Entitas-Lite is a helper extension of Entitas.
We focusses on easy development WITHOUT CodeGenerator.
AFAIK, CodeGenerator is less efficiency for large projects and teams.
So why not keep it simple and easy?
We are planning rewrite core implementation in Entitas-CSharp, provide less template and more easy interface.
Download and extract "Entitas-Lite/src", "Entitas-Lite/unity" and "Entitas" folder into your Unity Project/Assets/.
Just write your own Components and Systems, then a GameController class for game entry.
No CodeGenerator required! Have fun!
Get Entitas-Lite : https://github.com/rocwood/Entitas-Lite
Get Entitas : https://github.com/sschmid/Entitas-CSharp
using System;
using Entitas;
// [DefaultContext] by default
public class PositionComponent : IComponent {
public int x;
public int y;
}
public class VelocityComponent : IComponent {
public int x;
public int y;
public void SetValue(int nx, int ny) { x = nx; y = ny; } // don't be afraid of writing helper accessor
}
// [DefaultFeature] by default
public class MovementSystem : IExecuteSystem {
public void Execute() {
var context = Contexts.Default; // NewAPI
var entities = context.GetEntities(
Match<DefaultContext>.AllOf<PositionComponent, VelocityComponent>()); // NewAPI
foreach (var e in entities) {
var pos = e.Get<PositionComponent>(); // NewAPI
var vel = e.Get<VelocityComponent>();
pos.x += vel.x;
pos.y += vel.y;
e.MarkUpdated<PositionComponent>(); // NewAPI, we must trigger modification for ReactiveSystem
}
}
}
// Sample view just display Entity's Position if changed
public class ViewSystem : ReactiveSystem {
// constructor now only accepts collector
public ViewSystem()
: base(Contexts.Default.CreateCollector(Match<DefaultContext>.AllOf<PositionComponent>().AddedOrRemoved()))
{}
protected override void Execute(List<Entity> entities) {
foreach (var e in entities) {
var pos = e.GetComponent<PositionComponent>();
Console.WriteLine("Entity" + e.creationIndex + ": x=" + pos.x + " y=" + pos.y);
}
}
}
// Game Entry
public class GameController {
private Systems _feature;
public void Start() {
var contexts = Contexts.sharedInstance;
#if UNITY_EDITOR
ContextObserverHelper.ObserveAll(contexts); // Unity-only API
#endif
// create random entity
var rand = new Random();
var context = Contexts.Default;
var e = context.CreateEntity();
e.AddComponent<PositionComponent>(); // NewAPI
e.AddComponent<VelocityComponent>().SetValue(rand.Next()%10, rand.Next()%10);
// init systems, auto collect matched systems, no manual Systems.Add(ISystem) required
#if UNITY_EDITOR
_feature = new FeatureObserverHelper.Create(); // Unity-only API, shorter for Create("DefaultFeature")
#else
_feature = new Feature();
#endif
_feature.Initialize();
}
public void Update() {
_feature.Execute();
_feature.Cleanup();
}
}- Entity, Context, Contexts, Matcher, Feature are now just one class.
No more generated GameEntity, GameContext, GameMatcher, InputEntity ...
Use new attributes like ContextScope, FeatureScope for scoping.
public class Game : ContextScope {
}
public class GameFeature : FeatureScope {
public GameFeature(int prior = 0) : base("GameFeature", prior) { }
}
[Game]
public class MyComponent : IComponent {}
[GameFeature]
public class MySystem : IExecuteSystem {}
- Entity: Generic API for Add/Replace/Get/RemoveComponents. Forget component-index!
e.AddComponent<PositionComponent>();
e.RemoveComponent<PositionComponent>();
var vel = e.GetComponent<VelocityComponent>();
var pos = e.Get<PositionComponent>(); // shorter API
- Context: Auto register all components. Add API for getting entity with creationIndex.
Entity e = context.GetEntity(100);
- Contexts: Auto register all context. Add name-Context lookup and a defaultContext for notitled Components.
Context c = Contexts.Default; // = Contexts.sharedInstance.defaultContext;
Context game = Contexts.Get("Game"); // = Contexts.sharedInstance.GetContext("Game");
Context input = Contexts.Get<Input>(); // = Contexts.sharedInstance.GetContext<Input>();
- Matcher: Generic templates for easy Matcher creation
var matcher = Match<Game>.AllOf<PositionComponent, VelocityComponent>();
var matcher2 = MatchDefault.AllOf<PositionComponent, VelocityComponent>(); // shorter for Match<DefaultContext>
-
Feature: Auto add matched Systems, no manual Systems.Add(ISystem) required
-
new ReactiveSystem: simplify ReactiveSystem for subclass
constructor ReactiveSystem(ICollector<Entity> collector) // only accept Collector, no need to override GetTrigger()
bool Filter(Entity entity) // return true by default, not override required
- new ExecuteSystem: simplify IExecuteSystem for subclass
constructor ExecuteSystem(Context context, IMatcher<Entity> matcher) // requre both context and matcher
abstract void Execute(Entity entity) // override this for executing on each matched entity
- Performance tweak
- Clean document
- More examples