DPI calculator plugin for rbot

dpi-0.1.rb

class DpiPlugin < Plugin
  def help(plugin, topic="") 
    "!dpi width height diagonal"
  end

  def dpi(m, params)
    begin
      x = params[:width].to_f
      y = params[:height].to_f
      d = params[:diagonal].to_f

      if x == 0 or y == 0 
        m.reply "oops"
        return    
      end

      dpi = (x / Math.sqrt(d**2 / (1 + ((y/x)**2)))).to_i

      m.reply "#{dpi}DPI"
    rescue Exception => e
      m.reply "error: #{e.message}"
    end
  end
end
plugin = DpiPlugin.new
plugin.map 'dpi [:width] [:height] [:diagonal]',
  :defaults => { :width => 2048, :height => 1536, :diagonal => 9.7 }, 
  :thread => true