Jammer is a ready-to-use game server to speed up game creation in the context of game jams.
It is written in Javascript so it focuses on web based games.
It is designed for games with multiple players playing simultaneously on the same screen.
To run the server in a docker container, and mount your front-end files:
docker build -t $USER/jammer .
docker run -t --name=jammer -v /path/to/your/public/files:/app/public:ro -p 4321:4321 $USER/jammer
Doing so, you only have to provide the files doing the client side work, and let node serve them. This is the easiest way to get started. Even though the server will run in a docker container, it is still possible to modify it and rebuild an image, in case you have specific requirements.
The files are served from the /app/public
folder. So if you have two files named game.html
and player.html
, visit localhost:4321/game.html to create a game instance and localhost:4321/player.html to spawn up a player.
It is also possible to run jammer manually by first installing node.js, and then:
npm install jammer -g
Followed by:
jammer
This will generate all the files you need in the current working directory and run npm install automatically:
public/game.html
public/player.html
public/js/gameClient.js
public/js/gameServer.js
server.js
package.json
node_modules/
Then:
node server.js
And you have a server listening on port 4321. To start the server listening on port 7890:
node server.js -p 7890
To generate the files at a specific path:
jammer /path/to/destination/
The generated files include an example showing the basics.
public/player.html
public/game.html
They include or the Javascript files:
public/js/gameClient.js
public/js/gameServer.js
There is a global depedency on socket.io, so make sure to include it (see example).
var gameServer = new GameServer();
var players = {};
gameServer.on('gameID', function (gameID) {
// display the game ID on screen for the players
});
gameServer.on('newPlayer', function (player) {
// player connected
var playerID = player.id;
players[playerID] = player; // save it for later use
player.x = Math.random() * 500;
player.y = Math.random() * 500;
player.size = 50;
// Player listeners
// Example of a player event: changeSize
player.on('changeSize', function (size) {
player.size = size || 50;
});
// Send command to the player
player.send('changeColor', '#FF0000');
player.on('disconnect', function () {
delete players[player.id];
});
});
var gameClient = new GameClient();
gameClient.join(12); // join the game 12
gameClient.on('joined', function () {
// player joined, do something with it, for example change the size
gameClient.send('changeSize', Math.random() * 100 + 100);
});
gameClient.on('changeColor', function (color) {
// change the color of the player
});
gameServer.on('gameID', function (gameID) {
// Do something here to display the game ID on the screen for the players
});
gameServer.on('newPlayer', function (player) {
// A new player just joined, do something with the player object, store it for later use
// Default events for the player
player.on('disconnect', function () {
// Player disconnected, do something with, remove it from the game for example
});
});
gameServer.on('disconnect', function (player) {
// The game disconnected, could be due to network problems, display something to the players or die silently
});
// join game number 2
gameClient.join(2);
gameClient.on('joined', function () {
// the player joined the game, display controller or anything else
});
A game jam is all about making a great game fast, so you shouldn't spend to much time in repetitive and time consuming tasks. If you want to go for a multi-player game, you are going to spend quite a lot of time on the network part, testing it, debugging it.
This idea popped up after using HappyFunTimes in a game jam. HappyFunTimes is great, but is limited to a local network. The missing part for us was to be able to put the game online to make it accessible by everyone. Jammer uses game sessions to make it work with multiple game running at the same time.
MIT