Qt 5 to-do in qpaintengineex_p.h

    // ### Qt5: remove, once QtGui is merged into QtGui and QtWidgets
    // Return a pixmap filter of "type" that can render the parameters
    // in "prototype".  The returned filter is owned by the engine and
    // will be destroyed when the engine is destroyed.  The "prototype"
    // allows the engine to pick different filters based on the parameters
    // that will be requested, and not just the "type".
    virtual QPixmapFilter *pixmapFilter(int /*type*/, const QPixmapFilter * /*prototype*/) { return 0; }

    QPixmapFilter *filter = painter->paintEngine() && painter->paintEngine()->isExtended() ?
        static_cast<QPaintEngineEx *>(painter->paintEngine())->pixmapFilter(type(), this) : 0;
    QPixmapConvolutionFilter *convolutionFilter = static_cast<QPixmapConvolutionFilter*>(filter);
    if (convolutionFilter) {
        convolutionFilter->setConvolutionKernel(d->convolutionKernel, d->kernelWidth, d->kernelHeight);
        convolutionFilter->d_func()->convoluteAlpha = d->convoluteAlpha;
        convolutionFilter->draw(painter, p, src, srcRect);
        return;
    }