{
            cplx z = f(o);
            double d = sqrt(z.x*z.x + z.y*z.y);
            d = 1-pow(1-0.4*exp (-d*7),2);
            //d = .5*(1-afunc (d+d*log(d), 0.2, 0.5));
            
            
            v += d*pow(1-v,4);
            
            v = p_distort (v,1);
            //v = pow(v,2);
            iv = (-.1+JCOLORS)*v;
            
            z = cpolar (o);
            h = 1.4999*(z.y+M_PI)/M_PI;
            int ih = h;
            ih = (ih+2)%3;
            iv += ih * JCOLORS;
            
            double hh[3] = {0, 1./3., 7./12.};
            
            h = hh[ih];

            return hsv2rgb (h, 1.-v, v);
        }