Flixel tutorial part 1

For the uninitiated, Flixel is a game engine made in/for flash. It is said to be much faster than regular flash because it ditches vector graphics for bitmap ones.

This is a tutorial series that will try to introduce you to the flixel sdk one step at a time. So here we go with part 1.

Flixel tutorial part 1: Set up flixel for Flex.

This part is for OS X users of Flex 3.0 IDE.

Step 1: Download the latest flixel version from http://github.com/AdamAtomic/flixel/archives/master and save on your favorite location on your disk.

Step 2: Start Flex and select File -> New -> ActionScript Project

Step 3: Type your project name (Tutorial_01) and store at a convenient location

Step 4: Click on «Next» button (not Finish) and at the source path field add the path to the library you downloaded from step 1 (you expanded it right?) and then click Finish

That’s it.. you’re done!.. well almost since you aren’t using the library just yet. The Flex IDE created a file titled «Tutorial_01.as» which we’ll have to replace so replace it with this one:

package {
	import org.flixel.*;
	[SWF(width="640", height="480", backgroundColor="#000000")]
	public class Tutorial_01 extends FlxGame
		public function Tutorial_01()

In the first lines we use a 640×480 canvas with black color and later on we pass control to the class «PlayState». We didn’t define Playstate did we? No!. So Select File -> New -> ActionScript Class and at the window that will appear type Name: PlayState, Superclass: FlxState and hit Finish. Now paste inside this one the following:

	import org.flixel.*;
	public class PlayState extends FlxState
		public var myText:FlxText;
		override public function create():void
			myText=new FlxText(0,30,100,"Hello, World!"); 

What we do here is we create a new FlxText object called myText to print on screen «Hello, World!» and then we pass it to the game engine to attach it to the rendering loop with the add() function. We don’t need to use the update() function yet as we don’t change anything yet.

Flixel uses states to manage the code. This means that when you are for example in the main screen you should create a separate FlxState called Intro and write code there on what should happen and then pass control to another FlxState called for example PlayState which will have the main game code.

Although we didn’t write much you will notice that if you click on the flash area (to activate it) and then hit ~ then you will see the flixel console (we enabled it using FlxG.debug=true). You will be able to see the flixel library version you are using and the fps you are reaching (frames per second). In the time of writing I get 58-62fps (it’s trying to stay to 60 fps) and flixel version 2.21.

This concludes part 1 of this series. Stay tuned for more 🙂

Who steals my interwebs ?

You want to see if someone is hijacking your wireless connection? Here is how to do it.

First of all you have to figure out your ip address. There are several ways to do it. You can go get it from AppleMenu->SystemPreferences->Network->Advanced->TCP/IP or you can type at the Terminal.app:

ifconfig -a

now search for the part for en1 (Mac OS X’s wireless connection is on the interface called en1) or simply type

ifconfig -a|grep inet -B1|grep en1 -a1

you should get something like

ifconfig -a|grep inet -B1|grep en1 -a1
inet netmask 0xffffff00 broadcast<br

We will now do some sniffing and we will exclude our own address from the data, so at the Terminal.app type

sudo tcpflow -s -c -i en1 host not

It will ask you for your password etc etc. What it does is this

Strip non-printables. Convert all non-printable characters to the «.» character before printing packets to the console or storing them to a file.
Console print. Print the contents of packets to stdout as they are received, without storing any captured data to files (implies -s ).
Interface name. Capture packets from the network interface named iface. If no interface is specified with -i , a reasonable default will be used by libpcap automatically.

So we are basically asking to present us on screen what happens using our wireless interface (en1) as our source. The next part (host not xxxx) is restricting the process by excluding our own address and thus we can monitor if someone else is using our wireless connection.

If you see anything beyond this point then you are not alone on your network (you can exclude more addresses you know like printers and other computers using «not host and». You get the picture I hope)

What you can do beyond this point is try driftnet. Driftnet is a modern EtherPEG clone. EtherPEG was a small hack to show the images (jpegs) your co-workers were viewing on your network. It was rewritten for OSX but now it’s broken for Leopard (10.5). So you need something more fresh.

Driftnet is here to help your needs. Please read the man page first. The fun part is at just peeking, so by simply invoking at the Terminal.app:

sudo driftnet -i en1  host not

you will be able to see what the highjacker sees online (!)by using X11 technology to display the images. If you want to be mean then you can try

sudo driftnet -i en1 -a -s -d . host not

which will store all the images and mpeg media (audio tracks) on the current folder (you should better create an empty one before you do this). The titles of the files stored will be written on the terminal for you to see that something is actually happening.

By this point you should be clearly very frustrated you can’t find these commands on your Terminal.app. You should use fink and install them from there (very easy).

MacBook heating problems (solved)

Recently I fell into trouble with my White MacBook. It was heating beyond 80 degrees Celcious and at the same time the fan was rotating at 6200 rpm. I bought a cannister of compressed air to try and blow anything that might be stuck in the fan but instead the fan stopped working!

So I opened the MacBook myself since it was already after midnight and cleared the fan from the inside. The MacBook now runs fine and rotates at 3000 rpm with <50C (quite cool since the ambient temperature is 35C) with a movie playing and NNW & Mail running at the background.

Here is a nice pic I took for you.


Παράφορα ερωτευτευμένος και πάλι…

Επιτέλους βρήκα κάτι άξιο λόγου πέρα από το αλκοόλ και νομίζω θα τα πάμε αρκετά καλά για μεγάλο χρονικό διάστημα. Σήμερα ξεκίνησα με 1200 βαθμούς και αύριο θα πάω να βρώ σε supermarket τι άλλο υπάρχει διαθέσιμο 😀 😀 😀


Τέλειος ήχος (MacBook+iTunes)

Ως κλασσικός τελειομανής θέλησα να βελτιώσω την ποιότητα και την ένταση που παράγει το MacBookάκι μου στο μέγιστο. Πειραματιζόμενος λοιπόν έφτασα στο «τέλειο» αποτέλεσμα. Η παραμετροποίηση του equalizer του iTunes με αυτό τον τρόπο παράγει, χωρίς να χρησιμοποιήσω plugins, την μέγιστη ένταση χωρίς να peakάρει ποτέ ο ήχος τόσο χρησιμοποιώντας τα ενσωματωμένα ηχεία όσο και εξωτερική εγκατάσταση ήχου. Αν πεακάρει λόγω κομματιού (π.χ. ebm/D&B) τότε κατεβάστε κατά 4 db.