Workshop info: Build a cross-platform game in Haxe

This is an agar.io clone to demonstrate the capability of Haxe in building cross platform games, where codes are shared among multiple game platforms (web, mac, windows, android & ios), as well as between game client and game server for multiplayer games.

Demo: https://kevinresol.github.io/hkoscon2017-haxe-game/ (single player mode)

Participants should have programming experience with at least one programming language. Proficiency with JavaScript, Java, or C# is ideal, but experience with other languages such as C/C++, Python, or Ruby is also sufficient. Participants should have some familiarity using the command line. Participants should bring their own laptop computer, with either Windows, Mac, or Linux installed.

Please follow the instruction listed below before the workshop, such that you can progress smoothly.

Get Haxe from http://haxe.org/download/.

Get Node.js from https://nodejs.org/, and optionally yarn.

Get Git and make it available in the command line. i.e. git --version should print something like git version 2.7.4.

Note: if it is the first time you are using haxelib, you will have to run haxelib setup first.

• Luxe. According to the instruction at https://luxeengine.com/get/:

  haxelib install snowfall
  haxelib run snowfall update luxe

• haxe-ws

  haxelib install haxe-ws

• hxnodejs

  haxelib install hxnodejs

Although in theory you can use any IDE or text editor, we recommend using Visual Studio Code with the Haxe Extension Pack, which offers the best Haxe support at the moment.

(Optional, for building native targets, e.g. mac, windows, linux, ios, android) Depending on your OS, Visual Studio (Windows), XCode (Mac), or gcc (Linux).

We will introduce Haxe and go through creating a simple multi-player game during the workshop together. The instruction will be given during the workshop. Below are some notes for future reference.

• Haxe Manual: http://haxe.org/manual/introduction.html
• Haxe API docs: https://devdocs.io/ (or http://api.haxe.org/)
• Try Haxe: https://try.haxe.org/
• Luxe engine beginners guide: https://luxeengine.com/guide/
• Luxe engine API docs: https://luxeengine.com/docs/api/
• haxe-ws library: http://lib.haxe.org/p/haxe-ws
• ws npm package: https://www.npmjs.com/package/ws#usage-examples

haxe server.hxml
cd bin/server
npm install ws # or `yarn add ws`
node server.js

haxelib run flow run web
haxelib run flow run mac
haxelib run flow run windows

By default the game client is built for multiplayer mode (yes, multiplayer/singleplayer is determined at compile-time for simplicity). To build for single player mode, simply go to project.flow and comment out the MULTIPLAYER flag:

// defines : ["MULTIPLAYER"],

To give proper code completion, VS Code needs a hxml file, which can be generated by

haxelib run flow info [web|windows|mac|linux] --hxml > client.hxml

See https://github.com/vshaxe/vshaxe/wiki/Framework-Notes#snow.

The World class contains the core game logic. When the game is set to single-player mode, the World is run in the client. In other words, the same piece of Haxe code for the World class is compiled into different platforms (web, mac, windows, android & ios). When the game is in multi-player mode, the World is run on the server. Again, the same piece of Haxe code for the World class is compiled into the server language (nodejs for our choice here).

The Command and Message enums represents the protocol between the client and server in multiplayer mode. The same piece of code is used in both client and server.

Feel free to open issues or contact us directly.

To the extent possible under law, Andy Li & Kevin Leung has waived all copyright and related or neighboring rights to "Build a cross-platform game in Haxe" workshop. This work is published from: Hong Kong.