     }
     if (!toplevel->damage().isEmpty()) {
-        pixmap->update();
+        pixmap->updateBuffer();
         toplevel->resetDamage();
     }
 
@@ -453,6 +453,9 @@ void QPainterWindowPixmap::create()
     }
     // performing deep copy, this could probably be improved
     m_image = buffer()->data().copy();
+    if (auto s = surface()) {
+        s->resetTrackedDamage();
+    }
 }
 
 WindowPixmap *QPainterWindowPixmap::createChild(const QPointer<KWayland::Server::SubSurfaceInterface> &subSurface)
@@ -474,18 +477,9 @@ void QPainterWindowPixmap::updateBuffer()
     }
     // perform deep copy
     m_image = b->data().copy();
-}
-
-bool QPainterWindowPixmap::update()
-{
-    // TODO: there is lots of things which can be removed here
-    const auto oldBuffer = buffer();
-    updateBuffer();
-    const auto &b = buffer();
-    if (b == oldBuffer || b.isNull()) {
-        return false;
+    if (auto s = surface()) {
+        s->resetTrackedDamage();
     }
-    return true;
 }
 
 QPainterEffectFrame::QPainterEffectFrame(EffectFrameImpl *frame, SceneQPainter *scene)

scene_qpainter.h

@@ -156,12 +156,11 @@ public:
     virtual ~QPainterWindowPixmap();
     virtual void create() override;
 
-    bool update();
+    void updateBuffer() override;
     const QImage &image();
 
 protected:
     WindowPixmap *createChild(const QPointer<KWayland::Server::SubSurfaceInterface> &subSurface) override;
-    void updateBuffer() override;
 private:
     explicit QPainterWindowPixmap(const QPointer<KWayland::Server::SubSurfaceInterface> &subSurface, WindowPixmap *parent);
     QImage m_image;