function param1()
  return "interval", 10, 100, 50
end

function main( x, y, p )

  local w = bs_width_max()
  if w < 5 then
    w = 5
  end

  if not firstDraw then
    local distance = bs_distance( lastDrawX - x, lastDrawY - y )
    if distance < w * bs_param1()/50 then
      return 0
    end
  end

  local dx,dy = bs_dir()
  local nx,ny = bs_normal()

  bs_bezier_begin( 0, -0.5 )
  bs_bezier_c( 0.8, 0.5, -0.8, 0.5, 0, -0.5 )
  bs_bezier_mul( w, w )
  bs_bezier_move( x, y )

  local r,g,b = bs_fore()
  bs_fill( r,g,b, 255 )

  lastDrawX = x
  lastDrawY = y
  firstDraw = false

  return 1
end

lastDrawX = 0
lastDrawY = 0
firstDraw = true