// recursion
void setup() { 
  size(600, 600, P3D); 
  setColors(); 
  sphereDetail(12); //smooth();
  PFont font = loadFont("Courier-14.vlw"); textFont(font, 12);  // font for writing labels on screen
  loadView(); setView(); 
  } 
 

void draw() {
  if (showHelpText) {background(white); showHelp(); return;}
  lights(); directionalLight(0,0,128,0,1,0); directionalLight(0,0,128,0,0,1);  background(white); 
  if (mousePressed) {
      if (!keyPressed) { viewPar[4][0]+=mouseX-pmouseX; viewPar[4][1]+=mouseY-pmouseY; }; // Rotate view
      if ( keyPressed) changeViewParameters(); // checks which numeric key was pressed and updates corresponding parameters
     } // end if mousePresed
  setView();

  noStroke(); 
  tree(0, nfr);
  }  // end draw

void keyPressed() { keys(); };

int nfr=0; // number of recursions
void tree(int i, int nfr) { 
   fill(rampGR(i,nfr));  
   cone();
   if (i<nfr) {
     pushMatrix(); translate(0,650,0); scale(0.55);                  rotateZ(PI/5);   tree(i+1, nfr); popMatrix();
     pushMatrix(); translate(0,500,0); scale(0.75); rotateY(PI*0.7); rotateZ(PI/3.5); tree(i+1, nfr); popMatrix();
     pushMatrix(); translate(0,350,0); scale(0.45); rotateY(PI*1.6); rotateZ(PI/3);   tree(i+1, nfr); popMatrix();
     }
   }
  
void cone() {cone(P(0,0,0),50,P(0,1000,0),20,6);}
void cone(pt A, float a, pt B, float b, int s) { // shows a cone between 2 balls. s is the number of sides around the cone
  vec T = A.vecTo(B); float d=T.norm(); T.makeUnit();
  vec U = new vec (1,0,0); vec N = cross(U,T);
  if (N.norm()<0.1) {U.setTo(0,1,0);  N.setTo(cross(U,T)); };
  N.makeUnit(); U.setTo(cross(N,T));
  float dd = A.disTo(B);
  float x=(a-b)/dd;
  float y=sqrt((dd-a+b)*(dd+a-b))/dd;
  pt PP = A.make();   pt QQ = B.make();
  PP.addScaledVec(a*x,T);   QQ.addScaledVec(b*x,T);
  pt P = new pt(); pt Q = new pt();
  beginShape(QUAD_STRIP);
  for (float t=0; t<TWO_PI; t+=TWO_PI/s) {
    P.setTo(PP);   Q.setTo(QQ);
    P.addScaledVec(a*y*cos(t),N);   Q.addScaledVec(b*y*cos(t),N); 
    P.addScaledVec(a*y*sin(t),U);   Q.addScaledVec(b*y*sin(t),U); 
    P.vert(); Q.vert();
    };
  endShape();
  }