Collections

MonoGame.Extended contains Collections extensions to the C# collections that are useful for game programming.

Installation

Collections is part of MonoGame.Extended and is distributed via a NuGet package. You can add the NuGet package to your C# project through your IDE of choice (Visual Studio, Xamarin Studio, Rider, etc) or through the Command Line Interface (CLI) using the dotnet command.

dotnet add MonoGame.Extended

Bag

A Bag is an un-ordered array of items with fast Add and Remove properties.

It is much faster than an array when removing items, and takes less space than a linked list.

Bag will resize itself only when it needs to.

var bag = new Bag<int>(3);

bag.Add(4);

bag.Add(8);

bag.Add(15);

// bag is now [4, 8, 15]

bag.Add(16);

// bag is extended here, capacity is now 4 instead of 3 with items [4, 8, 15, 16]

bag.Remove(1);

// bag is now [4, 16, 15] with a capacity of 4

Deque

Represents a collection of objects in which elements can be added to or removed either from the front or back. See double ended queue.

var deque = new Deque<int>();

deque.AddToBack(1);

deque.AddToBack(2);

deque.AddToFront(4);

deque.AddToFront(5);

deque.AddToBack(3);

while (deque.Count > 0)

{

int item = deque.Pop();

Console.WriteLine(item);

}

Result

3

2

1

4

5

keyedCollection

KeyedCollection is a wrapper around the Dictionary class where the key is obtained by a delegate.

var keyedCollection = new KeyedCollection<int, MyEntity>(e => e.Id);

keyedCollection.Add(new MyEntity {Id = 1, Name = "Player1"});

keyedCollection.Add(new MyEntity {Id = 2, Name = "Player2"});

keyedCollection.TryGetValue(1, out MyEntity entity); // gets Player1

Object Pooling

An ObjectPool<T> allows reuse of memory for a group of items to avoid Garbage Collection. More information is in the Object Pooling documentation.

ObservableCollection

ObservableCollection<T> manages an IList<T> of items firing ItemAdded, ItemRemoved, Clearing, and Cleared events when the collection is changed.

ListExtensions

Adds Shuffle(Random) to all IList<> classes.

DictionaryExtensions

Extends all Dictionary<> classes with GetValueOrDefault(key, default).