function flatten(path,num){
  var l = path.getTotalLength()
  var p = path.getPointAtLength(0)
  var d = `M${p.x} ${p.y}`
  for(var i = (l/num);i<=l;i+=(l/num)){
    p = path.getPointAtLength(i)
    d+=`L${p.x} ${p.y}`
  }
  path.setAttribute("d",d+"z")
}