SOURCE

var Inanimates = []

function setup(){
  createCanvas(600, 400);
  // 帧率
  frameRate(20)
}

function draw(){
  background(0)
  Inanimates.push(new test())

  for(let j=Inanimates.length-1; j>0; j--){
    Inanimates[j].run();
    // 控制内存
    if(Inanimates[j].isRemove()){
      Inanimates.splice(j, 1);
    }
  }
}

class test {
  constructor(){
    this.x = random(-40, 100);
    this.y = random(height);
    this.xSpeet = 3;
    this.opacty = 255;
    this.w = random(2, 5)
  }
  
  run(){
    this.update();
    this.move()
    
    this.show()
  }
  
  // 创建无生命物体
  show(){
    noStroke()
    fill(255, 255, 255, this.opacty)
    ellipse(this.x, this.y, this.w)
  }
  
  // 赋予力和速度
   move(){
     this.x += this.xSpeet
   }
  
  isRemove(){
    return this.x > width + 10;
  }
  // 赋予行为
  update(){
    var r = random(1)
    if(r < 0.01){
      this.opacty -= 100;
    }else{
      this.opacty = 255;
    }
  }
}