5 files changed, 43 insertions, 19 deletions
diff --git a/src/quick/scenegraph/coreapi/qsgbatchrenderer.cpp b/src/quick/scenegraph/coreapi/qsgbatchrenderer.cpp
index d45a0ea75d..bee2015007 100644
--- a/src/quick/scenegraph/coreapi/qsgbatchrenderer.cpp
+++ b/src/quick/scenegraph/coreapi/qsgbatchrenderer.cpp
@@ -2768,6 +2768,7 @@ struct RenderNodeState : public QSGRenderNode::RenderState
     bool scissorEnabled() const override { return m_scissorEnabled; }
     int stencilValue() const override { return m_stencilValue; }
     bool stencilEnabled() const override { return m_stencilEnabled; }
+    const QRegion *clipRegion() const override { return nullptr; }
 
     const QMatrix4x4 *m_projectionMatrix;
     QRect m_scissorRect;
diff --git a/src/quick/scenegraph/coreapi/qsgrendererinterface.cpp b/src/quick/scenegraph/coreapi/qsgrendererinterface.cpp
index 04e71441f6..fa543aecad 100644
--- a/src/quick/scenegraph/coreapi/qsgrendererinterface.cpp
+++ b/src/quick/scenegraph/coreapi/qsgrendererinterface.cpp
@@ -81,9 +81,10 @@ QT_BEGIN_NAMESPACE
 
 /*!
     \enum QSGRendererInterface::Resource
-    \value Device The graphics device
-    \value CommandQueue The graphics command queue used by the scenergaph
-    \value CommandList The command list or buffer used by the scenegraph
+    \value Device The graphics device, when applicable.
+    \value CommandQueue The graphics command queue used by the scenegraph, when applicable.
+    \value CommandList The command list or buffer used by the scenegraph, when applicable.
+    \value Painter The active QPainter used by the scenegraph, when running with the software backend.
  */
 
 /*!
@@ -134,10 +135,13 @@ QSGRendererInterface::~QSGRendererInterface()
     example, \c{VkDevice dev = *static_cast<VkDevice *>(result)}). The latter
     is necessary since such handles may have sizes different from a pointer.
 
+    \note The ownership of the returned pointer is never transferred to the caller.
+
     \note This function must only be called on the render thread.
  */
-void *QSGRendererInterface::getResource(Resource resource) const
+void *QSGRendererInterface::getResource(QQuickWindow *window, Resource resource) const
 {
+    Q_UNUSED(window);
     Q_UNUSED(resource);
     return nullptr;
 }
@@ -147,10 +151,13 @@ void *QSGRendererInterface::getResource(Resource resource) const
     allows supporting any future resources that are not listed in the
     Resource enum.
 
+    \note The ownership of the returned pointer is never transferred to the caller.
+
     \note This function must only be called on the render thread.
  */
-void *QSGRendererInterface::getResource(const char *resource) const
+void *QSGRendererInterface::getResource(QQuickWindow *window, const char *resource) const
 {
+    Q_UNUSED(window);
     Q_UNUSED(resource);
     return nullptr;
 }
diff --git a/src/quick/scenegraph/coreapi/qsgrendererinterface.h b/src/quick/scenegraph/coreapi/qsgrendererinterface.h
index 234a061d0e..a50b362aeb 100644
--- a/src/quick/scenegraph/coreapi/qsgrendererinterface.h
+++ b/src/quick/scenegraph/coreapi/qsgrendererinterface.h
@@ -44,6 +44,8 @@
 
 QT_BEGIN_NAMESPACE
 
+class QQuickWindow;
+
 class Q_QUICK_EXPORT QSGRendererInterface
 {
 public:
@@ -57,7 +59,8 @@ public:
     enum Resource {
         Device,
         CommandQueue,
-        CommandList
+        CommandList,
+        Painter
     };
 
     enum ShaderType {
@@ -83,8 +86,8 @@ public:
 
     virtual GraphicsApi graphicsApi() const = 0;
 
-    virtual void *getResource(Resource resource) const;
-    virtual void *getResource(const char *resource) const;
+    virtual void *getResource(QQuickWindow *window, Resource resource) const;
+    virtual void *getResource(QQuickWindow *window, const char *resource) const;
 
     virtual ShaderType shaderType() const = 0;
     virtual ShaderCompilationTypes shaderCompilationType() const = 0;
diff --git a/src/quick/scenegraph/coreapi/qsgrendernode.cpp b/src/quick/scenegraph/coreapi/qsgrendernode.cpp
index 29e8251cb2..365abd09e2 100644
--- a/src/quick/scenegraph/coreapi/qsgrendernode.cpp
+++ b/src/quick/scenegraph/coreapi/qsgrendernode.cpp
@@ -111,6 +111,10 @@ QSGRenderNodePrivate::QSGRenderNodePrivate()
     call related settings (root signature, descriptor heaps, etc.) are always
     set again by the scenegraph so render() can freely change them.
 
+    The software backend exposes its QPainter and saves and restores before and
+    after invoking render(). Therefore reporting any changed states from here
+    is not necessary.
+
     \note This function may be called before render().
   */
 QSGRenderNode::StateFlags QSGRenderNode::changedStates() const
@@ -125,17 +129,6 @@ QSGRenderNode::StateFlags QSGRenderNode::changedStates() const
     directly invoking commands in the graphics API (OpenGL, Direct3D, etc.)
     currently in use.
 
-    The states necessary for clipping has already been set before the function
-    is called. The clip is a combination of a stencil clip and scissor clip.
-    Information about the clip is found in \a state.
-
-    \note This means that setting viewport, scissor rectangle, stencil
-    reference value, and similar is not necessary in render() since the
-    corresponding commands are on the command list (or, in case of OpenGL, the
-    context) already. However, for APIs other than OpenGL stencil-based
-    clipping will need enabling stencil testing in the pipeline state that is
-    used by render().
-
     The effective opacity can be retrieved with \l inheritedOpacity().
 
     The projection matrix is available through \a state, while the model-view
@@ -156,6 +149,12 @@ QSGRenderNode::StateFlags QSGRenderNode::changedStates() const
     QQuickFramebufferObject, QQuickWindow::beforeRendering(), or the
     equivalents of those for APIs other than OpenGL.
 
+    Clip information is calculated before the function is called, it is however
+    not enabled. Implementations wishing to take clipping into account can set
+    up scissoring or stencil based on the information in \a state. Some
+    scenegraph backends, software in particular, use no scissor or stencil.
+    There the clip region is provided as an ordinary QRegion.
+
     For OpenGL the following states are set on the render thread's context
     before this function is called:
     \list
@@ -287,6 +286,19 @@ QSGRenderNode::RenderState::~RenderState()
  */
 
 /*!
+    \fn const QRegion *QSGRenderNode::clipRegion() const
+
+    \return the current clip region or null for backends where clipping is
+    implemented via stencil or scissoring.
+
+    The software backend uses no projection, scissor or stencil, meaning most
+    of the render state is not in use. However, the clip region that can be set
+    on the QPainter still has to be communicated since reconstructing this
+    manually in render() is not reasonable. It can therefore be queried via
+    this function.
+ */
+
+/*!
     \return pointer to a \a state value.
 
     Reserved for future use.
diff --git a/src/quick/scenegraph/coreapi/qsgrendernode.h b/src/quick/scenegraph/coreapi/qsgrendernode.h
index 17569f8c59..6eb425c03b 100644
--- a/src/quick/scenegraph/coreapi/qsgrendernode.h
+++ b/src/quick/scenegraph/coreapi/qsgrendernode.h
@@ -68,6 +68,7 @@ public:
         virtual bool scissorEnabled() const = 0;
         virtual int stencilValue() const = 0;
         virtual bool stencilEnabled() const = 0;
+        virtual const QRegion *clipRegion() const = 0;
         virtual void *get(const char *state) const;
     };