// http://codingtra.in

// http://patreon.com/codingtrain

// Code for: https://youtu.be/BjoM9oKOAKY

​

class Particle {

  constructor() {

    this.pos = createVector(random(width), random(height));

    this.vel = createVector(0, 0);

    this.acc = createVector(0, 0);

    this.maxspeed = 4;

    this.prevPos = this.pos.copy();

    this.lifespan = 50;

    this.width=50;

  }

​

  update() {

    this.vel.add(this.acc);

    this.vel.limit(this.maxspeed);

    this.pos.add(this.vel);

    this.acc.mult(0);

    if (this.lifespan<255){

      this.lifespan=this.lifespan+4;

    }

    this.width=this.width-1;

  }

​

  follow(vectors) {

    var x = floor(this.pos.x / scl);

    var y = floor(this.pos.y / scl);

    var index = x + y * cols;

    var force = vectors[index];

    this.applyForce(force);

  }

​

  applyForce(force) {

    this.acc.add(force);

  }

​

  show() {

    stroke(255,this.lifespan,this.lifespan);

    console.log(this.lifespan);

    strokeWeight(this.width);

    line(this.pos.x, this.pos.y, this.prevPos.x, this.prevPos.y);

    this.updatePrev();

  }

​

  updatePrev() {

    this.prevPos.x = this.pos.x;

    this.prevPos.y = this.pos.y;

  }

​

  edges() {

    if (this.pos.x > width) {

      this.pos.x = 0;

      this.updatePrev();

    }

    if (this.pos.x < 0) {

      this.pos.x = width;

      this.updatePrev();

    }

    if (this.pos.y > height) {

      this.pos.y = 0;

      this.updatePrev();

    }

    if (this.pos.y < 0) {

      this.pos.y = height;

      this.updatePrev();

    }

​

  }

​

}