Boidsの実装について調査となんか作りたい

let vehicles;

function setup() {
  createCanvas(windowWidth, windowHeight);

  vehicles = [];
  for (let i = 0; i < 50; i++) {
    const position = createVector(random(width), random(height));
    const velocity = p5.Vector.random2D();
    velocity.setMag(random(2, 4));
    const maxSpeed = 4;
    const maxForce = 2;
    vehicles.push(Vehicle.create(position, velocity, maxSpeed, maxForce));
  }
}

function draw() {
  clear();

  vehicles.forEach((v) => {
    Vehicle.flock(v, vehicles);
    Vehicle.update(v);
    Vehicle.draw(v, "#aaa");
  });
}

const Vehicle = {
  create: function (position, velocity, maxSpeed, maxForce) {
    return { position, velocity, acceleration: createVector(), maxSpeed, maxForce };
  },

  update: function (v) {
    v.acceleration.limit(v.maxForce);
    v.velocity.add(v.acceleration);
    v.velocity.limit(v.maxSpeed);
    v.position.add(v.velocity);
    v.acceleration.set(0);

    Vehicle.adjustEdge(v);
  },

  adjustEdge: function (v) {
    if (v.position.x < 0) {
      v.position.x = 0;
      v.velocity.x *= -1;
    } else if (v.position.x >= width) {
      v.position.x = width - 1;
      v.velocity.x *= -1;
    }

    if (v.position.y < 0) {
      v.position.y = 0;
      v.velocity.y *= -1;
    } else if (v.position.y >= height) {
      v.position.y = height - 1;
      v.velocity.y *= -1;
    }
  },

  draw: function (v, strokeColor) {
    push();
    noFill();
    strokeWeight(2);
    stroke(strokeColor);
    translate(v.position);
    rotate(v.velocity.heading());
    beginShape();
    const r = 8;
    vertex(r * 2, 0);
    vertex(-r, r);
    vertex(-r, -r);
    endShape(CLOSE);
    pop();
  },

  seek: function (v, target) {
    const tv = p5.Vector.sub(target, v.position);
    tv.limit(v.maxSpeed);
    const force = p5.Vector.sub(tv, v.velocity);
    v.acceleration.add(force);
  },

  flee: function (v, target) {
    const tv = p5.Vector.sub(target, v.position);
    tv.limit(v.maxSpeed);
    const force = p5.Vector.sub(tv, v.velocity);
    v.acceleration.sub(force);
  },

  inSight(v, other) {
    const d = dist(v.position.x, v.position.y, other.position.x, other.position.y);
    return d < 100;
  },

  align(v, vehicles) {
    const avgVel = createVector();
    let n = 0;
    for (const other of vehicles) {
      if (v === other || !Vehicle.inSight(v, other)) continue;
      avgVel.add(other.velocity);
      n++;
    }
    if (n > 0) {
      avgVel.div(n);
      avgVel.limit(v.maxSpeed);
      v.acceleration.add(p5.Vector.sub(avgVel, v.velocity));
    }
  },

  separation(v, boids) {
    for (const other of boids) {
      if (v === other || !Vehicle.inSight(v, other)) continue;
      const d = dist(v.position.x, v.position.y, other.position.x, other.position.y);
      if (d < 50) {
        Vehicle.flee(v, other.position);
      }
    }
  },

  cohesion(v, boids) {
    let avgPos = createVector();
    let n = 0;
    for (const other of boids) {
      if (v === other || !Vehicle.inSight(v, other)) continue;
      avgPos.add(other.position);
      n++;
    }
    if (n > 0) {
      avgPos.div(n);
      Vehicle.seek(v, avgPos);
    }
  },

  flock(v, boids) {
    Vehicle.align(v, boids);
    Vehicle.cohesion(v, boids);
    Vehicle.separation(v, boids);
  },
};

let vehicles;

function setup() {
  createCanvas(windowWidth, windowHeight);

  vehicles = [];
  for (let i = 0; i < 50; i++) {
    const position = createVector(random(width), random(height));
    const velocity = p5.Vector.random2D();
    velocity.setMag(random(2, 4));
    const maxSpeed = 4;
    const maxForce = 2;
    vehicles.push(Vehicle.create(position, velocity, maxSpeed, maxForce));
  }
}

function draw() {
  clear();

  vehicles.forEach((v) => {
    Vehicle.flock(v, vehicles);
    Vehicle.update(v);
    Vehicle.draw(v, "#aaa");
  });
}

const Vehicle = {
  create: function (position, velocity, maxSpeed, maxForce) {
    return {
      position,
      velocity,
      acceleration: createVector(),
      maxSpeed,
      maxForce,
    };
  },

  /**
   * Update関数。
   * 加速度を速度に、速度を位置に加算している。
   * また速度制限や境界処理などを行っている。
   * ここの中でpos,velocity,accなどが最終決定されそう。
   * @param {Vehilcle} v
   */
  update: function (v) {
    v.acceleration.limit(v.maxForce);
    v.velocity.add(v.acceleration);
    v.velocity.limit(v.maxSpeed);
    v.position.add(v.velocity);
    v.acceleration.set(0);

    Vehicle.adjustEdge(v);
  },

  /**
   * 境界にたどり着いたときに、
   * その境界よりも大きくならないようにPositionを調整し
   * velocityを反転させている
   * @param {Vehicle} v
   */
  adjustEdge: function (v) {
    if (v.position.x < 0) {
      v.position.x = 0;
      v.velocity.x *= -1;
    } else if (v.position.x >= width) {
      v.position.x = width - 1;
      v.velocity.x *= -1;
    }

    if (v.position.y < 0) {
      v.position.y = 0;
      v.velocity.y *= -1;
    } else if (v.position.y >= height) {
      v.position.y = height - 1;
      v.velocity.y *= -1;
    }
  },

  /**
   * 一個一個のVehicleを描画するための関数
   * @param {Vehicle} v Vehicleオブジェクト
   * @param {string} strokeColor 色
   */
  draw: function (v, strokeColor) {
    push();
    noFill();
    strokeWeight(2);
    stroke(strokeColor);
    translate(v.position);
    rotate(v.velocity.heading());
    beginShape();
    const r = 8;
    vertex(r * 2, 0);
    vertex(-r, r);
    vertex(-r, -r);
    endShape(CLOSE);
    pop();
  },

  /**
   * targetの方向にVehicleを近づける処理。
   * 自身からtargetに向かうベクトルと
   * 自身の速度ベクトルの差を
   * 自身の加速度に加えることで近づくような処理をしている
   * @param {Vehicle} v 
   * @param {Vector2D} target 
   */
  seek: function (v, target) {
    const tv = p5.Vector.sub(target, v.position);
    tv.limit(v.maxSpeed);
    const force = p5.Vector.sub(tv, v.velocity);
    v.acceleration.add(force);
  },

  /**
   * 特定のVehicleを避ける処理。
   * （自身からtargetへのベクトル）から
   * 自身のVelocityの差を取り
   * さらにそれをaccから差し引くという処理。
   * これによって相手のVehicleを避けるような加速度が加わる
   * @param {Vehicle} v 
   * @param {Vector2D} target 
   */
  flee: function (v, target) {
    const tv = p5.Vector.sub(target, v.position);
    tv.limit(v.maxSpeed);
    const force = p5.Vector.sub(tv, v.velocity);
    v.acceleration.sub(force);
  },

  /**
   * 範囲内にあるかの判定。
   * 関数内では距離が100未満であれば範囲内と判定する。
   * @param {Vehicle} v 
   * @param {Vehicle} other 
   * @returns 
   */
  inSight(v, other) {
    const d = dist(
      v.position.x,
      v.position.y,
      other.position.x,
      other.position.y
    );
    return d < 100;
  },

  /**
   * 整列。
   * 範囲内の自分以外のvehicleに対して
   * velocityの平均を算出し
   * 自信のvelocityとの差分をaccに加算する
   * @param {Vehicle} v 
   * @param {Vehicle[]} vehicles 
   */
  align(v, vehicles) {
    const avgVel = createVector();
    let n = 0;
    for (const other of vehicles) {
      if (v === other || !Vehicle.inSight(v, other)) continue;
      avgVel.add(other.velocity);
      n++;
    }
    if (n > 0) {
      avgVel.div(n);
      avgVel.limit(v.maxSpeed);
      v.acceleration.add(p5.Vector.sub(avgVel, v.velocity));
    }
  },

  /**
   * 分離。
   * 範囲内の自分以外のvehicleに対して
   * 距離が近かった場合に避けるように動作する
   * @param {Vehicle} v 
   * @param {Vehicle[]} boids 
   */
  separation(v, boids) {
    for (const other of boids) {
      if (v === other || !Vehicle.inSight(v, other)) continue;
      const d = dist(
        v.position.x,
        v.position.y,
        other.position.x,
        other.position.y
      );
      if (d < 50) {
        Vehicle.flee(v, other.position);
      }
    }
  },

  /**
   * 結合。
   * 範囲内の自分以外のpositionの平均ベクトルへseekする
   * @param {Vehicle} v 
   * @param {Vehicle[]} boids 
   */
  cohesion(v, boids) {
    let avgPos = createVector();
    let n = 0;
    for (const other of boids) {
      if (v === other || !Vehicle.inSight(v, other)) continue;
      avgPos.add(other.position);
      n++;
    }
    if (n > 0) {
      avgPos.div(n);
      Vehicle.seek(v, avgPos);
    }
  },

  /**
   * Boids処理の3要素である
   * - 整列
   * - 結合
   * - 分離
   * を順番に実行するだけの関数
   * @param {Vehicle} v 
   * @param {Vehicle[]} boids 
   */
  flock(v, boids) {
    Vehicle.align(v, boids);
    Vehicle.cohesion(v, boids);
    Vehicle.separation(v, boids);
  },
};