Change antialiasing method for QML2.

Since multisampling can require a lot of memory, and might not
be supported on some hardware, turn off multisampling and
implement antialiasing in the vertex shader instead. The
alternative method of antialiasing is implemented for Rectangle,
Image, BorderImage and AnimatedImage, and must be explicitly
enabled by setting the new antialiasing property.

Task-number: QTBUG-26268
Change-Id: I39a93d978658a494bf51e9f0fd02d8414eb8be12
Reviewed-by: Gunnar Sletta <gunnar.sletta@nokia.com>

1 files changed, 566 insertions, 288 deletions

diff --git a/src/quick/scenegraph/qsgdefaultrectanglenode.cpp b/src/quick/scenegraph/qsgdefaultrectanglenode.cpp
index 18cac36550..b204fff2ef 100644
--- a/src/quick/scenegraph/qsgdefaultrectanglenode.cpp
+++ b/src/quick/scenegraph/qsgdefaultrectanglenode.cpp
@@ -54,45 +54,195 @@
 
 QT_BEGIN_NAMESPACE
 
+namespace
+{
+    struct Color4ub
+    {
+        unsigned char r, g, b, a;
+    };
+
+    Color4ub operator *(Color4ub c, float t) { c.a *= t; c.r *= t; c.g *= t; c.b *= t; return c; }
+    Color4ub operator +(Color4ub a, Color4ub b) {  a.a += b.a; a.r += b.r; a.g += b.g; a.b += b.b; return a; }
+
+    inline Color4ub colorToColor4ub(const QColor &c)
+    {
+        Color4ub color = { uchar(c.redF() * c.alphaF() * 255),
+                           uchar(c.greenF() * c.alphaF() * 255),
+                           uchar(c.blueF() * c.alphaF() * 255),
+                           uchar(c.alphaF() * 255)
+                         };
+        return color;
+    }
+
+    // Same layout as QSGGeometry::ColoredPoint2D, but uses Color4ub for convenience.
+    struct Vertex
+    {
+        float x, y;
+        Color4ub color;
+        void set(float nx, float ny, Color4ub ncolor)
+        {
+            x = nx; y = ny; color = ncolor;
+        }
+    };
+
+    struct SmoothVertex : public Vertex
+    {
+        float dx, dy;
+        void set(float nx, float ny, Color4ub ncolor, float ndx, float ndy)
+        {
+            Vertex::set(nx, ny, ncolor);
+            dx = ndx; dy = ndy;
+        }
+    };
+
+    const QSGGeometry::AttributeSet &smoothAttributeSet()
+    {
+        static QSGGeometry::Attribute data[] = {
+            QSGGeometry::Attribute::create(0, 2, GL_FLOAT, true),
+            QSGGeometry::Attribute::create(1, 4, GL_UNSIGNED_BYTE, false),
+            QSGGeometry::Attribute::create(2, 2, GL_FLOAT, false)
+        };
+        static QSGGeometry::AttributeSet attrs = { 3, sizeof(SmoothVertex), data };
+        return attrs;
+    }
+}
+
+class SmoothColorMaterialShader : public QSGMaterialShader
+{
+public:
+    virtual void updateState(const RenderState &state, QSGMaterial *newEffect, QSGMaterial *oldEffect);
+    virtual char const *const *attributeNames() const;
+
+private:
+    virtual void initialize();
+    virtual const char *vertexShader() const;
+    virtual const char *fragmentShader() const;
+
+    int m_matrixLoc;
+    int m_opacityLoc;
+    int m_pixelSizeLoc;
+};
+
+void SmoothColorMaterialShader::updateState(const RenderState &state, QSGMaterial *, QSGMaterial *oldEffect)
+{
+    if (state.isOpacityDirty())
+        program()->setUniformValue(m_opacityLoc, state.opacity());
+
+    if (state.isMatrixDirty())
+        program()->setUniformValue(m_matrixLoc, state.combinedMatrix());
+
+    if (oldEffect == 0) {
+        // The viewport is constant, so set the pixel size uniform only once.
+        QRect r = state.viewportRect();
+        program()->setUniformValue(m_pixelSizeLoc, 2.0f / r.width(), 2.0f / r.height());
+    }
+}
+
+char const *const *SmoothColorMaterialShader::attributeNames() const
+{
+    static char const *const attributes[] = {
+        "vertex",
+        "vertexColor",
+        "vertexOffset",
+        0
+    };
+    return attributes;
+}
+
+void SmoothColorMaterialShader::initialize()
+{
+    m_matrixLoc = program()->uniformLocation("matrix");
+    m_opacityLoc = program()->uniformLocation("opacity");
+    m_pixelSizeLoc = program()->uniformLocation("pixelSize");
+}
+
+const char *SmoothColorMaterialShader::vertexShader() const
+{
+    return
+            "uniform highp vec2 pixelSize; \n"
+            "uniform highp mat4 matrix; \n"
+            "uniform lowp float opacity; \n"
+            "attribute highp vec4 vertex; \n"
+            "attribute lowp vec4 vertexColor; \n"
+            "attribute highp vec2 vertexOffset; \n"
+            "varying lowp vec4 color; \n"
+            "void main() { \n"
+            "    highp vec4 pos = matrix * vertex; \n"
+            "    gl_Position = pos; \n"
+
+            "    if (vertexOffset.x != 0.) { \n"
+            "        highp vec4 delta = matrix[0] * vertexOffset.x; \n"
+            "        highp vec2 dir = delta.xy * pos.w - pos.xy * delta.w; \n"
+            "        highp vec2 ndir = .5 * pixelSize * normalize(dir / pixelSize);  \n"
+            "        dir -= ndir * delta.w * pos.w; \n"
+            "        highp float scale = min(1., dot(dir, ndir * pos.w * pos.w) / dot(dir, dir)); \n"
+            "        if (scale < 0.) scale = 1.; \n"
+            "        gl_Position += scale * delta; \n"
+            "    } \n"
+
+            "    if (vertexOffset.y != 0.) { \n"
+            "        highp vec4 delta = matrix[1] * vertexOffset.y; \n"
+            "        highp vec2 dir = delta.xy * pos.w - pos.xy * delta.w; \n"
+            "        highp vec2 ndir = .5 * pixelSize * normalize(dir / pixelSize);  \n"
+            "        dir -= ndir * delta.w * pos.w; \n"
+            "        highp float scale = min(1., dot(dir, ndir * pos.w * pos.w) / dot(dir, dir)); \n"
+            "        if (scale < 0.) scale = 1.; \n"
+            "        gl_Position += scale * delta; \n"
+            "    } \n"
+
+            "    color = vertexColor * opacity; \n"
+            "}";
+}
+
+const char *SmoothColorMaterialShader::fragmentShader() const
+{
+    return
+            "varying lowp vec4 color; \n"
+            "void main() { \n"
+            "    gl_FragColor = color; \n"
+            "}";
+}
+
+SmoothColorMaterial::SmoothColorMaterial()
+{
+    setFlag(RequiresFullMatrixExceptTranslate, true);
+    setFlag(Blending, true);
+}
+
+int SmoothColorMaterial::compare(const QSGMaterial *) const
+{
+    return 0;
+}
+
+QSGMaterialType *SmoothColorMaterial::type() const
+{
+    static QSGMaterialType type;
+    return &type;
+}
+
+QSGMaterialShader *SmoothColorMaterial::createShader() const
+{
+    return new SmoothColorMaterialShader;
+}
+
+
 QSGDefaultRectangleNode::QSGDefaultRectangleNode()
-    : m_border(0)
-    , m_radius(0)
+    : m_radius(0)
     , m_pen_width(0)
     , m_aligned(true)
+    , m_antialiasing(false)
     , m_gradient_is_opaque(true)
     , m_dirty_geometry(false)
-    , m_default_geometry(QSGGeometry::defaultAttributes_Point2D(), 4)
+    , m_geometry(QSGGeometry::defaultAttributes_ColoredPoint2D(), 0)
 {
-    setGeometry(&m_default_geometry);
-    setMaterial(&m_fill_material);
-    m_border_material.setColor(QColor(0, 0, 0));
-
-    m_material_type = TypeFlat;
+    setGeometry(&m_geometry);
+    setMaterial(&m_material);
 
 #ifdef QML_RUNTIME_TESTING
     description = QLatin1String("rectangle");
 #endif
 }
 
-QSGDefaultRectangleNode::~QSGDefaultRectangleNode()
-{
-    if (m_material_type == TypeVertexGradient)
-        delete material();
-    delete m_border;
-}
-
-QSGGeometryNode *QSGDefaultRectangleNode::border()
-{
-    if (!m_border) {
-        m_border = new QSGGeometryNode;
-        m_border->setMaterial(&m_border_material);
-        QSGGeometry *geometry = new QSGGeometry(QSGGeometry::defaultAttributes_Point2D(), 0);
-        m_border->setGeometry(geometry);
-        m_border->setFlag(QSGNode::OwnsGeometry);
-    }
-    return m_border;
-}
-
 void QSGDefaultRectangleNode::setRect(const QRectF &rect)
 {
     if (rect == m_rect)
@@ -103,22 +253,20 @@ void QSGDefaultRectangleNode::setRect(const QRectF &rect)
 
 void QSGDefaultRectangleNode::setColor(const QColor &color)
 {
-    if (color == m_fill_material.color())
+    if (color == m_color)
         return;
-    m_fill_material.setColor(color);
-    if (m_gradient_stops.isEmpty()) {
-        Q_ASSERT(m_material_type == TypeFlat);
-        markDirty(DirtyMaterial);
-    }
+    m_color = color;
+    if (m_gradient_stops.isEmpty())
+        m_dirty_geometry = true;
 }
 
 void QSGDefaultRectangleNode::setPenColor(const QColor &color)
 {
-    if (color == m_border_material.color())
+    if (color == m_border_color)
         return;
-    m_border_material.setColor(color);
-    if (m_border)
-        m_border->markDirty(DirtyMaterial);
+    m_border_color = color;
+    if (m_pen_width > 0)
+        m_dirty_geometry = true;
 }
 
 void QSGDefaultRectangleNode::setPenWidth(qreal width)
@@ -126,10 +274,6 @@ void QSGDefaultRectangleNode::setPenWidth(qreal width)
     if (width == m_pen_width)
         return;
     m_pen_width = width;
-    if (m_pen_width <= 0 && m_border && m_border->parent())
-        removeChildNode(m_border);
-    else if (m_pen_width > 0 && !border()->parent())
-        appendChildNode(m_border);
     m_dirty_geometry = true;
 }
 
@@ -144,30 +288,6 @@ void QSGDefaultRectangleNode::setGradientStops(const QGradientStops &stops)
     m_gradient_is_opaque = true;
     for (int i = 0; i < stops.size(); ++i)
         m_gradient_is_opaque &= stops.at(i).second.alpha() == 0xff;
-
-    if (stops.isEmpty()) {
-        // No gradient specified, use flat color.
-        if (m_material_type != TypeFlat) {
-            delete material();
-
-            setMaterial(&m_fill_material);
-            m_material_type = TypeFlat;
-
-            setGeometry(&m_default_geometry);
-            setFlag(OwnsGeometry, false);
-        }
-    } else {
-        if (m_material_type == TypeFlat) {
-            QSGVertexColorMaterial *material = new QSGVertexColorMaterial;
-            setMaterial(material);
-            m_material_type = TypeVertexGradient;
-            QSGGeometry *g = new QSGGeometry(QSGGeometry::defaultAttributes_ColoredPoint2D(), 0);
-            setGeometry(g);
-            setFlag(OwnsGeometry);
-        }
-        static_cast<QSGVertexColorMaterial *>(material())->setFlag(QSGMaterial::Blending, !m_gradient_is_opaque);
-    }
-
     m_dirty_geometry = true;
 }
 
@@ -179,6 +299,23 @@ void QSGDefaultRectangleNode::setRadius(qreal radius)
     m_dirty_geometry = true;
 }
 
+void QSGDefaultRectangleNode::setAntialiasing(bool antialiasing)
+{
+    if (antialiasing == m_antialiasing)
+        return;
+    m_antialiasing = antialiasing;
+    if (m_antialiasing) {
+        setMaterial(&m_smoothMaterial);
+        setGeometry(new QSGGeometry(smoothAttributeSet(), 0));
+        setFlag(OwnsGeometry, true);
+    } else {
+        setMaterial(&m_material);
+        setGeometry(&m_geometry);
+        setFlag(OwnsGeometry, false);
+    }
+    m_dirty_geometry = true;
+}
+
 void QSGDefaultRectangleNode::setAligned(bool aligned)
 {
     if (aligned == m_aligned)
@@ -195,73 +332,41 @@ void QSGDefaultRectangleNode::update()
     }
 }
 
-struct Color4ub
-{
-    unsigned char r, g, b, a;
-};
-
-Color4ub operator *(Color4ub c, float t) { c.a *= t; c.r *= t; c.g *= t; c.b *= t; return c; }
-Color4ub operator +(Color4ub a, Color4ub b) {  a.a += b.a; a.r += b.r; a.g += b.g; a.b += b.b; return a; }
-
-static inline Color4ub colorToColor4ub(const QColor &c)
-{
-    Color4ub color = { uchar(c.redF() * c.alphaF() * 255),
-                       uchar(c.greenF() * c.alphaF() * 255),
-                       uchar(c.blueF() * c.alphaF() * 255),
-                       uchar(c.alphaF() * 255)
-                     };
-    return color;
-}
-
-struct Vertex
-{
-    QVector2D position;
-};
-
-struct ColorVertex
-{
-    QVector2D position;
-    Color4ub color;
-};
-
 void QSGDefaultRectangleNode::updateGeometry()
 {
-    qreal penWidth = m_aligned ? qreal(qRound(m_pen_width)) : m_pen_width;
-
-    // fast path for the simple case...
-    if ((penWidth == 0 || m_border_material.color().alpha() == 0)
-            && m_radius == 0
-            && m_material_type == TypeFlat) {
-        QSGGeometry::updateRectGeometry(&m_default_geometry, m_rect);
-        return;
-    }
-
-    QSGGeometry *fill = geometry();
-
-    // Check that the vertex type matches the material.
-    Q_ASSERT(m_material_type != TypeFlat || fill->sizeOfVertex() == sizeof(Vertex));
-    Q_ASSERT(m_material_type != TypeVertexGradient || fill->sizeOfVertex() == sizeof(ColorVertex));
-
-    QSGGeometry *borderGeometry = 0;
-    if (m_border) {
-        borderGeometry = m_border->geometry();
-        Q_ASSERT(borderGeometry->sizeOfVertex() == sizeof(Vertex));
-    }
-
-    int fillVertexCount = 0;
-
-    // Preallocate arrays for a rectangle with 18 segments per corner and 3 gradient stops.
-    uchar *fillVertices = 0;
-    Vertex *borderVertices = 0;
-
-    Color4ub fillColor = colorToColor4ub(m_fill_material.color());
+    float penWidth = m_aligned ? float(qRound(m_pen_width)) : float(m_pen_width);
+    float width = float(m_rect.width());
+    float height = float(m_rect.height());
+
+    QSGGeometry *g = geometry();
+    g->setDrawingMode(GL_TRIANGLE_STRIP);
+    int vertexStride = g->sizeOfVertex();
+
+    union {
+        Vertex *vertices;
+        SmoothVertex *smoothVertices;
+    };
+
+    Color4ub fillColor = colorToColor4ub(m_color);
+    Color4ub borderColor = colorToColor4ub(m_border_color);
+    Color4ub transparent = { 0, 0, 0, 0 };
     const QGradientStops &stops = m_gradient_stops;
 
+    int nextGradientStop = 0;
+    float gradientPos = 0.5f * penWidth / height;
+    while (nextGradientStop < stops.size() && stops.at(nextGradientStop).first <= gradientPos)
+        ++nextGradientStop;
+    int lastGradientStop = stops.size() - 1;
+    float lastGradientPos = 1.0f - 0.5f * penWidth / height;
+    while (lastGradientStop >= nextGradientStop && stops.at(lastGradientStop).first >= lastGradientPos)
+        --lastGradientStop;
+    int gradientIntersections = (lastGradientStop - nextGradientStop + 1);
+
     if (m_radius > 0) {
         // Rounded corners.
 
         // Radius should never exceeds half of the width or half of the height
-        qreal radius = qMin(qMin(m_rect.width() * qreal(0.5), m_rect.height() * qreal(0.5)), m_radius);
+        float radius = qMin(qMin(width, height) * 0.5f, float(m_radius));
         QRectF innerRect = m_rect;
         innerRect.adjust(radius, radius, -radius, -radius);
         if (m_aligned && (int(penWidth) & 1)) {
@@ -270,120 +375,158 @@ void QSGDefaultRectangleNode::updateGeometry()
             innerRect.moveTop(innerRect.top() + qreal(0.5));
         }
 
-        qreal innerRadius = radius - penWidth * qreal(0.5);
-        qreal outerRadius = radius + penWidth * qreal(0.5);
+        float innerRadius = radius - penWidth * 0.5f;
+        float outerRadius = radius + penWidth * 0.5f;
+        float delta = qMin(width, height) * 0.5f;
 
         // Number of segments per corner, approximately one per 3 pixels.
         int segments = qBound(3, qCeil(outerRadius * (M_PI / 6)), 18);
 
         /*
 
-        --+-__
-          | segment
-          |       _+
-        --+-__  _-   \
-              -+  segment
-        --------+      \        <- gradient line
-                 +-----+
-                 |     |
+        --+--__
+        --+--__--__
+          |    --__--__
+          |  seg   --__--+
+        --+-__  ment  _+  \
+        --+-__--__   -  \  \
+              --__--+ se \  \
+                  +  \  g \  \
+                   \  \  m \  \
+         -----------+--+  e \  \     <- gradient line
+                     \  \  nt\  \
+           fill       +--+----+--+
+                      |  |    |  |
+                         border
+                  inner AA    outer AA (AA = antialiasing)
 
         */
 
-        int nextGradientStop = 0;
-        qreal gradientPos = (radius - innerRadius) / (innerRect.height() + 2 * radius);
-        while (nextGradientStop < stops.size() && stops.at(nextGradientStop).first <= gradientPos)
-            ++nextGradientStop;
-        int lastGradientStop = stops.size() - 1;
-        qreal lastGradientPos = (innerRect.height() + radius + innerRadius) / (innerRect.height() + 2 * radius);
-        while (lastGradientStop >= nextGradientStop && stops.at(lastGradientStop).first >= lastGradientPos)
-            --lastGradientStop;
-
-        int borderVertexHead = 0;
-        int borderVertexTail = 0;
+        int innerVertexCount = (segments + 1) * 4 + gradientIntersections * 2;
+        int outerVertexCount = (segments + 1) * 4;
+        int vertexCount = innerVertexCount;
+        if (m_antialiasing || penWidth)
+            vertexCount += innerVertexCount;
+        if (penWidth)
+            vertexCount += outerVertexCount;
+        if (m_antialiasing && penWidth)
+            vertexCount += outerVertexCount;
+
+        int fillIndexCount = innerVertexCount;
+        int innerAAIndexCount = innerVertexCount * 2 + 2;
+        int borderIndexCount = innerVertexCount * 2 + 2;
+        int outerAAIndexCount = outerVertexCount * 2 + 2;
+        int indexCount = 0;
+        int fillHead = 0;
+        int innerAAHead = 0;
+        int innerAATail = 0;
+        int borderHead = 0;
+        int borderTail = 0;
+        int outerAAHead = 0;
+        int outerAATail = 0;
+        bool hasFill = m_color.rgba() != 0 || !stops.isEmpty();
+        if (hasFill)
+            indexCount += fillIndexCount;
+        if (m_antialiasing) {
+            innerAATail = innerAAHead = indexCount + (innerAAIndexCount >> 1) + 1;
+            indexCount += innerAAIndexCount;
+        }
         if (penWidth) {
-            // The reason I add extra vertices where the gradient lines intersect the border is
-            // to avoid pixel sized gaps between the fill and the border caused by floating point
-            // inaccuracies.
-            borderGeometry->allocate((segments + 1) * 2 * 4 + (lastGradientStop - nextGradientStop + 1) * 4 + 2);
-            borderVertexHead = borderVertexTail = (borderGeometry->vertexCount() >> 1) - 1;
-            borderVertices = (Vertex *)borderGeometry->vertexData();
+            borderTail = borderHead = indexCount + (borderIndexCount >> 1) + 1;
+            indexCount += borderIndexCount;
+        }
+        if (m_antialiasing && penWidth) {
+            outerAATail = outerAAHead = indexCount + (outerAAIndexCount >> 1) + 1;
+            indexCount += outerAAIndexCount;
         }
 
-        fill->allocate((segments + 1) * 4 + (lastGradientStop - nextGradientStop + 1) * 2);
-        fillVertices = (uchar *)fill->vertexData();
+        g->allocate(vertexCount, indexCount);
+        vertices = reinterpret_cast<Vertex *>(g->vertexData());
+        memset(vertices, 0, vertexCount * vertexStride);
+        quint16 *indices = g->indexDataAsUShort();
+        quint16 index = 0;
 
-        qreal py = 0; // previous inner y-coordinate.
-        qreal plx = 0; // previous inner left x-coordinate.
-        qreal prx = 0; // previous inner right x-coordinate.
+        float py = 0; // previous inner y-coordinate.
+        float plx = 0; // previous inner left x-coordinate.
+        float prx = 0; // previous inner right x-coordinate.
 
-        qreal angle = qreal(0.5) * M_PI / qreal(segments);
-        qreal cosStep = qFastCos(angle);
-        qreal sinStep = qFastSin(angle);
+        float angle = 0.5f * float(M_PI) / segments;
+        float cosStep = qFastCos(angle);
+        float sinStep = qFastSin(angle);
 
         for (int part = 0; part < 2; ++part) {
-            qreal c = 1 - part;
-            qreal s = part;
+            float c = 1 - part;
+            float s = part;
             for (int i = 0; i <= segments; ++i) {
-                qreal y, lx, rx;
+                float y, lx, rx;
                 if (innerRadius > 0) {
                     y = (part ? innerRect.bottom() : innerRect.top()) - innerRadius * c; // current inner y-coordinate.
                     lx = innerRect.left() - innerRadius * s; // current inner left x-coordinate.
                     rx = innerRect.right() + innerRadius * s; // current inner right x-coordinate.
-                    gradientPos = ((part ? innerRect.height() : 0) + radius - innerRadius * c) / (innerRect.height() + 2 * radius);
+                    gradientPos = ((part ? innerRect.height() : 0) + radius - innerRadius * c) / height;
                 } else {
                     y = (part ? innerRect.bottom() + innerRadius : innerRect.top() - innerRadius); // current inner y-coordinate.
                     lx = innerRect.left() - innerRadius; // current inner left x-coordinate.
                     rx = innerRect.right() + innerRadius; // current inner right x-coordinate.
-                    gradientPos = ((part ? innerRect.height() + innerRadius : -innerRadius) + radius) / (innerRect.height() + 2 * radius);
+                    gradientPos = ((part ? innerRect.height() + innerRadius : -innerRadius) + radius) / height;
                 }
-                qreal Y = (part ? innerRect.bottom() : innerRect.top()) - outerRadius * c; // current outer y-coordinate.
-                qreal lX = innerRect.left() - outerRadius * s; // current outer left x-coordinate.
-                qreal rX = innerRect.right() + outerRadius * s; // current outer right x-coordinate.
+                float Y = (part ? innerRect.bottom() : innerRect.top()) - outerRadius * c; // current outer y-coordinate.
+                float lX = innerRect.left() - outerRadius * s; // current outer left x-coordinate.
+                float rX = innerRect.right() + outerRadius * s; // current outer right x-coordinate.
 
                 while (nextGradientStop <= lastGradientStop && stops.at(nextGradientStop).first <= gradientPos) {
                     // Insert vertices at gradient stops.
-                    qreal gy = (innerRect.top() - radius) + stops.at(nextGradientStop).first * (innerRect.height() + 2 * radius);
-                    Q_ASSERT(fillVertexCount >= 2);
-                    qreal t = (gy - py) / (y - py);
-                    qreal glx = plx * (1 - t) + t * lx;
-                    qreal grx = prx * (1 - t) + t * rx;
+                    float gy = (innerRect.top() - radius) + stops.at(nextGradientStop).first * height;
+                    float t = (gy - py) / (y - py);
+                    float glx = plx * (1 - t) + t * lx;
+                    float grx = prx * (1 - t) + t * rx;
 
-                    if (penWidth) {
-                        const Vertex &first = borderVertices[borderVertexHead];
-                        borderVertices[--borderVertexHead].position = QVector2D(glx, gy);
-                        borderVertices[--borderVertexHead] = first;
+                    fillColor = colorToColor4ub(stops.at(nextGradientStop).second);
 
-                        const Vertex &last = borderVertices[borderVertexTail - 2];
-                        borderVertices[borderVertexTail++] = last;
-                        borderVertices[borderVertexTail++].position = QVector2D(grx, gy);
+                    if (hasFill) {
+                        indices[fillHead++] = index;
+                        indices[fillHead++] = index + 1;
                     }
 
-                    ColorVertex *vertices = (ColorVertex *)fillVertices;
-
-                    fillColor = colorToColor4ub(stops.at(nextGradientStop).second);
-                    vertices[fillVertexCount].position = QVector2D(grx, gy);
-                    vertices[fillVertexCount].color = fillColor;
-                    ++fillVertexCount;
-                    vertices[fillVertexCount].position = QVector2D(glx, gy);
-                    vertices[fillVertexCount].color = fillColor;
-                    ++fillVertexCount;
+                    if (penWidth) {
+                        --borderHead;
+                        indices[borderHead] = indices[borderHead + 2];
+                        indices[--borderHead] = index + 2;
+                        indices[borderTail++] = index + 3;
+                        indices[borderTail] = indices[borderTail - 2];
+                        ++borderTail;
+                    }
 
+                    if (m_antialiasing) {
+                        indices[--innerAAHead] = index + 2;
+                        indices[--innerAAHead] = index;
+                        indices[innerAATail++] = index + 1;
+                        indices[innerAATail++] = index + 3;
+
+                        bool lower = stops.at(nextGradientStop).first > 0.5f;
+                        float dy = lower ? qMin(0.0f, height - gy - delta) : qMax(0.0f, delta - gy);
+                        smoothVertices[index++].set(grx, gy, fillColor, width - grx - delta, dy);
+                        smoothVertices[index++].set(glx, gy, fillColor, delta - glx, dy);
+                        if (penWidth) {
+                            smoothVertices[index++].set(grx, gy, borderColor, 0.49f * penWidth * s, -0.49f * penWidth * c);
+                            smoothVertices[index++].set(glx, gy, borderColor, -0.49f * penWidth * s, -0.49f * penWidth * c);
+                        } else {
+                            dy = lower ? delta : -delta;
+                            smoothVertices[index++].set(grx, gy, transparent, delta, dy);
+                            smoothVertices[index++].set(glx, gy, transparent, -delta, dy);
+                        }
+                    } else {
+                        vertices[index++].set(grx, gy, fillColor);
+                        vertices[index++].set(glx, gy, fillColor);
+                        if (penWidth) {
+                            vertices[index++].set(grx, gy, borderColor);
+                            vertices[index++].set(glx, gy, borderColor);
+                        }
+                    }
                     ++nextGradientStop;
                 }
 
-                if (penWidth) {
-                    borderVertices[--borderVertexHead].position = QVector2D(lx, y);
-                    borderVertices[--borderVertexHead].position = QVector2D(lX, Y);
-                    borderVertices[borderVertexTail++].position = QVector2D(rX, Y);
-                    borderVertices[borderVertexTail++].position = QVector2D(rx, y);
-                }
-
-                if (stops.isEmpty()) {
-                    Q_ASSERT(m_material_type == TypeFlat);
-                    Vertex *vertices = (Vertex *)fillVertices;
-                    vertices[fillVertexCount++].position = QVector2D(rx, y);
-                    vertices[fillVertexCount++].position = QVector2D(lx, y);
-                } else {
+                if (!stops.isEmpty()) {
                     if (nextGradientStop == 0) {
                         fillColor = colorToColor4ub(stops.at(0).second);
                     } else if (nextGradientStop == stops.size()) {
@@ -391,18 +534,61 @@ void QSGDefaultRectangleNode::updateGeometry()
                     } else {
                         const QGradientStop &prev = stops.at(nextGradientStop - 1);
                         const QGradientStop &next = stops.at(nextGradientStop);
-                        qreal t = (gradientPos - prev.first) / (next.first - prev.first);
-                        fillColor = (colorToColor4ub(prev.second) * (1 - t) + colorToColor4ub(next.second) * t);
+                        float t = (gradientPos - prev.first) / (next.first - prev.first);
+                        fillColor = colorToColor4ub(prev.second) * (1 - t) + colorToColor4ub(next.second) * t;
                     }
+                }
+
+                if (hasFill) {
+                    indices[fillHead++] = index;
+                    indices[fillHead++] = index + 1;
+                }
+
+                if (penWidth) {
+                    indices[--borderHead] = index + 4;
+                    indices[--borderHead] = index + 2;
+                    indices[borderTail++] = index + 3;
+                    indices[borderTail++] = index + 5;
+                }
 
-                    ColorVertex *vertices = (ColorVertex *)fillVertices;
-                    vertices[fillVertexCount].position = QVector2D(rx, y);
-                    vertices[fillVertexCount].color = fillColor;
-                    ++fillVertexCount;
-                    vertices[fillVertexCount].position = QVector2D(lx, y);
-                    vertices[fillVertexCount].color = fillColor;
-                    ++fillVertexCount;
+                if (m_antialiasing) {
+                    indices[--innerAAHead] = index + 2;
+                    indices[--innerAAHead] = index;
+                    indices[innerAATail++] = index + 1;
+                    indices[innerAATail++] = index + 3;
+
+                    float dy = part ? qMin(0.0f, height - y - delta) : qMax(0.0f, delta - y);
+                    smoothVertices[index++].set(rx, y, fillColor, width - rx - delta, dy);
+                    smoothVertices[index++].set(lx, y, fillColor, delta - lx, dy);
+
+                    dy = part ? delta : -delta;
+                    if (penWidth) {
+                        smoothVertices[index++].set(rx, y, borderColor, 0.49f * penWidth * s, -0.49f * penWidth * c);
+                        smoothVertices[index++].set(lx, y, borderColor, -0.49f * penWidth * s, -0.49f * penWidth * c);
+                        smoothVertices[index++].set(rX, Y, borderColor, -0.49f * penWidth * s, 0.49f * penWidth * c);
+                        smoothVertices[index++].set(lX, Y, borderColor, 0.49f * penWidth * s, 0.49f * penWidth * c);
+                        smoothVertices[index++].set(rX, Y, transparent, delta, dy);
+                        smoothVertices[index++].set(lX, Y, transparent, -delta, dy);
+
+                        indices[--outerAAHead] = index - 2;
+                        indices[--outerAAHead] = index - 4;
+                        indices[outerAATail++] = index - 3;
+                        indices[outerAATail++] = index - 1;
+                    } else {
+                        smoothVertices[index++].set(rx, y, transparent, delta, dy);
+                        smoothVertices[index++].set(lx, y, transparent, -delta, dy);
+                    }
+                } else {
+                    vertices[index++].set(rx, y, fillColor);
+                    vertices[index++].set(lx, y, fillColor);
+                    if (penWidth) {
+                        vertices[index++].set(rx, y, borderColor);
+                        vertices[index++].set(lx, y, borderColor);
+                        vertices[index++].set(rX, Y, borderColor);
+                        vertices[index++].set(lX, Y, borderColor);
+                    }
                 }
+
                 py = y;
                 plx = lx;
                 prx = rx;
@@ -413,25 +599,29 @@ void QSGDefaultRectangleNode::updateGeometry()
                 s = s * cosStep + tmp * sinStep;
             }
         }
+        Q_ASSERT(index == vertexCount);
 
+        // Close the triangle strips.
+        if (m_antialiasing) {
+            indices[--innerAAHead] = indices[innerAATail - 1];
+            indices[--innerAAHead] = indices[innerAATail - 2];
+            Q_ASSERT(innerAATail <= indexCount);
+        }
         if (penWidth) {
-            // Close border.
-            const Vertex &first = borderVertices[borderVertexHead];
-            const Vertex &second = borderVertices[borderVertexHead + 1];
-            borderVertices[borderVertexTail++] = first;
-            borderVertices[borderVertexTail++] = second;
-
-            Q_ASSERT(borderVertexHead == 0 && borderVertexTail == borderGeometry->vertexCount());
+            indices[--borderHead] = indices[borderTail - 1];
+            indices[--borderHead] = indices[borderTail - 2];
+            Q_ASSERT(borderTail <= indexCount);
+        }
+        if (m_antialiasing && penWidth) {
+            indices[--outerAAHead] = indices[outerAATail - 1];
+            indices[--outerAAHead] = indices[outerAATail - 2];
+            Q_ASSERT(outerAATail == indexCount);
         }
-        Q_ASSERT(fillVertexCount == fill->vertexCount());
-
     } else {
-
         // Straight corners.
         QRectF innerRect = m_rect;
         QRectF outerRect = m_rect;
 
-        qreal halfPenWidth = 0;
         if (penWidth) {
             if (m_aligned && (int(penWidth) & 1)) {
                 // Pen width is odd, so add the offset as documented.
@@ -439,61 +629,114 @@ void QSGDefaultRectangleNode::updateGeometry()
                 innerRect.moveTop(innerRect.top() + qreal(0.5));
                 outerRect = innerRect;
             }
-            halfPenWidth = penWidth * qreal(0.5);
-            innerRect.adjust(halfPenWidth, halfPenWidth, -halfPenWidth, -halfPenWidth);
-            outerRect.adjust(-halfPenWidth, -halfPenWidth, halfPenWidth, halfPenWidth);
+            innerRect.adjust(0.5f * penWidth, 0.5f * penWidth, -0.5f * penWidth, -0.5f * penWidth);
+            outerRect.adjust(-0.5f * penWidth, -0.5f * penWidth, 0.5f * penWidth, 0.5f * penWidth);
         }
 
-        int nextGradientStop = 0;
-        qreal gradientPos = halfPenWidth / m_rect.height();
-        while (nextGradientStop < stops.size() && stops.at(nextGradientStop).first <= gradientPos)
-            ++nextGradientStop;
-        int lastGradientStop = stops.size() - 1;
-        qreal lastGradientPos = (m_rect.height() - halfPenWidth) / m_rect.height();
-        while (lastGradientStop >= nextGradientStop && stops.at(lastGradientStop).first >= lastGradientPos)
-            --lastGradientStop;
-
-        int borderVertexCount = 0;
+        float delta = qMin(width, height) * 0.5f;
+        int innerVertexCount = 4 + gradientIntersections * 2;
+        int outerVertexCount = 4;
+        int vertexCount = innerVertexCount;
+        if (m_antialiasing || penWidth)
+            vertexCount += innerVertexCount;
+        if (penWidth)
+            vertexCount += outerVertexCount;
+        if (m_antialiasing && penWidth)
+            vertexCount += outerVertexCount;
+
+        int fillIndexCount = innerVertexCount;
+        int innerAAIndexCount = innerVertexCount * 2 + 2;
+        int borderIndexCount = innerVertexCount * 2 + 2;
+        int outerAAIndexCount = outerVertexCount * 2 + 2;
+        int indexCount = 0;
+        int fillHead = 0;
+        int innerAAHead = 0;
+        int innerAATail = 0;
+        int borderHead = 0;
+        int borderTail = 0;
+        int outerAAHead = 0;
+        int outerAATail = 0;
+        bool hasFill = m_color.rgba() != 0 || !stops.isEmpty();
+        if (hasFill)
+            indexCount += fillIndexCount;
+        if (m_antialiasing) {
+            innerAATail = innerAAHead = indexCount + (innerAAIndexCount >> 1) + 1;
+            indexCount += innerAAIndexCount;
+        }
         if (penWidth) {
-            borderGeometry->allocate((1 + lastGradientStop - nextGradientStop) * 4 + 10);
-            borderVertices = (Vertex *)borderGeometry->vertexData();
+            borderTail = borderHead = indexCount + (borderIndexCount >> 1) + 1;
+            indexCount += borderIndexCount;
+        }
+        if (m_antialiasing && penWidth) {
+            outerAATail = outerAAHead = indexCount + (outerAAIndexCount >> 1) + 1;
+            indexCount += outerAAIndexCount;
         }
-        fill->allocate((3 + lastGradientStop - nextGradientStop) * 2);
-        fillVertices = (uchar *)fill->vertexData();
 
-        QVarLengthArray<qreal, 16> ys(3 + lastGradientStop - nextGradientStop);
-        int yCount = 0;
+        g->allocate(vertexCount, indexCount);
+        vertices = reinterpret_cast<Vertex *>(g->vertexData());
+        memset(vertices, 0, vertexCount * vertexStride);
+        quint16 *indices = g->indexDataAsUShort();
+        quint16 index = 0;
 
-        for (int part = 0; part < 2; ++part) {
-            qreal y = (part ? innerRect.bottom() : innerRect.top());
-            gradientPos = (y - innerRect.top() + halfPenWidth) / m_rect.height();
+        float lx = innerRect.left();
+        float rx = innerRect.right();
+        float lX = outerRect.left();
+        float rX = outerRect.right();
+
+        for (int part = -1; part <= 1; part += 2) {
+            float y = (part == 1 ? innerRect.bottom() : innerRect.top());
+            float Y = (part == 1 ? outerRect.bottom() : outerRect.top());
+            gradientPos = (y - innerRect.top() + 0.5f * penWidth) / height;
 
             while (nextGradientStop <= lastGradientStop && stops.at(nextGradientStop).first <= gradientPos) {
                 // Insert vertices at gradient stops.
-                qreal gy = (innerRect.top() - halfPenWidth) + stops.at(nextGradientStop).first * m_rect.height();
-                Q_ASSERT(fillVertexCount >= 2);
-
-                ColorVertex *vertices = (ColorVertex *)fillVertices;
+                float gy = (innerRect.top() - 0.5f * penWidth) + stops.at(nextGradientStop).first * height;
 
                 fillColor = colorToColor4ub(stops.at(nextGradientStop).second);
-                vertices[fillVertexCount].position = QVector2D(innerRect.right(), gy);
-                vertices[fillVertexCount].color = fillColor;
-                ++fillVertexCount;
-                vertices[fillVertexCount].position = QVector2D(innerRect.left(), gy);
-                vertices[fillVertexCount].color = fillColor;
-                ++fillVertexCount;
 
-                ys[yCount++] = gy;
+                if (hasFill) {
+                    indices[fillHead++] = index;
+                    indices[fillHead++] = index + 1;
+                }
+
+                if (penWidth) {
+                    --borderHead;
+                    indices[borderHead] = indices[borderHead + 2];
+                    indices[--borderHead] = index + 2;
+                    indices[borderTail++] = index + 3;
+                    indices[borderTail] = indices[borderTail - 2];
+                    ++borderTail;
+                }
+
+                if (m_antialiasing) {
+                    indices[--innerAAHead] = index + 2;
+                    indices[--innerAAHead] = index;
+                    indices[innerAATail++] = index + 1;
+                    indices[innerAATail++] = index + 3;
 
+                    bool lower = stops.at(nextGradientStop).first > 0.5f;
+                    float dy = lower ? qMin(0.0f, height - gy - delta) : qMax(0.0f, delta - gy);
+                    smoothVertices[index++].set(rx, gy, fillColor, width - rx - delta, dy);
+                    smoothVertices[index++].set(lx, gy, fillColor, delta - lx, dy);
+                    if (penWidth) {
+                        smoothVertices[index++].set(rx, gy, borderColor, 0.49f * penWidth, (lower ? 0.49f : -0.49f) * penWidth);
+                        smoothVertices[index++].set(lx, gy, borderColor, -0.49f * penWidth, (lower ? 0.49f : -0.49f) * penWidth);
+                    } else {
+                        smoothVertices[index++].set(rx, gy, transparent, delta, lower ? delta : -delta);
+                        smoothVertices[index++].set(lx, gy, transparent, -delta, lower ? delta : -delta);
+                    }
+                } else {
+                    vertices[index++].set(rx, gy, fillColor);
+                    vertices[index++].set(lx, gy, fillColor);
+                    if (penWidth) {
+                        vertices[index++].set(rx, gy, borderColor);
+                        vertices[index++].set(lx, gy, borderColor);
+                    }
+                }
                 ++nextGradientStop;
             }
 
-            if (stops.isEmpty()) {
-                Q_ASSERT(m_material_type == TypeFlat);
-                Vertex *vertices = (Vertex *)fillVertices;
-                vertices[fillVertexCount++].position = QVector2D(innerRect.right(), y);
-                vertices[fillVertexCount++].position = QVector2D(innerRect.left(), y);
-            } else {
+            if (!stops.isEmpty()) {
                 if (nextGradientStop == 0) {
                     fillColor = colorToColor4ub(stops.at(0).second);
                 } else if (nextGradientStop == stops.size()) {
@@ -501,43 +744,78 @@ void QSGDefaultRectangleNode::updateGeometry()
                 } else {
                     const QGradientStop &prev = stops.at(nextGradientStop - 1);
                     const QGradientStop &next = stops.at(nextGradientStop);
-                    qreal t = (gradientPos - prev.first) / (next.first - prev.first);
-                    fillColor = (colorToColor4ub(prev.second) * (1 - t) + colorToColor4ub(next.second) * t);
+                    float t = (gradientPos - prev.first) / (next.first - prev.first);
+                    fillColor = colorToColor4ub(prev.second) * (1 - t) + colorToColor4ub(next.second) * t;
                 }
-
-                ColorVertex *vertices = (ColorVertex *)fillVertices;
-                vertices[fillVertexCount].position = QVector2D(innerRect.right(), y);
-                vertices[fillVertexCount].color = fillColor;
-                ++fillVertexCount;
-                vertices[fillVertexCount].position = QVector2D(innerRect.left(), y);
-                vertices[fillVertexCount].color = fillColor;
-                ++fillVertexCount;
             }
 
-            ys[yCount++] = y;
-        }
-
-        if (penWidth) {
-            borderVertices[borderVertexCount++].position = QVector2D(outerRect.right(), outerRect.top());
-            borderVertices[borderVertexCount++].position = QVector2D(innerRect.right(), ys[0]);
-            for (int i = 1; i < fillVertexCount / 2; ++i) {
-                borderVertices[borderVertexCount++].position = QVector2D(outerRect.right(), outerRect.bottom());
-                borderVertices[borderVertexCount++].position = QVector2D(innerRect.right(), ys[i]);
+            if (hasFill) {
+                indices[fillHead++] = index;
+                indices[fillHead++] = index + 1;
             }
 
-            borderVertices[borderVertexCount++].position = QVector2D(outerRect.left(), outerRect.bottom());
-            borderVertices[borderVertexCount++].position = QVector2D(innerRect.left(), ys[fillVertexCount / 2 - 1]);
-            for (int i = fillVertexCount / 2 - 2; i >= 0; --i) {
-                borderVertices[borderVertexCount++].position = QVector2D(outerRect.left(), outerRect.top());
-                borderVertices[borderVertexCount++].position = QVector2D(innerRect.left(), ys[i]);
+            if (penWidth) {
+                indices[--borderHead] = index + 4;
+                indices[--borderHead] = index + 2;
+                indices[borderTail++] = index + 3;
+                indices[borderTail++] = index + 5;
             }
 
-            borderVertices[borderVertexCount++].position = QVector2D(outerRect.right(), outerRect.top());
-            borderVertices[borderVertexCount++].position = QVector2D(innerRect.right(), innerRect.top());
+            if (m_antialiasing) {
+                indices[--innerAAHead] = index + 2;
+                indices[--innerAAHead] = index;
+                indices[innerAATail++] = index + 1;
+                indices[innerAATail++] = index + 3;
+
+                float dy = part == 1 ? qMin(0.0f, height - y - delta) : qMax(0.0f, delta - y);
+                smoothVertices[index++].set(rx, y, fillColor, width - rx - delta, dy);
+                smoothVertices[index++].set(lx, y, fillColor, delta - lx, dy);
+
+                if (penWidth) {
+                    smoothVertices[index++].set(rx, y, borderColor, 0.49f * penWidth, 0.49f * penWidth * part);
+                    smoothVertices[index++].set(lx, y, borderColor, -0.49f * penWidth, 0.49f * penWidth * part);
+                    smoothVertices[index++].set(rX, Y, borderColor, -0.49f * penWidth, -0.49f * penWidth * part);
+                    smoothVertices[index++].set(lX, Y, borderColor, 0.49f * penWidth, -0.49f * penWidth * part);
+                    smoothVertices[index++].set(rX, Y, transparent, delta, delta * part);
+                    smoothVertices[index++].set(lX, Y, transparent, -delta, delta * part);
+
+                    indices[--outerAAHead] = index - 2;
+                    indices[--outerAAHead] = index - 4;
+                    indices[outerAATail++] = index - 3;
+                    indices[outerAATail++] = index - 1;
+                } else {
+                    smoothVertices[index++].set(rx, y, transparent, delta, delta * part);
+                    smoothVertices[index++].set(lx, y, transparent, -delta, delta * part);
+                }
+            } else {
+                vertices[index++].set(rx, y, fillColor);
+                vertices[index++].set(lx, y, fillColor);
+                if (penWidth) {
+                    vertices[index++].set(rx, y, borderColor);
+                    vertices[index++].set(lx, y, borderColor);
+                    vertices[index++].set(rX, Y, borderColor);
+                    vertices[index++].set(lX, Y, borderColor);
+                }
+            }
+        }
+        Q_ASSERT(index == vertexCount);
 
-            Q_ASSERT(borderVertexCount == borderGeometry->vertexCount());
+        // Close the triangle strips.
+        if (m_antialiasing) {
+            indices[--innerAAHead] = indices[innerAATail - 1];
+            indices[--innerAAHead] = indices[innerAATail - 2];
+            Q_ASSERT(innerAATail <= indexCount);
+        }
+        if (penWidth) {
+            indices[--borderHead] = indices[borderTail - 1];
+            indices[--borderHead] = indices[borderTail - 2];
+            Q_ASSERT(borderTail <= indexCount);
+        }
+        if (m_antialiasing && penWidth) {
+            indices[--outerAAHead] = indices[outerAATail - 1];
+            indices[--outerAAHead] = indices[outerAATail - 2];
+            Q_ASSERT(outerAATail == indexCount);
         }
-        Q_ASSERT(fillVertexCount == fill->vertexCount());
     }
 
     markDirty(DirtyGeometry);