!@thi.ng/ecs

!npm downloads

> [!NOTE]
> This is one of 214 standalone projects, maintained as part
> of the @thi.ng/umbrella monorepo
> and anti-framework.
>
> 🚀 Please help me to work full-time on these projects by sponsoring me on
> GitHub. Thank you! ❤️

- About
- Status
- Installation
- Dependencies
- Usage examples
- API
- Basic usage
- Authors
- License

About

Entity Component System based around typed arrays & sparse sets.

- Entities are merely numeric identifiers
- Component types:
- Numeric / vectors are stored as typed array views with customizable striding
- arbitrary JS values are stored in vanilla JS arrays
- Component grouping w/ optional group ownership to allow re-ordering
components for optimized iteration
- Systems are plain functions
- Configurable caching of component views: LRU, Unbounded, Null (no-cache)

Status

ALPHA - bleeding edge / work-in-progress

Search or submit any issues for this package

Installation

``bash
yarn add @thi.ng/ecs
`

ESM import:

`ts
import * as ecs from "@thi.ng/ecs";
`

Browser ESM import:

`html

`

JSDelivr documentation

For Node.js REPL:

`js
const ecs = await import("@thi.ng/ecs");
`

Package sizes (brotli'd, pre-treeshake): ESM: 3.17 KB

Dependencies

- @thi.ng/api
- @thi.ng/associative
- @thi.ng/binary
- @thi.ng/checks
- @thi.ng/dcons
- @thi.ng/errors
- @thi.ng/idgen
- @thi.ng/logger
- @thi.ng/malloc
- @thi.ng/transducers

Note: @thi.ng/api is in _most_ cases a type-only import (not used at runtime)

Usage examples

One project in this repo's
/examples
directory is using this package:

| Screenshot | Description | Live demo | Source |
|:--------------------------------------------------------------------------------------------------------------------|:---------------------------------------------|:----------------------------------------------|:---------------------------------------------------------------------------|
| | Entity Component System w/ 100k 3D particles | Demo | Source |

API

Generated API docs

$3

`ts tangle:export/readme-1.ts
import { ECS } from "@thi.ng/ecs";

interface CompSpecs {
pos: Float32Array;
vel: Float32Array;
color: string;
}

// init ECS w/ given max number of entities
const ecs = new ECS({ capacity: 1000 });

// define components (and their memory layout)
const pos = ecs.defComponent({
id: "pos",
type: "f32",
size: 2,
})!;

const vel = ecs.defComponent({
id: "vel",
type: "f32",
size: 2,
stride: 4,
default: () => [Math.random() 2 - 1, Math.random() 2 - 1],
})!;

// this component stores string values (not mem-mapped)
const color = ecs.defComponent({
id: "color",
default: () => ["red", "green", "blue"][(Math.random() * 3) | 0],
})!;

// define group of given components
// the group will obtain ownership of all by default, meaning
// it is allowed to re-order entities to optimize iteration performance
const group = ecs.defGroup([pos, vel, color]);

// add entities and associate them w/ different components
// if a component is part of a group, the group will be notified/updated
// entities are just numeric IDs assigned using the ECS's internal ID generator
console.log(ecs.defEntity(["pos", "vel", "color"]));
// 0

console.log(ecs.defEntity([pos, vel]));
// 1

console.log(
ecs.defEntity({
pos: new Float32Array([1, 2]),
vel: new Float32Array([-1, 0]),
color: "orange",
})
);
// 2

// apply given function to each entity in the group
// note: entity (id=1) is NOT part of the group,
// since it doesn't have a color component...
group.forEach((x) => console.log(x));

// Note: The color and velocity of this first item are randomly assigned
// (see component default methods above)

// {
// id: 0,
// color: 'green',
// vel: Float32Array [ 0.16836269199848175, -0.36699679493904114 ],
// pos: Float32Array [ 0, 0 ]
// }

// {
// id: 2,
// color: "orange",
// vel: Float32Array(2) [ -1, 0 ],
// pos: Float32Array(2) [ 1, 2 ],
// }
`

Authors

- Karsten Schmidt

If this project contributes to an academic publication, please cite it as:

`bibtex
@misc{thing-ecs,
title = "@thi.ng/ecs",
author = "Karsten Schmidt",
note = "https://thi.ng/ecs",
year = 2019
}
``

License

© 2019 - 2026 Karsten Schmidt // Apache License 2.0