public LineSegment GetDescentLine()
{
// per GetFontDescription() API, descent is returned as a negative number, so we apply that as a normal vertical offset
float descent = gs.GetFont().GetFontDescriptor(BaseFont.DESCENT, gs.GetFontSize());
return GetUnscaledBaselineWithOffset(descent + gs.rise).TransformBy(textToUserSpaceTransformMatrix);
}