let population = 100;

let maxSize = 20;

let minSize = 5;

let zOff = 0;

let lock = false;

let lockP;

var fps = 60

let count = 0; 

let recordGate = false;

var capturer =  new CCapture({ format: 'png', framerate: fps });

​

// function mousePressed(){

//   // recordGate = !recordGate;

//   for(let particle of particles){

//     if(mouseX > particle.pos.x-particle.size && mouseX < particle.pos.x+particle.size && mouseY > particle.pos.y-particle.size && mouseY < particle.pos.y+particle.size){

//       lock = true;

//       lockP = particle;

//     }

//   }

//   // if(recordGate){

//   //   capturer.start();

//   // }else{

//   //   capturer.stop();

//   //   capturer.save();

//   // }

// }

​

// function mouseDragged(){

//   if(lock){

//     lockP.pos.x = mouseX;

//     lockP.pos.y = mouseY;

//   }

// }

​

// function mouseReleased() {

//   lock = false;

//   lockP = null;

// }

​

function setup() {

  createCanvas(windowWidth,windowHeight);

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

    particles.push(new Particle());

  }

  frameRate(fps);

}

​

function draw() {

  background(0);

  zOff += 0.5;

  for(let i = particles.length - 1; i >= 0; i--){

    let particle = particles[i];

    let xOff = particle.pos.x/width;

    let xNoise = noise(xOff,zOff);

    particle.applyForce(createVector(xNoise,0));

    particle.findBuddies();

    particle.update();

    particle.show();

    if(particle.edge()){

      particles.splice(i,1);

    } 

  }

  if(particles.length < population){

    let dif = population - particles.length;

    for(let i = 0; i < dif; i++){

      particles.push(new Particle());

    }

  }

  capturer.capture(document.getElementById('defaultCanvas0'));

}

​

class Particle{

  constructor(){

    this.pos = createVector(random(-100,-10),random(height));

    this.vel = createVector(0,0);

    this.acc = createVector(0,0);

    this.size = random(minSize,maxSize);

    let s = map(this.size, minSize, maxSize, 50, 100);

    this.sight = s;

    this.buddies = [];

    //this.maxSpeed = 0.8;

    this.maxSpeed = 1;

    this.maxForce = 0.5;

  }

  flock(){

​

    var sep = this.seperate(this.buddies);

    var ali = this.align(this.buddies);

    var coh = this.cohesion(this.buddies);

​

​

    sep.mult(3);

    ali.mult(4);

    coh.mult(1.5);

​

    this.applyForce(sep);

    this.applyForce(ali);

    this.applyForce(coh);

  }

  seperate(others) {

    var desiredseparation = this.size*2;

    var sum = createVector();

    var count = 0;

​

    for (var i = 0; i < others.length; i++) {

      var other = others[i];

      var distance = p5.Vector.dist(this.pos, other.pos);

​

      if ((distance > 0) && (distance < desiredseparation)) {

        var opposite = p5.Vector.sub(this.pos, other.pos);

        opposite.normalize();

        opposite.div(distance);

        sum.add(opposite);

        count++;

      }

    }

​

    if (count > 0) {

      sum.div(count);

      sum.setMag(this.maxSpeed);

      var steer = p5.Vector.sub(sum, this.vel);

      steer.limit(this.maxForce);

      return steer;

    } else {

      return createVector();

    }

  }

​

​

  align(others) {

    var range = this.sight*2;

    var sum = createVector();

    var count = 0;

​

    for (var i = 0; i < others.length; i++) {

      var other = others[i];

      var d = p5.Vector.dist(this.pos, other.pos);

​

      if ((d > 0) && (d < range)) {

        sum.add(other.vel);

        count++;

      }

    }

​

    if (count > 0) {

      sum.div(others.length);

      sum.setMag(this.maxSpeed);

      var steer = p5.Vector.sub(sum, this.vel);

      steer.limit(this.maxForce);

      return steer;

    } else {

      return createVector();

    }

  }

​

​

  cohesion(others) {

    var range = 10;

    var sum = createVector();

    var count = 0;

​

    for (var i = 0; i < others.length; i++) {

      var other = others[i];

      var d = p5.Vector.dist(this.pos, other.pos);

​

      if ((d > 0) && (d < range)) {

        sum.add(other.pos);

        count++;

      }

    }

​

    if (count > 0) {

      sum.div(others.length);

      sum.setMag(this.maxSpeed);

      var steer = p5.Vector.sub(sum, this.vel);

      steer.limit(this.maxForce);

      return this.seek(sum);

    } else {

      return createVector();

    }

  }

​

  seek(t) {

    var dir = p5.Vector.sub(t, this.pos);

    var d = dir.mag();

    var speed = this.maxSpeed;

​

    dir.setMag(speed);

    var steer = p5.Vector.sub(dir, this.vel);

    steer.limit(this.maxForce);

    return steer;

  }

​

  findBuddies(){

    this.buddies = [];

    for(let particle of particles){

      if(particle != this){

        let d = dist(this.pos.x,this.pos.y,particle.pos.x,particle.pos.y);

        if(d < this.sight){

          this.buddies.push(particle);

        }

      }

    }

  }

  edge(){

    if(this.pos.x-this.sight/2 > width || this.pos.y+this.sight/2 < -5 || this.pos.y-this.sight/2 > height){

      return true;

    }

  }

  applyForce(force){

    let f = force.copy();

    let m = map(this.size,minSize,maxSize,0.005,0.001)

    f.mult(m)

    this.acc.add(f);

  }

  update(){

    this.flock();

    this.vel.add(this.acc);

    this.vel.limit(this.maxSpeed);

    this.pos.add(this.vel);

    this.acc.mult(0);

  }

  show(){

    if(this.buddies.length > 0){

      stroke(220,220,220,10);

      fill(220,220,220,15);

      beginShape();

      vertex(this.pos.x,this.pos.y);

      for(let bud of this.buddies){

        vertex(bud.pos.x,bud.pos.y);

      }

      vertex(this.pos.x,this.pos.y);

      endShape();

    }

    stroke(0);

    fill(100);

    //point(this.pos.x,this.pos.y);

  }

}