private void RenderGaussian(Texture2D current)
        {
            // pass the current image to sample from
            _blurEffect.SampleFrom = current;

            // pass blur size
            // TODO: Parameterize this
            _blurEffect.BlurSize = 0.2f;

            // blur horizontal then vertical in 2 explicit passes
            _blurEffect.ApplyHorizontalBlur();
            _quadRenderer.Render(Vector2.One * -1.0f, Vector2.One);

            // resolve the render target and pass it back in
            _device.SetRenderTarget(null);
            Texture2D next = _postRT;

            _blurEffect.SampleFrom = next;
            _device.SetRenderTarget(_postRT);
            _device.Clear(Color.Red);

            _blurEffect.ApplyVerticalBlur();
            _quadRenderer.Render(Vector2.One * -1.0f, Vector2.One);

        }