title: SDL library: does SDL_UpdateRect() really need to be called for an SDL_HWSURFACE?
body: <p>I'm a newbie to SDL and I've read about a dozen introductory tutorials so far.  I'm a bit puzzled about the difference between hardware and software surfaces (i.e. the SDL_HWSURFACE and SDL_SWSURFACE flags in the call to SDL_SetVideoMode()), and how SDL_UpdateRect() behaves for each type of surface.  My understanding is that for a hardware surface, there is no need to call SDL_UpdateRect() because one is drawing directly to the display screen.  However, the example in this Wikibooks tutorial (<a href="http://en.wikibooks.org/wiki/SDL_%28Simple_DirectMedia_Layer%29" rel="nofollow">http://en.wikibooks.org/wiki/SDL_%28Simple_DirectMedia_Layer%29</a>) shows otherwise:  it calls SDL_UpdateRect() on a hardware surface.</p>