Mettre à jour une fenêtre SDL

//l'implémentation:  Raquette.cpp
Raquette::Raquette ( int initialX, int initialY, int nbrFramesW, int nbrFramesH, char* file,SDL_Surface* screen){
                 loadSpriteSheet ( file );
  
    _x = initialX;
    _y = initialY;
    _w =nbrFramesW;
    _screen=screen;
    _h =nbrFramesH;
 
                   }
                   
                   
void Raquette::loadSpriteSheet(char* file){
      _spriteSheet = SDL_LoadBMP ( file );
        }
   
void Raquette::move(){
     bool running=true;
       //  Uint8 *keys = SDL_GetKeyState(NULL);
                 SDL_WaitEvent ( &event );
          
           while (running){
                 
     if (SDL_PollEvent(&event)){
       switch ( event.type ) {
               case SDL_QUIT:
                     running = false;
                      break;
                      
                 case SDL_KEYDOWN:
                      
                       switch ( event.key.keysym.sym ) {
                       
                          case SDLK_LEFT:
                   if (_x<0)_x=10;
                                                     
                             _x=_x-15; break;
    
                            
                          case SDLK_RIGHT:
                               if (_x>480)_x=500;
                               _x=_x+15;break;
                                            
                 }
                               
                 }
               
                  show(_screen);
                  
                 
                
                }
                
                 }
               
   
                 }
                         
                 void Raquette::show(SDL_Surface* sscreen){
                      SDL_Rect frameRect;
     
     Brique b(12,12,12,12,"Brique/brique1.bmp",sscreen);
     b.show();
     SDL_Rect pos;
     
     pos.x = _x;
     pos.y = _y;
     
        SDL_FillRect ( _screen, NULL, SDL_MapRGB ( _screen->format, 20, 200, 20 ) );
     SDL_BlitSurface ( _spriteSheet, NULL, sscreen, &pos );
                  //  SDL_Flip ( _screen );
                  //  SDL_Delay ( 60 );  
  
                      }
                 
void Raquette::limite(){
     bool running=true;
     if (_x<0){
     
     while(running){
      _x=_x+15;              
     show(_screen);
    running=false;
    }
     
     }
     
     
     }
//l'implémentation : brique.cpp
 
Brique::Brique(int x,int y,int w,int h,char *file,SDL_Surface * Screen)
{
                   loadFile(file);
                   _x=x;
                   _y=y;
                   _w=w;
                   _h=h;
                   _screen=Screen;
                   }
                   void Brique::loadFile(char* file)
                   {
                        
                        _sbrique=SDL_LoadBMP(file);
                                                }
                                                void Brique::placerBrique(){
                                                        show();
                                                                                                                      
                             }
                             void Brique::show(){
                                  SDL_Rect pos;
     
     pos.x = _x;
     pos.y = _y;
     
      
     SDL_BlitSurface ( _sbrique, NULL, _screen, &pos );
                          SDL_Flip(_screen);
                           //SDL_Delay(60)       ;
                                  }
 
//  main.cpp
    SDL_Init(SDL_INIT_VIDEO);
  Screen=SDL_SetVideoMode(_SCREEN_WIDTH,_SCREEN_HEIGHT,32,SDL_HWSURFACE | SDL_DOUBLEBUF);
  SDL_EnableKeyRepeat(SDL_DEFAULT_REPEAT_DELAY,SDL_DEFAULT_REPEAT_INTERVAL+(1/100));
  
  fond=SDL_LoadBMP("fond.bmp");
   Raquette r(_SCREEN_WIDTH/3,_SCREEN_HEIGHT-20,15,5,"raquet.bmp",Screen);
         
  
   SDL_BlitSurface(fond,NULL,Screen,&rfond);
                
        r.move(); 
        SDL_Flip(Screen);
  SDL_Delay(60);    

   SDL_BlitSurface(fond,NULL,Screen,&rfond);
                
        r.move(); // Ici le fond n'est pas blitté.
        SDL_Flip(Screen);
  SDL_Delay(60);

Raquette::Raquette ( int initialX, int initialY, int nbrFramesW, int nbrFramesH, char* file,SDL_Surface* screen, SDL_Surface* fond){
	loadSpriteSheet ( file );
{
...
wFond = fond;
}
void Raquette::move()
{
//...
while (running)
{
//...
SDL_Rect posFond;
posFond.x = 0;
posFond.y = 0; 
           SDL_BlitSurface(wFond,NULL,Screen, &posFond);
		show(_screen);
}
}