code: func (t *Text) calcX(width, line int) int {
  	if t.align&HAlignCenter != 0 {
  		return (width - t.lengths[line]) / 2
  	}
  	if t.align&HAlignRight != 0 {
  		return width - t.lengths[line]
  	}
  	return 0
  }
docs: // calcX figures the initial X offset for the given line.
  // Alignment is left by default.