//Pedro Feniman 083991

// ======================================================================
// CORES E TEXTURAS

background{ color rgb < 0.75, 0.80, 0.85 > }

#declare tx_fosca = 
  texture{
    pigment{ color rgb < 0.70, 0.80, 0.40 > }
    finish{ diffuse 0.9 ambient 0.1 }
  }

// ======================================================================
// DESCRIÇÃO DA CENA 

#macro interpola(f0,v0,f1,v1,f)
	#local ss = (f - f0) / (f1 - f0);
	#local rr = 1 - ss;
	(rr * v0 + ss * v1)
#end

#macro interpola4(t0,y0,y1,y2,y3, t3, tt)
	#local y01 = interpola(t0, y0, t3, y1, tt);  
	#local y12 = interpola(t0, y1, t3, y2, tt);
	#local y23 = interpola(t0, y2, t3, y3, tt);
	#local y012 = interpola(t0, y01, t3, y12, tt);
	#local y123 = interpola(t0, y12, t3, y23, tt);
	#local y01234 = interpola(t0, y012, t3, y123, tt);
	interpola(t0, y012, t3, y01234, tt);
#end

#macro desenha(a0, b0, b1, b2, b3, a3, n)
	#local delta = (a3-a0)/n;
	#local i = 0;
	#local xx = a0;

	#while(i < n)
		#local yy = interpola4(a0, b0, b1, b2, b3, a3, xx);		
		object { sphere{<0, xx, yy>, 0.2 texture{tx_fosca} } }
		#local xx = xx + delta;
		#local i = i + 1;
	#end
#end
 
#macro desenha4(x0, g0, g1, g2, h1, h2, i1, i2, j1, j2, j3, x3, n)
	#local g3 = (g2+h1)/2;
	#local h0 = g3;
	#local h3 = (h2+i1)/2;
	#local i0 = h3;
	#local i3 = (i2+j1)/2;
	#local j0 = i3;

	#local dt = (x3-x0)/4;

	desenha(x0, g0, g1, g2, g3, x0+dt, n)
	desenha(x0+dt, h0, h1, h2, h3, x0+2*dt, n)
	desenha(x0+2*dt, i0, i1, i2, i3, x0+3*dt, n)
	desenha(x0+3*dt, j0, j1, j2, j3, x0+4*dt, n)

#end

union{
	desenha4(0, -2, 4, -4, 6, 0, -7, 7, 3, 1, 3, 8, 50)
}

#include "camlight.inc"
#declare centro_cena = < 0, 4, 01 >;
#declare raio_cena = 9.0;
#declare dir_camera = < 50.00, 0.00, 1.00 >;
#declare dist_camera = 30.0;
#declare intens_luz = 1.00;
camlight(centro_cena, raio_cena, dir_camera, dist_camera , z, intens_luz)