void analyse(){
  int ecke1 = get(round(vx+x)-klaenge/2+6, round(vy+y)-khoehe/2+6);
  int ecke2 = get(round(vx+x)-klaenge/2+6, round(vy+y)-khoehe/2-6);
  int ecke3 = get(round(vx+x)-klaenge/2-6, round(vy+y)-khoehe/2+6);
  int ecke4 = get(round(vx+x)-klaenge/2-6, round(vy+y)-khoehe/2-6);
  if (abs(ecke1-pixel)<analyse){
    int hueref = get(round(vx+x)-klaenge/2+7, round(vy+y)-khoehe/2+6);
    if (abs(hueref-ecke1)<analyse){
      vy=-vy;
    }
    else{
      vx=-vx;
    }
  }
  if (abs(ecke2-pixel)<analyse){
    int hueref = get(round(vx+x)-klaenge/2+7, round(vy+y)-khoehe/2-6);
    if (abs(hueref-ecke2)<analyse){
      vy=-vy;
    }
    else{
      vx=-vx;
    }
  }
  if (abs(ecke3-pixel)<analyse){
    int hueref = get(round(vx+x)-klaenge/2-7, round(vy+y)-khoehe/2+6);
    if (abs(hueref-ecke3)<analyse){
      vy=-vy;
    }
    else{
      vx=-vx;
    }
  }
  if (abs(ecke4-pixel)<analyse){
    int hueref = get(round(vx+x)-klaenge/2-7, round(vy+y)-khoehe/2-6);
    if (abs(hueref-ecke3)<analyse){
      vy=-vy;
    }
    else{
      vx=-vx;
    }
  }
}