This class implements the IGraphicsService for a game. (See also IGraphicsService for more information.)

The method Update(TimeSpan) must be called once per frame to update the graphics screens. The methods Render(Boolean) or Render(IPresentationTarget) must be called to render the screens. Render(Boolean) renders the screens to the back buffer; the XNA game will automatically display this back buffer in the game window. Render(IPresentationTarget) renders the screens into the back buffer and manually presents the result into the given presentation target. The method Present(IPresentationTarget) can be used to display the current back buffer content in a presentation target (without re-rendering the screens).