-- Snake on love2d

function love.load()
  love.graphics.setDefaultFilter("nearest", "nearest")

  img = love.graphics.newImage("circle01_96x96_32col.png")

  x = love.graphics.getWidth() / 2
  y = love.graphics.getHeight() / 2

  pos_buf = {}
  for i = 1, 128 do
    pos_buf[i] = {x, y}
  end
  idx = #pos_buf
end

function love.update(dt)
  -- move head
  mx, my = love.mouse.getPosition()
  local dx = (mx - x) * 0.1
  local dy = (my - y) * 0.1
  x = x + dx
  y = y + dy

  -- Updated index to record head position
  idx = idx - 1
  if idx <= 0 then
    idx = #pos_buf
  end

  -- record head position
  pos_buf[idx] = {x, y}
end

function love.draw()
  -- fill window background
  love.graphics.clear(0.4, 0.7, 0.8, 1.0)

  -- draw snake
  local ox, oy = img:getWidth() / 2, img:getHeight() / 2
  love.graphics.setColor(1.0, 1.0, 1.0, 1.0)

  for i = 16, 0, -1 do
    local n = ((idx + i * 4) % #pos_buf) + 1
    local px = pos_buf[n][1]
    local py = pos_buf[n][2]
    love.graphics.draw(img, px, py, 0, 1.0, 1.0, ox, oy)
  end

  -- draw FPS txet
  love.graphics.print("FPS: " .. tostring(love.timer.getFPS()), 2, 2)
end

function love.keypressed(key, isrepeat)
  if key == "escape" then
    -- ESC key to exit
    love.event.quit()
  end
end