public void RenderText(TextRenderInfo renderInfo)
{
if (textRectangle == null)
textRectangle = renderInfo.GetDescentLine().GetBoundingRectange();
else
textRectangle.Add(renderInfo.GetDescentLine().GetBoundingRectange());
textRectangle.Add(renderInfo.GetAscentLine().GetBoundingRectange());
}