# File wm.rb, line 500
    def diamond!
      if (numClients = num_grounded_clients) > 0
        subtriArea = numClients / 2
        crestArea = numClients % subtriArea

        # build fist sub-triangle upwards
          height = area = 0
          lastCol = nil

          each_column do |col|
            if area < subtriArea
              height += 1

              col.length = height
              area += height

              col.mode = :default
              lastCol = col
            else
              break
            end
          end

        # build crest of overall triangle
          if crestArea > 0
            lastCol.length = height + crestArea
          end

        # build second sub-triangle downwards
          each_column(lastCol.index + 1) do |col|
            if area > 0
              col.length = height
              area -= height

              height -= 1
            else
              break
            end
          end
      end
    end