torch [] t;
boolean [][][][] pix;
int xm = 50;
int ym = 50;
int zm = 50;
int tm = 50;
int tf = 25;
int flow = 1;
void setup(){
  pix = new boolean [tm][xm][ym][zm];
  for (int ix = 0; ix < xm; ix++){
    for (int iy = 0; iy < ym; iy++){
      for (int iz = 0; iz < zm; iz++){
        for (int it = 0; it < tm; it++){
          pix [it][ix][iy][iz] = false;
        }
      }
    }
  }
  framerate(12);
  noFill();
  size (400,400);
  t = new torch[50];
  for (int i = 0; i < t.length; i++){
    //t[i]=new torch(25,25,25,0);
    t[i] = new torch(int(random(xm-2))+1,int(random(ym-2))+1,int(random(zm-2))+1,int(random(tm-2))+1,int(random(4)));
  }
}
void loop(){
  background(255);
  push();
  translate(200,200,250);
  rotateY((TWO_PI/width)*mouseX);
  rotateZ((TWO_PI/width)*mouseY);
  for (int i = 0; i < t.length; i++){
    t[i].trace();
      t[i].draw(); //for trails
  }
  cubeBlue();
  //rotateX(PI);
  strokeWeight(3);
  drawCube(tf);
  pop();
  flowDisplay();
  tf += flow;
  if (keyPressed && key == '+'){
    flow ++;
    if (flow > 1){
      flow = 1;
    }
  }
  if (keyPressed && key == '-'){
    flow --;
    if (flow < -1){
      flow = -1;
    }
  }
  if (tf > tm - 2){
    tf = 2;
  }
  if (tf < 2){
    tf = tm - 2;
  }
}
//debugging cube
void drawCube(int it){
  stroke(0);
  for (int ix = 1; ix < xm-1; ix++){
    for (int iy = 1; iy < ym-1; iy++){
      for (int iz = 1; iz < zm-1; iz++){
        if(pix[it][ix][iy][iz])
        point(ix-(xm/2),iy-(ym/2),iz-(zm/2));
      }
    }
  }
}//draw;
//render boundaries
void flowDisplay(){
strokeWeight(1);
stroke(0,0,100);
rect(175,0,50,10);
stroke(0);
line(175+tf,0,175+tf,10);
}
void cubeBlue(){
  strokeWeight(1);
  stroke(20,20,255,100);
  line(-(xm/2),-(ym/2),-(zm/2),(xm/2),-(ym/2),-(zm/2));
  line(-(xm/2),-(ym/2),-(zm/2),-(xm/2),(ym/2),-(zm/2));
  line(-(xm/2),-(ym/2),-(zm/2),-(xm/2),-(ym/2),(zm/2));
  line((xm/2),-(ym/2),-(zm/2),(xm/2),(ym/2),-(zm/2));
  line((xm/2),-(ym/2),-(zm/2),(xm/2),-(ym/2),(zm/2));
  line(-(xm/2),(ym/2),-(zm/2),(xm/2),(ym/2),-(zm/2));
  line(-(xm/2),-(ym/2),(zm/2),(xm/2),-(ym/2),(zm/2));
  line(-(xm/2),-(ym/2),(zm/2),-(xm/2),(ym/2),(zm/2));
  line(-(xm/2),(ym/2),(zm/2),(xm/2),(ym/2),(zm/2));
  line(-(xm/2),(ym/2),(zm/2),-(xm/2),(ym/2),-(zm/2));
  line((xm/2),(ym/2),(zm/2),(xm/2),(ym/2),-(zm/2));
  line((xm/2),(ym/2),(zm/2),(xm/2),-(ym/2),(zm/2));
}
class torch{
  int [] x;
  int [] y;
  int [] z;
  int [] t;
  int d,len,le;
  torch(int x, int y, int z, int t, int d){
    len = 2;
    le = len-1;
    this.x = new int [len];
    this.y = new int [len];
    this.z = new int [len];
    this.t = new int [len];
    this.d = d;
    for (int i = 0; i < len; i++){
      this.x[i] = x;
      this.y[i] = y;
      this.z[i] = z;
      this.t[i] = t;
    }
  }
  void trace(){
    int xp = x[le];
    int yp = y[le];
    int zp = z[le];
    int tp = t[le];
    //println(xp+" "+yp+" "+zp);
    boolean c = pix[tp][xp][yp][zp];
    pix[tp][xp][yp][zp] = true;
    if (d == 0 && !pix[tp][xp+1][yp][zp]){x[le]++;
   }else if(d == 0 && pix[tp][xp+1][yp][zp]){d = (d+1)%8;}

     if (d == 1 && !pix[tp][xp][yp+1][zp]){y[le]++;
    }else if(d == 1 && pix[tp][xp][yp+1][zp]){d = (d+1)%8;}

      if (d == 2 && !pix[tp][xp][yp][zp+1]){z[le]++;
     }else if(d == 2 && pix[tp][xp][yp][zp+1]){d = (d+1)%8;}

       if (d == 3 && !pix[tp+1][xp][yp][zp]){t[le]++;
      }else if(d == 3 && pix[tp+1][xp][yp][zp]){d = (d+1)%8;}

        if (d == 4 && !pix[tp][xp-1][yp][zp]){x[le]--;
       }else if(d == 4 && pix[tp][xp-1][yp][zp]){d = (d+1)%8;}

         if (d == 5 && !pix[tp][xp][yp-1][zp]){y[le]--;
        }else if(d == 5 && pix[tp][xp][yp-1][zp]){d = (d+1)%8;}

          if (d == 6 && !pix[tp][xp][yp][zp-1]){z[le]--;
         }else if(d == 6 && pix[tp][xp][yp][zp-1]){d = (d+1)%8;}

           if (d == 7 && !pix[tp-1][xp][yp][zp]){t[le]--;
          }else if(d == 7 && pix[tp-1][xp][yp][zp]){d = (d+1)%8;}
          if (x[le] > xm - 2){x[le] = 2;}
          if (x[le] < 2){x[le] = xm - 2;}
          if (y[le] > ym - 2){y[le] = 2;}
          if (y[le] < 2){y[le] = ym - 2;}
          if (z[le] > zm - 2){z[le] = 2;}
          if (z[le] < 2){z[le] = zm - 2;}
          if (t[le] > tm - 2){t[le] = 2;}
          if (t[le] < 2){t[le] = tm - 2;}
            //pix[xp][yp][zp] = c;
            for (int i = 1; i < len; i++){
              x[i-1] = x[i];
              y[i-1] = y[i];
              z[i-1] = z[i];
              t[i-1] = t[i];
            }
            if(x[0] == x[1] && y[0] == y[1] && z[0] == z[1] && t[0] == t[1]){
              pix[t[0]][x[0]][y[0]][z[0]] = true;
            }else{
              pix[t[0]][x[0]][y[0]][z[0]] = true;//set to false for trails
            }
          }
          //draw trails
          void draw (){
            for (int i = 1; i < len; i++){
              if(t[i-1] == tf){
                if (abs(x[i-1]-x[i])<2 && abs(y[i-1]-y[i])<2 && abs(z[i-1]-z[i])<2){
                  //stroke(((255.0)/le)*i,((255.0)/le)*i,((255.0)/le)*i,((255.0)/le)*i);
                  //stroke((((155.0)/le)*i)+100,(((155.0)/le)*i)+100,255,((255.0)/le)*i);
                  stroke(255);
                  line(x[i-1]-(xm/2),y[i-1]-(ym/2),z[i-1]-(zm/2),x[i]-(xm/2),y[i]-(ym/2),z[i]-(zm/2));
                }
              }
            }
          }
        }