@serpentity/serpentity

Serpentity

Serpentity is a simple entity framework inspired by Ash.

Usage:

import Serpentity from '@serpentity/serpentity';

Instantiating an engine

const engine = new Serpentity();

Add entities or systems, systems are added with a priority (the smaller the number, the earlier it will be called):

engine.addEntity(entityFactory());
engine.addSystem(new GameSystem(), priority);

Update all systems:

engine.update(dt);

Remove entities or systems:

engine.removeEntity(entityReference);
engine.removeSystem(systemReference);

Creating Entities

Entities are the basic object of Serpentity, and they do nothing.

import { Entity } from '@serpentity/serpentity';
const entity = new Entity();

All the behavior is added through components

Creating Components

Components define data that we can add to an entity. This data will eventually be consumed by "Systems"

import { Component } from '@serpentity/serpentity';
const PositionComponent = class PositionComponent extends Component {
  constructor(config) {

    this.x = 0;
    this.y = 0;

    super(config);
  }
};

You can add components to entities by using the add method:

entity.addComponent(new PositionComponent());

Systems can refer to entities by requesting nodes.

Working with Nodes

Nodes are sets of components that you define, so your system can require entities that always follow the API defined in the node.

import { Node } from '@serpentity/serpentity';
const MovementNode = class MovementNode extends Node;
MovementNode.position = PositionComponent;
MovementNode.motion = MotionComponent;

You can then request an array of all the nodes representing entities that comply with that API

engine.getNodes(MovementNode);

Creating Systems

Systems are called on every update, and they use components through nodes.

import { System } from '@serpentity/serpentity';
const TestSystem = class TestSystem extends System {
  added(engine){

    this.nodeList = engine.getNodes(MovementNode);
  }

  removed(engine){

    this.nodeList = undefined;
  }

  update(dt){

    for (const node of this.nodeList) {
      console.log(`Current position is: ${node.position.x},${node.position.y}`);
    }
  }
};

That's it

Just run engine.update(dt) in your game loop :D