碰撞检测

speed:2,
timers: {
  dirX: 1,
  dirY: 1,
  posX: 0,
  posY: 0
},

this.timer = setInterval(() => {
  this.timers.posX += (this.speed * this.timers.dirX);
  this.timers.posY += (this.speed * this.timers.dirY);
  $(".music-fly").css({
    top: this.timers.posY,
    left: this.timers.posX
  });
  /* 碰撞检测*/
  if (this.timers.posX < 1 || this.timers.posX > document.body.clientWidth) {
    this.timers.dirX = -this.timers.dirX
  }

  if (this.timers.posY < 1 || this.timers.posY > document.body.clientHeight) {
    this.timers.dirY = -this.timers.dirY
  }

}, 30);