def render( content, ctx )
    
    ####################
    ## todo/fix: move ctx to Gen.initialize - why? why not?
    @name     = ctx[:name]

    @outdir   = ctx[:outdir]
    @srcdir   = ctx[:srcdir]
    @usrdir   = ctx[:usrdir]
    
    # run text filters
  
    config.text_filters.each do |filter|
      mn = filter.tr( '-', '_' ).to_sym  # construct method name (mn)
      puts "  run filter #{mn}..."
      content = send( mn, content )   # call filter e.g.  include_helper_hack( content )  
    end

    if config.takahashi?
      content = takahashi_slide_breaks( content )
    end

    # convert light-weight markup to hypertext

    content = markdown_to_html( content )
    content
  end
def render( content, ctx )
    
    ####################
    ## todo/fix: move ctx to Gen.initialize - why? why not?
    @name     = ctx[:name]

    @outdir   = ctx[:outdir]
    @srcdir   = ctx[:srcdir]
    @usrdir   = ctx[:usrdir]
    
    # run text filters
  
    config.text_filters.each do |filter|
      mn = filter.tr( '-', '_' ).to_sym  # construct method name (mn)
      puts "  run filter #{mn}..."
      content = send( mn, content )   # call filter e.g.  include_helper_hack( content )  
    end

    if config.takahashi?
      content = takahashi_slide_breaks( content )
    end

    # convert light-weight markup to hypertext

    content = markdown_to_html( content )
    content
  end
NB: "initalized" in create_slideshow