• At the start of the game players are randomly assigned their roles (roughly 20% of players will be mafia, the rest will be citizens). Only mafia know who each other are. There is no way for citizens to know any other player’s role until that player dies. Citizens win when all mafia are dead. Mafia win when all citizens are dead.
• The game is made up of 5 turns. Day, Lynch Vote, Lynch Vote Result, Night and Morning. This cycle repeats until one faction is the winner.
• All players can talk in a public chat channel during non night turns. Mafia can talk to each other in a hidden channel at night.
• At the Lynch Vote everyone can place a vote to lynch a player (Citizens will aim to vote for players they think are Mafia, Mafia will vote for Citizens). The player who receives the most votes will be lynched. They are out of the game and their role will be revealed to everyone else.
• At Night all Citizens sleep. Mafia can choose to assassinate one player.

A more complicated game can involve other roles such as:

• Doctor – Aligned with the Citizens, can specify a target to save each night. This target’s life will be saved even if they were hit by the mafia.
• Jester – Independent. Wins the game if he is lynched during the day.
• Serial Killer – Independent, can kill 1 player each night. Wins the game if he is the last person left alive.
• Detective – Aligned with the Citizens. Can target a player to investigate at night and view their actions. (eg. If they investigated a mafia role, they would see that the player had killed someone that night).
• Witch – Independent. Can take control of a player at night. (eg. If she took control of a Serial Killer she could choose a different target to kill).

Game Strategy

The complexity in the game comes from imperfect knowledge and false information.

All citizens in the game share the same goal (to kill all Mafia) but each citizen is forced to develop their strategy independent of each other. Citizens can’t win unless they cooperate (by lynching mafia). Only Mafia can identify and privately communicate with each other, yet citizens out number them 5:1. Staying quiet in the game will not guarantee mafia a win. So mafia must actively deceive citizens by spreading lies and casting suspicion on other players. Independent roles have powerful abilities, yet are almost always targetted by both the town and mafia once their role is discovered. They must balance the use of their power with the attention they receive in order to win.

Murder and Lies

My browser based version of Mafia is called Murder and Lies. I’ll be posting more about it (both technical and gameplay aspects) in the weeks to come. In the meantime here is a screenshot of the splash screen.

Looking at the SOCKS5 protocol we can see that it’s possible to test the status of a SOCKS5 proxy just by reading the response to the initial greeting packet. Both PyCurl and socksipy establish a full SOCKS connection with the server. This full connection is necessary if we want to send data through the proxy, but because we only need to check the status of the proxy, we can write a script to send just the first packet and read the response.

The format of the greeting packet is as follows (source):

• field 1: SOCKS version number (must be 0×05 for this version)
• field 2: number of authentication methods supported, 1 byte
• field 3: authentication methods, variable length, 1 byte per method supported

And the server responds:

• field 1: SOCKS version, 1 byte (0×05 for this version)
• field 2: chosen authentication method, 1 byte, or 0xFF if no acceptable methods were offered

Using Python we can write a small script to test this:

import socket
import struct

sen = struct.pack('BBB', 0x05, 0x01, 0x00)

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect(('localhost', 9050))
s.sendall(sen)

data = s.recv(2)

version, auth = struct.unpack('BB', data)
s.close()

If version is 5 and auth is 0 (no authentication), then the proxy is up and available for us to connect to.

If you are coming from a dynamic language such as Python or PHP the concept of Method Overloading may seem foreign. Because you cannot have multiple methods with the same name, you may do type checking from within the function body as shown below.

def say(phrase):

    if type(phrase) == str:
        return "The phrase is: " + phrase
    elif type(phrase) == list:
        r = "The phrase is: "
        m = " ".join(phrase)
        return r + m


print say("hi")
print say(["Hello", "how", "are", "you?"])

Here is how you would write the above code in Java. You would declare two say methods which accept different parameters. When the first o.say() is executed, the JVM looks for a method named say which accepts a single String as an argument. When the second o.say() is executed, the JVM looks for a method named say which accepts an array of String as an argument. Since both of these method declarations exist, the code runs fine.

public class Overloading {

    public static void main(String [] args){

        String[] words = {"Hello", "how", "are", "you?"};

        Overloading o = new Overloading();

        System.out.println(o.say("Howdy"));
        System.out.println(o.say(words));

    }

    public String say(String phrase){
        return "The phrase is: " + phrase;
    }

    public String say(String[] phrases){

        String r = "The phrase is: ";

        for(String s : phrases){
            r += s + " ";
        }

        return r;
    }

}

One limitation of Method Overloading in Java is that you cannot have two methods which accept the same parameters but have different return types. This code won’t compile.

    public String say(String phrase){
        return "The phrase is: " + phrase;
    }

    public int say(String phrase){
        return 53;
    }

You can however declare methods with the same name that have different parameters and different return types. This code will compile.

    public String say(String phrase){
        return "The phrase is: " + phrase;
    }

    public int say(String phrase, int i){
        return 53;
    }

Installation

I used the ubuntu-12.04-desktop-amd64+mac.iso disk image from the Ubuntu servers. For some reason Canonical don’t list the amd64+mac version on their website so if you are wanting to download it off a local mirror you may need to do a bit of digging.

Burn the .iso to a disc, put it in your DVD drive and restart your Macbook. Hold down the c key to boot from the disc. Once loaded choose the ‘Install’ option. The installation process is straight forward. If (like me) you are wanting to single boot Ubuntu on your Macbook then let Ubuntu do a guided/recommended setup of your entire hard disk. If you are wanting to dual boot with OSX then follow this guide on the Ubuntu Wiki.

Work out of the box..

• Bluetooth
• Wifi (need to install restricted driver)
• Graphics card (need to install restricted driver)
• Sleep / open and close lid
• Sound
• Brightness and sound keys
• Desktop effects

Touchpad

By default the touchpad is very jerky and hard to control. I recommend plugging in a USB mouse for initial installation and setup. Once installed getting the trackpad to behave is simple. synclient is a program that allows you to make live changes to the X Server Synaptics Touchpad driver. While there are many options and parameters you can change, you only really need to alter FingerLow and FingerHigh. My settings are as follows (enter them into the terminal):

synclient FingerLow=1
synclient FingerHigh=10

These make live changes to the system, but don’t persist after a system restart. There are several ways to make sure they do persist (most notably an xorg configuration file) but the easiest way I found was to simply make a new Startup Application entry with the command:

synclient FingerLow=1 && synclient FingerHigh=10

That will run every time you login and your trackpad will behave as expected. You can configure other touchpad settings such as multitouch, clicking and scrolling via the Mouse & Touchpad GUI in System Settings.

Keyboard and Command Key

Remapping the apple command key to the Ctrl key saves a lot of finger stretching. Open the Keyboard Layout application -> Layouts tab -> Options -> Alt/win key behavior -> Control is mapped to Win keys (and the usual Ctrl keys).

Battery

With a default screen brightness, no system tweaks and a GNOME 3 desktop the GNOME power manager estimated that a full battery charge would last 2hrs and 11 minutes. This is compared to 2hrs and 48 minutes for a vanilla OSX install under the same conditions.

• There is an HTML5 WebSocket connection between client and server, so no waiting around for AJAX polling. Also no heavyweight Flash solution which can clog up the browser.
• Each proxy is checked asynchronously in it’s own future.
• As soon as a proxy has been checked, the result is immediately sent to the web browser.

Installation is very easy. View on Github

• PhoneGap Location API
• jQueryMobile
• Google Maps Javascript API
• HTML5 localStorage

Here is a screenshot of the Track Info page (plotting the exercise route on a Google Map).

Tutorials & Source:

• Part 1 – Geolocation and Tracking
• Part 2 – Persistence and Graphing
• App Source

Here is a short tutorial on setting up an Eclipse + Clojure + Counterclockwise + Leiningen development environment. Most of which was learnt from Chad Emerick’s excellent Starting Clojure screencast.

Eclipse

Download and install the latest version of Eclipse Classic

Leiningen

Download the latest Leiningen script and add it to your system path. I have a ~/bin/ directory for user scripts.

To add ~/bin/ to your path just:

OSX: echo 'export PATH=~/bin:$PATH' >> ~/.profile

Linux: export PATH=~/bin:$PATH

Then make lein executable..

chmod 777 ~/bin/lein

Run the lein command. It will automatically download the dependencies and install itself.

Eclipse Counterclockwise Plugin

Help -> Install New Software -> Add http://ccw.cgrand.net/updatesite/

Eclipse Leiningen Plugin

Help -> Install New Software -> Add http://ccw.cgrand.net/updatesite-lein-betas

Usage

Start a new project with leiningen lein new foo

Open that Project as a “normal” project (NOT Clojure project) in Eclipse.

Right click on that project -> Configure -> Convert to Leiningen Project -> Enable Clojure support -> Run as -> Clojure Application

The REPL should now launch and automatically load whatever Clojure file you were working in.

Tor itself doesn’t come with a proxy server so you will need to use a 3rd party proxy server such as Polipo or Privoxy. The Tor bundle comes with Polipo, so I use that. By default, Polipo runs on port 9050.

Below we declare our proxy, then tell Qt to route all Qt traffic through it using the setApplicationProxy() static method.

from PySide.QNetwork import QNetworkProxy

proxy = QNetworkProxy()
proxy.setType(QNetworkProxy.Socks5Proxy)
proxy.setHostName('127.0.0.1')
proxy.setPort(9050)

QNetworkProxy.setApplicationProxy(proxy)

We can also force Tor to change our identity (essentially IP address) with a few simple lines of code. By default Tor listens on port 9051. I have disabled password authentication for my Tor process (so I don’t need to pass a password in the AUTHENTICATE command).

import socket

s = socket.socket()
s.connect(('127.0.0.1', 9051))
s.send("AUTHENTICATE \r\n")
s.send("SIGNAL NEWNYM \r\n")
s.close()

If your application uses Tor, consider volunteering to help the Tor project.

import javax.swing.UIManager;

try {
    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch(Exception e) {
    System.out.println("Error setting native LAF: " + e);
}

import javax.swing.JLabel;
import javax.swing.ImageIcon;


JLabel label_captchaIcon = new JLabel();
some_jpanel_instance.add(label_captchaIcon);

ImageIcon icon = new ImageIcon("captcha.jpg");
label_captchaIcon.setIcon(icon);

In my application when the user clicks a JButton, a new image is downloaded which overwrites the old captcha.jpg. Even with ImageIcon code in the JButton event handler, the JLabel would display the old image, not the newly downloaded captcha.jpg.

This problem can be fixed by flushing the old image.

//Needs to be called every time a new image is being set
icon.getImage().flush();