ring/ring/ring.pde

class Leaf {
  PVector pos;
  
  Leaf() {
    pos = PVector.random2D();
  }
}

class Branch {
  PVector pos;
  
  Branch(PVector pos) {
    this.pos = pos;
  }
  
  Branch(Branch b) {
     this.pos = b.pos;
  }
}

class Tree {
  ArrayList<Branch> branches = new ArrayList<>();
  ArrayList<Leaf> leaves = new ArrayList<>();
  
  Tree() {
    for (int i = 0; i < 2000; i++) leaves.add(new Leaf());
    
    Branch root = new Branch(new PVector(width/2, height/2));
    branches.add(root);
    Branch current = new Branch(root);
    
    while(!closeEnough(current)) {
      Branch trunk = new Branch(current);
      branches.add(trunk);
      current = trunk;
    }
  }
  
  boolean closeEnough(Branch b) {
    for (Leaf l : leaves) {
       float d = PVector.dist(b.pos, l.pos);
       if (d < max_dist) return true;
    }
    return false;
  }
  
  void show() {
  }
  
  void grow() {
    Branch closest = null;
    PVector closestDir = null;
    float record = -1;
    
    for (Branch b : branches) {
      PVector dir = PVector.sub(l.pos, b.pos);
      float d = dir.mag();
      if (d < min_dist) {
        l.reached();
        closest = null;
        break;
      } else if (closest == null && d <= max_dist) {
        closest = b;
        closestDir = dir;
        record = d;
      }
    }
  }
}

Tree tree;

float min_dist = 5;
float max_dist = 50;

void setup() {
  size(600, 600);
  frameRate(5);
  tree = new Tree();
}

void draw() {
   background(40);
   tree.show();
   tree.grow();
}