private static void Main()
        {
            var window         = new ExampleWindow();
            var visual         = new GameVisual(window.RenderContext.RenderState, window.ContentLoader);
            var postProcessing = new PostProcessingVisual(window.GameWindow.Width, window.GameWindow.Height, window.ContentLoader);

            window.Update += visual.Update;
            window.Render += () =>
            {
                bool doPostProcessing = !window.Input.IsButtonDown("Space");
                if (doPostProcessing)
                {
                    postProcessing.Render(visual.Render);
                }
                else
                {
                    visual.Render();
                }
            };
            window.Run();
        }
        private static void Main()
        {
            var window         = new ExampleWindow();
            var visual         = new GameVisual(window.RenderContext.RenderState, window.ContentLoader);
            var postProcessing = new PostProcessingVisual(window.GameWindow.Width, window.GameWindow.Height, window.ContentLoader);

            window.Update += visual.Update;
            window.Render += () =>
            {
                bool doPostProcessing = !Keyboard.GetState()[Key.Space];
                if (doPostProcessing)
                {
                    postProcessing.Render(visual.Render);
                }
                else
                {
                    visual.Render();
                }
            };
            window.Run();
        }