Claw

.NET Core Component Framework

Claw is a very simple .NET Core component framework that doesn't allocate after the first call and is fast enough for most uses (including games).

Getting Started

Defining a Component Object

public class Thing : ComponentObject
{
    public void DoSomething(string s, int i)
    {
        Console.WriteLine($"Thing: DoSomething({s}, {i})");
        this.InvokeComponents(s, Boxer.Box(i));
    }
}

Value types need to be wrapped in a Boxed<T>. Boxer will pool boxes.

Defining a Component

public class Behavior : Component
{
    public void DoSomething(Thing source, string s, Boxed<int> i)
    {
        Console.WriteLine($"Behavior: DoSomething({s}, {i})");
    }
}

Creating a Component Object and extending it with a Component

Thing thing = new Thing();
thing.AddComponent<Behavior>();
thing.DoSomething("abcd", 1234);
Console.ReadLine();

Result:

Thing: DoSomething(abcd, 1234)
Behavior: DoSomething(abcd, 1234)

Returning Results

public class Thing : ComponentObject
{
    public bool DoSomethingResult(string s, int i)
    {
        Console.WriteLine($"Thing: DoSomethingResult({s}, {i})");
        Boxed<bool> result = Boxer.Box(false);
        this.InvokeComponents(s, Boxer.Box(i), result);
        return result;
    }
}

Return values need to be wrapped in a Boxed<T> regardless of whether they're a value type. Boxer will pool boxes.

public class Behavior : Component
{
    public void DoSomethingResult(Thing source, string s, Boxed<int> i, Boxed<bool> result)
    {
        Console.WriteLine($"Behavior: DoSomethingResult({s}, {i})");
        result.Value = true;
    }
}

Thing thing = new Thing();
thing.AddComponent<Behavior>();
bool result = thing.DoSomethingResult("efgh", 5678);
Console.WriteLine($"Result: {result}");
Console.ReadLine();

Result:

Thing: DoSomethingResult(efgh, 5678)
Behavior: DoSomethingResult(efgh, 5678)
Result: True

Hierarchical Components

You can add components to components to compose behaviors from other behaviors.

Thing thing = new Thing();
Behavior behavior1 = new Behavior();
Behavior behavior2 = new Behavior();
behavior1.AddComponent(behavior2);
thing.AddComponent(behavior1);
thing.DoSomething("abcd", 1234);
Console.ReadLine();

A Real World Example

Enemy enemy = new Enemy();
enemy.AddComponent<WalkBehavior>();
enemy.AddComponent<JumpBehavior>();
enemy.AddComponent<ShootProjectilesBehavior>();
enemy.Update();
Console.ReadLine();