Drawing QPolygonF to QSGGeometry

[posix]

I'm trying to draw a polygon using QSGGeometry/QSGFlatColorMaterial. If I draw a rectangle with right corners, then everything works correctly:

QPolygonF polygon;

// Rectangle with right corners
polygon << QPointF(0, 0)
        << QPointF(230, 0)
        << QPointF(230, 230)
        << QPointF(0, 230)
        << QPointF(0, 0);

QSGGeometry *geometry = new QSGGeometry(QSGGeometry::defaultAttributes_Point2D(), polygon.count());
QSGFlatColorMaterial *material = new QSGFlatColorMaterial();

material->setColor(QColor("red"));
QSGGeometry::Point2D *vertices = geometry->vertexDataAsPoint2D();

for (int i = 0; i < polygon.count(); i++) {
    QPointF point = polygon.at(i);
    vertices[i].set(point.x(), point.y());
}

QSGGeometryNode *node = new QSGGeometryNode();
node->setGeometry(geometry);
node->setMaterial(material);

Correct result:

But if I try to draw a rectangle with rounded corners:

// Rounded rectangle
polygon << QPointF(0, 10)
        << QPointF(0.78585, 6.10755)
        << QPointF(2.92893, 2.92893)
        << QPointF(6.10755, 0.78585)
        << QPointF(10, 0)
        << QPointF(220, 0)
        << QPointF(223.892, 0.78585)
        << QPointF(227.071, 2.92893)
        << QPointF(229.214, 6.10755)
        << QPointF(230, 10)
        << QPointF(230, 220)
        << QPointF(229.214, 223.892)
        << QPointF(227.071, 227.071)
        << QPointF(223.892, 229.214)
        << QPointF(220, 230)
        << QPointF(10, 230)
        << QPointF(6.10755, 229.214)
        << QPointF(2.92893, 227.071)
        << QPointF(0.78585, 223.892)
        << QPointF(0, 220)
        << QPointF(0, 10);

Then I get this result:

I need the outline of the rectangle to be filled with color. What could be the problem and how to fix it?