bench.gsl

color shader_bench (float u, float v)
{
     float i;
     float x = 0,  y = 0;
     float MAXIT = 256;
     for (i = 0; i < MAXIT; i += 1) {
             float oldx = x, oldy = y;
             x = oldx*oldx - oldy*oldy + u;
             y = 2*oldx*oldy + v;

	     /* skip noise since it is renderer-dependent
             point noiz = (point) noise (point (10*x, 10*y, 0));
             x += 0.07 * noiz[0];
             y += 0.07 * noiz[1];
	     */

	     float rsquared = x*x+y*y;
	     if (rsquared > 10) {
		     break;
            }
     }

     float c = i/MAXIT;
     return (color) spline (pow (1-c, 2),
			    (color) (0),
			    (color) (0),
			    color (1, 0, 0),
			    color (0, 0, 1),
			    (color)  (1), (color) (1));
}

surface bench (string mode = "simple",
	       float samples = 16,
	       float ray_bias = 0.001)
{
	normal NN = normalize (N);

	if(mode == "raydiff") {
		float occ = occlusion ("ALL",
				       P, NN, M_PI_2,
				       "bias", ray_bias,
				       "maxhitdist", 5000,
				       "samples", samples);
		C = opacity * (1 - occ);
		
	} else if(mode == "rayspec") {
		float depth = raylevel();
		if (depth > 1) {
			C =(color)  (0);
		} else {
			float maxsamples,  minsamples,  coneangle;
			if (depth == 0) {
				maxsamples = samples;
				minsamples = samples/4;
				coneangle = radians (2.5);
			} else {
				maxsamples = 1;
				minsamples = 1;
				coneangle = 0;
			}
			vector II = normalize (I);
			color hitcolor = 0,  total = 0;

			// XXX Haven't done statement: Gather
			total /= maxsamples;
			C = opacity * total;
		}
	} else if(mode == "shader") {
		point oP = transform ("object", P);
		C = opacity * shader_bench(oP[0], oP[1]);
	} else if(mode == "simple") {
		C = opacity * (diffuse(NN) + ambient());
	}
}