Darker-Engine

Lightweight functional library implementation of the Entity-Component-System pattern with typescript.

Installation

Deno

Import the package with deno:

import { engine as darkerEngine } from "https://deno.land/x/darker_engine/mod.ts";

npm

Install the package with npm:

npm install darker-engine

Code Example

Declaration

import { engine as darkerEngine } from "darker-engine";

export const Engine = darkerEngine();

Engine.setSystems(...[]);

Engine.load();

Enums

enum EntityType {
  EXAMPLE,
}

enum Components {
  EXAMPLE_COMPONENT = "EXAMPLE_COMPONENT",
}

Entity

import { EntityType } from "darker-engine";

const exampleEntity = (): EntityType => ({
  id: Engine.getUID(),
  type: EntityType.EXAMPLE,
  data: {},
  components: [],
});

Systems

import { SystemFunction } from "darker-engine";

const exampleSystem: SystemFunction = () => {
  const onAdd = (entityId: number) => {};
  const onUpdate = (entityId: number, component: string) => {};
  const onRemove = (entityId: number) => {};

  return {
    components: [],
    onAdd,
    onUpdate,
    onRemove,
  };
};

Full code

import {
  engine as darkerEngine,
  EntityType,
  SystemFunction,
} from "darker-engine";

export const Engine = darkerEngine();

enum EntityType {
  EXAMPLE,
}

enum Components {
  EXAMPLE_COMPONENT = "EXAMPLE_COMPONENT",
}

const exampleEntity = (): EntityType => ({
  id: Engine.getUID(),
  type: EntityType.EXAMPLE,
  data: {
    [Components.EXAMPLE_COMPONENT]: {
      foo: "faa",
    },
  },
  components: [
    Components.EXAMPLE_COMPONENT,
  ],
});

const exampleSystem: SystemFunction = () => {
  let interval;

  Engine.onLoad(() => {
    console.log("welcome!");
    Engine.addEntity(exampleEntity());

    interval = setInterval(() => {
      const entityList = Engine.getEntityList();
      const entityListByType = Engine.getEntityListByType(EntityType.EXAMPLE);
      const entityListByComponents = Engine.getEntityListByComponents(
        Components.EXAMPLE_COMPONENT,
      );

      console.log(`Entities`);
      console.log(` - total: ${entityList.length}`);
      console.log(` - type: ${entityListByType.length}`);
      console.log(` - component: ${entityListByComponents.length}`);
    }, 5_000);
  });

  Engine.onDestroy(() => {
    clearInterval(interval);
    console.log("bye!");
  });

  const onAdd = (entityId: number) => {
    const entity = Engine.getEntity(id);
    entity.updateComponent(Components.EXAMPLE_COMPONENT, { foo: "fii" });
  };

  const onUpdate = (entityId: number, component: string) => {
    const entity = Engine.getEntity(id);

    if (component !== Components.EXAMPLE_COMPONENT) return;

    const { foo } = entity.getComponent(Components.EXAMPLE_COMPONENT);
    if (foo === "fii" && !entity.hasComponent("FAKE_COMPONENT")) {
      entity.removeComponent(Components.EXAMPLE_COMPONENT);
    }
  };

  const onRemove = (entityId: number) => {
    Engine.removeEntity(entityId);
  };

  return {
    components: [
      Components.EXAMPLE_COMPONENT,
    ],
    onAdd,
    onUpdate,
    onRemove,
  };
};

Engine.setSystems(exampleSystem);
Engine.load();