void CompoundUpdateInputVisitor::_updateZoom( const Compound* compound,
                                              Frame* frame,
                                              const Frame* outputFrame )
{
    Zoom zoom = frame->getNativeZoom();
    if( !zoom.isValid( )) // if zoom is not set, inherit from parent
        zoom = compound->getInheritZoom();

    // Zoom difference between output and input
    const FrameData* frameData = outputFrame->getMasterData();
    zoom /= frameData->getZoom();

    frame->setZoom( zoom );
}
void CompoundUpdateOutputVisitor::_updateZoom(const Compound* compound,
                                              Frame* frame)
{
    Zoom zoom = frame->getNativeZoom();
    Zoom zoom_1;

    if (!zoom.isValid()) // if zoom is not set, auto-calculate from parent
    {
        zoom_1 = compound->getInheritZoom();
        LBASSERT(zoom_1.isValid());
        zoom.x() = 1.0f / zoom_1.x();
        zoom.y() = 1.0f / zoom_1.y();
    }
    else
    {
        zoom_1.x() = 1.0f / zoom.x();
        zoom_1.y() = 1.0f / zoom.y();
    }

    if (frame->getType() == Frame::TYPE_TEXTURE)
    {
        FrameData* frameData = frame->getMasterData();
        frameData->setZoom(zoom_1); // textures are zoomed by input frame
        frame->setZoom(Zoom::NONE);
    }
    else
    {
        Zoom inputZoom;
        /* Output frames downscale pixel data during readback, and upscale it on
         * the input frame by setting the input frame's inherit zoom. */
        if (zoom.x() > 1.0f)
        {
            inputZoom.x() = zoom_1.x();
            zoom.x() = 1.f;
        }
        if (zoom.y() > 1.0f)
        {
            inputZoom.y() = zoom_1.y();
            zoom.y() = 1.f;
        }

        FrameData* frameData = frame->getMasterData();
        frameData->setZoom(inputZoom);
        frame->setZoom(zoom);
    }
}