float xmag, ymag = 0;
float newXmag, newYmag = 0; 

List listRec = new ArrayList();


void setup() 
{ 
  size(500, 300, P3D); 
  noStroke(); 
  colorMode(RGB, 255);
  //smooth(); 

  for (int i=0; i<200; i++) {
    listRec.add(new Rec(random(2, 3), random(0.05, 0.1), 40, random(0, 2*PI), random(0, 2*PI) ));
  }
} 

int count = 0;
void draw() 
{ 

  background(0.5);

  translate(width/2, height/2, -30); 

  newXmag = mouseX/float(width) * TWO_PI;
  newYmag = mouseY/float(height) * TWO_PI;

  float diff = xmag-newXmag;
  if (abs(diff) >  0.01) { 
    xmag -= diff/4.0;
  }

  diff = ymag-newYmag;
  if (abs(diff) >  0.01) { 
    ymag -= diff/4.0;
  }

  rotateX(-ymag); 
  rotateY(-xmag); 
  Rec rec;
  count++;

  for (int i=0; i<listRec.size(); i++) {
    rec = (Rec)listRec.get(i);

    if (count > 2) {
      rec.update();
    }
    rec.draw();
  }
  if (count > 2) {

    count = 0  ;
  }
}

void mouseClicked() {
  listRec.clear();
  for (int i=0; i<100; i++) {
    listRec.add(new Rec(random(2, 3), random(0.05, 0.1), 40, random(0, 2*PI), random(0, 2*PI) ));
  }
}

/**
 * RGB Cube.
 * 
 * The three primary colors of the additive color model are red, green, and blue.
 * This RGB color cube displays smooth transitions between these colors. 
 */
private static float scale = 30;
private static final int stateInc = 0;
private static final int stateDec = 1;


public class Rec {

  float longueur;
  float epaisseur;
  float rotateY;
  float rotateZ;
  float distanceFromCenter;
  float r;
  float g;
  float b;
  private int maxIterInState = (int)random(5,10);

  private int currentState = stateInc;
  private int nbIterInState = 0;

  public Rec(float _longueur, float _epaisseur, float _distanceFromCenter, float _rotateY, float _rotateZ) {
    longueur = _longueur;
    epaisseur = _epaisseur;
    distanceFromCenter = _distanceFromCenter;
    rotateY = _rotateY;
    rotateZ = _rotateZ;

    r = _rotateY * 255 / PI;
    g = _rotateZ * 255 / PI;
  }

  public void update() {
     b = (b<255?b++:0);
    if (currentState == stateInc) {
      if (nbIterInState == maxIterInState) {
        currentState = stateDec;
        nbIterInState = 0;
        return;
      }
      else {
        nbIterInState++;
        longueur+=0.05;
        
        return;
      }
    }

    else if (currentState == stateDec) {
      if (nbIterInState == maxIterInState) {
        currentState = stateInc;
        nbIterInState = 0;
        return;
      }
      else {
        nbIterInState++;
        
        longueur-=0.05;
        return;
      }
    }
  }

  public void draw() 
  { 

    pushMatrix(); 

    rotateY(rotateY);
    rotateZ(rotateZ);

    translate(distanceFromCenter, - scale / 2.0 *  epaisseur, scale / 2.0 *  epaisseur); 


    scale(scale);
    beginShape(QUADS);
    fill(r, g, b);
    vertex(0, 0, 0);
    vertex(longueur, 0, 0);
    vertex(longueur, epaisseur, 0);
    vertex(0, epaisseur, 0);

    vertex(0, 0, 0);
    vertex(longueur, 0, 0);
    vertex(longueur, 0, -epaisseur);
    vertex(0, 0, -epaisseur);

    vertex(0, epaisseur, 0);
    vertex(longueur, epaisseur, 0);
    vertex(longueur, epaisseur, -epaisseur);    
    vertex(0, epaisseur, -epaisseur);

    vertex(0, 0, -epaisseur);
    vertex(longueur, 0, -epaisseur);
    vertex(longueur, epaisseur, -epaisseur);
    vertex(0, epaisseur, -epaisseur);    

    endShape();

    popMatrix();
  }
}