Hello, I'm trying to make a sketch where a lightning bolt hits the ground and, as soon as it does, a particle is emitted from where the bolt hit. I can get the particle to appear, but I can't get it to animate. Instead, every single frame of the animation appears simultaneously. What am I doing wrong? Here is the code (the first chunk is what goes in the main tab; press the SPACE BAR to activate the lightning):

LightningBolt bolt;

void setup(){
  size(640, 480);
  smooth();
  background(0);
}

void draw(){
  noStroke();
  fill(0,20);
  rect(0,0,width,height);
}

void keyTyped(){
  if(key==' ')
  {
    bolt = new LightningBolt();
    bolt.drawBolt();
  }
}


++++++++++++++++++++++++++++++++

class LightningBolt{
  float lineWidth0;
  float angle;
  float x1,y1;
  float x2,y2;
  float straightJump;
  float straightJumpMax;
  float straightJumpMin;
  float lineWidth;

  LightningBolt(){
    float randomX = random(0+(width/4), width-(width/4));
    this.x1 = randomX;
    this.x2 = randomX;
    this.y1 = 0;
    this.y2 = 0;

    this.lineWidth0 = random(8,10); //starting thickness of bolt
    this.angle = 0;
    this.straightJumpMin = 1;
    this.straightJumpMax = 10;
  }

  void drawBolt()
  {
    while((y2 < height) && ((x2 > 0) && (x2 < width)))
    {
      angle = randomSign()*random(PI/20, PI/5);
      straightJump = random(straightJumpMin, straightJumpMax);

      x2 = x1-straightJump * cos(angle - HALF_PI);
      y2 = y1-straightJump * sin(angle - HALF_PI);

      lineWidth = map(y2, height, 0, 1, lineWidth0);
      stroke(255);
      strokeWeight(lineWidth);
      line(x1,y1,x2,y2);
      x1=x2;
      y1=y2;
     
      if (y1 >= height){
        fill(255);
        noStroke();
        Circle circle = new Circle(x1, height);
        circle.drawCircle();
      }
    }
  }

  int randomSign()
  {
    float num = random(-1,1);
    if(num == 0)
      return -1;
    else
      return int(num/abs(num));
  }
}

+++++++++++++++++++++++++++++++++

class Circle{
  float x, y;
  int radius;

  float xSpeed;
  float ySpeed;
  float angle;
  float speed;
  float accel = .98;

  Circle(float xCoord, float yCoord){
    this.x = xCoord;
    this.y = yCoord;
    this.radius = 10;

    this.angle = random(255.0, 285.0);
    this.speed = random(12.0, 20.0);
    this.xSpeed = speed * cos(radians(angle));
    this.ySpeed = speed * sin(radians(angle));
  }

  void drawCircle(){
    for (int i = height; i > 0; i--) {
      y += ySpeed + 0.5 * accel;
      ySpeed += accel;
      x+= xSpeed;
      ellipse(x, y, radius, radius);
    }
  }
}