const NUM_BOIDS = 500;

let canvasWidth;

let canvasHeight;

const colors = ['red', 'blue', 'orange', 'green', 'yellow', 'magenta'];

let qt;

​

function setup() {

  canvasWidth = windowWidth;

  canvasHeight = windowHeight;

  createCanvas(canvasWidth, canvasHeight);

  angleMode(DEGREES);

​

  // Initialize 

  for (let i = 0; i < NUM_BOIDS; i++) {

    boids.push(new Boid(Boid.viewRange * 2 * cos(i * 5) + canvasWidth / 2, Boid.viewRange * 2 * sin(i * 5) + canvasHeight / 2));

  }

  // Setup tree

  qt = new Quadtree({

    x: 0,

    y: 0,

    width: canvasWidth,

    height: canvasHeight

  }, 10, 4);

}

​

function draw() {

  qt.clear();

  background('black');

  // Stars

  stroke('white');

  randomSeed(1);

  for (let i=0; i<250; i++)

    point(random()*canvasWidth,random()*canvasHeight);

  stroke('black');

  // Boids

  boids.forEach(boid => {

    boid.display();

    qt.insert({

      x: boid.position.x - boid.diameter,

      y: boid.position.y - boid.diameter,

      width: boid.diameter * 2,

      height: boid.diameter * 2,

      b: boid

    });

  });

  moveBoids();

}

​

function mouseClicked() {

  boids.push(new Boid(mouseX, mouseY, Math.random() * 4 - 2, Math.random() * 4 - 2));

}

​

function moveBoids() {

  boids.forEach(boid => {

    let close = qt.retrieve({

      x: boid.position.x - boid.diameter,

      y: boid.position.y - boid.diameter,

      width: boid.diameter * 2,

      height: boid.diameter * 2,

      b: boid

    });

​

    let v1 = rule1(boid, close);

    let v2 = rule2(boid, close);

    let v3 = rule3(boid, close);

    let v4 = rule4(boid, close);

​

    boid.vel.add(v1);

    boid.vel.add(v2);

    boid.vel.add(v3);

    boid.vel.add(v4);

  });

  boids.forEach(boid => {

    boid.limitVel();

    boid.position.add(p5.Vector.div(boid.vel, 1));

  });

}