code: def calc_pointsize(width, height, text, min_pointsize)
        current_pointsize = min_pointsize
  
        metrics = nil
  
        loop {
          self.pointsize = current_pointsize
          last_metrics = metrics
          metrics = get_multiline_type_metrics(text)
  
          if metrics.width + stroke_padding > width or
            metrics.height + stroke_padding > height
            if current_pointsize > min_pointsize
              current_pointsize -= 1
              metrics = last_metrics
            end
            break
          else
            current_pointsize += 1
          end
        }
  
        [current_pointsize, metrics]
      end
docs: Calculate the largest pointsize for text that will be in a width x
   height box.
  
   Return [pointsize, metrics] where pointsize is the largest pointsize and
   metrics is the RMagick multiline type metrics of the best fit.