let moths = [];

let light;

​

function preload() {

  img = loadImage("porch.jpg");

}

​

function setup() {

  createCanvas(600, 600);

  angleMode(DEGREES)

  for (let i = 0; i < 10; i++) {

    moths.push(

      new Moth(random(-width / 2, width / 2), random(-height / 2, height / 2))

    );

  }

  light = new Light(-35, 0);

}

​

function draw() {

  background(220);

  texture(img)

  translate(width / 2, height / 2);

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

    moths[i].update(light);

    moths[i].display(light);

  }

}

​

class Moth {

  constructor(x, y) {

    this.size = random(8, 15)

    this.pos = createVector(x, y);

    this.prev = createVector(x, y);

    this.vel = createVector(0, 0);

    this.acc = createVector(0.5, 0.5);

    this.counter = 0;

  }

​

  move() {

    this.pos.add(this.vel);

    this.pos.add(random(-5,5), random(-5,5))

  }

​

  update(light) {

    let direction;

    direction = createVector(

      light.pos.x - this.pos.x,

      light.pos.y - this.pos.y

    );

    direction.normalize();

​

    this.vel.add(direction.mult(this.acc));

    this.vel.limit(10);

    this.move();

  }

​

  display(light) {

    noStroke();

    let distance = Math.abs(Math.sqrt(Math.pow(this.pos.x-light.pos.x, 2)+Math.pow(this.pos.y-light.pos.y, 2)))

    let theta = this.vel.heading() + PI / 2;

    map(distance, 0, height, 50, 200)

    fill(Math.abs(255-distance));

    push()

    translate(this.pos.x, this.pos.y)

    rotate(theta);

    ellipse(0, 0, this.size*0.6, this.size);

    if (this.counter%2 == 0) {

      rotate(290)

    } else {

      rotate(310)

    }

    fill(Math.abs(200-distance));

    ellipse(4, -2, this.size*0.8, this.size*0.5);

    ellipse(-4, -2, this.size*0.8, this.size*0.5);

    pop()

    this.counter++

  }

}

​

class Light {

  constructor(x, y) {

    this.pos = createVector(x, y);

  }

​

  attract(moth) {

    let force = p5.Vector.sub(this.pos, moth.pos);

    let distanceSq = constrain(force.magSq(), 25, 2500);

    let G = 1;

    let strength = (G * (this.m * moth.m)) / distanceSq;

    force.setMag(strength);

    moth.applyForce(force);

  }

}

​