HECS Entity Component System
An experimental ECS written in Javascript.
I have transfered the npm package to a new project. The last maintained version of hecs is 0.1.1. I am currently maintaining a new ECS project ECSY and encourage users to move to it.
- Performance
- As little memory allocation and garbage collection as possible
- Fast iterators
- Predictability
- Systems run in the order they are registered
- Events are processed in the game loop with the rest of the system's logic
- Custom Schedulers
- Specify dependencies between systems
- Enable systems to run in parallel
- Parallelism
- Using transferable objects in WebWorkers
- Using SharedArrayBuffer
- WASM Integration
- Rust API that can be used to write high performance systems in WASM
npm install -S [email protected]
import { World, System, EntityId, Read, Write } from "hecs";
const world = new World();
class Position {
constructor(x) {
this.x = x;
}
}
class Velocity {
constructor(v) {
this.v = v;
}
}
world.registerComponent(Position);
world.registerComponent(Velocity);
class VelocitySystem extends System {
setup() {
return {
entities: this.world.createQuery(Write(Position), Read(Velocity))
};
}
update() {
for (const [position, velocity] of this.ctx.entities) {
position.x += velocity.v;
}
}
}
class LoggingSystem extends System {
setup() {
return {
entities: this.world.createQuery(EntityId, Read(Position))
};
}
update() {
for (const [entityId, position] of this.ctx.entities) {
console.log(`Entity ${entityId} has position: ${position.x}`);
}
}
}
world.registerSystem(new VelocitySystem());
world.registerSystem(new LoggingSystem());
const entity1 = world.createEntity();
world.addComponent(entity1, new Position(0));
world.addComponent(entity1, new Velocity(1));
const entity2 = world.createEntity();
world.addComponent(entity2, new Position(10));
world.addComponent(entity2, new Velocity(0.5));
function update() {
world.update();
requestAnimationFrame(update);
}
requestAnimationFrame(update);- API heavily inspired by Specs