let boids;

let vaporwave = [

  // (0, 0, 0),

  // (20, 20, 20),

  // (220, 220, 220),

  "#ff71ce",

  "#01cdfe",

  "#05ffa1",

  "#b967ff",

  "#fffb96",

  // (0, 0, 0),

  // (0, 0, 0),

  // (0,0,0),

];

​

function setup() {

  createCanvas(800,800);

  boids = [];

  for (let _ = 0; _ < 1000; _++) {

    boids.push(new Boid(random(width), random(height)))

  }

  background(220);

}

​

let kickoff = false;

function draw() {

  background(color(220,220,220,10));

  for (let b of boids) {

    b.run(boids);

  }

  if (!kickoff && frameCount > 1000) {

    kickoff = true;

    saveGif("boids.gif", 8);

  }

}

​

class Boid {

  constructor(x, y) {

    this.accel = createVector(0,0);

    this.velo = createVector(random(-1,1), random(-1,1));

    this.pos = createVector(x, y);

    this.size = 3.0;

    this.max_speed = 3;

    this.max_force = 0.05;

    this.color = color(random(vaporwave));

  }

  run(boids) {

    this.flock(boids);

    this.update();

    this.borders();

    this.render();

  }

  applyForce(force) {

    this.accel.add(force); // add mass later: mass: A = F/M

  }

  flock(boids) {

    let separation = this.separate(boids);

    let alignment = this.align(boids);

    let cohesion = this.cohesion(boids);

    // weight

    separation.mult(1.5);

    alignment.mult(1.0);

    cohesion.mult(1.0);

    this.applyForce(separation);

    this.applyForce(alignment);

    this.applyForce(cohesion);

  }

  update() {

    this.velo.add(this.accel);

    this.velo.limit(this.max_speed);

    this.pos.add(this.velo);

    this.accel.mult(0); // reset

  }

  seek(target) {

    let desired = p5.Vector.sub(target, this.pos);

    desired.normalize();

    desired.mult(this.max_speed);

    let steer = p5.Vector.sub(desired, this.velo);

    steer.limit(this.max_force);

    return steer;

  }

  render() {

    let theta = this.velo.heading() + radians(90);

    fill(this.color);

    noStroke();

    push();

    translate(this.pos.x, this.pos.y);

    rotate(theta);

    beginShape();

    vertex(0, -this.size*2);

    vertex(-this.size, this.size*2);

    vertex(this.size, this.size*2);

    endShape(CLOSE);

    pop();

  }

  borders() {

    if (this.pos.x < -this.size) this.pos.x = width + this.size;

    if (this.pos.y < -this.size) this.pos.y = height + this.size;

    if (this.pos.x > width+this.size) this.pos.x = -this.size;

    if (this.pos.y > height+this.size) this.pos.y = -this.size;

  }

  separate(boids) {

    let desired_separation = 25.0;

    let steer = createVector(0, 0);

    let count = 0;

    for (let boid of boids) {

      let distToNeighbor = p5.Vector.dist(this.pos, boid.pos);

      if (distToNeighbor > 0 && distToNeighbor < desired_separation) {

        let diff = p5.Vector.sub(this.pos, boid.pos);

        diff.normalize();

        diff.div(distToNeighbor);

        steer.add(diff);

        count++;

      }

    }

    if (count > 0) steer.div(count) // averaging

    if (steer.mag() > 0) {

      steer.normalize();

      steer.mult(this.max_speed);

      steer.sub(this.velo);

      steer.limit(this.max_force);

    }

    return steer;

  }

  align(boids) {

    let neighbor_dist = 50;

    let sum = createVector(0, 0);

    let count = 0;

    for (let i = 0; i < boids.length; i++) {

      let d = p5.Vector.dist(this.pos, boids[i].pos);

      if (d > 0 && d < neighbor_dist) {

        sum.add(boids[i].velo);

        count++;

      }

    }

    if (count > 0) {

      sum.div(count);

      sum.normalize();

      sum.mult(this.max_speed);

      let steer = p5.Vector.sub(sum, this.velo);

      steer.limit(this.max_force);

      return steer;

    } else {

      return createVector(0, 0);

    }

  }

  cohesion(boids) {

    let neighbor_distance = 50;

    let sum = createVector(0, 0);

    let count = 0;

    for (let i = 0; i < boids.length; i++) {

      let d = p5.Vector.dist(this.pos, boids[i].pos);

      if (d > 0 && d < neighbor_distance) {

        sum.add(boids[i].pos);

        count++;

      }

    }

    if (count > 0) {

      sum.div(count);

      return this.seek(sum);

    } else {

      return createVector(0, 0);

    }

  }

}