class UtilityController < ApplicationController
  # translates TMS formats from one ordering to another
  def tms_alt
    # /z/x/y.png
    # /z/x/y.png
    # /z/x/(2*z-y-1).png
    y = 2**params[:z].to_i - params[:y].to_i - 1
    redirect_to("/tms/#{params[:id]}/#{params[:z]}/#{params[:x]}/#{y}.png")
  end
end