int ClipBlit ( int dtaillew , int dtailleh , int staillew , int stailleh ,
                int *dposx , int *dposy , int *sposx , int *sposy , int *taillew , int *tailleh ) ;

int ClipStretch ( int dtaillew , int dtailleh , int staillew , int stailleh ,
                 int *dposx1 , int *dposy1 , int *dposx2 , int *dposy2 , 
                 int *sposx1 , int *sposy1 , int *sposx2 , int *sposy2 );