using System;

using System.Collections.Generic;

using System.Text;

using Microsoft.Xna.Framework;

using Microsoft.Xna.Framework.Graphics;

namespace SimplexCore

{

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 ParticleEngine()

{

}

private Particle GenerateNewParticle()

{

Texture2D texture = textures[random.Next(textures.Count)];

Vector2 position = EmitterLocation;

double rr = random.NextDouble() * 5;

Vector2 velocity = new Vector2((float)random.NextDouble() * 5 * Sgml.choose(1, -1), (float)random.NextDouble() * 5 * Sgml.choose(1, -1));

float angle = 0;

float angularVelocity = 0.1f * (float)(random.NextDouble() * 5 - 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, 1);

}

public void Setup()

{

int total = 10;

for (int i = 0; i < total; i++)

{

particles.Add(GenerateNewParticle());

}

}

public void Update()

{

for (int particle = 0; particle < particles.Count; particle++)

{

particles[particle].Update();

if (particles[particle].TTL <= 0)

{

particles.RemoveAt(particle);

particle--;

}

}

}

public void Draw(SpriteBatch spriteBatch)

{

spriteBatch.Begin(transformMatrix: Sgml.m);

for (int index = 0; index < particles.Count; index++)

{

particles[index].Draw(spriteBatch);

}

spriteBatch.End();

}

}

}