shape.mode = 'deleted'

          if shape.mode == 'polygon' then
            local idx = table.find(shape.vertices, i)
            assert(idx)
            table.remove(shape.vertices, idx)
            if #shape.vertices < 3 then
              shape.mode = 'deleted'
            end
          else
            shape.mode = 'deleted'
          end

    print(p, shape.p1, shape.p2)

end
function table.find(h, x)
  for k,v in pairs(h) do
    if v == x then
      return k
    end
  end