filename = nil

function love.load()

function love.load(arg)
  if #arg > 0 then
    filename = arg[1]
    lines = load_from_disk(filename)
  end

    return
  end
  if lines.current then

  elseif lines.current then

  save_to_disk(lines, filename)

function load_from_disk(filename)
  local result = {}
  local infile = io.open(filename)
  if infile then
    while true do
      local line = infile:read()
      if line == nil then break end
      if line == '```lines' then  -- inflexible with whitespace since these files are always autogenerated
        table.insert(result, load_drawing(infile))
      else
        table.insert(result, line)
      end
    end
  end
  return result
end
function save_to_disk(lines, filename)
  local outfile = io.open(filename, 'w')
  for _,line in ipairs(lines) do
    if type(line) == 'table' then
      store_drawing(outfile, line)
    else
      outfile:write(line..'\n')
    end
  end
end
json = require 'json'
function load_drawing(infile)
  local drawing = {h=256/2, points={}, shapes={}, pending={}}
  while true do
    local line = infile:read()
    assert(line)
    if line == '```' then break end
    local shape = json.decode(line)
    if shape.mode == 'line' then
      shape.p1 = insert_point(drawing.points, shape.p1.x, shape.p1.y)
      shape.p2 = insert_point(drawing.points, shape.p2.x, shape.p2.y)
    end
    table.insert(drawing.shapes, shape)
  end
  return drawing
end
function store_drawing(outfile, drawing)
  outfile:write('```lines\n')
  for _,shape in ipairs(drawing.shapes) do
    if shape.mode == 'line' then
      local line = json.encode({mode=shape.mode, p1=drawing.points[shape.p1], p2=drawing.points[shape.p2]})
      outfile:write(line..'\n')
    end
  end
  outfile:write('```\n')
end