/* I'm trying to get my particle manager working in my game.
* Everything works fine, EXCEPT for a particle appearing in the top left corner during initialization.
* It stems from the line             shortParticle = new ShortParticle(textures, new Vector2());
* under my Bat constructor. if I leave it blank, or use 0,0 for the Vector2 then the particle remains in *the top left corner until the ball and bat make contact. At that point the new particle continues to *display point of contact until the ball hits the bat on the other side.
*/

// 1)  How do I NOT have the particle display in the top left corner when the game starts?
// 2) How do I kill the particle after 2 seconds? I tried adjusting the TTL in my ShortParticle class, but
// it doesn't seem to change much.

    Public Class Ball
{
    // Ball constructor
       public Ball(ContentManager contentManager, Vector2 ScreenSize, Bat bat, AIBat aiBat)
        {
    ......
        shortParticle = new ShortParticle(textures, new Vector2());
        ......
         }

        public void Draw(SpriteBatch spriteBatch)
        {
                // Draws the short particle
                shortParticle.Draw(spriteBatch);
        }

    Update
         }
        shortParticle.Update(gameTime);
         }

 public void BatHit(int block)
        {
            if (direction > Math.PI * 1.5f || direction < Math.PI * 0.5f)
            {
        /// Generates particle when bat and ball collide
                RightBatParticles();
                ......
             }
            }
}



#region File Description
//----------------------------------------------------------------------------------------------
// Engine is designed by RB Whitaker http://rbwhitaker.wikidot.com/2d-particle-engine-1
//----------------------------------------------------------------------------------------------------
#endregion

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;

namespace Pong
{
    public class ParticleEngine
    {
        private Random random;
        public Vector2 EmitterLocation { get; set; }
        private List<Particle> particles;
        private List<Texture2D> textures;

        public ParticleEngine(List<Texture2D> textures, Vector2 location)
        {
            EmitterLocation = location;
            this.textures = textures;
            this.particles = new List<Particle>();
            random = new Random();
        }

        public void Update()
        {
            int total = 10;

            for (int i = 0; i < total; i++)
            {
                particles.Add(GenerateNewParticle());
            }

            for (int particle = 0; particle < particles.Count; particle++)
            {
                particles[particle].Update();
                if (particles[particle].TTL <= 0)
                {
                    particles.RemoveAt(particle);
                    particle--;
                }
            }
        }


        /// <summary>
        /// Generates a normal particle
        /// </summary>
        public Particle GenerateNewParticle()
        {
            Texture2D texture = textures[random.Next(textures.Count)];
            Vector2 position = EmitterLocation;
            Vector2 velocity = new Vector2(
                                    1f * (float)(random.NextDouble() * 2 - 1),
                                    1f * (float)(random.NextDouble() * 2 - 1));
            float angle = 0;
            float angularVelocity = 0.1f * (float)(random.NextDouble() * 2 - 1);
            Color color = new Color(
                        (float)random.NextDouble(),
                        (float)random.NextDouble(),
                        (float)random.NextDouble());
            float size = (float)random.NextDouble();
            int ttl = 20 + random.Next(40);

            return new Particle(texture, position, velocity, angle, angularVelocity, color, size, ttl);
        }


        /// <summary>
        /// Draws particles. I commented out spriteBatch for now, as I've adjusted it to be drawn during the bat's spriteBatch
        /// </summary>
        public void Draw(SpriteBatch spriteBatch)
        {
        //    spriteBatch.Begin();
            for (int index = 0; index < particles.Count; index++)
            {
                particles[index].Draw(spriteBatch);
            }
      //      spriteBatch.End();
        }
    }
}

////////////////////////////////////////////////////////////////////

#region File Description
//----------------------------------------------------------------------------------------------
// Engine is designed by RB Whitaker http://rbwhitaker.wikidot.com/2d-particle-engine-1
//----------------------------------------------------------------------------------------------------
#endregion

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;

namespace Pong
{
    public class ShortParticle
    {
        private Random random;
        public Vector2 EmitterLocation { get; set; }
        private List<Particle> particles;
        private List<Texture2D> textures;
        private int threeSecondTime = 3;
        private int elapsedTime;

        public ShortParticle(List<Texture2D> textures, Vector2 location)
        {
            EmitterLocation = location;
            this.textures = textures;
            this.particles = new List<Particle>();
            random = new Random();
        }

        public void Update(GameTime gameTime)
        {
            // Keps track of time
            elapsedTime = gameTime.ElapsedGameTime.Milliseconds;
            // How many particles appear on screen at once
            int total = 7;

            for (int i = 0; i < total; i++)
            {
                particles.Add(GenerateNewParticle());
            }

            for (int particle = 0; particle < particles.Count; particle++)
            {
                particles[particle].Update();
                if (particles[particle].TTL <= 0)
                {
                    particles.RemoveAt(particle);
                    particle--;
                }

            }

            for (int particle = 0; particle < particles.Count; particle++)
            {
                particles[particle].Update();
                if (threeSecondTime <= elapsedTime)
                {
                    particles.RemoveAt(particle);
                }
            }
        }


        /// <summary>
        /// Generates a normal particle
        /// </summary>
        public Particle GenerateNewParticle()
        {
            Texture2D texture = textures[random.Next(textures.Count)];
            Vector2 position = EmitterLocation;
            Vector2 velocity = new Vector2(
                                    1f * (float)(random.NextDouble() * 2 - 1),
                                    1f * (float)(random.NextDouble() * 2 - 1));
            float angle = 0;
            float angularVelocity = 0.1f * (float)(random.NextDouble() * 2 - 1);
            Color color = new Color(
                        (float)random.NextDouble(),
                        (float)random.NextDouble(),
                        (float)random.NextDouble());
            float size = (float)random.NextDouble();
            int ttl = 20 + random.Next(40);

            return new Particle(texture, position, velocity, angle, angularVelocity, color, size, ttl);
        }


        /// <summary>
        /// Draws particles. I commented out spriteBatch for now, as I've adjusted it to be drawn during the bat's spriteBatch
        /// </summary>
        public void Draw(SpriteBatch spriteBatch)
        {
            //    spriteBatch.Begin();
            for (int index = 0; index < particles.Count; index++)
            {
                particles[index].Draw(spriteBatch);
            }
            //      spriteBatch.End();
        }
    }
}