MrGravity.Level.UpdateParticles C# (CSharp) Метод

        public void UpdateParticles(object sender, DoWorkEventArgs e)
        {
            for (var i = 0; i < _backGroundParticleCount; i++)// && !IsMainMenu; i++)
            {
                var random = new Random();
                var randomness = new Vector2((float)(random.NextDouble() * 2 - 1), (float)(random.NextDouble() * 2 - 1));
                _backgroundParticles[i].Velocity = Vector2.Multiply(_mPhysicsEnvironment.GravityForce, 15) +
                                           Vector2.Multiply(_mPlayer.Velocity, .25f) + _backgroundParticles[i].Randomness;
                _backgroundParticles[i].Update();

                Vector2 posDiff;
                Vector2 shiftValue;
                if (!IsMainMenu)
                    posDiff = (shiftValue = _mPlayer.Position) - _backgroundParticles[i].Position;
                else
                    posDiff = (shiftValue = new Vector2(_mBounds.Center.X,_mBounds.Center.Y)) - _backgroundParticles[i].Position;

                if (posDiff.X < -_mBounds.Width || posDiff.Y < -_mBounds.Height ||
                    posDiff.X > _mBounds.Width || posDiff.Y > _mBounds.Height)
                        _backgroundParticles[i].Position = posDiff + shiftValue;
            }
        }