// The Coding Train

// Coding Challenge 69: Steering Evolution

// Part 1: https://youtu.be/flxOkx0yLrY

// Part 2: https://youtu.be/XaOVH8ZSRNA

// Part 3: https://youtu.be/vZUWTlK7D2Q

// Part 4: https://youtu.be/ykOcaInciBI

// Part 5: https://youtu.be/VnFF5V5DS8s

​

// https://editor.p5js.org/codingtrain/sketches/xgQNXkxx1

​

var mr = 0.01;

​

class Vehicle {

  constructor(x, y, dna) {

    this.acceleration = createVector(0, 0);

    this.velocity = createVector(0, -2);

    this.position = createVector(x, y);

    this.r = 4;

    this.maxspeed = 3;

    this.maxforce = 0.5;

​

    this.health = 1;

​

    this.dna = [];

    if (dna === undefined) {

      // Food weight

      this.dna[0] = random(-2, 2);

      // Poison weight

      this.dna[1] = random(-2, 2);

      // Food perception

      this.dna[2] = random(0, 100);

      // Poision Percepton

      this.dna[3] = random(0, 100);

    } else {

      // Mutation

      this.dna[0] = dna[0];

      if (random(1) < mr) {

        this.dna[0] += random(-0.1, 0.1);

      }

      this.dna[1] = dna[1];

      if (random(1) < mr) {

        this.dna[1] += random(-0.1, 0.1);

      }

      this.dna[2] = dna[2];

      if (random(1) < mr) {

        this.dna[2] += random(-10, 10);

      }

      this.dna[3] = dna[3];

      if (random(1) < mr) {

        this.dna[3] += random(-10, 10);

      }

    }

  }

​

​

  // Method to update location

  update() {

​

    this.health -= 0.005;

​

    // Update velocity

    this.velocity.add(this.acceleration);

    // Limit speed

    this.velocity.limit(this.maxspeed);

    this.position.add(this.velocity);

    // Reset accelerationelertion to 0 each cycle

    this.acceleration.mult(0);

  }

​

  applyForce(force) {

    // We could add mass here if we want A = F / M

    this.acceleration.add(force);

  }

​

  behaviors(good, bad) {

    const steerG = this.eat(good, 0.2, this.dna[2]);

    const steerB = this.eat(bad, -1, this.dna[3]);

​

    steerG.mult(this.dna[0]);

    steerB.mult(this.dna[1]);

​

    this.applyForce(steerG);

    this.applyForce(steerB);

  }

​

  clone() {

    if (random(1) < 0.002) {

      return new Vehicle(this.position.x, this.position.y, this.dna);

    } else {

      return null;

    }

  }

​

  eat(list, nutrition, perception) {

    let record = Infinity;

    let closest = null;

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

      const d = this.position.dist(list[i]);

​

      if (d < this.maxspeed) {

        list.splice(i, 1);

        this.health += nutrition;

      } else {

        if (d < record && d < perception) {

          record = d;

          closest = list[i];

        }

      }

    }

​

    // This is the moment of eating!

​

    if (closest != null) {

      return this.seek(closest);

    }

​

    return createVector(0, 0);

  }

​

  // A method that calculates a steering force towards a target

  // STEER = DESIRED MINUS VELOCITY

  seek(target) {

​

    const desired = p5.Vector.sub(target, this.position); // A vector pointing from the location to the target

​

    // Scale to maximum speed

    desired.setMag(this.maxspeed);

​

    // Steering = Desired minus velocity

    const steer = p5.Vector.sub(desired, this.velocity);

    steer.limit(this.maxforce); // Limit to maximum steering force

​

    return steer;

    //this.applyForce(steer);

  }

​

  dead() {

    return (this.health < 0)

  }

​

  display(sw = 1) {

    // Draw a triangle rotated in the direction of velocity

    const angle = this.velocity.heading() + PI / 2;

​

    push();

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

    rotate(angle);

​

​

    if (debug.checked()) {

      strokeWeight(3);

      stroke(0, 255, 0);

      noFill();

      line(0, 0, 0, -this.dna[0] * 25);

      strokeWeight(2);

      ellipse(0, 0, this.dna[2] * 2);

      stroke(255, 0, 0);

      line(0, 0, 0, -this.dna[1] * 25);

      ellipse(0, 0, this.dna[3] * 2);

    }

​

    const gr = color(0, 255, 0);

    const rd = color(255, 0, 0);

    const col = lerpColor(rd, gr, this.health);

​

    fill(col);

    stroke(col);

    strokeWeight(sw);

    beginShape();

    vertex(0, -this.r * 2);

    vertex(-this.r, this.r * 2);

    vertex(this.r, this.r * 2);

    endShape(CLOSE);

​

    pop();

  }

​

​

  boundaries() {

    const d = 25;

​

    let desired = null;

​

    if (this.position.x < d) {

      desired = createVector(this.maxspeed, this.velocity.y);

    } else if (this.position.x > width - d) {

      desired = createVector(-this.maxspeed, this.velocity.y);

    }

​

    if (this.position.y < d) {

      desired = createVector(this.velocity.x, this.maxspeed);

    } else if (this.position.y > height - d) {

      desired = createVector(this.velocity.x, -this.maxspeed);

    }

​

    if (desired !== null) {

      desired.normalize();

      desired.mult(this.maxspeed);

      const steer = p5.Vector.sub(desired, this.velocity);

      steer.limit(this.maxforce);

      this.applyForce(steer);

    }

  }

}