random grey walker in processing

walker.pde

class Walker {
  int x, y, range;
  String tag;
  Walker(int x1, int y1, int rng) {
    x = x1;
    y = y1;
    range = rng;
    // start at center
  }
  int rndclr () {
    return int(random(255));
  }

  void display() {
    stroke(rndclr());
    strokeWeight(int(random(range)));
    point(x, y);
  }

  void step() {
    int choice = int(random(4)); // this picks from [0,4)
    if ( choice == 0 ) {
      x++;
    } 
    else if ( choice == 1 ) {
      x--;
    } 
    else if ( choice == 2 ) {
      y++;
    } 
    else {
      y--;
    }
  }

  void jump () {
    if (x > range || y > range) {
      x = x - int(random(5));
      y = y - int(random(5));
    }
    if (x < -range || y < -range) {
      x = x + int(random(5));
      y = y + int(random(5));
    }
  }
}  

Walker w, x, y, z;

void setup () {
  size(800, 800);
  w = new Walker(400, 400, 30);
  x = new Walker(200, 200, 240);
  y = new Walker(600, 500, 360);
  z = new Walker(300, 100, 50);
  background(#FA6400);
}



void draw () {
  w.step();
  //w.jump();
  w.display();
  x.step();
  //x.jump();
  x.display();
  y.step();
  //y.jump();
  y.display();
  z.step();
  //z.jump();
  z.display();
}

make walkers draggable :)