class PDF::Reader::PageLayout

def initialize(runs, mediabox)
  # mediabox is a 4-element array for now, but it'd be nice to switch to a
  # PDF::Reader::Rectangle at some point
  PDF::Reader::Error.validate_not_nil(mediabox, "mediabox")
  @mediabox = process_mediabox(mediabox)
  @runs = runs
  @mean_font_size   = mean(@runs.map(&:font_size)) || DEFAULT_FONT_SIZE
  @mean_font_size = DEFAULT_FONT_SIZE if @mean_font_size == 0
  @median_glyph_width = median(@runs.map(&:mean_character_width)) || 0
  @x_offset = @runs.map(&:x).sort.first || 0
  lowest_y = @runs.map(&:y).sort.first || 0
  @y_offset = lowest_y > 0 ? 0 : lowest_y
end