Flash Develop

I've just started using Flash Develop, not enough to give a decent review, but enough to say, 'Hey... I kinda' like this!' but it didn't start out so well... I figured, what better way to dive back into AS3 and get used to Flash Develop, than by going through Michael James William's AS3 Avoider Game Tutorial? So I started on section 1, everything was going great... FD booted right up, it asked me to create a package, and... oh crud, which one should I pick? AS3 Project? Flash IDE project? AS3 with Preloader? HaXe? ...what the heck is HaXe? I definitely don't want Haxe, I guess... right? No, no, course not...
Would you believe Michael helped me again? I found this post over on Active Tuts+ which explained which one was for me.

OK, Really getting started now
Ok, so my project is open and I jump right into section 1 of the AS3 tutorial. I scan down because a lot of the prep doesn't seem to apply... then I make my first enemy (using the Flash IDE), export the SWC, and import it into FD (the whole reason I jumped into FD in the first place - but that's for another story)
I'm just humming along now! I create a new class: Enemy.as and then I press Ctrl+Enter to test my 'game'!
...wait, there's no enemy on the screen! Where the heck is the enemy I just created? I check, double-check, TRIPLE check my spelling. I copy and paste from the tutorial.

Will. Not. Appear.

I remove the AS file from my project and add that code to my main AS file and now my enemy is there. ...huh?
Time to hit Google again... thankfully I found this post on One Giant Medias website before I went completely bald from frustration. It notes:

Issue:
Using custom classes with the same names as linkage library movie clips in Flash IDE would trace output but not show up on stage

and then it goes on to explain how to get it working.

So, I went back to the Flash IDE, right-clicked my Enemy in the library and chose Linkage...

I changed the class to FL_Enemy, saved, and published the file.

Time to go back to Flash Develop, now open up that Enemy.as class file and change

public class Enemy extends MovieClip

to

public class Enemy extends FL_Enemy

...by the way, you don't have to pick FL_Enemy for the library class, it can be anything, but appending FL_ is a suggestion from the OneGiantMedia blog article. Of course, you'd have known that if you clicked the link above!

...back to programming!

-Bigfoot

Getting rid of duplicate lines of code

I just finished one of MJW's sh'm'up tutorials and by the end I had multiple lines that were duplicates of each other. For example:

1. {


2. removeChild( bullet );


3. bullets.splice( j, 1 );


4. }

While this used to be okay - I just wanted working code! - Now, after these tutorials I'm spoiled. Some would say a better (though very beginner!) programmer. I feel like I need to compact it and clean it up as much as possible.
So I created a public function called removeClip (first it was removeEnemy, then I figured I could use it for the bullets too, and maybe other things later!) and passed it three variables:

instance of the clip I wanted to remove.

the position it was in the array

and, the array name.

Tada!

1. public function removeClip( movieClip:MovieClip, i:int, array:Array ):void


2. {


3.     removeChild( movieClip );


4.     array.splice( i, 1 );


5. }

Then I just went back through AvoiderGame.as and replaced all those lines that removed the bullet / enemy with:
removeClip( enemy, i, army );
or
removeClip( bullet, j, bullets );

Michael, thanks for teaching us how to code.

EDIT: MJW posted a comment on trimming down my code even more that I'd like to share! (Especially in case you don't read the comments...)

He wrote: "I'm not sure if you know this, but all arrays have a method, .indexOf( item ), that returns the index of the item specified (or -1 if the item is not in the array).

So you can write "array.splice( array.indexOf( movieClip ), 1 )", for example. This way you don't have to pass the index of the item through to the function each time!"

I've used his suggestion, and changed my removeClip function to this:

1. public function removeClip( movieClip:MovieClip, array:Array ):void


2. {


3.     removeChild( movieClip );


4.     array.splice( array.indexOf( movieClip ), 1 );


5. }

I guess if you wanted, you could also make a check to make sure it was part of that array before trying to splice, like this:

1. public function removeClip( movieClip:MovieClip, array:Array ):void


2. {


3.     removeChild( movieClip );


4.     if( array.indexOf( movieClip ) != -1  )


5.     {


6.         array.splice( array.indexOf( movieClip ), 1 );


7.     }


8. }

Anyways, it might not seem like a lot at first. You're only slimming it down by one small variable. But that's one less variable for every bullet that leaves the screen, or hits an enemy, plus every enemy that gets hit, or leaves the screen, and in a much bigger game it would really start adding up.

A little more information about it here from Senocular

MJW Avoider Game ep11ch1

Alrighty-- Another challenge! I already wrote below about my fun with isNaN during this challenge. But let me try to document what I did for the challenge itself. Won't be too long...

Staying in the GameOverScreen.as file, I added the following to the constructor. (I called my array bestScoreArray) I wanted to check if the array was undefined or empty, and if so, create it.

1. if( isNaN(sharedObject.data.bestScoreArray) )


2. {


3.     sharedObject.data.bestScoreArray = new Array();


4. }

Then, I figured I'd plug information when the final score was set. So down in the setFinalScre function:

1. else if( scoreValue > sharedObject.data.bestScore )


2. {


3. //  sharedObject.data.bestScore = scoreValue;


4.     sharedObject.data.bestScoreArray = [scoreValue, sharedObject.data.totalGames, "Test"];         


5. }

I'm grabbing three pieces of information and sticking it in an array -- score, total number of games played when that score was reached, and an arbitrary string of text just to test.

Ok, now I need to make sure it's working, so I threw this down below in the same 'setFinalScore' function. It will loop through the array and 'trace' every item to the output window.

1. for (var i:int = 0; i < sharedObject.data.bestScoreArray.length; i++ )


2. {


3.     trace( i, sharedObject.data.bestScoreArray[i] );


4. }

Now run it.

D'oh! Didn't work... why not? Looking back through my code I realized this was wrong:

1. if( isNaN( sharedObject.data.bestScoreArray ) )

Can you spot why? Because we're creating an array... so it's NEVER going to be a "number" (isNaN checks if something is 'not a number')

So, change that to this, and try again:

1. if( sharedObject.data.bestScoreArray == null )


2. {


3.     sharedObject.data.bestScoreArray = new Array();


4. }

Voila! Should work now. If you have any problems, let me know.

Michael asked for it...

MJW left a comment asking if I was going to post my game anytime soon. So by, umm... popular demand (Hey, 50% of my blogs' commenters asked for it!!) - here it is!

The game gets difficult REALLY quick. But I don't really expect you to play it long. I'm just trying to get the basics down right now.



http://bigfoot-avoidergame.googlecode.com/files/Avoider.swf

Comments, banter, criticism? Close your browser...
Want to lavish praise? Leave it in the comment section!
Kidding... I want to hear it all - leave me a comment if you play. We'll call it "Comment-Ware"

MJW Avoider Game ep8ch1

...That'd be episode 8, challenge 1

So now that he's shown us the magic of adding sound, he wants us to figure out how to create a Mute button on our own... sheesh. :) This was the easiest challenge, so far. But, so that I can solidify this in my own head, and in case you need help, here goes my thought process:

The first step I wanted to complete, had nothing (directly) to do with sound. I wanted Flash to recognize another button was being pressed. Instead of being original, I picked "m" as my mute button... Feel free to pick L, meaning "Let the music stop", or ß (ALT+0223) for "This music was picked for the beta. If you don't like it you can turn it off."

Going back and referencing my old code, I made these additions:

All of them are in the AvoiderGame.as file.

Create a publicly accessible variable (outside contructor)...

1. public var mKeyIsBeingPressed:Boolean;)

Initialize it in the contructor...

1. mKeyIsBeingPressed = false;

Inside the onKeyPress function

1. if( keyboardEvent.keyCode == 77 )


2. {


3.     mKeyIsBeingPressed = true;


4. }

Michael let you figure out the onKeyRelease function, and a student is not above his teacher, so I'll let you figure that out too.... :P

Then in the onTick function, I used a trace() command as a placeholder

1. if( mKeyIsBeingPressed )


2. {


3.     trace( "You're pressing M!!!" );


4. }

Don't forget to "Disable Keyboard Shortcuts"

...and then watch your Output window. When you press m, it should fill up with "You're pressing M!!!" over and over...



Ok, so it's working, I have a stream of useless output to prove it. Now I want it to actually do something useful! I created some new global variables:

1. public var musicPosition:int;


2. public var musicIsMuted:Boolean;

musicPosition is an integer. It's going to be equal to where the music was muted, so that when it's unmuted it'll play from the same spot. I guess that makes it a pause button... so, sue me.
musicIsMuted is straight forward. It's a true/false value of whether the music is muted.

...and then I initialized them, one in the constructor (musicIsMuted), and one in the onTick function

1. musicIsMuted = false;

and

1. if( mKeyIsBeingPressed )


2. {


3.     if( musicIsMuted )


4.     {


5.  


6.     }


7.     else


8.     {


9.         musicPosition = Math.floor(bgmSoundChannel.position);


10.     }


11. }

Ok, ok.... I did a little more then initialize it. I put together the basic if...else structure I was going to use. If the m key is being pressed, then if the music is already muted, do nothing right now, else check the position (in milliseconds) it was muted at, and put that into our variable, as a whole number (that's what Math.floor() does, if you don't remember)

Now, let's flesh it out some. If the music wasn't muted already, what do we want to do? We want to stop the background music from playing, and we want to change our variable (musicIsMuted) which tells us if the music is playing to true.

1. else


2. {


3.     musicPosition = Math.floor(bgmSoundChannel.position);


4.     bgmSoundChannel.stop();


5.     musicIsMuted = true;


6. }

If the player already muted the music, and now wants it to play again (cause they miss those jazzy synth beats!) then we would want it to play from where it stopped (we can do that by passing the play() function an argument), and change the musicIsMuted variable back to false.

1. if( musicIsMuted )


2. {


3.     bgmSoundChannel = backgroundMusic.play( musicPosition );


4.     musicIsMuted = false;


5. }

Now save everything and test your game... Easy, huh?
Oh, wait, you say it keeps rapidly turning off and on? Crud! Well, we can fix that using some tidbits from Michael's sh'm'up tutorial.

Create another global variable:

1. public var ticksSinceMutePressed:int;

Initialize it in the constructor:

1. ticksSinceMutePressed = 0;

and change your function to:

1. if( mKeyIsBeingPressed )


2. {


3.     if( ticksSinceMutePressed > 10 )


4.     {


5.         if( musicIsMuted )


6.         {


7.             bgmSoundChannel = backgroundMusic.play( musicPosition );


8.             musicIsMuted = false;


9.         }


10.         else


11.         {


12.             musicPosition = Math.floor(bgmSoundChannel.position);


13.             bgmSoundChannel.stop();


14.             musicIsMuted = true;


15.         }


16.     ticksSinceMutePressed = 0;


17.     }


18. }


19. ticksSinceMutePressed += 1;

If you haven't read that tutorial already, and can't piece together what I did, head over and check it out. No use in me re-inventing the wheel.

Avoider Game Shmup

That should do it. Now you can hear the 'thump, thump, thump' of the enemys coming on screen without that pesky synth-music playing in the background!