void RtpRender::quePrivateRender(BBox& viewPort,
const QSize& bufSize)
{
// Set to mark that private rendering is queued.
_privateRenderQueued = true;
_queuedViewPort = viewPort;
_queuedSize = bufSize;
// If the _timer is inactive, start the private
// rendering now.
if (!(_timer.isActive()))
switchToPrivate();
}