void SVGRadialGradientElement::buildGradient() const
{
    RadialGradientAttributes attributes = collectGradientProperties();

    RefPtr<SVGPaintServerRadialGradient> radialGradient = WTF::static_pointer_cast<SVGPaintServerRadialGradient>(m_resource);

    double adjustedFocusX = attributes.fx();
    double adjustedFocusY = attributes.fy();

    double fdx = attributes.fx() - attributes.cx();
    double fdy = attributes.fy() - attributes.cy();

    // Spec: If (fx, fy) lies outside the circle defined by (cx, cy) and
    // r, set (fx, fy) to the point of intersection of the line through
    // (fx, fy) and the circle.
    if (sqrt(fdx * fdx + fdy * fdy) > attributes.r()) {
        double angle = atan2(attributes.fy() * 100.0, attributes.fx() * 100.0);
        adjustedFocusX = cos(angle) * attributes.r();
        adjustedFocusY = sin(angle) * attributes.r();
    }

    FloatPoint focalPoint = FloatPoint::narrowPrecision(attributes.fx(), attributes.fy());
    FloatPoint centerPoint = FloatPoint::narrowPrecision(attributes.cx(), attributes.cy());

    RefPtr<Gradient> gradient = Gradient::create(
        FloatPoint::narrowPrecision(adjustedFocusX, adjustedFocusY),
        0.f, // SVG does not support a "focus radius"
        centerPoint,
        narrowPrecisionToFloat(attributes.r()));
    gradient->setSpreadMethod(attributes.spreadMethod());

    Vector<SVGGradientStop> stops = attributes.stops();
    float previousOffset = 0.0f;
    for (unsigned i = 0; i < stops.size(); ++i) {
         float offset = std::min(std::max(previousOffset, stops[i].first), 1.0f);
         previousOffset = offset;
         gradient->addColorStop(offset, stops[i].second);
    }

    radialGradient->setGradient(gradient);

    if (attributes.stops().isEmpty())
        return;

    radialGradient->setBoundingBoxMode(attributes.boundingBoxMode());
    radialGradient->setGradientTransform(attributes.gradientTransform());
    radialGradient->setGradientCenter(centerPoint);
    radialGradient->setGradientFocal(focalPoint);
    radialGradient->setGradientRadius(narrowPrecisionToFloat(attributes.r()));
    radialGradient->setGradientStops(attributes.stops());
}
void SVGRadialGradientElement::buildGradient() const
{
    RadialGradientAttributes attributes = collectGradientProperties();

    // If we didn't find any gradient containing stop elements, ignore the request.
    if (attributes.stops().isEmpty())
        return;

    RefPtr<SVGPaintServerRadialGradient> radialGradient = WTF::static_pointer_cast<SVGPaintServerRadialGradient>(m_resource);

    radialGradient->setGradientStops(attributes.stops());
    radialGradient->setBoundingBoxMode(attributes.boundingBoxMode());
    radialGradient->setGradientSpreadMethod(attributes.spreadMethod()); 
    radialGradient->setGradientTransform(attributes.gradientTransform());
    radialGradient->setGradientCenter(FloatPoint::narrowPrecision(attributes.cx(), attributes.cy()));
    radialGradient->setGradientFocal(FloatPoint::narrowPrecision(attributes.fx(), attributes.fy()));
    radialGradient->setGradientRadius(narrowPrecisionToFloat(attributes.r()));
}
float RenderSVGResourceRadialGradient::radius(const RadialGradientAttributes& attributes) const
{
    return SVGLengthContext::resolveLength(static_cast<const SVGElement*>(node()), attributes.gradientUnits(), attributes.r());
}
float LayoutSVGResourceRadialGradient::radius(const RadialGradientAttributes& attributes) const
{
    return SVGLengthContext::resolveLength(element(), attributes.gradientUnits(), *attributes.r());
}