Samples

Trecs includes a progressive tutorial series and two full game samples. Each sample builds on concepts from previous ones.

Tutorial Series (Trecs 101)

#	Sample	Concepts
01	Hello Entity	Components, tags, templates, systems, world setup
02	Spawn & Destroy	Entity lifecycle, dynamic spawning, timed destruction
03	Aspects	Bundled component access for clean iteration
04	Predator Prey	Cross-entity references, template inheritance, event cleanup
05	Job System	Burst compilation, parallel jobs, WrapAsJob
06	Partitions	Template partitions, partition transitions, group-based iteration
07	Feeding Frenzy	Complex simulation, visual smoothing, multiple interacting systems
08	Sets	Dynamic entity subsets, overlapping membership
09	Interpolation	Fixed-to-variable timestep interpolation
10	Pointers	SharedPtr, UniquePtr, managed data on the heap

Game Samples

#	Sample	Description
11	Snake	Complete grid-based game with input handling and recording/playback
12	Feeding Frenzy Benchmark	Performance benchmark comparing partition approaches and iteration styles
13	Save Game	Sokoban puzzle demonstrating bookmark-based save/load slots

Running the Samples

Open UnityProject/Trecs/Assets/Samples/Main.unity in Unity 6000.3+ to run all samples. Each sample has its own composition root that builds the world and initializes the scene.

Sample Architecture: Bootstrap & CompositionRoot

Each sample uses a simple two-class pattern to wire everything together:

• Bootstrap — a MonoBehaviour that drives the Unity lifecycle. It calls the composition root's Construct() in Awake(), then forwards Update() → tick, LateUpdate() → late tick, and OnDestroy() → dispose.
• CompositionRootBase — an abstract MonoBehaviour that each sample subclasses. The Construct() method builds the WorldBuilder, creates systems, and returns lists of callbacks for initialization, tick, late tick, and disposal.

// Simplified — each sample's composition root looks roughly like this:
public class MyCompositionRoot : CompositionRootBase
{
    public override void Construct(
        out List<Action> initializables,
        out List<Action> tickables,
        out List<Action> lateTickables,
        out List<Action> disposables)
    {
        var world = new WorldBuilder()
            .AddEntityType(MyEntity.Template)
            .Build();

        world.AddSystems(new ISystem[] { new MySystem() });

        initializables = new() { world.Initialize };
        tickables = new() { world.Tick };
        lateTickables = new() { world.LateTick };
        disposables = new() { world.Dispose };
    }
}

Note

This pattern is just a lightweight convenience for the samples. Trecs is deliberately unopinionated about how you structure your application — it doesn't register MonoBehaviours, manage singletons, or hook into Unity's update loop automatically. In a real project, you would use whatever approach you prefer for building your object graph: a dependency injection framework (e.g., Reflex, Zenject, VContainer), plain MonoBehaviours, ScriptableObjects, or anything else. All Trecs needs is for your code to call world.Tick(), world.LateTick(), and world.Dispose() at the appropriate times.

Shared Utilities

The Common/ directory contains utilities shared across samples:

• GameObjectRegistry — maps GameObjectId components to Unity GameObjects
• RendererSystem — GPU-instanced indirect rendering for high entity counts
• RecordAndPlaybackController — recording/replay with bookmark support
• Common components, templates, tags

Note that the samples use some of this helper code in Common/ and that this code is not part of the Trecs library itself. So if you copy code from the samples, be sure to also copy any dependencies from Common