code: func (t *Text) calcY(height int) int {
  	if t.align&VAlignCenter != 0 {
  		return (height - len(t.lengths)) / 2
  	}
  	if t.align&VAlignBottom != 0 {
  		return height - len(t.lengths)
  	}
  	return 0
  }
docs: // calcY figures the initial Y offset.  Alignment is top by default.