public void AddParticles(Vector2 position, int count)
{
var particles = new List<Vector2>();
var velocities = new List<Vector2>();
for(var i=0; i < count; i++) {
particles.Add(new Vector2(position.X + (float)Math.Cos(2 * Math.PI * i / count)*0.5f, position.Y + (float)Math.Sin(2 * Math.PI * i / count)*0.5f));
velocities.Add( new Vector2( (float)Math.Cos(2 * Math.PI * i / count)*3.0f, (float)Math.Sin(2 * Math.PI * i / count)*3.0f ) );
}
Particles = Particles.ToList().Concat(particles).ToArray();
Velocities = Velocities.ToList().Concat(velocities).ToArray();
_velocityBuffer = _velocityBuffer.ToList ().Concat (velocities).ToArray ();
var tmp = ParticleCount + count;
var tmp_arr = new float[tmp, tmp];
for (int i = 0; i < ParticleCount; i++)
for (int j = 0; j < ParticleCount; j++)
tmp_arr [i, j] = _w [i, j];
ParticleCount += count;
_w = tmp_arr;
}
