QskGradientNode introduced for rectangles filled with any type of

gradient being supported by QskGradient. It is lighter than QskBoxNode,
that is a compositition of border/gradient/shadow. Used for the
background node now - what means, that background can have radial/conic
gradients now as well.

src/controls/QskSkinlet.cpp

@@ -19,6 +19,7 @@
 #include "QskControl.h"
 #include "QskFunctions.h"
 #include "QskGradient.h"
+#include "QskGradientNode.h"
 #include "QskGraphicNode.h"
 #include "QskGraphic.h"
 #include "QskSGNode.h"
@@ -350,9 +351,9 @@ QSGNode* QskSkinlet::updateBackgroundNode(
     if ( !gradient.isValid() )
         return nullptr;
 
-    auto rectNode = static_cast< QskBoxRectangleNode* >( node );
+    auto rectNode = static_cast< QskGradientNode* >( node );
     if ( rectNode == nullptr )
-        rectNode = new QskBoxRectangleNode();
+        rectNode = new QskGradientNode();
 
     rectNode->updateNode( rect, gradient );
     return rectNode;

src/nodes/QskGradientNode.cpp

@@ -0,0 +1,166 @@
+/******************************************************************************
+ * QSkinny - Copyright (C) 2016 Uwe Rathmann
+ * This file may be used under the terms of the QSkinny License, Version 1.0
+ *****************************************************************************/
+
+#include "QskGradientNode.h"
+#include "QskGradient.h"
+#include "QskSGNode.h"
+#include "QskBoxRenderer.h"
+#include "QskGradientMaterial.h"
+
+#include <qglobalstatic.h>
+#include <qsgvertexcolormaterial.h>
+
+QSK_QT_PRIVATE_BEGIN
+#include <private/qsgnode_p.h>
+QSK_QT_PRIVATE_END
+
+Q_GLOBAL_STATIC( QSGVertexColorMaterial, qskMaterialColorVertex )
+
+static inline QskGradient qskEffectiveGradient( const QskGradient& gradient )
+{
+    if ( gradient.type() == QskGradient::Stops || gradient.isMonochrome() )
+    {
+        // the shader for linear gradients is the fastest
+        QskGradient g;
+        g.setLinearDirection( Qt::Vertical );
+        g.setStops( gradient.stops() );
+
+        return g;
+    }
+
+    return gradient;
+}
+
+class QskGradientNodePrivate final : public QSGGeometryNodePrivate
+{
+  public:
+    QskGradientNodePrivate()
+        : geometry( QSGGeometry::defaultAttributes_ColoredPoint2D(), 0 )
+    {
+    }
+
+    QSGGeometry geometry;
+
+    QRectF rect;
+    QskHashValue gradientHash = 0;
+
+    int gradientType = -1;
+};
+
+QskGradientNode::QskGradientNode()
+    : QSGGeometryNode( *new QskGradientNodePrivate )
+{
+    Q_D( QskGradientNode );
+
+    setFlag( OwnsMaterial, true );
+    setGeometry( &d->geometry );
+}
+
+QskGradientNode::~QskGradientNode()
+{
+}
+
+void QskGradientNode::updateNode(
+    const QRectF& rect, const QskGradient& gradient )
+{
+    Q_D( QskGradientNode );
+
+    if ( rect.isEmpty() || !gradient.isVisible() )
+    {
+        d->rect = QRectF();
+        d->gradientHash = 0;
+        QskSGNode::resetGeometry( this );
+
+        return;
+    }
+
+    const auto effectiveGradient = qskEffectiveGradient( gradient );
+
+    const auto gradientHash = effectiveGradient.hash( 54228 );
+
+    const bool dirtyGradient = gradientHash != d->gradientHash;
+    const bool dirtyRect = rect != d->rect;
+
+    if ( !( dirtyGradient || dirtyRect ) )
+        return;
+
+    d->gradientHash = gradientHash;
+    d->rect = rect;
+
+    if ( QskBoxRenderer::isGradientSupported( effectiveGradient ) )
+    {
+        if ( material() != qskMaterialColorVertex )
+        {
+            setMaterial( qskMaterialColorVertex );
+            setFlag( OwnsMaterial, false );
+
+            d->gradientType = -1;
+        }
+
+        if ( d->geometry.attributeCount() == 1 )
+        {
+            const QSGGeometry g( QSGGeometry::defaultAttributes_ColoredPoint2D(), 0 );
+            memcpy( ( void* ) &d->geometry, ( void* ) &g, sizeof( QSGGeometry ) );
+        }
+    }
+    else
+    {
+        if ( material() == qskMaterialColorVertex )
+        {
+            setMaterial( nullptr );
+            setFlag( OwnsMaterial, true );
+
+            d->gradientType = -1;
+        }
+
+        if ( d->geometry.attributeCount() != 1 )
+        {
+            const QSGGeometry g( QSGGeometry::defaultAttributes_Point2D(), 0 );
+            memcpy( ( void* ) &d->geometry, ( void* ) &g, sizeof( QSGGeometry ) );
+        }
+    }
+
+    if ( material() == qskMaterialColorVertex )
+    {
+        /*
+            Colors are added to the vertices, while the material does
+            not depend on the gradient at all
+         */
+        if ( dirtyRect || dirtyGradient )
+        {
+            QskBoxRenderer::renderRect( rect, effectiveGradient, d->geometry );
+            markDirty( QSGNode::DirtyGeometry );
+        }
+    }
+    else
+    {
+        /*
+            Colors are added by the shaders
+
+            Monochrome gradients or QskGradient::Stops are supported by the
+            QskBoxRenderer. So we don't need to handle them here.
+         */
+        if ( dirtyRect )
+        {
+            QskBoxRenderer::renderRect( rect, d->geometry );
+            markDirty( QSGNode::DirtyGeometry );
+        }
+
+        if ( dirtyGradient )
+        {
+            const auto gradientType = effectiveGradient.type();
+
+            if ( gradientType != d->gradientType )
+            {
+                setMaterial( QskGradientMaterial::createMaterial( gradientType ) );
+                d->gradientType = gradientType;
+            }
+
+            auto mat = static_cast< QskGradientMaterial* >( material() );
+            if ( mat->updateGradient( rect, effectiveGradient ) )
+                markDirty( QSGNode::DirtyMaterial );
+        }
+    }
+}

src/nodes/QskGradientNode.h

@@ -0,0 +1,27 @@
+/******************************************************************************
+ * QSkinny - Copyright (C) 2016 Uwe Rathmann
+ * This file may be used under the terms of the QSkinny License, Version 1.0
+ *****************************************************************************/
+
+#ifndef QSK_GRADIENT_NODE_H
+#define QSK_GRADIENT_NODE_H
+
+#include "QskGlobal.h"
+#include <qsgnode.h>
+
+class QskGradient;
+class QskGradientNodePrivate;
+
+class QSK_EXPORT QskGradientNode : public QSGGeometryNode
+{
+  public:
+    QskGradientNode();
+    ~QskGradientNode() override;
+
+    void updateNode( const QRectF&, const QskGradient& );
+
+  private:
+    Q_DECLARE_PRIVATE( QskGradientNode )
+};
+
+#endif

src/src.pro

@@ -109,6 +109,7 @@ HEADERS += \
     nodes/QskBoxRendererColorMap.h \
     nodes/QskBoxShadowNode.h \
     nodes/QskColorRamp.h \
+    nodes/QskGradientNode.h \
     nodes/QskGraphicNode.h \
     nodes/QskPaintedNode.h \
     nodes/QskPlainTextRenderer.h \
@@ -136,6 +137,7 @@ SOURCES += \
     nodes/QskBoxRendererDEllipse.cpp \
     nodes/QskBoxShadowNode.cpp \
     nodes/QskColorRamp.cpp \
+    nodes/QskGradientNode.cpp \
     nodes/QskGraphicNode.cpp \
     nodes/QskPaintedNode.cpp \
     nodes/QskPlainTextRenderer.cpp \