gistfile1.txt

  # formats - array of MediaFormat objects
  # :width - desired width
  # :height - desired height
  # :fuzz - number of pixels it's ok to be off by
  # :constrain - scale image client-side to specified :width and :height, using image best matching specified :width and :height
  # :include_cropped - include cropped images

  def image_helper(formats, options={})
    options[:constrain] = true unless options[:constrain].blank?
    options[:fuzz] ||= 0
    options[:include_cropped] ||= false

    desired_w = options[:width]  + options[:fuzz]
    desired_h = options[:height] + options[:fuzz]

    closest = 10000
    format = formats.first

    #LOG.debug "looking for #{options[:width]}/#{options[:height]}"
    # choose the format that is closest to the desired size, as long as it's not larger (+ fuzz)
    formats.each do |f|
      next if !options[:include_cropped] && ImageFormat::FORMATS[f.name][:crop] rescue false
      next if (f.original and f.content_type != 'image/jpeg')

      #LOG.debug "#{f.name}: #{f.width}/#{f.height}"

      [desired_w - f.width, desired_h - f.height].each do |dist|
        #LOG.debug "not considering #{f.name} because #{dist} < 0" unless dist >= 0

        # negative means too big.
        break if dist < 0

        #LOG.debug "is #{dist} < #{closest}?"
        if dist < closest
          closest = dist
          format = f
          #LOG.debug "yes, using #{format.name} (#{format.width}/#{format.height}). closest is now #{closest}"
        else
          #LOG.debug "no."
        end
      end
    end

    if options[:constrain]
      w, h = scale_image_params(format.width, format.height, options[:width], options[:height])
    else
      w = format.width
      h = format.height
    end
    #LOG.debug "fmt: #{format.width}/#{format.height}, wanting #{options[:width]}/#{options[:height]}, scaled to #{w}/#{h}"

    image_tag(format.uri, :width => w, :height => h)
  end