QskArcRenderNode stays inside its given rectangle

playground/shadows/ArcPage.cpp

@@ -8,6 +8,7 @@
 #include "Slider.h"
 
 #include <QskGridBox.h>
+#include <QskRgbValue.h>
 
 namespace
 {
@@ -54,6 +55,9 @@ namespace
       public:
         Arc()
         {
+            setBackgroundColor( QskRgb::LemonChiffon );
+            setClip( true ); // for testing if the arc stays inside its bounding rectangle
+
             setStartAngle( 45.0 );
             setSpanAngle( 270.0 );
             setThickness( 10.0 );
@@ -101,7 +105,6 @@ ArcPage::ArcPage( QQuickItem* parent )
     : QskLinearBox( Qt::Vertical, parent )
 {
     auto arc = new Arc();
-    arc->setMargins( 40 ); // some extra space for testing the offsets
 
     auto panel = new ControlPanel( arc );
     panel->setSizePolicy( Qt::Vertical, QskSizePolicy::Fixed );

src/nodes/QskArcNode.cpp

@@ -56,15 +56,6 @@ static inline QskGradient qskEffectiveGradient(
     return gradient;
 }
 
-static inline QRectF qskEffectiveRect(
-    const QRectF& rect, const qreal borderWidth )
-{
-    if ( borderWidth <= 0.0 )
-        return rect;
-
-    return qskValidOrEmptyInnerRect( rect, QskMargins( 0.5 * borderWidth ) );
-}
-
 static void qskUpdateChildren( QSGNode* parentNode, quint8 role, QSGNode* node )
 {
     static const QVector< quint8 > roles =
@@ -114,8 +105,7 @@ void QskArcNode::setArcData( const QRectF& rect, const QskArcMetrics& arcMetrics
     auto borderNode = static_cast< BorderNode* >(
         QskSGNode::findChildNode( this, BorderRole ) );
 
-    const auto arcRect = qskEffectiveRect( rect, borderWidth );
+    if ( metricsArc.isNull() || rect.isEmpty() )
-    if ( metricsArc.isNull() || arcRect.isEmpty() )
     {
         delete shadowNode;
         delete pathNode;
@@ -125,12 +115,10 @@ void QskArcNode::setArcData( const QRectF& rect, const QskArcMetrics& arcMetrics
     }
 
     const auto isFillNodeVisible = gradient.isVisible();
-    const auto isStrokeNodeVisible = ( borderWidth > 0.0 ) && ( borderColor.alpha() > 0 );
+    const auto isBorderNodeVisible = ( borderWidth > 0.0 ) && ( borderColor.alpha() > 0 );
     const auto isShadowNodeVisible = isFillNodeVisible &&
         shadowColor.isValid() && ( shadowColor.alpha() > 0.0 );
 
-    const auto path = metricsArc.painterPath( arcRect, radial );
-
     if ( isShadowNodeVisible )
     {
         if ( shadowNode == nullptr )
@@ -146,8 +134,8 @@ void QskArcNode::setArcData( const QRectF& rect, const QskArcMetrics& arcMetrics
             and not only to its radius. TODO ...
          */
 
-        const auto sm = shadowMetrics.toAbsolute( arcRect.size() );
+        const auto sm = shadowMetrics.toAbsolute( rect.size() );
-        const auto shadowRect = sm.shadowRect( arcRect );
+        const auto shadowRect = sm.shadowRect( rect );
         const auto spreadRadius = sm.spreadRadius() + 0.5 * metricsArc.thickness();
 
         shadowNode->setShadowData( shadowRect, spreadRadius, sm.blurRadius(),
@@ -172,7 +160,7 @@ void QskArcNode::setArcData( const QRectF& rect, const QskArcMetrics& arcMetrics
                 QskSGNode::setNodeRole( arcNode, ArcRole );
             }
 
-            arcNode->updateNode( arcRect, metricsArc, radial,
+            arcNode->updateNode( rect, metricsArc, radial,
                 borderWidth, QColor(), gradient );
         }
         else
@@ -186,7 +174,8 @@ void QskArcNode::setArcData( const QRectF& rect, const QskArcMetrics& arcMetrics
                 QskSGNode::setNodeRole( pathNode, PathRole );
             }
 
-            pathNode->updateNode( path, QTransform(), arcRect,
+            const auto path = metricsArc.painterPath( rect, radial );
+            pathNode->updateNode( path, QTransform(), rect,
                 qskEffectiveGradient( gradient, metricsArc ) );
         }
     }
@@ -199,7 +188,7 @@ void QskArcNode::setArcData( const QRectF& rect, const QskArcMetrics& arcMetrics
         arcNode = nullptr;
     }
 
-    if ( isStrokeNodeVisible )
+    if ( isBorderNodeVisible )
     {
         if ( borderNode == nullptr )
         {
@@ -208,12 +197,13 @@ void QskArcNode::setArcData( const QRectF& rect, const QskArcMetrics& arcMetrics
         }
 
 #ifdef ARC_BORDER_NODE
-        borderNode->updateNode( arcRect, metricsArc, radial,
+        borderNode->updateNode( rect, metricsArc, radial,
             borderWidth, borderColor, QskGradient() );
 #else
         QPen pen( borderColor, borderWidth );
         pen.setCapStyle( Qt::FlatCap );
 
+        const auto path = metricsArc.painterPath( rect, radial );
         borderNode->updateNode( path, QTransform(), pen );
 #endif
     }

src/nodes/QskArcRenderNode.cpp

@@ -68,11 +68,15 @@ void QskArcRenderNode::updateNode(
     Q_D( QskArcRenderNode );
 
     const auto metrics = arcMetrics.toAbsolute( rect.size() );
+    const auto borderMax = 0.5 * metrics.thickness();
+
+    const auto hasFilling = gradient.isVisible()
+        && ( borderWidth < borderMax );
 
     bool visible = !( rect.isEmpty() || metrics.isNull() );
     if ( visible )
     {
-        visible = gradient.isVisible();
+        visible = hasFilling;
         if ( !visible )
         {
             visible = ( borderWidth > 0.0 )
@@ -103,11 +107,12 @@ void QskArcRenderNode::updateNode(
 
         if ( borderWidth > 0.0 && borderColor.isValid() )
         {
+            borderWidth = std::min( borderWidth, borderMax );
             QskArcRenderer::renderBorder(
                 rect, metrics, radial, borderWidth, borderColor, *geometry() );
         }
 
-        if ( gradient.isVisible() )
+        if ( hasFilling )
         {
             QskArcRenderer::renderFillGeometry(
                 rect, metrics, radial, borderWidth, gradient, *geometry() );

src/nodes/QskArcRenderer.cpp

@@ -378,8 +378,7 @@ void QskArcRenderer::renderFillGeometry( const QRectF& rect,
 {
     geometry.setDrawingMode( QSGGeometry::DrawTriangleStrip );
 
-    const auto b2 = 0.5 * borderWidth;
+    const auto r = rect.adjusted( borderWidth, borderWidth, -borderWidth, -borderWidth );
-    const auto r = rect.adjusted( b2, b2, -b2, -b2 );
 
     FillStroker stroker( r, metrics, radial, gradient );
 
@@ -390,7 +389,7 @@ void QskArcRenderer::renderFillGeometry( const QRectF& rect,
         return;
 
     const auto effectiveCount = stroker.setLines(
-        metrics.thickness() - borderWidth, lines );
+        metrics.thickness() - 2 * borderWidth, lines );
 
     if ( effectiveCount > lineCount )
     {