PG0007.Question01

[jack81722]

Introduction

Background

川口哲也是一名遊戲設計師，他發想了一款彈幕射擊遊戲，原本程式的設計會讓子彈在每次發射時建立一個物件，但開發到一半時，他發現每次到子彈特別多的情況下，系統的幀數就會明顯的下降，在大量的建立、清除物件情況下，會消耗大量的系統資源，作為他的好同事，你提出了一個方案，利用物件池儲存應該被清除的子彈，當再次發射時，從物件池取出回收的子彈，可以減少物件大量建立、清除的情形...

Conditions

• 子彈總數(儲存與取出總和)不會超過1000
• 所有子彈編號(id)每個都是獨立的
• 物件池子彈數不足時，批次增加32顆子彈
• 回收的子彈需判斷是否已存在物件池中

Answer

解答

public class Pool<T> : IPool<T>
{
    protected const int _batchSpawnCount = 32;

    /// <summary>
    /// 產生物件的工廠
    /// </summary>
    protected IFactory<T> _factory { get; }

    /// <summary>
    /// 儲存物件的空間
    /// </summary>
    protected List<T> _storage { get; }

    /// <summary>
    /// 目前儲存的物件數
    /// </summary>
    public int Count => _storage.Count;

    #region -- Constructors --
    public Pool(IFactory<T> factory)
    {
        _factory = factory;
        _storage = new List<T>();
    }
    #endregion

    /// <summary>
    /// 主動呼叫並建立物件
    /// </summary>
    /// <param name="count">建立的數量</param>
    public void Ready(int count)
    {
        for (int i = 0; i < count; i++)
        {
            var item = _factory.Spawn();
            _storage.Add(item);
        }
    }

    public void Push(T item)
    {
        if (item == null)
            return;
        if (_storage.Contains(item))
            return;
        _storage.Add(item);
    }

    public T Pop()
    {
        if(_storage.Count < 1)
        {
            Ready(_batchSpawnCount);
        }
        var item = _storage[_storage.Count - 1];
        _storage.RemoveAt(_storage.Count - 1);
        return item;
    }
}

public class BulletFactory : IFactory<Bullet>
{
    private int _idGenerator;

    #region -- Constructors --
    public BulletFactory()
    {
        _idGenerator = 0;
    }

    public BulletFactory(int initId)
    {
        _idGenerator = initId;
    }
    #endregion

    public Bullet Spawn()
    {
        return new Bullet(_idGenerator++);
    }
}

public static class PoolExtension
{
    public static T[] MultiPop<T>(this IPool<T> pool, int count)
    {
        if (pool == null)
            throw new ArgumentNullException("pool is null");
        if (count < 0)
            throw new ArgumentException("count must be greater than zero");
        var items = new T[count];
        for (int i = 0; i < count; i++)
        {
            var item = pool.Pop();
            items[i] = item;
        }
        return items;
    }

    public static void MultiPush<T>(this IPool<T> pool, params T[] items)
    {
        if (pool == null)
            throw new ArgumentNullException("pool is null");
        if (items == null)
            return;
        foreach(var  item in items)
        {
            pool.Push(item);
        }
    }
}

[louise-bwsx]

小4 ( 程式 )

答案

public class Pool<T> : IPool<T>
        {
            protected const int _batchSpawnCount = 32;

            // 產生物件的工廠
            protected IFactory<T> _factory { get; }

            // 儲存物件的空間
            protected List<T> _storage { get; }

            // 目前儲存的物件數
            public int Count => _storage.Count;

            public Pool(IFactory<T> factory)
            {
                _factory = factory;
                _storage = new List<T>();
            }

            /// <summary>
            /// 主動呼叫並建立物件
            /// </summary>
            /// <param name="count">建立的數量</param>
            public void Ready(int count)
            {
                for (int i = 0; i < count; i++)
                {
                    var item = _factory.Spawn();
                    _storage.Add(item);
                }
            }

            public void Push(T item)
            {
                if (item == null)
                {
                    throw new ArgumentNullException("item == null");
                }
                if (_storage.Contains(item))
                {
                    return;
                }
                _storage.Add(item);
            }

            public T Pop()
            {
                if (_storage.Count < 1)
                {
                    Ready(_batchSpawnCount);
                }
                var item = _storage[0];
                _storage.RemoveAt(0);
                return item;
            }
        }

        public class Bullet
        {
            public int Id { get; }

            public Bullet(int id)
            {
                Id = id;
            }
        }

        public class BulletFactory : IFactory<Bullet>
        {
            private int uniqueID;
            public BulletFactory()
            {
                uniqueID = 0;
            }

            public Bullet Spawn()
            {
                uniqueID++;
                return new Bullet(uniqueID);
            }
        }

    public static class PoolExtension
    {
        public static T[] MultiPop<T>(this IPool<T> pool, int count)
        {
            if (pool == null)
                throw new ArgumentNullException("pool is null");
            if (count < 0)
                throw new ArgumentException("count must be greater than zero");
            var items = new T[count];
            for (int i = 0; i < items.Length; i++)
            {
                items[i] = pool.Pop();
            }
            return items;
        }

        public static void MultiPush<T>(this IPool<T> pool, params T[] items)
        {
            if (pool == null)
                throw new ArgumentNullException("pool is null");
            if (items == null)
                return;
            for (int i = 0; i < items.Length; i++)
            {
                pool.Push(items[i]);
            }
        }
    }

反饋

好難啊 我甚至全部丟給ChatGPT都沒得到答案
想了一段時間就放棄了 看了看老師的答案改點東西就交作業了
然後關於Pop 是不是應該先進先出比較好? 如果遇到影片中的例子https://www.youtube.com/watch?v=tdSmKaJvCoA&t=766s
就會變成Push後 馬上被Pop出來? 變成前面被噴出來掉在地上的cube不會消失 但是剛噴出來的cube噴出來馬上被push回去
其實我也不知道我說的對不對 因為我看教學ObjectPool都是用Queue比較多 就算用List也都是從0開始Pop

[jack81722]

你總是能想到不錯的問題XD
用FIFO或是FILO都可以，
考慮到List從0開始取的效率會較差，
因為List內部還是以array為核心，
勢必會在取出第一個元素的時候，
將後面所有元素進行一次shift，
時間複雜度為O(n)，所以我都盡量避免使用這寫法。

Queue是好解法，不過我沒打算現在就提到(那是資料結構與演算法範圍)

[A24575255]

JIA（程式新手）

我的答案

using System;
using System.Collections.Generic;
using UnityEngine;

namespace PG0007.Questions
{
    public class Question1 : MonoBehaviour
    {
        public class Pool<T> : IPool<T>
        {
            protected const int _batchSpawnCount = 32;

            protected IFactory<T> _factory { get; }

            protected List<T> _storage { get; }

            public int Count { get { return _storage.Count; } }

            public Pool(IFactory<T> factory)
            {
                _factory = factory;
                _storage = new List<T>();
            }

            public void Ready(int count)
            {
                for (int i = 0; i < count; i++)
                {
                    var item = _factory.Spawn();
                    _storage.Add(item);
                }
            }

            public void Push(T item)
            {
                if (item == null) return;
                if (_storage.Contains(item)) return;

                _storage.Add(item);
            }

            public T Pop()
            {
                if (_storage.Count <= 0)
                    Ready(32);

                int lastIndex = _storage.Count - 1;
                var item = _storage[lastIndex];
                _storage.RemoveAt(lastIndex);

                return item;
            }
        }

        public class Bullet
        {
            public int Id { get; }

            public Bullet(int id)
            {
                Id = id;
            }
        }

        public class BulletFactory : IFactory<Bullet>
        {
            private Pool<Bullet> bulletPool;

            public BulletFactory()
            {
                bulletPool = new Pool<Bullet>(this);
            }

            public Bullet Spawn()
            {
                int id = bulletPool.Count + 1;

                Bullet bullet = new Bullet(id);
                bulletPool.Push(bullet);

                return bullet;
            }
        }
    }

    public static class PoolExtension
    {
        public static T[] MultiPop<T>(this IPool<T> pool, int count)
        {
            if (pool == null)
                throw new ArgumentNullException("pool is null");

            if (count < 0)
                throw new ArgumentException("count must be greater than zero");

            T[] items = new T[count];

            for (int i = 0; i < count; i++)
                items[i] = pool.Pop();

            return items;
        }

        public static void MultiPush<T>(this IPool<T> pool, params T[] items)
        {
            if (pool == null)
                throw new ArgumentNullException("pool is null");

            if (items == null)
                return;

            int itemCount = items.Length;
            for (int i = 0; i < itemCount; i++)
            {
                pool.Push(items[i]);
            }
        }
    }
}

[OLDShaw1022]

老蕭OLDShaw（程式）

我的答案

    public class Question1 : MonoBehaviour
    {
        public class Pool<T> : IPool<T>
        {
            protected const int _batchSpawnCount = 32;

            /// <summary>
            /// ｲ｣･ﾍｪｫ･ｺ､uｼt
            /// </summary>
            protected IFactory<T> _factory { get; }

            /// <summary>
            /// ﾀxｦsｪｫ･ｺｪﾅｶ｡
            /// </summary>
            protected List<T> _storage { get; }

            /// <summary>
            /// ･ﾘｫeﾀxｦsｪｺｪｫ･ﾆ
            /// </summary>
            public int Count { get { return _storage.Count; } }

            #region -- Constructors --
            public Pool(IFactory<T> factory)
            {
                _factory = factory;
                _storage = new List<T>();
            }
            #endregion

            /// <summary>
            /// ･DｰﾊｩI･sｨﾃｫﾘ･ﾟｪｫ･・
            /// </summary>
            /// <param name="count">ｫﾘ･ﾟｪｺｼﾆｶq</param>
            public void Ready(int count)
            {
                for (int i = 0; i < count; i++)
                {
                    _storage.Add(_factory.Spawn());
                }
            }

            public void Push(T item)
            {
                if (_storage.Contains(item)) return;

                _storage.Add(item);
            }

            public T Pop()
            {
                if( _storage.Count == 0)
                {
                    Ready(_batchSpawnCount);
                }

                T item = _storage[_storage.Count - 1];
                _storage.RemoveAt(_storage.Count - 1);
                return item;
            }
        }

        /// <summary>
        /// A bullet object
        /// </summary>
        public class Bullet
        {
            public int Id { get; }

            public Bullet(int id)
            {
                Id = id;
            }
        }

        public class BulletFactory : IFactory<Bullet>
        {
            int _uniqueId;

            #region -- Constructors --
            public BulletFactory()
            {
                _uniqueId = 0;
            }
            #endregion

            public Bullet Spawn()
            {
                return new Bullet(_uniqueId++);
            }
        }
    }

    public static class PoolExtension
    {
        public static T[] MultiPop<T>(this IPool<T> pool, int count)
        {
            if (pool == null)
                throw new ArgumentNullException("pool is null");
            if (count < 0)
                throw new ArgumentException("count must be greater than zero");
            T[] result = new T[count];

            for (int i = 0; i < count; i++)
            {
                result[i] = pool.Pop();
            }

            return result;
        }

        public static void MultiPush<T>(this IPool<T> pool, params T[] items)
        {
            if (pool == null)
                throw new ArgumentNullException("pool is null");
            if (items == null)
                return;
            foreach (var item in items)
            {
                pool.Push(item);
            }
        }
    }

測試截圖

[jack81722]

亂碼不打算處理嗎XD
算了，也算我的鍋啦哈哈

[OLDShaw1022]

我是有查過VS轉碼相關的教學，但測試出來都沒變，後來就懶得找原因了。我想可能是我電腦調過語系之類的問題，不然正常亂碼應該會是中文的亂碼而不是日文的。

後記：
是的，的確是windows語系設定相關的問題，調整完後是正常的字了。

[ISnoweve]

Snoweve (程式)

我的答案

using System;
using System.Collections.Generic;
using UnityEngine;
using static UnityEditor.Progress;

namespace PG0007.Questions
{
    public class Question1 : MonoBehaviour
    {
        public class Pool<T> : IPool<T>
        {
            protected const int _batchSpawnCount = 32;

            /// <summary>
            /// 產生物件的工廠
            /// </summary>
            protected IFactory<T> _factory { get; }

            /// <summary>
            /// 儲存物件的空間
            /// </summary>
            protected List<T> _storage { get; }

            /// <summary>
            /// 目前儲存的物件數
            /// </summary>
            public int Count { get { return _storage.Count; } }

            #region -- Constructors --
            public Pool(IFactory<T> factory)
            {
                _factory = factory;
                _storage = new List<T>();
            }
            #endregion

            /// <summary>
            /// 主動呼叫並建立物件
            /// </summary>
            /// <param name="count">建立的數量</param>
            public void Ready(int count)
            {
                for (int i = 0; i < count; i++)
                {
                    var item = _factory.Spawn();
                    _storage.Add(item);
                }
            }

            public void Push(T item)
            {
                if (item == null)
                    return;
                if (_storage.Contains(item))
                    return;
                _storage.Add(item);
            }

            public T Pop()
            {
                if (_storage.Count < 1)
                {
                    Ready(_batchSpawnCount);
                }
                T item = _storage[_storage.Count - 1];
                _storage.RemoveAt(_storage.Count - 1);
                return item;
            }
        }

        /// <summary>
        /// A bullet object
        /// </summary>
        public class Bullet
        {
            public int Id { get; }

            public Bullet(int id)
            {
                Id = id;
            }
        }

        public class BulletFactory : IFactory<Bullet>
        {
            private int _distinctId;

            #region -- Constructors --
            public BulletFactory()
            {
                _distinctId = 0;
            }
            #endregion
            public Bullet Spawn()
            {
                return new Bullet(_distinctId++);
            }
        }
    }

    public static class PoolExtension
    {
        public static T[] MultiPop<T>(this IPool<T> pool, int count)
        {
            if (pool == null)
                throw new ArgumentNullException("pool is null");
            if (count < 0)
                throw new ArgumentException("count must be greater than zero");
            var items = new T[count];
            for (int i = 0; i < count; i++)
            {
                var item = pool.Pop();
                items[i] = item;
            }
            return items;
        }

        public static void MultiPush<T>(this IPool<T> pool, params T[] items)
        {
            if (pool == null)
                throw new ArgumentNullException("pool is null");
            if (items == null)
                return;
            foreach (var item in items)
            {
                pool.Push(item);
            }
        }
    }
}