double n = 5   ;
    unsigned char *ptr;
    ptr = img->bits();
    int v = 0;
        double g = 3.1415 / n;
    //    for(double t = 0; t <= 2 * 3.1415 ; t+=2 * g){
       for(double t = 0; t <= 2 * 3.1415 + 0.1; t+= 2 * g){
            x = abs(x1 - x2) * cos(t);
            y = abs(y1 - y2) * sin(t);
            tab[v][0] = x + x1;
            tab[v][1] = y + y1;
            rysuj(tab[v][0],tab[v][1]);
            v++;
        }
        for(int i = 0 ; i < v - 1; i++){
           rysujprosta(tab[i][0],tab[i + 1][0],tab[i][1],tab[i + 1][1]);
        }


        rysujprosta(tab[v - 1][0],tab[0][0],tab[v - 1][1],tab[0][1]);