// The Nature of Code

// The Coding Train / Daniel Shiffman

// https://youtu.be/syR0klfncCk

// https://thecodingtrain.com/learning/nature-of-code/4.1-particle-system-simulation.html

// https://editor.p5js.org/codingtrain/sketches/QRzgzQLnQ

​

class Particle {

  constructor(x, y) {

    this.pos = createVector(x, y);

    this.vel = createVector(0, 0);

    this.acc = createVector(0, 0);

    this.r = 4;

    this.lifetime = 255;

​

​

    const options = {

      inputs: 2,

      outputs: 1,

      task: "regression",

      noTraining: true,

    };

    this.brain = new ml5.neuralNetwork(options);

    this.brain.mutate(1);

​

​

  }

​

  finished() {

    return this.lifetime < 0;

  }

​

​

  think() {

    let normX = this.pos.x / width;

    let normY = this.pos.y / height;

​

    let inputs = [normX, normY];

    let output = this.brain.predictSync(inputs);

    //console.log(output);

    let angle = output[0].value * TWO_PI;

    let force = p5.Vector.fromAngle(angle);

    // if (label == "up") {

    //   force.set(0,-1);

    // } else if (label == "down") {

    //   force.set(0,1);

    // } else if (label == "left") {

    //   force.set(-1,0);

    // } else if (label == "right") {

    //   force.set(1,0);

    // }

    force.mult(0.2);

    this.applyForce(force);

  }

​

​

  applyForce(force) {

    this.acc.add(force);

  }

​

  edges() {

    if (this.pos.y >= height - this.r) {

      this.pos.y = height - this.r;

      this.vel.y *= -1;

    }

​

    if (this.pos.x >= width - this.r) {

      this.pos.x = width - this.r;

      this.vel.x *= -1;

    } else if (this.pos.x <= this.r) {

      this.pos.x = this.r;

      this.vel.x *= -1;

    }

  }

​

  update() {

    this.vel.add(this.acc);

    this.pos.add(this.vel);

    this.acc.set(0, 0);

​

    this.lifetime -= 5;

  }

​

  show() {

    stroke(255, this.lifetime);

    strokeWeight(2);

    fill(255, this.lifetime);

​

    ellipse(this.pos.x, this.pos.y, this.r * 2);

  }

}