source: 2010/23/sijoseha/alpha/Effects/ParticleSystem.cs @ 803

using System;
using System.Collections.Generic;
using System.Linq;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Audio;
using Microsoft.Xna.Framework.Content;
using Microsoft.Xna.Framework.GamerServices;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using Microsoft.Xna.Framework.Media;
using Microsoft.Xna.Framework.Net;
using Microsoft.Xna.Framework.Storage;

namespace Effects
{
    public abstract class ParticleSystem : DrawableGameComponent
    {
        private Game game;

        private Particle[] particles;

        #region Subclass variables
        protected Vector2 position;

        protected String textureName;

        protected String innerTextureName;
        protected String outerTextureName;

        protected float minScale;
        protected float maxScale;

        protected float rotation;

        protected Vector2 origin;

        protected Vector2 minVelocity;
        protected Vector2 maxVelocity;

        protected float minLifetime;
        protected float maxLifetime;

        #endregion

        private enum TextureType
        {
            Single,
            Dual
        };

        private TextureType textureType;

        private Texture2D texture, innerTexture, outerTexture;

        private int maxAmountOfParticles;
        public int MaxAmountOfParticles
        {
            get { return maxAmountOfParticles; }
            set { maxAmountOfParticles = value; }
        }

        public ParticleSystem(Game game, Vector2 position, String textureName)
            : base(game)
        {
            textureType = TextureType.Single;
            this.game = game;
        }

        public ParticleSystem(Game game, Vector2 position, String innerTextureName, String outerTextureName)
            : base(game)
        {
            textureType = TextureType.Dual;
            this.game = game;
        }

        protected abstract void InitializeParticles();

        protected override void LoadContent()
        {
            if (textureType == TextureType.Single)
            {
                texture = game.Content.Load<Texture2D>(textureName.ToString());
            }
            if (textureType == TextureType.Dual)
            {
                innerTexture = game.Content.Load<Texture2D>(innerTextureName.ToString());
                outerTexture = game.Content.Load<Texture2D>(outerTextureName.ToString());
            }
            base.LoadContent();
        }
    }
}