Create a quick game whereby players simply move squares along the x-axis. I know, it's boring, but it keeps things simple and to the point. For a more thorough demonstration of how GarageServer.IO works, look at the example included in the source code.

Server

1. Create instance of GarageServer.IO - pass in a Socket.IO instance and GarageServer.IO options.

var garageServer = require('garageserver.io'),

var server = garageServer.createGarageServer(sockets, 
    {
        interpolation: true,
        clientSidePrediction: true,
        worldState: { width: '400px', height: '400px'; }
    });

2. Start GarageServer.IO instance prior to starting physics loop. This starts the clock that is used for broadcasting state and storing state history.

server.start();

3. Inside physics loop, process inputs for players, process entites and update states. Note that state is an object literal effectively offering up any grab bag of properties that pertain to your game's state.

var players = server.getPlayers(),
    entities = server.getEntities();

players.forEach(function (player) {
    var newState = {};
    if (!player.state.x) {
       player.state.x = 0;
    }
    for (i = 0; i < player.inputs.length; i ++) {
        if (player.inputs[i].input === 'left') {
            newState.x = player.state.x - (50 * deltaTime);
        } else if (inputs[i].input === 'right') {
            newState.x = player.state.x + (50 * deltaTime);
        }
    }
    server.updatePlayerState(player.id, newState);
});
entities.forEach(function (entity) {
    // Calculate new state from entity.state and send GarageServer.IO new state
    server.updateEntityState(entity.id, newState);
});

Client

1. Initialize GarageServer.IO.

GarageServerIO.initializeGarageServer('http://insertmygameurlhere.com', {
    onReady: function () {
        // Call your game loop
    },
    onUpdatePlayerPrediction: function (state, inputs, deltaTime) {
        var newState = {};
        if (!player.state.x) {
        player.state.x = 0;
        }
        for (i = 0; i < player.inputs.length; i ++) {
            if (player.inputs[i].input === 'left') {
                newState.x = player.state.x - (50 * deltaTime);
            } else if (inputs[i].input === 'right') {
                newState.x = player.state.x + (50 * deltaTime);
            }
        }
        return newState;
    },
    onInterpolation: function (previousState, targetState, amount) {
        return { x: (previousState.x + amount * (targetState.x - previousState.x)) };
    },
    onWorldState: function (state) {
        document.getElementById('gameCanvas').style.width = state.width;
        document.getElementById('gameCanvas').style.height = state.height;
    }
};

2. Inside physics loop, capture and send input via GarageServer.IO.

GarageServerIO.addInput(myInput);

3. Inside render loop, extract player and entity states.

var playerStates = GarageServerIO.getPlayerStates(),
    entityStates = GarageServerIO.getEntityStates();  
    playerStates.forEach(function (player) {
        ctxCanvas.fillRect(player.state.x, 0, 5, 5);
    });
    entityStates.forEach(function (entity) {
        ctxCanvas.fillRect(entity.state.x, 0, 5, 5);
    });

API

Client

initializeGarageServer

GarageServerIO.initializeGarageServer(path, options)

Establish connection to GarageServer.IO on the server via Socket.IO and register events.
path string
The URL that points to where GarageServer.IO is running at on the server.
options object literal
Configure the different options, events, callbacks that you would like to consume on the client.

options.onPlayerConnect(callback)

Once the client has made a connection to the server, this event will fire.
callback function
Function to be invoked upon event firing.

options.onPlayerDisconnect(callback)

If client has has disconnected from the server, this event will fire.
callback function
Function to be invoked upon event firing.

options.onPlayerReconnect(callback)

If client has has disconnects and reconnects to the server, this event will fire.
callback function
Function to be invoked upon event firing.

options.onPlayerUpdate(callback(state))

callback function
Function to be invoked upon event firing.
state object literal

options.onEntityUpdate(callback(state))

callback function
Function to be invoked upon event firing.

state object literal

options.onPlayerRemove(callback(id))

callback function

id string

options.onEntityRemove(callback(id))

callback function

id string

options.onEvent(callback(data))

callback function

data object literal

options.onWorldState(callback(state))

callback function

state object literal

options.onPing(callback(pingDelay))

callback function

pingDelay number

options.onUpdatePlayerPrediction(callback(state, inputs, deltaTime) : newState)

Returns: object literal

callback function

state object literal

inputs array

deltaTime number

options.onInterpolation(callback(previousState, targetState, amount) : newState)

Returns: object literal

callback function

previousState object literal

targetState object literal

amount number

options.onReady(callback)

callback function

options.logging: true

logging boolean

addInput

GarageServerIO.addInput(input)

input object literal

getPlayerStates

GarageServerIO.getPlayerStates() : [, {id, state}]

Returns: array

id string

state object literal

getEntityStates

GarageServerIO.getEntityStates() : [, {id, state}]

Returns: array

id string

state object literal

getId

GarageServerIO.getId() : playerid

Returns: string

playerid string

sendServerEvent

GarageServerIO.sendServerEvent(data)

data object literal

Server

createGarageServer

require('garageserver.io').createGarageServer(io, options) : GarageServerIO

io Socket.IO instance

options object literal

options.stateInterval

number

options.logging

boolean

options.clientSidePrediction

boolean

options.interpolation

boolean

options.interpolationDelay

number

options.smoothingFactor

number

options.pingInterval

number

options.maxUpdateBuffer

number

options.maxHistorySecondBuffer

number

options.worldState

object literal

options.onPlayerConnect(callback(socket))

callback function

socket Socket

options.onPlayerInput(callback(socket, input))

callback function

socket Socket

input object literal

options.onPlayerDisconnect(callback(socket))

callback function

socket Socket

options.onPing(callback(socket, data))

callback function

socket Socket

data object literal

options.onEvent(callback(data))

callback function

data object literal

start

GarageServerIO.start()

stop

GarageServerIO.stop()

getPlayers

GarageServerIO.getPlayers() : [, {id, state, [, inputs], [, {states, executionTimes}]}]

Returns: array

id string

state object literal

inputs array of object literals

stateHistory array of object literals

getEntities

GarageServerIO.getEntities() : [,{id, state, [, {state, executionTime }]}]

Returns: array

id string

state object literal

stateHistory array of object literals

updatePlayerState

GarageServerIO.updatePlayerState(id, state)

id string

state object literal

updateEntityState

GarageServerIO.updateEntityState(id, state)

id string

state object literal

addEntity

GarageServerIO.addEntity(id)

id string

removeEntity

GarageServerIO.removeEntity(id)

id string

sendPlayerEvent

GarageServerIO.sendPlayerEvent(id, data)

id string

data object literal

sendPlayersEvent

GarageServerIO.sendPlayersEvent(data)

data object literal

License

MIT License