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

#include "eixos.inc"

//------------------------------------Macros

#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, v0, v1, v2, v3, t3, tt)
  #local v01 = interpola(t0, v0, t3, v1, tt);
  #local v12 = interpola(t0, v1, t3, v2, tt);
  #local v23 = interpola(t0, v2, t3, v3, tt);
  #local v012 = interpola(t0, v01, t3, v12, tt);
  #local v123 = interpola(t0, v12, t3, v23, tt);
  #local v0123 = interpola(t0, v012, t3, v123, tt);
  
  v0123;
#end


#macro grafico(x0, y0, y1, y2, y3, x3, N)
 union {
 #local xx = x0;

  #while(xx <= x3)
    #local yy = interpola4(x0, y0, y1, y2, y3, x3, xx);
    sphere{<xx, yy,0> 0.15}
    #local xx = xx + ((x3-x0)/N);
  #end
}
#end


#macro grafico4(x0, y0, y11, y12, y21, y22, y31, y32, y41, y42, yf, x3, N)
union{
  #local xx0 = x0;
  #local xx3 = xx0 + (x3-x0)/4;
  #local yy = (y12+y21)/2;
  object{grafico(xx0, y0, y11, y12, yy, xx3, N/4)}

  #local xx0 = xx3;
  #local xx3 = xx3 + ((x3-x0)/4);
  #local yi = yy;
  #local yy = (y22+y31)/2;
  object{grafico(xx0, yi, y21, y22, yy, xx3, N/4)}
  
  #local xx0 = xx3;
  #local xx3 = xx3 + ((x3-x0)/4);
  #local yi = yy;
  #local yy = (y32+y41)/2;
  object{grafico(xx0, yi, y31, y32, yy, xx3, N/4)}
  
  #local xx0 = xx3;
  #local xx3 = xx3 + ((x3-x0)/4);
  #local yi = yy;
  object{grafico(xx0, yi, y41, y42, yf, xx3, N/4)}
}
#end

//------------------------------------Descrição

object{grafico4(0, 1, -5, 2, -3, 7, -8, 3, -6, 4, -9, 4, 100)}
  

//Camera
#include "camlight.inc"
#declare centro_cena = < 0.00, 0.00, 1.00 >;
#declare raio_cena = 10.0;
#declare dir_camera = < 1.00, 0.00, 20.00 >;
#declare dist_camera = 16.0;
#declare intens_luz = 1.00;
camlight(centro_cena, raio_cena, dir_camera, dist_camera , z, intens_luz)