void mandelbrot::init(double aa,double bb,
                 double cc,double dd,
                 double rp,double ip,
                 double RR, int nnumits,
                 int sstartx,int sstarty,
                 int ww,int ddp)
{
      a = aa;b = bb;c = cc;d = dd;
      R = RR;
      numits = nnumits;
      startx = sstartx;
      starty = sstarty;
      w = ww;
      dp = ddp;
      realp = rp;
      imagp = ip;
}

void mandelbrot::iterate()
{
   long int p,q;
   int n;
   double k,l,x,y,newx,newy;

   for (p = 1; p < w; p++)
   {
        for (q = 1; q < dp; q++)
        {
             k = (double)a+(c-a)*p /(w);
             l = (double)b+(d-b)*q / (dp);
             x = realp;
             y = imagp;
             for (n = 1; n < numits; n++)
             {
                  newx = x*x-y*y+k;
                  newy = 2*x*y+l;
                  x = newx;
                  y = newy;
                  sound((unsigned int)(y*x*5000+440));
        	      putpixel(x*10+160,y*10+100,(unsigned char)n);
                  if (x*x+y*y>R)
                  {
                      putpixel(p+startx-1,q+starty-1,n);
                      n = numits;
                  }
                  if (bioskey(1)>0)
                  {
                      nosound();
                      n = numits;
                      q = dp;
                      p = w;
                  }
             }//n
        }//p
   }//q
}