Time for action – finishing the Particle class

We will now finish the Particle class we just created by performing the following steps:

1. 1. Add the Activate() method to the Particle class as follows:

   #region Particle Activation
   public void Activate(
       Vector3 position, 
       Vector3 velocity, 
       float duration, 
       float scale)
   {
       this.duration = duration;
       initialDuration = duration;
       this.position = position;
       this.velocity = velocity;
       this.scale = scale;
   }
   #endregion

2. 2. Add the Update() method to the Particle class as follows:

   #region Update
   public void Update(GameTime gameTime)
   {
       float elapsed = (float)gameTime.ElapsedGameTime.TotalSeconds;
       duration -= elapsed;
       velocity += (Gravity * elapsed);
       position += (velocity * elapsed);
   }        
   #endregion

3. 3. Add the Draw() method to the Particle class as follows:

   #region Draw
   public void Draw(ArcBallCamera camera, Effect effect)
   {
       Matrix billboard = Matrix.CreateBillboard(
           position, 
           camera...