colyseus.py-prototype

In this repo you will find my own study of the colyseus state sync mechanism, the motivation being an attempt to use ws to create a new SDK that brings interoperability between python & Colyseus.

For most people the repo won't be useful as this is way too experimental. However, you can learn with me if you wish to.

Such a project can be viewed as the first step to possibly expand the following list: List of all multiplayer SDKs tied to Colyseus

Getting started

• to perform online analysis, in general npm install followed by npm run start is enough.

Using online analysis and connecting to the Colyseus server using websocket you can get raw data, as shown below:

That message/raw data collected from a websocket connection is based upon this data format declaration:

// file originally named "MyRoomState.ts"

import { Schema, Context, type, MapSchema } from "@colyseus/schema";

export interface InputData {
  left: false;
  right: false;
  up: false;
  down: false;
  tick: number;
}

export class Player extends Schema {
  @type("number") x: number;
  @type("number") y: number;
  @type("number") tick: number;

  inputQueue: InputData[] = [];
}

export class MyRoomState extends Schema {
  @type("number") mapWidth: number;
  @type("number") mapHeight: number;

  @type({ map: Player }) players = new MapSchema<Player>();
}

The serializer used by Colyseus is named "schema". See This repo from Colyseus author.

Ideas to consider

• use only msgpack with this NodeJS tool: "msgpackr": ^1.9.1 as @colyseus/core still relies on it
• use an ancient version to avoid the "schema" serializer for easier prototyping using py
• fork the current ColyseusJS and modify it to use plain JS objects for state synchronization
• use a schema generator for py that produces dataclasses only
• use JSON-Patch instead of schema, similar to what has been done in older versions of Colyseus.

Writing the de-serializer

• parse primitive types:
  https://github.com/colyseus/schema/blob/master/decoders/cpp/schema.h#L703

Useful links

• https://github.com/Starcounter-Jack/JSON-Patch/

Old releases of Colyseus:

• https://github.com/colyseus/colyseus/releases?page=2
  I don't know at what point the "schema" serializer has been introducted

Alternatives to the schema serializer:

• https://www.npmjs.com/package/msgpackr