GetTextBounds
void GetTextBounds(int32 textOffset,
info.layout->GetTextBounds(textOffset, x1, y1, x2, y2);
void GetTextBounds(int32 textOffset,
fTextDocumentLayout.GetTextBounds(textOffset, x1, y1, x2, y2);
fTextDocumentLayout.GetTextBounds(start, startX1, startY1, startX2,
fTextDocumentLayout.GetTextBounds(end, endX1, endY1, endX2, endY2);
fLayout->GetTextBounds(caret, x1, y1, x2, y2);