let CITY_SIZE = 600;

​

class Road {

  constructor(level, position, angle) {

    this.level = level;

    this.position = position.copy();

    this.angle = angle; 

    this.building = true;

  }

  update() {

    if (!this.building) {

      return;

    }

    this.position.add(cos(this.angle)*this.level, sin(this.angle)*this.level);

    if (red(get(this.position.x, this.position.y)) >= 80) {

      this.building = false;

    }

    if (this.position.x > width - MARGIN || 

        this.position.y > height - MARGIN || 

        this.position.x < MARGIN || 

        this.position.y < MARGIN) {

      this.building = false;

    }

    if (random() > 0.99) {

      this.angle += random([-PI/4, -PI/8, PI/8, PI/4]);

    }

    if (random() > 0.99 && this.level == 5) {

      roads.push(new Road(this.level, this.position, this.angle + random([PI/2, -PI/2]) + random(-0.01,0.01)));

    }

    if (random() > 0.7 && this.level == 5) {

      roads.push(new Road(this.level-2, this.position, this.angle + random([PI/2, -PI/2]) + random(-0.01,0.01)));

    }

    if (random() > 0.8 && this.level == 3) {

      roads.push(new Road(this.level-2, this.position, this.angle + random([PI/2, -PI/2])));

    }

    if (random() > 0.98 && this.level == 3) {

      roads.push(new Road(this.level, this.position, this.angle + random([PI/2, -PI/2])));

    }

    if (random() > 0.995 && this.level == 1) {

      roads.push(new Road(this.level, this.position, this.angle + random([PI/2, -PI/2])));

    }

  }

  draw() {

    if (!this.building) {

      return;

    }

    strokeWeight(this.level);

    stroke(map(this.level, 1, 5, 100, 230));

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

  }

}

​

let roads = [];

​

function setup() {

  createCanvas(CITY_SIZE + MARGIN*2, CITY_SIZE + MARGIN*2);

  roads = [];

  for (let i = 0; i < ceil(random(1, 5)); i++) {

    roads.push(new Road(5, createVector(random(width/2, width/2), random(width/2, width/2)), random(TWO_PI)));

  }

  background(0);

  stroke(230);

}

​

function draw() {

  roads.forEach(road => { road.draw(); road.update(); });

}

​

function mousePressed() {

  roads = [];

  for (let i = 0; i < ceil(random(1, 5)); i++) {

    roads.push(new Road(5, createVector(random(width/2, width/2), random(width/2, width/2)), random(TWO_PI)));

  }

  background(0);

}