Squashed commit of the following:

commit 84b7cb31a62edee3ceae702ce52be68cbe222f8a
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Tue Dec 19 12:30:23 2023 +0100

    wip

commit 07c4b93e0611298e5e3981017c988fc7e45b6977
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Tue Dec 19 12:21:55 2023 +0100

    wip

commit 019448f5e1ea6eed7b767f09ae7fdb0802928a98
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Tue Dec 19 12:01:01 2023 +0100

    wip

commit b79f5cba8abc50bd487f08480a62d5c8bcc3c148
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Tue Dec 19 11:50:55 2023 +0100

    wip

commit 942291edb6016f29fb2f5c786b84fb7defa10ae2
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Tue Dec 19 11:23:28 2023 +0100

    wip

commit 5ae203a03a8413416f723155bf364190937929da
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Tue Dec 19 11:23:16 2023 +0100

    wip

commit b5b4453be94c9bdc6655370c949b096061ad1c3a
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Tue Dec 19 11:04:15 2023 +0100

    wip

commit cd519b840c6436bdec74a6a92cc5ba69a3f162de
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Tue Dec 19 10:50:13 2023 +0100

    wip

commit 9daed04a2c1dde10340764b6ea7769598edeff3d
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Tue Dec 19 09:46:10 2023 +0100

    wip

commit c6190b84dde26b4e2790f8154ed3d81db4630b3b
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Tue Dec 19 09:34:28 2023 +0100

    wip

commit 837b14e8f688a29aa3294eaaa0c0dbfe66f95dce
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Tue Dec 19 09:23:01 2023 +0100

    wip

commit 6486c343a8cfa2a56370f20374939180b576ce2a
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Tue Dec 19 08:41:40 2023 +0100

    wip

commit 230aca347b97c0a1bdb75fad6d52153688941aa6
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Tue Dec 19 08:37:56 2023 +0100

    wip

commit ec4018de7e8d1940a2e693e9e8183413e02f06c2
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Tue Dec 19 08:33:22 2023 +0100

    wip

commit bc3480a01f34d2e92b2445f5e73c0f12262f63a0
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Tue Dec 19 08:30:41 2023 +0100

    wip

commit dd896518938f7828f3bc5b5275fccb90d34b08a3
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Tue Dec 19 07:50:13 2023 +0100

    wip

commit c534c54ff8af674a45669bc4b688f3a28448a055
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Tue Dec 19 07:07:19 2023 +0100

    wip

commit bd7af3f28e8a1a79590acb9be41e0ac9046f1fbc
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Mon Dec 18 17:50:34 2023 +0100

    wip

commit 639926d3beccdc49aa98db5fe53f5eb70694a763
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Mon Dec 18 17:48:16 2023 +0100

    wip

commit b74c790aa15a23cf3d5875f6280407170d2113bb
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Mon Dec 18 17:35:51 2023 +0100

    wip

commit 1403da5a05c5782567b8e34e9a6672e041b483ed
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Mon Dec 18 16:52:45 2023 +0100

    wip

commit 74d69d44fc8876d95d25c1e5ab96dcf416f93a0e
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Mon Dec 18 16:04:22 2023 +0100

    wip

commit 81269cab9a4a2f07b86442c0b5524b0364909124
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Mon Dec 18 15:50:08 2023 +0100

    wip

commit a4f0b8c98960155ee8174e0b5253affc73881158
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Mon Dec 18 15:49:54 2023 +0100

    wip

commit fc9c5f032671d9b2b8798c97e3803ef8cb98e647
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Mon Dec 18 15:39:34 2023 +0100

    wip

commit 2ca8789fed5ee98355662933fed04e8ed9b5e164
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Mon Dec 18 15:28:53 2023 +0100

    wip

commit 3a325b6dab6ee558d6d0407c4e7c639575da4f6d
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Mon Dec 18 15:24:42 2023 +0100

    wip

commit 102f872db8a158274de674230f23573f941bed23
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Mon Dec 18 15:22:26 2023 +0100

    wip

commit 829eb67b0e6351e77f702acab90705f3cb3e9b4a
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Mon Dec 18 14:39:31 2023 +0100

    wip

commit 5f89fc9257fdbd169c5f80d6776aa707848dd5c3
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Mon Dec 18 14:18:18 2023 +0100

    wip

commit 4b9e2964c3cc3d4b08e55e98ea5b7b06b169b5f2
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Mon Dec 18 13:21:48 2023 +0100

    wip

commit 8c94d26ed98d906a010401d7357e45249d9b11e8
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Mon Dec 18 12:42:51 2023 +0100

    wip

commit 096180f6034f93725ebc9d97b8934dcca6e4b41d
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Mon Dec 18 12:15:04 2023 +0100

    wip

commit f9f794a19e9b9d6455793a6c61c26e5e1d0e12e0
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Mon Dec 18 11:34:07 2023 +0100

    wip

commit 8b5a8c859503b3b155737b975fb344b2dc87bf94
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Mon Dec 18 11:32:03 2023 +0100

    wip

commit 67f78561f3bae7c4a779d75921cfabbebf802f9b
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Mon Dec 18 11:29:32 2023 +0100

    wip

commit ad6515a95ea6803698f76c221c10f4160e82a668
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Mon Dec 18 11:19:28 2023 +0100

    wip

commit 2e719e809f29f07dc38ae2f3213e10bbb730c968
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Mon Dec 18 11:16:43 2023 +0100

    wip

commit 2212e09f165130e1621df564aa37bdbefe7377db
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Mon Dec 18 11:16:00 2023 +0100

    wip

commit 171aae01c802ad10ad268e35da3dcd33fc6c2b6c
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Mon Dec 18 10:52:06 2023 +0100

    wip

commit ab117a43f0a405f4c09f1c395ab215bbcb09a57e
Author: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date:   Mon Dec 18 10:47:41 2023 +0100

    wip

playground/CMakeLists.txt

@@ -7,10 +7,7 @@ add_subdirectory(shadows)
 add_subdirectory(shapes)
 add_subdirectory(charts)
 add_subdirectory(plots)
-
+add_subdirectory(parrots)
-if (QT_VERSION_MAJOR VERSION_GREATER 5)
-    add_subdirectory(parrots)
-endif()
 
 if (BUILD_INPUTCONTEXT)
     add_subdirectory(inputpanel)

playground/parrots/Overlay.cpp

@@ -7,12 +7,12 @@
 #include "TextureFilterNode.h"
 
 #include <QskSkinlet.h>
-#include <QskSceneTexture.h>
 #include <QskQuick.h>
 #include <QskBoxShapeMetrics.h>
 #include <QskBoxBorderMetrics.h>
 #include <QskBoxBorderColors.h>
 #include <QskGradient.h>
+#include <QskSceneTexture.h>
 #include <QskSGNode.h>
 #include <QskRgbValue.h>
 

playground/parrots/TextureFilterNode.cpp

@@ -42,8 +42,12 @@ namespace
             return &staticType;
         }
 
+#if QT_VERSION < QT_VERSION_CHECK( 6, 0, 0 )
+        QSGMaterialShader* createShader() const override;
+#else
         QSGMaterialShader* createShader(
             QSGRendererInterface::RenderMode ) const override;
+#endif
 
         QSGTexture* texture = nullptr;
     };
@@ -51,6 +55,53 @@ namespace
 
 namespace
 {
+#if QT_VERSION < QT_VERSION_CHECK( 6, 0, 0 )
+    class MaterialShaderGL : public QSGMaterialShader
+    {
+      public:
+        MaterialShaderGL()
+        {
+            setShaderSourceFile( QOpenGLShader::Vertex, ":/shaders/blur.vert" );
+            setShaderSourceFile( QOpenGLShader::Fragment, ":/shaders/blur.frag" );
+        }
+
+        char const* const* attributeNames() const override
+        {
+            static char const* const names[] = { "in_vertex", "in_coord", nullptr };
+            return names;
+        }
+
+       void initialize() override
+        {
+            QSGMaterialShader::initialize();
+
+            auto p = program();
+
+            m_matrixId = p->uniformLocation( "matrix" );
+            m_opacityId = p->uniformLocation( "opacity" );
+        }
+
+       void updateState( const QSGMaterialShader::RenderState& state,
+            QSGMaterial* newMaterial, QSGMaterial* ) override
+        {
+            auto p = program();
+
+            if ( state.isMatrixDirty() )
+                p->setUniformValue( m_matrixId, state.combinedMatrix() );
+
+            if ( state.isOpacityDirty() )
+                p->setUniformValue( m_opacityId, state.opacity() );
+
+            auto material = static_cast< Material* >( newMaterial );
+            if ( material->texture )
+                material->texture->bind();
+        }
+
+      private:
+        int m_matrixId = -1;
+        int m_opacityId = -1;
+    };
+#else
     class MaterialShader : public QSGMaterialShader
     {
       public:
@@ -114,14 +165,26 @@ namespace
             }
         }
     };
+#endif
 }
 
+#if QT_VERSION < QT_VERSION_CHECK( 6, 0, 0 )
+QSGMaterialShader* Material::createShader() const
+{
+    Q_ASSERT( !( flags() & QSGMaterial::RhiShaderWanted ) );
+    return new MaterialShaderGL();
+}
+
+#else
+
 QSGMaterialShader* Material::createShader(
     QSGRendererInterface::RenderMode ) const
 {
     return new MaterialShader();
 }
 
+#endif
+
 class TextureFilterNodePrivate final : public QSGGeometryNodePrivate
 {
   public:
@@ -152,6 +215,7 @@ TextureFilterNode::~TextureFilterNode()
 void TextureFilterNode::setTexture( QSGTexture* texture )
 {
     d_func()->material.texture = texture;
+    markDirty( QSGNode::DirtyMaterial );
 }
 
 QSGTexture* TextureFilterNode::texture()

playground/parrots/TextureFilterNode.h

@@ -23,6 +23,11 @@ class TextureFilterNode : public QSGGeometryNode
     void setTexture( QSGTexture* );
     QSGTexture* texture();
 
+#if 0
+    // deriving from QSGImageNode ???
+    void setOwnsTexture( bool );
+    bool ownsTexture() const;
+#endif
     void setRect( const QRectF& );
 
   private:

src/CMakeLists.txt

@@ -120,6 +120,7 @@ list(APPEND HEADERS
     nodes/QskPaintedNode.h
     nodes/QskPlainTextRenderer.h
     nodes/QskRichTextRenderer.h
+    nodes/QskSceneTexture.h
     nodes/QskSGNode.h
     nodes/QskStrokeNode.h
     nodes/QskStippledLineRenderer.h
@@ -157,6 +158,7 @@ list(APPEND SOURCES
     nodes/QskPlainTextRenderer.cpp
     nodes/QskRectangleNode.cpp
     nodes/QskRichTextRenderer.cpp
+    nodes/QskSceneTexture.cpp
     nodes/QskSGNode.cpp
     nodes/QskStrokeNode.cpp
     nodes/QskStippledLineRenderer.cpp
@@ -169,11 +171,6 @@ list(APPEND SOURCES
     nodes/QskVertex.cpp
 )
 
-if (QT_VERSION_MAJOR VERSION_GREATER 5)
-    list(APPEND HEADERS nodes/QskSceneTexture.h)
-    list(APPEND SOURCES nodes/QskSceneTexture.cpp)
-endif()
-
 qt_add_resources(SOURCES nodes/shaders.qrc)
 
 list(APPEND HEADERS

src/nodes/QskSceneTexture.cpp

@@ -10,11 +10,21 @@
 
 QSK_QT_PRIVATE_BEGIN
 #include <private/qquickwindow_p.h>
+#include <private/qsgtexture_p.h>
+
+#define QT_BUILD_QUICK_LIB // suppress Qt5 warnings
 #include <private/qsgbatchrenderer_p.h>
+#undef QT_BUILD_QUICK_LIB
+
 QSK_QT_PRIVATE_END
 
+#if QT_VERSION < QT_VERSION_CHECK( 6, 0, 0 )
+#include <qopenglframebufferobject.h>
+#endif
+
 namespace
 {
+#if QT_VERSION >= QT_VERSION_CHECK( 6, 0, 0 )
     inline QSGRendererInterface::RenderMode contextRenderMode(
         QSGDefaultRenderContext* context )
     {
@@ -22,6 +32,7 @@ namespace
             ? QSGRendererInterface::RenderMode2D
             : QSGRendererInterface::RenderMode2DNoDepthBuffer;
     }
+#endif
 
     class Renderer final : public QSGBatchRenderer::Renderer
     {
@@ -31,8 +42,14 @@ namespace
         Renderer( QskSceneTexture*, QSGDefaultRenderContext* );
         ~Renderer() override;
 
+#if QT_VERSION < QT_VERSION_CHECK( 6, 0, 0 )
+        inline int textureId() const { return m_fbo ? m_fbo->texture() : 0; }
+        inline void renderScene() { Inherited::renderScene( textureId() ); }
+#else
+        inline QRhiTexture* texture() const { return m_rhiTexture; }
+#endif
+
         void setFinalNode( QSGTransformNode* );
-        QRhiTexture* texture() const { return m_rhiTexture; }
 
         void setProjection( const QRectF& );
         void setTextureSize( const QSize& );
@@ -45,15 +62,22 @@ namespace
         void createTarget( const QSize& );
         void clearTarget();
 
-      private:
-        QRhiTexture* m_rhiTexture = nullptr;
         QSGTransformNode* m_finalNode = nullptr;
-
         QskSceneTexture* m_texture = nullptr;
+
+#if QT_VERSION < QT_VERSION_CHECK( 6, 0, 0 )
+        QOpenGLFramebufferObject* m_fbo;
+#else
+        QRhiTexture* m_rhiTexture = nullptr;
+#endif
     };
 
     Renderer::Renderer( QskSceneTexture* texture, QSGDefaultRenderContext* context )
+#if QT_VERSION < QT_VERSION_CHECK( 6, 0, 0 )
+        : Inherited( context )
+#else
         : Inherited( context, contextRenderMode( context ) )
+#endif
         , m_texture( texture )
     {
         setClearColor( Qt::transparent );
@@ -74,11 +98,17 @@ namespace
 
     void Renderer::setProjection( const QRectF& rect )
     {
-        const auto rhi = context()->rhi();
+#if QT_VERSION < QT_VERSION_CHECK( 6, 0, 0 )
+        const bool flipFramebuffer = true;
+        const bool flipMatrix = false;
+#else
+        const bool flipFramebuffer = rhi->isYUpInFramebuffer();
+        const bool flipMatrix = rhi->isYUpInNDC();
+#endif
 
         auto r = rect;
 
-        if ( rhi->isYUpInFramebuffer() )
+        if ( flipFramebuffer )
         {
             r.moveTop( r.bottom() );
             r.setHeight( -r.height() );
@@ -86,7 +116,7 @@ namespace
 
         MatrixTransformFlags matrixFlags;
 
-        if ( !rhi->isYUpInNDC() )
+        if ( flipMatrix )
             matrixFlags |= QSGAbstractRenderer::MatrixTransformFlipY;
 
         setProjectionMatrixToRect( r, matrixFlags );
@@ -94,11 +124,19 @@ namespace
 
     void Renderer::setTextureSize( const QSize& size )
     {
+#if QT_VERSION < QT_VERSION_CHECK( 6, 0, 0 )
+        if ( m_fbo && m_fbo->size() != size )
+            clearTarget();
+
+        if ( m_fbo == nullptr )
+            createTarget( size );
+#else
         if ( m_rt.rt && m_rt.rt->pixelSize() != size )
             clearTarget();
 
         if ( m_rt.rt == nullptr )
             createTarget( size );
+#endif
 
         const QRect r( 0, 0, size.width(), size.height() );
 
@@ -131,6 +169,14 @@ namespace
 
     void Renderer::createTarget( const QSize& size )
     {
+#if QT_VERSION < QT_VERSION_CHECK( 6, 0, 0 )
+        QOpenGLFramebufferObjectFormat format;
+        format.setInternalTextureFormat( GL_RGBA8 );
+        format.setSamples( 0 );
+        format.setAttachment( QOpenGLFramebufferObject::CombinedDepthStencil );
+
+        m_fbo = new QOpenGLFramebufferObject( size, format );
+#else
         const auto rhi = context()->rhi();
 
         auto flags = QRhiTexture::RenderTarget | QRhiTexture::UsedAsTransferSource;
@@ -151,10 +197,15 @@ namespace
 
         auto defaultContext = qobject_cast< QSGDefaultRenderContext* >( context() );
         m_rt.cb = defaultContext->currentFrameCommandBuffer();
+#endif
     }
 
     void Renderer::clearTarget()
     {
+#if QT_VERSION < QT_VERSION_CHECK( 6, 0, 0 )
+        delete m_fbo;
+        m_fbo = nullptr;
+#else
         delete m_rt.rt;
         m_rt.rt = nullptr;
 
@@ -163,6 +214,7 @@ namespace
 
         delete m_rhiTexture;
         m_rhiTexture = nullptr;
+#endif
     }
 }
 
@@ -170,11 +222,18 @@ class QskSceneTexturePrivate final : public QSGTexturePrivate
 {
   public:
     QskSceneTexturePrivate( const QQuickWindow* window, QskSceneTexture* texture )
+#if QT_VERSION < QT_VERSION_CHECK( 6, 0, 0 )
+        : QSGTexturePrivate()
+#else
         : QSGTexturePrivate( texture )
+#endif
         , devicePixelRatio( window->effectiveDevicePixelRatio() )
     {
-        context = dynamic_cast< QSGDefaultRenderContext* >(
+        Q_UNUSED( texture );
-            QQuickWindowPrivate::get( window )->context );
+
+        // Qt5 needs the extra const_cast
+        auto dw = QQuickWindowPrivate::get( const_cast< QQuickWindow* >( window ) );
+        context = dynamic_cast< QSGDefaultRenderContext* >( dw->context );
     }
 
     QRectF rect;
@@ -185,7 +244,7 @@ class QskSceneTexturePrivate final : public QSGTexturePrivate
 };
 
 QskSceneTexture::QskSceneTexture( const QQuickWindow* window )
-    : Inherited(*( new QskSceneTexturePrivate( window, this ) ) )
+    : Inherited( *new QskSceneTexturePrivate( window, this ) )
 {
     Q_ASSERT( d_func()->context );
 }
@@ -213,17 +272,6 @@ QSize QskSceneTexture::textureSize() const
     return size;
 }
 
-qint64 QskSceneTexture::comparisonKey() const
-{
-    return qint64( rhiTexture() );
-}
-
-QRhiTexture* QskSceneTexture::rhiTexture() const
-{
-    Q_D( const QskSceneTexture );
-    return d->renderer ? d->renderer->texture() : nullptr;
-}
-
 void QskSceneTexture::render( const QSGRootNode* rootNode,
     const QSGTransformNode* finalNode, const QRectF& rect )
 {
@@ -231,8 +279,6 @@ void QskSceneTexture::render( const QSGRootNode* rootNode,
 
     d->rect = rect;
 
-    const auto pixelSize = textureSize();
-
     if ( d->renderer == nullptr )
     {
         d->renderer = new Renderer( this, d->context );
@@ -243,7 +289,7 @@ void QskSceneTexture::render( const QSGRootNode* rootNode,
     d->renderer->setFinalNode( const_cast< QSGTransformNode* >( finalNode ) );
 
     d->renderer->setProjection( d->rect );
-    d->renderer->setTextureSize( pixelSize );
+    d->renderer->setTextureSize( textureSize() );
     d->renderer->renderScene();
 }
 
@@ -262,9 +308,35 @@ bool QskSceneTexture::hasMipmaps() const
     return false;
 }
 
-void QskSceneTexture::commitTextureOperations( QRhi*, QRhiResourceUpdateBatch* )
+#if QT_VERSION < QT_VERSION_CHECK( 6, 0, 0 )
+
+void QskSceneTexture::bind()
 {
-    // what to do here ?
+    auto funcs = QOpenGLContext::currentContext()->functions();
+    funcs->glBindTexture( GL_TEXTURE_2D, textureId() );
+
+    updateBindOptions();
 }
 
+int QskSceneTexture::textureId() const
+{
+    Q_D( const QskSceneTexture );
+    return d->renderer ? d->renderer->textureId() : 0;
+}
+
+#else
+
+qint64 QskSceneTexture::comparisonKey() const
+{
+    return qint64( rhiTexture() );
+}
+
+QRhiTexture* QskSceneTexture::rhiTexture() const
+{
+    Q_D( const QskSceneTexture );
+    return d->renderer ? d->renderer->texture() : nullptr;
+}
+
+#endif
+
 #include "moc_QskSceneTexture.cpp"

src/nodes/QskSceneTexture.h

@@ -29,15 +29,19 @@ class QSK_EXPORT QskSceneTexture : public QSGTexture
 
     QSize textureSize() const override;
 
+#if QT_VERSION < QT_VERSION_CHECK( 6, 0, 0 )
+    void bind() override;
+    int textureId() const override;
+#else
     qint64 comparisonKey() const override;
     QRhiTexture* rhiTexture() const override;
+#endif
 
     QRectF normalizedTextureSubRect() const override;
 
     // satisfy the QSGTexture API
     bool hasAlphaChannel() const override;
     bool hasMipmaps() const override;
-    void commitTextureOperations( QRhi*, QRhiResourceUpdateBatch* ) override;
 
   Q_SIGNALS:
     void updateRequested();