circle packing for the laser cutter

Circle.pde

// Daniel Shiffman
// http://codingtra.in
// http://patreon.com/codingtrain
// Code for: https://youtu.be/QHEQuoIKgNE

import processing.pdf.*;

ArrayList<Circle> circles;

void setup() {
  circles = new ArrayList<Circle>();

  for (int i = 0; i < 1000; i++) {
  int total = 10;
  int count = 0;
  int attempts = 0;

  while (count <  total) {
    Circle newC = newCircle();
    if (newC != null) {
      circles.add(newC);
      count++;
    }
    attempts++;
    if (attempts > 1000) {
      noLoop();
      println("FINISHED");
      break;
    } 
  }


  for (Circle c : circles) {
    if (c.growing) {
      if (c.edges()) {
        c.growing = false;
      } else {
        for (Circle other : circles) {
          if (c != other) {
            float d = dist(c.x, c.y, other.x, other.y);
            if (d - 0.5 < c.r + other.r) {
              c.growing = false;
              break;
            }
          }
        }
      }
    }
    c.grow();
  }
  }

  
  beginRecord(PDF, "/Users/barakchamo/Desktop/circle_packing.pdf");
  size(100, 100);
  pushMatrix();
}

void draw() {
  background(255);  
  for (Circle c : circles) {
    c.show();
  }
  endRecord();
}

Circle newCircle() {

  float x = random(width);
  float y = random(height);
  float r = 1;

  boolean valid = true;
  for (Circle c : circles) {
    float d = dist(x, y, c.x, c.y);
    if (d - 0.5 < r + c.r) {
      valid = false;
      break;
    }
  }

  if (valid) {
    return new Circle(x, y, r);
  } else {
    return null;
  }
}

circle_packing.pde

// Daniel Shiffman
// http://codingtra.in
// http://patreon.com/codingtrain
// Code for: https://youtu.be/QHEQuoIKgNE

class Circle {
  float x;
  float y;
  float r;

  boolean growing = true;

  Circle(float x_, float y_, float r_) {
    x = x_;
    y = y_;
    r = r_;
  }

  void grow() {
    if (growing) {
      r = r + 0.5;
    }
  }
  
  boolean edges() {
    return (x + r > width || x -  r < 0 || y + r > height || y -r < 0);
  }

  void show() {
    stroke(0);
    strokeWeight(1);
    noFill();
    ellipse(x, y, r*2, r*2);
  }
}