AS3 AI hitTestObject with itself? - actionscript-3

Im've created a timer that starts every 1 second.
This is the code what's happening every 1 second.
var Random_Value_X:Number = Math.ceil(Math.random() * 1500);
var Random_Value_Y:Number = Math.ceil(Math.random() * 2000);
var enemy:MovieClip = new AI(stage);
addChild(hero);
enemy.x = Random_Value_X;
enemy.y = Random_Value_Y;
Ok. Then I got the class called AI where I've made it so the AI follows my player. The thing is, I need to make a hitTest that testes if an AI hitting another AI? Is there a way I can give every new AI a ID? Like the first gets called "AI1" and second AI2" and then I can make a code that says like If(AT1.hitTestObject(AT2 || AT3))
Hope you understand what I trying to explain! :)

You should just put them all in an array. Then you can loop through the array and do the hit testing for each one. Depending on how many you have, you might need to split them up into groups so you don't have to do so many checks each frame.
I'm pretty sure you can't just use logical or in the hitTestObject method like that.

Considering that you are on root and keyword "this" referring root. If you make instance of class "enemy" then all objects of it will have type "enemy".
import flash.events.Event;
// for every enemy you create, addlistener to it
// it will force to check itself with others
enemy.addEventListener(Event.ENTER_FRAME,checkHit);
// this function will be available to all enemies
// will inform itself that it is hiting enemy instance
function checkHit(e:Event){
// for e.g. object is moving in x direction
// to keep it simple so you can run it in new file
// with two object one is called enemy and other enemy1
// in your case its changing position
e.target.x += 1;
// loop with all children, break when hit someone
for(var i:uint=0;i<this.numChildren;i++){
// in current situation e.target is also a child of root
// therefore avoid checking it
if(e.target==this.getChildAt(i)) continue;//trace("Its me");
// if hit
// currently testing hit with all objects on stage
// you can change it to check specific type
if(e.target.hitTestObject(this.getChildAt(i))){
trace("I got hit by: "+this.getChildAt(i).toString());
break;
}
}
}

Related

AS3: how do i stop two of the same function from playing at once?

i am using AS3 to create a function that will automatically play a movieclip all the way through and then remove it. my project is going to have a lot of animated cutscenes, so id like to be able to call this function, use the cutscene id like as a parameter, and then move on to the next. the problem is, im trying to use the function multiple times in a row to play clips sequentially, but they're all playing at the same time. is there a fix, or a better way to do this altogether?
playClip(new a_walk); //find a way to make these stop playing at the same time
playClip(new a_door);
//a_walk and a_door are the AS linkage class names for the movieclips im referring to
function playClip (clip:MovieClip):void {
addChildAt(clip, 0);
clip.mask = myMask;
clip.x=412.4;
clip.y=244.5;
clip.addEventListener(Event.ENTER_FRAME, checkframes);
function checkframes(event:Event) {
if (clip.currentFrame == clip.totalFrames) {
//trace("wow! youre an idiot!");
if (clip.parent) {
clip.parent.removeChild(clip);
trace (100);
return;
}
}
}
}
Sounds like you want a mechanism to play a queue of MovieClips? If so, here is a way you can accomplish this:
//create an array with the clips you want to play (in order), in my example here, the items can be a MovieClip derived Class, or a MovieClip instance
var playQueue:Array = [a_walk, a_door];
//create a var to store the currently playing clip
var currentClip:MovieClip;
playNext(); //call this when you want the queue of clips to start playing
function playNext():void {
//if there was an item previously playing (currentClip has a value), stop it and remove it/dispose of it
if(currentClip){
currentClip.stop(); //stop it from playing
currentClip.addFrameScript(currentClip.totalFrames-1, null); //remove the frame script that was added
currentClip.parent.removeChild(currentClip); //remove it from the display
currentClip = null;
}
//check if there's anything left to play
if(playQueue.length < 1) return;
var nextItem:* = playQueue.shift(); //shift retrieves and removes the first item in the array;
if(nextItem is Class){
//if it's a class, instantiate it
currentClip = new nextItem();
}else{
currentClip = MovieClip(nextItem);
}
//initialize the movie clip
addChildAt(currentClip, 0);
currentClip.gotoAndPlay(1);
//this is just what you were doing before:
currentClip.mask = myMask;
currentClip.x=412.4;
currentClip.y=244.5;
//add a command on the last frame of the movie clip to play the next item in the queue
currentClip.addFrameScript(currentClip.totalFrames-1, playNext);
//addFrameScript is 0 based, so 0 would refer to the first frame. This is why we subtract 1 to get the last frame
}
I should note, that addFrameScript is an undocumented function. It serves as a nice shortcut so you don't have to have an ENTER_FRAME listener checking currentFrame vs. totalFrames. Being undocumented however, one can not count on it's continued existence in future versions of the Flash/AIR runtimes (though it's been around for a long long time)
note
This answer is a work in progress. I'm waiting on a response from the OP.
// playClip(new a_door); don't call this yet, or they will just both play.
var clipData:CustomClass = new CustomClass(); // add an instance of a custom class to hold the value of the movie
//clip being played (so that you can use this value later in the event handler.)
// it will also hold a value of the next clip
clipData._currentClip = a_walk;
clipData._nextClip = a_door;
playClip(new a_walk);
function playClip (clip:MovieClip):void {
addChildAt(clip, 0);
clip.mask = myMask;
clip.x=412.4;
clip.y=244.5;
clip.addEventListener(Event.ENTER_FRAME, checkframes);
}
function checkframes(event:Event) {
if (clipData._currentClip.currentFrame == clipData._currentClip.totalFrames) {
//trace("wow! youre an idiot!");
if (clipData._currentClip.parent) {
playClip(clipData._nextClip);
clipData._currentClip.parent.removeChild(clipData._currentClip);
clipData._currentClip = clipData._nextClip; // moves the clips down
//clipData._nextClip = here we have
//a problem. Do these clips play in a set
//order, first to last? Or do the play out of
//order jumping back and forth? If so, how
//are you planning on controlling which clip
//plays next?
trace (100);
return;
}
}
}
I haven't checked this in Flash yet to see if it works, but I noticed that you are defining a function inside another function, which I don't think is good practice, so this might clean things up for you. Give it a try and let us know.
I'll try to fix my code above when I get a chance. In the meantime, you answered my question about playing the clips in order, so a simple solution would be to put all the clips in an array and then play them by playClip(clipArray[i]) and then when the clip ends and gets removed, do i++ and call the same function playClip(clipArray[i]) which will play the next clip in the array.

AS3 tween object not working with .hitTestObject()

I am having a major problem in my new browser app.
Okay so I made game where different cubes (squares) spawn at the top of the screen and I use the Tween class to make them go down the screen and then disappear.
However I want to detect a collision when a cube hits the player (that is also a flying cube).
I tried everything, truly everything but it does not seem to work. The problematic thing is that when I remove the "Tween" function it does detect collision with the hitTestObject method but when I add the "Tween" line collision won't be detected anymore.
It looks like this:
function enemiesTimer (e:TimerEvent):void
{
newEnemy = new Enemy1();
layer2.addChild(newEnemy);
newEnemy.x = Math.random() * 700;
newEnemy.y = 10;
if (enemiesThere == 0)
{
enemiesThere = true;
player.addEventListener(Event.ENTER_FRAME, collisionDetection)
}
var Tween1:Tween = new Tween(newEnemy, "y", null, newEnemy.y, newEnemy.y+distance, movingTime, true);
}
And the collision detection part:
private function collisionDetection (e:Event):void
{
if (player.hitTestObject(newEnemy))
{
trace("aaa");
}
}
I am desperate for some information/help on the topic, it's been bugging me for days.
Thanks for your time, I would be very happy if someone could help me out^^
First, make sure the "newEnemy" instance and the "player" instance are within the same container. If they are not, their coordinate systems might not match up and could be the source of your problem.
Otherwise, you need to keep a reference to each enemy instance you create. It looks like you are only checking against a single "newEnemy" variable which is being overwritten every time you create a new enemy. This might be why you can successfully detect collision between the player and the most recent "enemy" instance.
So... you need a list of the enemies, you can use an Array for that.
private var enemyList:Array = [];
Every time you create an enemy, push it to the Array.
enemyList.push(newEnemy);
In your "collisionDetection" function, you need to loop through all of the enemies and check if the player is touching any of them.
for(var i:int = 0; i < enemyList.length; i++)
{
var enemy = enemies[i];
if (player.hitTestObject(enemy))
{
trace("Collision Detected!");
enemy.parent.removeChild(enemy); // remove the enemy from the stage
enemies.splice(i, 1); // remove the enemy from the list
}
}
I'd suggest that you move to TweenMax, it just might solve your problem, and in my experience it's much better in every possible way.
Scroll down the following page to see a few variations of this library, I myself use TweenNano, they're completely free of charge:
https://greensock.com/gsap-as
I think some plugins cost money, but I doubt you'll ever need them.

Actionscript 3 - Passing one variable from one object to another in the same project

I'm fairly new at ActionScript 3 but I am working on it and trying to learn by reading and modifying ActionScript source codes.
So far so good, however I stumbled upon one problem which I seemingly can't solve by myself. It should be faily simple for you guys tho.
The situation:
I got one "object" which is clickable and gives a random value which is also being saved in a variable.
I got another "object" which does the same thing but only has a different name.
I want the variable from the first object to be passed to the second one, how can I do it?
One way to pass values relies on using references to objects...
// mc1 and mc2 exist as movieclips on the stage
mc1.addEventListener( MouseEvent.CLICK, onClick );
mc2.addEventListener( MouseEvent.CLICK, onClick );
function onClick( event:MouseEvent ):void
{
// reference clicked movieclip through click target
var mc:MovieClip = event.target as MovieClip;
// if our clip matches one, assign the other clip the value.
if ( mc === mc1 )
{
mc2.value = mc.value;
}
else if ( mc === mc2 )
{
mc1.value = mc.value;
}
}
There's a thousand ways to pass references around, and this is just one.
OK guys let me show you the important parts of the code (cant show it all since I paid for it and I don't know whether the author woudl be OK with me publishing all of it).
I got these two objects there. When I click on one of the objects (which is a DICE), it gives me this code basically
var faceValue:int = 6;
// Add mouse click functionality to roll the die
addEventListener(MouseEvent.CLICK, onClickDie, false, 0, true);
mouseChildren = false;
buttonMode = true;
function onClickDie(e:MouseEvent):void {
removeEventListener(MouseEvent.CLICK, onClickDie);
buttonMode = false;
// Initiate the roll-out sequence
if(faceValue == 6) {
gotoAndPlay("rollout6");
etc...
Then somewhere in the frame where it is SPINNING the dice it is randomizing a number and save it into facevalue
// Calculate a random face value between 1 and 6
faceValue = 1 + Math.floor(Math.random()*6);
// Initiate the roll-in sequence
if(faceValue == 6) {
gotoAndPlay("rollin6");
...etc
Now how can I get the randomized facevalue from the spinning the dice frame to pass it to the other dice?

I can't seem to access automatically named objects (instance##) placed on the stage in AS3, am I missing something?

I have a movieclip in the library that is added to the stage dynamically in the document class's actionscript. This movieclip contains many many child images that were imported directly from photoshop at their original positions (which must be preserved).
I do not want to manually name every single image instance, as there are dozens upon dozens.
I have already gone through and manually converted the images to symbols, as apparently flash won't recognize the "bitmap" objects as children of a parent movieclip in AS3 (numChildren doesn't see the bitmaps, but it sees the symbols).
I have an array filled with references to the dozens of children, and I loop through it, checking if each one is under the mouse when clicked. However, somehow, it is not detecting when I click over the items unless I manually name the child symbols (I tested by manually naming a few of them -- those ones became click-sensitive.)
I have already done trace() debugging all throughout the code, verifying that my array is full of data, that the data is, in fact, the names of the instances (automatically named, IE instance45, instance46, instance47, etc.), verifying that the function is running on click, verifying that the code works properly if I manually name the symbols.
Can any one see what's going wrong, or what aspect of flash I am failing to understand?
Here is the code:
//check each animal to see if it was clicked on
private function check_animal_hits():void
{
var i:int = 0;
var animal:Object = this.animal_container;
for (i=0; i<animal.mussels.length; i++)
{
if (this.instance_under_cursor(animal.mussels[i].name))
{
var animal_data = new Object();
animal_data.animal = "mussel";
this.send_data(animal_data);
}
}
}
Here is the code for the instance_under_cursor() method:
// Used for finding out if a certain instance is underneath the cursor the instance name is a string
private function instance_under_cursor(instance_name)
{
var i:Number;
var pt:Point = new Point(mouseX,mouseY);
var objects:Array = stage.getObjectsUnderPoint(pt);
var buttons:Array = new Array ;
var o:DisplayObject;
var myMovieClip:MovieClip;
// add items under mouseclick to an array
for (i = 0; i < objects.length; i++)
{
o = objects[i];
while (! o.parent is MovieClip)
{
o = o.parent;
}
myMovieClip = o.parent as MovieClip;
buttons.push(myMovieClip.name);
}
if (buttons.indexOf(instance_name) >= 0)
{
return true;
}
return false;
}
Update:
I believe I have narrowed it down to a problem with getObjectsUnderPoint() not detecting the objects unless they are named manually.
That is the most bizarre way to find objects under mouse pointer... There is a built-in function that does exactly that. But, that aside, you shouldn't probably rely on instance names as they are irrelevant / can be changed / kept solely for historical reasons. The code that makes use of this property is a subject to refactoring.
However, what you have observed might be this: when you put images on the scene in Flash CS, Flash will try to optimize it by reducing them all to a shape with a bitmap fill. Once you convert them to symbols, it won't be able to do it (as it assumes you want to use them later), but it will create Bitmpas instead - Bitmap is not an interactive object - i.e. it doesn't register mouse events - no point in adding it into what's returned from getObjectsUnderPoint(). Obviously, what you want to do, is to make them something interactive - like Sprite for example. Thus, your testing for parent being a MovieClip misses the point - as the parent needs not be MovieClip (could be Sprite or SimpleButton or Loader).
But, if you could explain what did you need the instance_under_cursor function for, there may be a better way to do what it was meant to do.

ActionScript - Forced Garbage Collection Not Working In ADL?

when launching the following code in ADL, why does the square continue to rotate?
var square:Sprite = new Sprite();
square.graphics.beginFill(0xFF0000);
square.graphics.drawRect(-25, -25, 50, 50);
square.x = square.y = 100;
addChild(square);
addEventListener(Event.ENTER_FRAME, rotateSquare, false, 0, true);
function rotateSquare(evt:Event):void
{
square.rotation += 2;
}
System.gc();
Update
the following display object has a weak referenced ENTER_FRAME event listener. however, calling:
removeChild(testInstance);
testInstance = null;
doesn't stop the ENTER_FRAME event:
package
{
import flash.display.Sprite;
import flash.events.Event;
public class Test extends Sprite
{
private var square:Sprite;
public function Test()
{
addEventListener(Event.ADDED_TO_STAGE, init);
}
private function init(evt:Event):void
{
removeEventListener(Event.ADDED_TO_STAGE, init);
square = new Sprite();
square.graphics.beginFill(0xFF0000);
square.graphics.drawRect(-25, -25, 50, 50);
square.x = square.y = 100;
addChild(square);
addEventListener(Event.ENTER_FRAME, rotateSquare, false, 0, true);
// //Current Solution - only works on display objects
// addEventListener(Event.REMOVED_FROM_STAGE, removeHandler);
}
private function rotateSquare(evt:Event):void
{
trace("square is rotating");
square.rotation += 2;
}
// private function removeHandler(evt:Event):void
// {
// removeEventListener(Event.REMOVED_FROM_STAGE, removeHandler);
// removeEventListener(Event.ENTER_FRAME, rotateSquare);
// }
}
}
i have added a REMOVED_FROM_STAGE event listener, but this will only work on display objects.
is this problem specific to ENTER_FRAME event?
Regarding your update, I think you are misunderstanding how GC works. The basic idea is rather simple.
When you create an object, flash allocates some memory in a storage called the heap. A reference to this object is returned. This reference is what you store in a variable. What is a reference? A means to access this object. Think of it as link to the object.
var foo:Bar = new Bar();
Now, in some languages, at some point you have to release the memory allocated for this object when you're done with it, or you have a memory leak.
In a GC environment, this is done automatically. Of course, you need some rules. This rules vary depending on the concrete GC, but in general terms, you could say the GC determines that an object is collectable if it's no longer reachable. This makes sense, because if you can't reach an object, you can't use it. You've lost your link to it. So, it's considered garbage and will be eventually collected.
The specifics on how reachability is determined vary, but in flash it's a mix of reference counting and a mark and sweep algorithm.
(The following is just a high level overview, the details might not be exact)
One method is reference counting: it's easy and fast but it doesn't work in all situations. Basically, each object has a reference count. Each time you assign this object to a variable (i.e. you store a reference to the object), the reference count is incremented. Each time you lost this reference (for instance, you null out your var), this count is decremented. If the count reaches 0, it means the object is unreachable and so it's collectable.
This works fine in some cases, but no others. Specially when there are crossed references.
var foo1:Bar = new Bar(); // let's call this object Bar_1
var foo2:Bar = new Bar(); // let's call this one Bar_2
// at this point, Bar_1 has reference count of 1 (foo1) and Bar_2 has a reference of 1 (foo2)
foo1.theOtherFoo = foo2;
// now Bar_2 has a RC of 2: foo2 and foo1.theOtherFoo
foo2.theOtherFoo = foo1;
// now Bar_1 has a RC of 2: foo1 and foo2.theOtherFoo
foo1 = null;
// foo1 no longer references Bar_1, so its RC is decremented.
foo2 = null;
// foo2 no longer references Bar_2, so its RC is decremented.
// but still both Bar_1 and Bar_2 have a RC of 1.
As you can see, both Bar_1 and Bar_2 have a RC of 1, but are unreachable. This is one of the cases where reference counting doesn't work. Because for all intents and purposes, both objects are unreachable and yet won't be collected.
That's why there's a mark/sweep algorithm. From a high level point of view, what it does is traversing your objects graph, starting from some root objects and analize its relationships to determine whether an object is reachable or not. This algorithm will determine that even though Bar_1 and Bar_2 have a RC of 1, they're not reachable and thus should be considered garbage and be collected at some point.
Events, listeners and dispatchers work the same way. They're not a special case. When you do:
function test():void {
foo1.addEventListener("someEvent",someHandler);
}
function someHandler(e:Event):void {
}
It's the same as doing:
function test():void {
foo1.someProperty = this;
}
The effect is that foo1 now has a reference to this. You'd normally call removeEventListener when you're done for 2 reasons:
1) You no longer want foo1 to have a reference to this.
2) You no longer want to listener for "someEvent" events.
Lots of people insist on using weak references, because they think that then you can pretend you don't have to call removeEventListener (which is apparently too hard...). This is wrong. removeEventListener does two things and both are important. If you want to stop receiving notifications for some event, you have to tell the dispatcher. It's really that simple. In my opinion, weak references are innecesary in most cases. Some advocate to use them by default; but in my experience, in practice this is a bad service to them, as it confuses people further, encourages them to write sloppy code and gives them the impression that you can ignore how this very basic feature of the language (which is not that hard to graps) works.
Now, after this rather long (but hopefuly constructive) rant, let's look at your code:
Your sprite is not going to be collected, because it has 2 references:
1) the square variable
2) the stage.
The first follows the rules outline above. The second too, but it might not be so obvious at first sight. But it makes sense if you think about it for a second. When you did this:
addChild(square);
square got added to the Test instance, which is in turn added to the stage. The stage is always alive, so if something can be reached from the stage, it's reachable. As long as square remains added to the stage, you can be sure it won't be collected.
So, if you at some point do what Sean Thayne suggested:
removeChild(square)
square = null;
your Sprite will be collectable. That doesn't affect the fact that you told your Test object that you wanted to be called whenever a frame is entered. And that's exactly what's happening. Until you don't tell it you don't want to receive this event anymore (calling removeEventListener), it will call you back.
Flash's garbage collection only clears out elements/objects/variables that have either a zero reference count or have only weak references.
This means you would need to do this. For it to truly be gc'd.
removeChild(square)
square = null;
System.gc()