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

  this.lastPosition = this.position.copy();

  this.angle = 0;

  this.stepSize = random(1, 5);

}

​

Agent.prototype.draw = function(alpha, strokeWidth) {

  stroke(0, alpha);

  strokeWeight(this.stepSize * strokeWidth);

  line(this.lastPosition.x, this.lastPosition.y, this.position.x, this.position.y);

}

​

Agent.prototype.update = function(noiseScale, noiseStrength) {

  this.lastPosition = this.position.copy();

  this.angle = noise(this.position.x * noiseScale, this.position.y * noiseScale)*noiseStrength;

  this.position.x += cos(this.angle) * this.stepSize;

  this.position.y += sin(this.angle) * this.stepSize;

  if (this.isOffscreen()) {

    this.position.set(random(width), random(height));

    this.lastPosition = this.position.copy();

  }

}

​

Agent.prototype.isOffscreen = function() {

  return this.position.x < 0 || this.position.x > width

    || this.position.y < 0 || this.position.y > height;

}