diff --git a/examples/frames/Frame.cpp b/examples/frames/Frame.cpp
index 4c89f3d33..88c11bb71 100644
--- a/examples/frames/Frame.cpp
+++ b/examples/frames/Frame.cpp
@@ -150,7 +150,7 @@ void Frame::updateFrameNode( const QRectF& rect, QskBoxRectangleNode* node )
     const QskBoxBorderColors borderColors( c1, c1, c2, c2 );
     const qreal radius = effectiveRadius( rect, m_radius );
 
-    node->updateBox( rect, radius, m_frameWidth, borderColors, m_color );
+    node->updateBox( window(), rect, radius, m_frameWidth, borderColors, m_color );
 }
 
 #include "moc_Frame.cpp"
diff --git a/examples/iotdashboard/DiagramSkinlet.cpp b/examples/iotdashboard/DiagramSkinlet.cpp
index 5e2ab79fb..4287bcf11 100644
--- a/examples/iotdashboard/DiagramSkinlet.cpp
+++ b/examples/iotdashboard/DiagramSkinlet.cpp
@@ -173,7 +173,7 @@ QSGNode* DiagramSkinlet::updateChartNode( const Diagram* diagram, QSGNode* node
                         color = diagram->color( barSubcontrol );
 
                         const auto shape = diagram->boxShapeHint( barSubcontrol );
-                        barNode->updateFilling( barRect, shape, color );
+                        barNode->updateFilling( diagram->window(), barRect, shape, color );
                     }
                 }
                 else
diff --git a/playground/gradients/GradientView.cpp b/playground/gradients/GradientView.cpp
index 78d90fedb..2804cbbee 100644
--- a/playground/gradients/GradientView.cpp
+++ b/playground/gradients/GradientView.cpp
@@ -166,7 +166,7 @@ QSGNode* GradientView::updatePaintNode(
         {
             auto node = gradientNode< QskBoxRectangleNode >( oldNode );
             node->setHint( QskFillNode::PreferColoredGeometry, false );
-            node->updateFilling( rect, shape, m_gradient );
+            node->updateFilling( window(), rect, shape, m_gradient );
 
             return node;
         }
@@ -174,7 +174,7 @@ QSGNode* GradientView::updatePaintNode(
         {
             auto node = gradientNode< QskBoxRectangleNode >( oldNode );
             node->setHint( QskFillNode::PreferColoredGeometry, true );
-            node->updateFilling( rect, shape, m_gradient );
+            node->updateFilling( window(), rect, shape, m_gradient );
 
             return node;
         }
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 151ed18fd..0c8fa8250 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -111,7 +111,6 @@ list(APPEND HEADERS
     nodes/QskBoxMetrics.h
     nodes/QskBoxBasicStroker.h
     nodes/QskBoxGradientStroker.h
-    nodes/QskBoxColorMap.h
     nodes/QskBoxShadowNode.h
     nodes/QskColorRamp.h
     nodes/QskFillNode.h
@@ -133,6 +132,7 @@ list(APPEND HEADERS
     nodes/QskTextRenderer.h
     nodes/QskTextureRenderer.h
     nodes/QskVertex.h
+    nodes/QskVertexHelper.h
 )
 
 list(APPEND PRIVATE_HEADERS
diff --git a/src/controls/QskSkinlet.cpp b/src/controls/QskSkinlet.cpp
index 7befc8377..33a9661f8 100644
--- a/src/controls/QskSkinlet.cpp
+++ b/src/controls/QskSkinlet.cpp
@@ -196,26 +196,37 @@ static inline QskTextColors qskTextColors(
     return c;
 }
 
+static inline QQuickWindow* qskWindowOfSkinnable( const QskSkinnable* skinnable )
+{
+    if ( auto item = skinnable->owningItem() )
+        return item->window();
+
+    return nullptr;
+}
+
 static inline QSGNode* qskUpdateBoxNode(
-    const QskSkinnable*, QSGNode* node, const QRectF& rect,
+    const QskSkinnable* skinnable, QSGNode* node, const QRectF& rect,
     const QskBoxShapeMetrics& shape, const QskBoxBorderMetrics& borderMetrics,
     const QskBoxBorderColors& borderColors, const QskGradient& gradient,
     const QskShadowMetrics& shadowMetrics, const QColor& shadowColor )
 {
-    if ( rect.isEmpty() )
-        return nullptr;
-
-    if ( !qskIsBoxVisible( borderMetrics, borderColors, gradient )
-        && !qskIsShadowVisible( shadowMetrics, shadowColor ) )
+    if ( !rect.isEmpty() )
     {
-        return nullptr;
-    }
+        if ( qskIsBoxVisible( borderMetrics, borderColors, gradient )
+            || qskIsShadowVisible( shadowMetrics, shadowColor ) )
+        {
+            if ( auto window = qskWindowOfSkinnable( skinnable ) )
+            {
+                auto boxNode = QskSGNode::ensureNode< QskBoxNode >( node );
+                boxNode->updateNode( window, rect, shape, borderMetrics,
+                    borderColors, gradient, shadowMetrics, shadowColor );
 
-    auto boxNode = QskSGNode::ensureNode< QskBoxNode >( node );
-    boxNode->updateNode( rect, shape, borderMetrics,
-        borderColors, gradient, shadowMetrics, shadowColor );
+                return boxNode;
+            }
+        }
+    }
 
-    return boxNode;
+    return nullptr;
 }
 
 static inline QSGNode* qskUpdateArcNode(
@@ -373,7 +384,7 @@ QSGNode* QskSkinlet::updateBackgroundNode(
         return nullptr;
 
     auto rectNode = QskSGNode::ensureNode< QskBoxRectangleNode >( node );
-    rectNode->updateFilling( rect, gradient );
+    rectNode->updateFilling( control->window(), rect, gradient );
 
     return rectNode;
 }
@@ -648,7 +659,8 @@ QSGNode* QskSkinlet::updateBoxClipNode( const QskSkinnable* skinnable,
         auto shape = skinnable->boxShapeHint( subControl );
         shape = shape.toAbsolute( clipRect.size() );
 
-        clipNode->setBox( clipRect, shape, borderMetrics );
+        const auto window = qskWindowOfSkinnable( skinnable );
+        clipNode->setBox( window, clipRect, shape, borderMetrics );
     }
 
     return clipNode;
diff --git a/src/nodes/QskArcRenderer.cpp b/src/nodes/QskArcRenderer.cpp
index 02e843f9c..72f644401 100644
--- a/src/nodes/QskArcRenderer.cpp
+++ b/src/nodes/QskArcRenderer.cpp
@@ -7,7 +7,7 @@
 #include "QskArcMetrics.h"
 #include "QskGradient.h"
 #include "QskVertex.h"
-#include "QskBoxColorMap.h"
+#include "QskVertexHelper.h"
 #include "QskRgbValue.h"
 
 #include <qsggeometry.h>
@@ -359,7 +359,7 @@ namespace
     void Renderer::renderLines( const LineStroker& lineStroker,
         Line* fillLines, Line* borderLines ) const
     {
-        QskBoxRenderer::GradientIterator it;
+        QskVertex::GradientIterator it;
 
         if ( fillLines )
         {
diff --git a/src/nodes/QskBoxBasicStroker.cpp b/src/nodes/QskBoxBasicStroker.cpp
index b893428ae..0221e3b9f 100644
--- a/src/nodes/QskBoxBasicStroker.cpp
+++ b/src/nodes/QskBoxBasicStroker.cpp
@@ -4,7 +4,6 @@
  *****************************************************************************/
 
 #include "QskBoxBasicStroker.h"
-#include "QskBoxColorMap.h"
 
 namespace
 {
@@ -144,7 +143,7 @@ namespace
     {
       public:
         inline FillMap( const QskBoxMetrics& metrics,
-                const QskBoxRenderer::ColorMap& colorMap )
+                const QskVertex::ColorMap& colorMap )
             : m_colorMap( colorMap )
             , m_corners( metrics.corners )
         {
@@ -184,7 +183,7 @@ namespace
             m_colorMap.setLine( x1, y1, x2, y2, line );
         }
 
-        const QskBoxRenderer::ColorMap& m_colorMap;
+        const QskVertex::ColorMap& m_colorMap;
         const QskBoxMetrics::Corner* m_corners;
     };
 }
@@ -379,12 +378,12 @@ QskBoxBasicStroker::QskBoxBasicStroker( const QskBoxMetrics& metrics )
 
 QskBoxBasicStroker::QskBoxBasicStroker( const QskBoxMetrics& metrics,
         const QskBoxBorderColors& borderColors )
-    : QskBoxBasicStroker( metrics, borderColors, QskBoxRenderer::ColorMap() )
+    : QskBoxBasicStroker( metrics, borderColors, QskVertex::ColorMap() )
 {
 }
 
 QskBoxBasicStroker::QskBoxBasicStroker( const QskBoxMetrics& metrics,
-        const QskBoxBorderColors& borderColors, const QskBoxRenderer::ColorMap& colorMap )
+        const QskBoxBorderColors& borderColors, const QskVertex::ColorMap& colorMap )
     : m_metrics( metrics )
     , m_borderColors( borderColors )
     , m_colorMap( colorMap )
diff --git a/src/nodes/QskBoxBasicStroker.h b/src/nodes/QskBoxBasicStroker.h
index b43e9fbcd..f65713dd6 100644
--- a/src/nodes/QskBoxBasicStroker.h
+++ b/src/nodes/QskBoxBasicStroker.h
@@ -8,7 +8,7 @@
 
 #include "QskBoxMetrics.h"
 #include "QskBoxBorderColors.h"
-#include "QskBoxColorMap.h"
+#include "QskVertexHelper.h"
 
 class QskBoxShapeMetrics;
 class QskBoxBorderMetrics;
@@ -25,7 +25,7 @@ class QskBoxBasicStroker
     QskBoxBasicStroker( const QskBoxMetrics& );
     QskBoxBasicStroker( const QskBoxMetrics&, const QskBoxBorderColors& );
     QskBoxBasicStroker( const QskBoxMetrics&,
-        const QskBoxBorderColors&, const QskBoxRenderer::ColorMap& );
+        const QskBoxBorderColors&, const QskVertex::ColorMap& );
 
     int fillCount() const;
     int borderCount() const;
@@ -78,7 +78,7 @@ class QskBoxBasicStroker
 
     const QskBoxMetrics& m_metrics;
     const QskBoxBorderColors m_borderColors;
-    const QskBoxRenderer::ColorMap m_colorMap;
+    const QskVertex::ColorMap m_colorMap;
     const GeometryLayout m_geometryLayout;
 
     const bool m_isColored;
diff --git a/src/nodes/QskBoxClipNode.cpp b/src/nodes/QskBoxClipNode.cpp
index c04d79e27..1006cb813 100644
--- a/src/nodes/QskBoxClipNode.cpp
+++ b/src/nodes/QskBoxClipNode.cpp
@@ -9,6 +9,8 @@
 #include "QskBoxShapeMetrics.h"
 #include "QskFunctions.h"
 
+#include <qquickitem.h>
+
 static inline QskHashValue qskMetricsHash(
     const QskBoxShapeMetrics& shape, const QskBoxBorderMetrics& border )
 {
@@ -29,7 +31,7 @@ QskBoxClipNode::~QskBoxClipNode()
 {
 }
 
-void QskBoxClipNode::setBox( const QRectF& rect,
+void QskBoxClipNode::setBox( const QQuickWindow* window, const QRectF& rect,
     const QskBoxShapeMetrics& shape, const QskBoxBorderMetrics& border )
 {
     const auto hash = qskMetricsHash( shape, border );
@@ -67,7 +69,9 @@ void QskBoxClipNode::setBox( const QRectF& rect,
     else
     {
         setIsRectangular( false );
-        QskBoxRenderer::setFillLines( rect, shape, border, m_geometry );
+
+        QskBoxRenderer renderer( window );
+        renderer.setFillLines( rect, shape, border, m_geometry );
     }
 
     /*
diff --git a/src/nodes/QskBoxClipNode.h b/src/nodes/QskBoxClipNode.h
index 9312334dd..1a6377922 100644
--- a/src/nodes/QskBoxClipNode.h
+++ b/src/nodes/QskBoxClipNode.h
@@ -12,13 +12,15 @@
 class QskBoxShapeMetrics;
 class QskBoxBorderMetrics;
 
+class QQuickWindow;
+
 class QSK_EXPORT QskBoxClipNode : public QSGClipNode
 {
   public:
     QskBoxClipNode();
     ~QskBoxClipNode() override;
 
-    void setBox( const QRectF&,
+    void setBox( const QQuickWindow*, const QRectF&,
         const QskBoxShapeMetrics&, const QskBoxBorderMetrics& );
 
   private:
diff --git a/src/nodes/QskBoxGradientStroker.cpp b/src/nodes/QskBoxGradientStroker.cpp
index ad2537ca3..97c444d91 100644
--- a/src/nodes/QskBoxGradientStroker.cpp
+++ b/src/nodes/QskBoxGradientStroker.cpp
@@ -5,8 +5,7 @@
 
 #include "QskBoxGradientStroker.h"
 #include "QskBoxBasicStroker.h"
-#include "QskVertex.h"
-#include "QskBoxColorMap.h"
+#include "QskVertexHelper.h"
 #include "QskBoxMetrics.h"
 
 static inline bool qskCanUseHVFiller(
@@ -172,7 +171,7 @@ namespace
         qreal m_t0, m_dt;
 
         const QskBoxMetrics::Corner* m_c1, * m_c2, * m_c3;
-        QskBoxRenderer::GradientIterator m_gradientIterator;
+        QskVertex::GradientIterator m_gradientIterator;
     };
 }
 
@@ -528,7 +527,7 @@ namespace
         int setLines( const QskGradient& gradient, ColoredLine* lines )
         {
             ContourIterator it( m_metrics, gradient.linearDirection() );
-            QskBoxRenderer::GradientIterator gradientIt( gradient.stops() );
+            QskVertex::GradientIterator gradientIt( gradient.stops() );
 
             ColoredLine* l = lines;
 
@@ -584,7 +583,7 @@ namespace
             const qreal y1 = m_metrics.innerRect.top();
             const qreal y2 = m_metrics.innerRect.bottom();
 
-            QskBoxRenderer::GradientIterator it( gradient.stops() );
+            QskVertex::GradientIterator it( gradient.stops() );
             ColoredLine* l = lines;
 
             const auto dir = gradient.linearDirection();
diff --git a/src/nodes/QskBoxMetrics.cpp b/src/nodes/QskBoxMetrics.cpp
index a0cf0cff0..4972ad3d6 100644
--- a/src/nodes/QskBoxMetrics.cpp
+++ b/src/nodes/QskBoxMetrics.cpp
@@ -6,7 +6,7 @@
 #include "QskBoxMetrics.h"
 #include "QskBoxShapeMetrics.h"
 #include "QskBoxBorderMetrics.h"
-#include "QskVertex.h"
+#include "QskVertexHelper.h"
 #include "QskFunctions.h"
 
 QskBoxMetrics::QskBoxMetrics( const QRectF& rect,
diff --git a/src/nodes/QskBoxNode.cpp b/src/nodes/QskBoxNode.cpp
index 22cc78c59..89af944d0 100644
--- a/src/nodes/QskBoxNode.cpp
+++ b/src/nodes/QskBoxNode.cpp
@@ -60,7 +60,7 @@ QskBoxNode::~QskBoxNode()
 {
 }
 
-void QskBoxNode::updateNode( const QRectF& rect,
+void QskBoxNode::updateNode( const QQuickWindow* window, const QRectF& rect,
     const QskBoxShapeMetrics& shapeMetrics, const QskBoxBorderMetrics& borderMetrics,
     const QskBoxBorderColors& borderColors, const QskGradient& gradient,
     const QskShadowMetrics& shadowMetrics, const QColor& shadowColor )
@@ -100,7 +100,8 @@ void QskBoxNode::updateNode( const QRectF& rect,
             {
                 // QskBoxRectangleNode allows scene graph batching
                 shadowFillNode = qskNode< QskBoxRectangleNode >( this, ShadowFillRole );
-                shadowFillNode->updateFilling( shadowRect, shadowShape, shadowColor );
+                shadowFillNode->updateFilling( window,
+                    shadowRect, shadowShape, shadowColor );
             }
             else
             {
@@ -125,13 +126,16 @@ void QskBoxNode::updateNode( const QRectF& rect,
 
             if ( fillNode )
             {
-                rectNode->updateBorder( rect, shapeMetrics, borderMetrics, borderColors );
-                fillNode->updateFilling( rect, shapeMetrics, borderMetrics, gradient );
+                rectNode->updateBorder( window, rect,
+                    shapeMetrics, borderMetrics, borderColors );
+
+                fillNode->updateFilling( window, rect,
+                    shapeMetrics, borderMetrics, gradient );
             }
             else
             {
-                rectNode->updateBox( rect, shapeMetrics,
-                    borderMetrics, borderColors, gradient );
+                rectNode->updateBox( window, rect,
+                    shapeMetrics, borderMetrics, borderColors, gradient );
             }
         }
     }
diff --git a/src/nodes/QskBoxNode.h b/src/nodes/QskBoxNode.h
index 999fa58c5..8e14d668a 100644
--- a/src/nodes/QskBoxNode.h
+++ b/src/nodes/QskBoxNode.h
@@ -15,6 +15,7 @@ class QskBoxBorderMetrics;
 class QskBoxBorderColors;
 class QskGradient;
 class QskShadowMetrics;
+class QQuickWindow;
 class QColor;
 
 class QSK_EXPORT QskBoxNode : public QSGNode
@@ -23,7 +24,7 @@ class QSK_EXPORT QskBoxNode : public QSGNode
     QskBoxNode();
     ~QskBoxNode() override;
 
-    void updateNode( const QRectF&,
+    void updateNode( const QQuickWindow*, const QRectF&,
         const QskBoxShapeMetrics&, const QskBoxBorderMetrics&,
         const QskBoxBorderColors&, const QskGradient&,
         const QskShadowMetrics&, const QColor& shadowColor );
diff --git a/src/nodes/QskBoxRectangleNode.cpp b/src/nodes/QskBoxRectangleNode.cpp
index 62fcb8c58..ce715e1d4 100644
--- a/src/nodes/QskBoxRectangleNode.cpp
+++ b/src/nodes/QskBoxRectangleNode.cpp
@@ -79,21 +79,22 @@ QskBoxRectangleNode::~QskBoxRectangleNode()
 {
 }
 
-void QskBoxRectangleNode::updateFilling(
+void QskBoxRectangleNode::updateFilling( const QQuickWindow* window,
     const QRectF& rect, const QskGradient& gradient )
 {
-    updateFilling( rect, QskBoxShapeMetrics(), QskBoxBorderMetrics(), gradient );
+    updateFilling( window, rect,
+        QskBoxShapeMetrics(), QskBoxBorderMetrics(), gradient );
 }
 
-void QskBoxRectangleNode::updateFilling( const QRectF& rect,
-    const QskBoxShapeMetrics& shape, const QskGradient& gradient )
+void QskBoxRectangleNode::updateFilling( const QQuickWindow* window,
+    const QRectF& rect, const QskBoxShapeMetrics& shape, const QskGradient& gradient )
 {
-    updateFilling( rect, shape, QskBoxBorderMetrics(), gradient );
+    updateFilling( window, rect, shape, QskBoxBorderMetrics(), gradient );
 }
 
-void QskBoxRectangleNode::updateFilling( const QRectF& rect,
-    const QskBoxShapeMetrics& shapeMetrics, const QskBoxBorderMetrics& borderMetrics,
-    const QskGradient& gradient )
+void QskBoxRectangleNode::updateFilling( const QQuickWindow* window,
+    const QRectF& rect, const QskBoxShapeMetrics& shapeMetrics,
+    const QskBoxBorderMetrics& borderMetrics, const QskGradient& gradient )
 {
     Q_D( QskBoxRectangleNode );
 
@@ -117,11 +118,13 @@ void QskBoxRectangleNode::updateFilling( const QRectF& rect,
 
     if ( dirtyGeometry || dirtyMaterial )
     {
+        QskBoxRenderer renderer( window );
+
         if ( coloredGeometry )
         {
             setColoring( QskFillNode::Polychrome );
 
-            QskBoxRenderer::setColoredFillLines( rect, shape,
+            renderer.setColoredFillLines( rect, shape,
                 borderMetrics, fillGradient, *geometry() );
 
             markDirty( QSGNode::DirtyGeometry );
@@ -132,18 +135,16 @@ void QskBoxRectangleNode::updateFilling( const QRectF& rect,
 
             if ( dirtyGeometry )
             {
-                QskBoxRenderer::setFillLines(
-                    rect, shape, borderMetrics, *geometry() );
-
+                renderer.setFillLines( rect, shape, borderMetrics, *geometry() );
                 markDirty( QSGNode::DirtyGeometry );
             }
         }
     }
 }
 
-void QskBoxRectangleNode::updateBorder( const QRectF& rect,
-    const QskBoxShapeMetrics& shapeMetrics, const QskBoxBorderMetrics& borderMetrics,
-    const QskBoxBorderColors& borderColors )
+void QskBoxRectangleNode::updateBorder( const QQuickWindow* window,
+    const QRectF& rect, const QskBoxShapeMetrics& shapeMetrics,
+    const QskBoxBorderMetrics& borderMetrics, const QskBoxBorderColors& borderColors )
 {
     Q_D( QskBoxRectangleNode );
 
@@ -166,11 +167,13 @@ void QskBoxRectangleNode::updateBorder( const QRectF& rect,
 
     if ( dirtyGeometry || dirtyMaterial )
     {
+        QskBoxRenderer renderer( window );
+
         if ( coloredGeometry )
         {
             setColoring( QskFillNode::Polychrome );
 
-            QskBoxRenderer::setColoredBorderLines( rect, shape,
+            renderer.setColoredBorderLines( rect, shape,
                 borderMetrics, borderColors, *geometry() );
 
             markDirty( QSGNode::DirtyGeometry );
@@ -181,7 +184,7 @@ void QskBoxRectangleNode::updateBorder( const QRectF& rect,
 
             if ( dirtyGeometry )
             {
-                QskBoxRenderer::setBorderLines( rect, shape,
+                renderer.setBorderLines( rect, shape,
                     borderMetrics, *geometry() );
 
                 markDirty( QSGNode::DirtyGeometry );
@@ -190,7 +193,7 @@ void QskBoxRectangleNode::updateBorder( const QRectF& rect,
     }
 }
 
-void QskBoxRectangleNode::updateBox( const QRectF& rect,
+void QskBoxRectangleNode::updateBox( const QQuickWindow* window, const QRectF& rect,
     const QskBoxShapeMetrics& shapeMetrics, const QskBoxBorderMetrics& borderMetrics,
     const QskBoxBorderColors& borderColors, const QskGradient& gradient )
 {
@@ -228,7 +231,8 @@ void QskBoxRectangleNode::updateBox( const QRectF& rect,
                 fillGradient.setDirection( QskGradient::Linear );
             }
 
-            QskBoxRenderer::setColoredBorderAndFillLines( rect, shape, borderMetrics,
+            QskBoxRenderer renderer( window );
+            renderer.setColoredBorderAndFillLines( rect, shape, borderMetrics,
                 borderColors, fillGradient, *geometry() );
 
             markDirty( QSGNode::DirtyGeometry );
@@ -236,11 +240,11 @@ void QskBoxRectangleNode::updateBox( const QRectF& rect,
     }
     else if ( hasFill )
     {
-        updateFilling( rect, shapeMetrics, borderMetrics, gradient );
+        updateFilling( window, rect, shapeMetrics, borderMetrics, gradient );
     }
     else if ( hasBorder )
     {
-        updateBorder( rect, shapeMetrics, borderMetrics, borderColors );
+        updateBorder( window, rect, shapeMetrics, borderMetrics, borderColors );
     }
     else
     {
diff --git a/src/nodes/QskBoxRectangleNode.h b/src/nodes/QskBoxRectangleNode.h
index 362f1afe8..1446bc3e6 100644
--- a/src/nodes/QskBoxRectangleNode.h
+++ b/src/nodes/QskBoxRectangleNode.h
@@ -13,9 +13,10 @@ class QskBoxShapeMetrics;
 class QskBoxBorderMetrics;
 class QskBoxBorderColors;
 class QskGradient;
-
 class QskBoxRectangleNodePrivate;
 
+class QQuickWindow;
+
 class QSK_EXPORT QskBoxRectangleNode : public QskFillNode
 {
     using Inherited = QskFillNode;
@@ -24,21 +25,21 @@ class QSK_EXPORT QskBoxRectangleNode : public QskFillNode
     QskBoxRectangleNode();
     ~QskBoxRectangleNode() override;
 
-    void updateBox( const QRectF&,
+    void updateBox( const QQuickWindow*, const QRectF&,
         const QskBoxShapeMetrics&, const QskBoxBorderMetrics&,
         const QskBoxBorderColors&, const QskGradient& );
 
-    void updateBorder( const QRectF&,
+    void updateBorder( const QQuickWindow*, const QRectF&,
         const QskBoxShapeMetrics&, const QskBoxBorderMetrics&,
         const QskBoxBorderColors& );
 
-    void updateFilling( const QRectF& rect, const QskGradient& );
+    void updateFilling( const QQuickWindow*, const QRectF&, const QskGradient& );
 
-    void updateFilling( const QRectF& rect,
+    void updateFilling( const QQuickWindow*, const QRectF&,
         const QskBoxShapeMetrics&, const QskGradient& );
 
-    void updateFilling( const QRectF& rect, const QskBoxShapeMetrics&,
-        const QskBoxBorderMetrics&, const QskGradient& );
+    void updateFilling( const QQuickWindow*, const QRectF&,
+        const QskBoxShapeMetrics&, const QskBoxBorderMetrics&, const QskGradient& );
 
     /*
         If true border/filling can be rendered together into the same geometry.
diff --git a/src/nodes/QskBoxRenderer.cpp b/src/nodes/QskBoxRenderer.cpp
index dd4afcdd1..f5f039fbd 100644
--- a/src/nodes/QskBoxRenderer.cpp
+++ b/src/nodes/QskBoxRenderer.cpp
@@ -70,6 +70,15 @@ static inline bool qskMaybeSpreading( const QskGradient& gradient )
     return true;
 }
 
+QskBoxRenderer::QskBoxRenderer( const QQuickWindow* window )
+    : m_window( window )
+{
+}
+
+QskBoxRenderer::~QskBoxRenderer()
+{
+}
+
 bool QskBoxRenderer::isGradientSupported( const QskGradient& gradient )
 {
     if ( !gradient.isVisible() || gradient.isMonochrome() )
@@ -177,7 +186,7 @@ void QskBoxRenderer::setColoredBorderAndFillLines( const QRectF& rect,
     const auto effectiveGradient = qskEffectiveGradient( metrics.innerRect, gradient );
 
     if ( metrics.innerRect.isEmpty() ||
-        QskBoxRenderer::ColorMap::isGradientSupported( effectiveGradient, metrics.innerRect ) )
+        QskVertex::ColorMap::isGradientSupported( effectiveGradient, metrics.innerRect ) )
     {
         /*
             The gradient can be translated to a QskBoxRenderer::ColorMap and we can do all
@@ -236,14 +245,14 @@ void QskBoxRenderer::setColoredBorderAndFillLines( const QRectF& rect,
 QskGradient QskBoxRenderer::effectiveGradient( const QskGradient& gradient )
 {
     if ( ( gradient.type() == QskGradient::Stops ) || gradient.isMonochrome() )
-    {   
+    {
         // the shader for linear gradients is the fastest
-    
+
         auto g = gradient;
         g.setDirection( QskGradient::Linear );
-    
+
         return g;
     }
-    
+
     return gradient;
 }
diff --git a/src/nodes/QskBoxRenderer.h b/src/nodes/QskBoxRenderer.h
index 9b30eb884..1352ff7c8 100644
--- a/src/nodes/QskBoxRenderer.h
+++ b/src/nodes/QskBoxRenderer.h
@@ -13,11 +13,16 @@ class QskBoxBorderColors;
 class QskBoxShapeMetrics;
 class QskGradient;
 
+class QQuickWindow;
 class QSGGeometry;
 class QRectF;
 
-namespace QskBoxRenderer
+class QSK_EXPORT QskBoxRenderer
 {
+  public:
+    QskBoxRenderer( const QQuickWindow* );
+    ~QskBoxRenderer();
+
     /*
         Filling the geometry without any color information:
             see QSGGeometry::defaultAttributes_Point2D()
@@ -26,13 +31,13 @@ namespace QskBoxRenderer
         - using shaders setting the color information
      */
 
-    QSK_EXPORT void setBorderLines( const QRectF&,
+    void setBorderLines( const QRectF&,
         const QskBoxShapeMetrics&, const QskBoxBorderMetrics&, QSGGeometry& );
 
-    QSK_EXPORT void setFillLines( const QRectF&,
+    void setFillLines( const QRectF&,
         const QskBoxShapeMetrics&, const QskBoxBorderMetrics&, QSGGeometry& );
 
-    QSK_EXPORT void setFillLines( const QRectF&,
+    void setFillLines( const QRectF&,
         const QskBoxShapeMetrics&, QSGGeometry& );
 
     /*
@@ -41,21 +46,25 @@ namespace QskBoxRenderer
 
         Usually used in combination with QSGVertexColorMaterial
      */
-    QSK_EXPORT bool isGradientSupported( const QskGradient& );
 
-    QSK_EXPORT void setColoredBorderLines( const QRectF&,
+    void setColoredBorderLines( const QRectF&,
         const QskBoxShapeMetrics&, const QskBoxBorderMetrics&,
         const QskBoxBorderColors&, QSGGeometry& );
 
-    QSK_EXPORT void setColoredFillLines( const QRectF&,
+    void setColoredFillLines( const QRectF&,
         const QskBoxShapeMetrics&, const QskBoxBorderMetrics&,
         const QskGradient&, QSGGeometry& );
 
-    QSK_EXPORT void setColoredBorderAndFillLines( const QRectF&,
+    void setColoredBorderAndFillLines( const QRectF&,
         const QskBoxShapeMetrics&, const QskBoxBorderMetrics&,
         const QskBoxBorderColors&, const QskGradient&, QSGGeometry& );
 
-    QSK_EXPORT QskGradient effectiveGradient( const QskGradient& );
-}
+    static bool isGradientSupported( const QskGradient& );
+    static QskGradient effectiveGradient( const QskGradient& );
+
+  private:
+    // for adjustments to the target ( f.e devicePixelRatio )
+    const QQuickWindow* m_window;
+};
 
 #endif
diff --git a/src/nodes/QskVertex.h b/src/nodes/QskVertex.h
index 967d2382d..e8ec92401 100644
--- a/src/nodes/QskVertex.h
+++ b/src/nodes/QskVertex.h
@@ -11,7 +11,6 @@
 #include <qcolor.h>
 #include <qsggeometry.h>
 #include <qline.h>
-#include <qmath.h>
 
 namespace QskVertex
 {
@@ -216,126 +215,6 @@ namespace QskVertex
     }
 }
 
-namespace QskVertex
-{
-    class ArcIterator
-    {
-      public:
-        inline ArcIterator() = default;
-
-        inline ArcIterator( int stepCount, bool inverted = false )
-        {
-            reset( stepCount, inverted );
-        }
-
-        void reset( int stepCount, bool inverted = false )
-        {
-            m_inverted = inverted;
-
-            if ( inverted )
-            {
-                m_cos = 1.0;
-                m_sin = 0.0;
-            }
-            else
-            {
-                m_cos = 0.0;
-                m_sin = 1.0;
-            }
-
-            m_stepIndex = 0;
-            m_stepCount = stepCount;
-
-            const auto angleStep = M_PI_2 / stepCount;
-            m_cosStep = qFastCos( angleStep );
-            m_sinStep = qFastSin( angleStep );
-        }
-
-        inline bool isInverted() const { return m_inverted; }
-
-        inline qreal cos() const { return m_cos; }
-        inline qreal sin() const { return m_inverted ? -m_sin : m_sin; }
-
-        inline int step() const { return m_stepIndex; }
-        inline int stepCount() const { return m_stepCount; }
-        inline bool isDone() const { return m_stepIndex > m_stepCount; }
-
-        inline void increment()
-        {
-            if ( ++m_stepIndex >= m_stepCount )
-            {
-                if ( m_stepIndex == m_stepCount )
-                {
-                    /*
-                        Doubles are not numerical stable and the small errors,
-                        sum up when iterating in steps. To avoid having to deal with
-                        fuzzy compares we manually fix cos/sin at the end.
-                     */
-                    if ( m_inverted )
-                    {
-                        m_cos = 0.0;
-                        m_sin = -1.0;
-                    }
-                    else
-                    {
-                        m_cos = 1.0;
-                        m_sin = 0.0;
-                    }
-                }
-            }
-            else
-            {
-                const auto cos0 = m_cos;
-
-                m_cos = m_cos * m_cosStep + m_sin * m_sinStep;
-                m_sin = m_sin * m_cosStep - cos0 * m_sinStep;
-            }
-        }
-
-        inline void decrement()
-        {
-            revert();
-            increment();
-            revert();
-        }
-
-        inline void operator++() { increment(); }
-
-        static int segmentHint( qreal radius )
-        {
-            const auto arcLength = radius * M_PI_2;
-            return qBound( 3, qCeil( arcLength / 3.0 ), 18 ); // every 3 pixels
-        }
-
-        inline void revert()
-        {
-            m_inverted = !m_inverted;
-            m_stepIndex = m_stepCount - m_stepIndex;
-
-            m_sin = -m_sin;
-        }
-
-        ArcIterator reverted() const
-        {
-            ArcIterator it = *this;
-            it.revert();
-
-            return it;
-        }
-
-      private:
-        qreal m_cos;
-        qreal m_sin;
-
-        int m_stepIndex;
-        qreal m_cosStep;
-        qreal m_sinStep;
-
-        int m_stepCount;
-        bool m_inverted;
-    };
-}
-
 namespace QskVertex
 {
     void debugGeometry( const QSGGeometry& );
diff --git a/src/nodes/QskBoxColorMap.h b/src/nodes/QskVertexHelper.h
similarity index 63%
rename from src/nodes/QskBoxColorMap.h
rename to src/nodes/QskVertexHelper.h
index 69f046044..6217f11e5 100644
--- a/src/nodes/QskBoxColorMap.h
+++ b/src/nodes/QskVertexHelper.h
@@ -3,14 +3,136 @@
  *           SPDX-License-Identifier: BSD-3-Clause
  *****************************************************************************/
 
-#ifndef QSK_BOX_RENDERER_COLOR_MAP_H
-#define QSK_BOX_RENDERER_COLOR_MAP_H
+#ifndef QSK_VERTEX_HELPER_H
+#define QSK_VERTEX_HELPER_H
 
-#include <QskGradient.h>
-#include <QskGradientDirection.h>
-#include <QskVertex.h>
+#include "QskGradient.h"
+#include "QskGradientDirection.h"
+#include "QskVertex.h"
 
-namespace QskBoxRenderer
+#include <cmath>
+
+namespace QskVertex
+{
+    class ArcIterator
+    {
+      public:
+        inline ArcIterator() = default;
+
+        inline ArcIterator( int stepCount, bool inverted = false )
+        {
+            reset( stepCount, inverted );
+        }
+
+        void reset( int stepCount, bool inverted = false )
+        {
+            m_inverted = inverted;
+
+            if ( inverted )
+            {
+                m_cos = 1.0;
+                m_sin = 0.0;
+            }
+            else
+            {
+                m_cos = 0.0;
+                m_sin = 1.0;
+            }
+
+            m_stepIndex = 0;
+            m_stepCount = stepCount;
+
+            const auto angleStep = M_PI_2 / stepCount;
+            m_cosStep = qFastCos( angleStep );
+            m_sinStep = qFastSin( angleStep );
+        }
+
+        inline bool isInverted() const { return m_inverted; }
+
+        inline qreal cos() const { return m_cos; }
+        inline qreal sin() const { return m_inverted ? -m_sin : m_sin; }
+
+        inline int step() const { return m_stepIndex; }
+        inline int stepCount() const { return m_stepCount; }
+        inline bool isDone() const { return m_stepIndex > m_stepCount; }
+
+        inline void increment()
+        {
+            if ( ++m_stepIndex >= m_stepCount )
+            {
+                if ( m_stepIndex == m_stepCount )
+                {
+                    /*
+                        Doubles are not numerical stable and the small errors,
+                        sum up when iterating in steps. To avoid having to deal with
+                        fuzzy compares we manually fix cos/sin at the end.
+                     */
+                    if ( m_inverted )
+                    {
+                        m_cos = 0.0;
+                        m_sin = -1.0;
+                    }
+                    else
+                    {
+                        m_cos = 1.0;
+                        m_sin = 0.0;
+                    }
+                }
+            }
+            else
+            {
+                const auto cos0 = m_cos;
+
+                m_cos = m_cos * m_cosStep + m_sin * m_sinStep;
+                m_sin = m_sin * m_cosStep - cos0 * m_sinStep;
+            }
+        }
+
+        inline void decrement()
+        {
+            revert();
+            increment();
+            revert();
+        }
+
+        inline void operator++() { increment(); }
+
+        static int segmentHint( qreal radius )
+        {
+            const auto arcLength = radius * M_PI_2;
+            return qBound( 3, qCeil( arcLength / 3.0 ), 18 ); // every 3 pixels
+        }
+
+        inline void revert()
+        {
+            m_inverted = !m_inverted;
+            m_stepIndex = m_stepCount - m_stepIndex;
+
+            m_sin = -m_sin;
+        }
+
+        ArcIterator reverted() const
+        {
+            ArcIterator it = *this;
+            it.revert();
+
+            return it;
+        }
+
+      private:
+        qreal m_cos;
+        qreal m_sin;
+
+        int m_stepIndex;
+        qreal m_cosStep;
+        qreal m_sinStep;
+
+        int m_stepCount;
+        bool m_inverted;
+    };
+}
+
+namespace QskVertex
 {
     class ColorMap
     {
@@ -101,7 +223,10 @@ namespace QskBoxRenderer
         const QskVertex::Color m_color1;
         const QskVertex::Color m_color2;
     };
+}
 
+namespace QskVertex
+{
     class GradientIterator
     {
       public: