The elusive hitTest explained

That works really well Tony, thanks again for your time and help.

I'd like to ask your opinion on something though if i may. The idea is to have 2 dots with a gap in the middle. So 1 will be say 20 pixels up from the center of the movie clip and the other will be -20 pixels from the center. Then you just guide the dots past a line, so the line goes in between the dots. Then the hit test will detect the hit between the dots and the line. Because the line will be curved and not just straight, i need to add some rotation to the movie clip using the left and right cursor keys. I've already done that before so that's not the problem as such. I'm just wondering if it might be easier to use the getbounds hit test code to just detect for a collision rather than actually stopping the movieclip from passing through it. I also need to work out where to put the reaction (a change in alpha percentage or a message saying the line has been hit, etc) to the hit test.

The more i think about it, the more i think that stopping the movieclip's movement on the hittest might be the wrong way to go. Instead maybe i should just let the movieclip pass through the line but include a message of some kind that says the line has been hit.

I hope you don't mind having me bounce these ideas off of you Tony, you've been a great help :D

Quote:

---

Originally posted by triple j
The idea is to have 2 dots with a gap in the middle. So 1 will be say 20 pixels up from the center of the movie clip and the other will be -20 pixels from the center. Then you just guide the dots past a line, so the line goes in between the dots. Then the hit test will detect the hit between the dots and the line. Because the line will be curved and not just straight, i need to add some rotation to the movie clip using the left and right cursor keys. I've already done that before so that's not the problem as such.

---

Maybe I didnt understand your idea correctly, but if you have 2 points to test against the line, then I would forget the getBounds and just hittest both point coordinates. Of course you would first need to convert them to stage coordinates to match the line.

Im not sure, but have you actually thought what happens, if the dots are moved very fast? They could get outside of the line without hitting it.

If that can be problem, you could cheat and not test the points at all. You could draw invisible line between the points (points remain only to show player the position) and hitTest between that invisible line and path line. As long they hit, points are placed either side of the path.

Its up to you, what to do when player goes out of the path. End the game, show warning, stop the movement... your choise :)

You must be some sort of mind reader Tony :D Earlier today i worked on using another movieclip that was just a line to detect for the hit test instead of the points.

I also realised your point too about the dots being moved too fast. It would detect the hit test and i just made it display a temporary message saying "ok" or "hit", but then if you move the mouse quick enough you can pretty much cheat, so that was no good.

I tried stopping the movement when the dots hit the line, but i couldn't get it to work correctly. Ideally, what i would like to aim for, is to have an energy bar so that when the dots are in contact with the line, the bar goes down ( i think i can make that ). But to also limit/stopping the movement of the dots, but i'm not sure how to go about this.

I tried several things today and i was getting more and more frustrated by it, so in the end i gave up. It's got me a little confused right now :confused:

hitTest for the lazy and dull-witted (such as myself)...
I know this thread was a hot topic a whole year ago, but i'm sure finding it interesting today. after having many of the problems expressed since Ed Mack's (Mack Daddy of HitTest) initial post, I used the simple shapFlag argument presented by "The_Xell" in Groovy.fla :

onClipEvent (mouseMove) {
if (_root.dumBell.hitTest(_root.circ._x,_root.circ._y , true)) {//checks if the circle is on the black area, not bounding box
_root.hit = true;
} else {
_root.hit = false;
}

}

I used a "dumbell" shaped object as the area to be hit and "circ" instead of the mouse position. I then CHEATED by duplicating the dumbell and putting the code on the duplicate a layer beneath, enlarging it so that the center of "circ" would hitTest before reaching the dumbell proper. works great if the dumbell doesn't have to move. Maybe I'm a dumbell for taking the less exciting route, but it was quick and simple. maybe novice actionscripters will dig it.

wat a topic!!

now i understand hittest much much better than b4.. n thx to ed mack now my game is workin..

i think u guys shud make more this kind of topic with attach movie clip etc.. or r there some already??

How do you make something happen on ... un hit. for instance

I have this on a MC

Code:

---

onClipEvent (enterFrame) {
    if (this.hitTest(_root.hero) && Key.isDown(Key.SPACE)) {
        _root.vocals.text= "I'm a mage!";
       
}
}

---

But when the hit test no longer exist on that object I want the _root.vocals.text to be set back to nothing.

I used this code to make my character move and detect collision but when the character hits/touches the building it gets stuck in it.
This is the script I used. Someone plz show me what i did wrong.

Code:

---

onClipEvent(load){
        s = 6;

        function move(x,y){
                if(!this.hitTest(_root.bldg)){
                                                _x += x;
                                                _y += y;
                                        }
                                }
                        }

onClipEvent(enterFrame){
        if(Key.isDown(Key.UP)){
                move(0,-s);
                if (_currentframe<5){
                        _root.hero.gotoAndPlay("walk up");
                        }
        }
        if(Key.isDown(Key.DOWN)){
                move(0,s);
                if (_currentframe<5){
                        _root.hero.gotoAndPlay("walk down");
                        }
        }
        if(Key.isDown(Key.LEFT)){
                move(-s,0);
                if (_currentframe<5){
                        _root.hero.gotoAndPlay("walk left");
                        }
        }
        if(Key.isDown(Key.RIGHT)){
                move(s,0);
                if (_currentframe<5){
                        _root.hero.gotoAndPlay("walk right");
                        }
        }
}
onClipEvent (keyUp) {
        if (_currentframe>4){
                        if(_currentframe>9){
                                if(_currentframe>14){
                                if(_currentframe>19){
                               
                                        _root.hero.gotoAndStop(4);
                               
                                }else{
                                        _root.hero.gotoAndStop(3);
                                        }
                                }else{
                                        _root.hero.gotoAndStop(2);
                                        }
                                }else{
                                        _root.hero.gotoAndStop(1);
                                        }
                        }
}

---

I don't believe it, this great thread is still not a sticky, even though all of the starters keep asking questions about hitTest, please mod squad, *glare* here!:)

PS:- I know the stickies have increased and there's a actionscript section at fk boards.....but people like me are so lazy :zzz:

the thread is sticky .. but in a different way ;) .. see this thread http://www.flashkit.com/board/showth...hreadid=518121

Quote:

---

Originally posted by havokking
I used this code to make my character move and detect collision but when the character hits/touches the building it gets stuck in it.
This is the script I used. Someone plz show me what i did wrong.

---

Look at the move function:

code:

---

function move(x,y){

	if(!this.hitTest(_root.bldg)){

		_x += x;

		_y += y;

	}

} 

---

Now think how this code works.

1. Check if the mc is currently colliding with the mc _root.bldg.
2. If it is colliding (hitTest returns true), then do nothing.
3. If mc is currently not colliding, then add x and y to its current position.

Whats wrong with this logic?
Lets say you have mc at _x=100 and x=10.
Lets suppose from the _x=110 it will hit the mc _root.bldg.
So, you run the code, hitTest returns false and mc is moved to _x=110.
Next time the mc tries to move, its already colliding with the building and the movement is ignored.
Result - mc is stuck in the building.

What you want to use?
You should use hitTest to check if the mc will collide in the position it will be positioned AFTER it moves. And only allow movement, when the NEW position doesnt collide with the building.

So, use point-based hitTest. You know mc's current position and how much it would to move, add those together:

if(!_root.bldg.hitTest(this._x+x, this._y+y, true)){

I know there hasnt been any activity in this topic since june of 2004 but while looking through here i've gotton some good examples but I cant get it to work.

Ok so heres my problem: I have a character who I want to stop when they hit a wall, but it needs to continue to hide the animations inside the characters movie clip.

I have this code on the character for the wall, got it from Ed Mack

code:

---

onClipEvent(load){

	s = 5;

	b = this.getBounds(this);



	function move(x,y){

		if(!_root.wall.hitTest(_x+x+b.xmin+1,_y+y+b.ymin+1  ,true)){

			if(!_root.wall.hitTest(_x+x+b.xmax-1,_y+y+b.ymin+1,true)){

				if(!_root.wall.hitTest(_x+x+b.xmin+1,_y+y+b.ymax-1,true)){

					if(!_root.wall.hitTest(_x+x+b.xmax-1,_y+y+b.ymax-1,true)){

						_x += x;

						_y += y;

					}

				}

			}

		}

	}

}



onClipEvent(enterFrame){

	if(Key.isDown(Key.UP)){

		move(0,-s);

	}

	if(Key.isDown(Key.DOWN)){

		move(0,s);

	}

	if(Key.isDown(Key.LEFT)){

		move(-s,0);

	}

	if(Key.isDown(Key.RIGHT)){

		move(s,0);

	}

}

---

and this is the code inside the character movie clip that hides the other animations

code:

---

function initialize()

{

	hideAllAnimations();

	wasDown = true;

	wasUp = false;

	wasRight = false;

	wasLeft = false;

}



function handleVidelMovement()

{

	if (Key.isDown(Key.RIGHT) && Key.isDown(Key.SPACE))

	{

		this._x+=0;

if(Key.isDown(Key.DOWN))

{

this._y+=0;

}

else if(Key.isDown(Key.UP))

{

this._y-=0;

}



		hideAllAnimations();

		this.videlblockr._visible = true;

		wasDown = false;

		wasUp = false;

		wasRight = true;

		wasLeft = false;

	}

	else if(Key.isDown(Key.RIGHT))

	{

		this._x+=3;

if(Key.isDown(Key.DOWN))

{

this._y+=3;

}

else if(Key.isDown(Key.UP))

{

this._y-=3;

}

		hideAllAnimations();

		this.videlwalkr._visible = true;

		wasDown = false;

		wasUp = false;

		wasRight = true;

		wasLeft = false;

	}

	else if (Key.isDown(Key.LEFT) && Key.isDown(Key.SPACE))

	{

		this._x-=0;

if(Key.isDown(Key.DOWN))

{

this._y+=0;

}

else if(Key.isDown(Key.UP))

{

this._y-=0;

}

		hideAllAnimations();

		this.videlblockingl._visible = true;

		wasDown = false;

		wasUp = false;

		wasRight = false;

		wasLeft = true;

	}

	else if(Key.isDown(Key.LEFT))

	{

		this._x-=3;

if(Key.isDown(Key.DOWN))

{

this._y+=3;

}

else if(Key.isDown(Key.UP))

{

this._y-=3;

}

		hideAllAnimations();

		this.videlwalkingl._visible = true;

		wasDown = false;

		wasUp = false;

		wasRight = false;

		wasLeft = true;

	}

	else if (Key.isDown(Key.UP) && Key.isDown(Key.SPACE))

	{

		this._y-=0;

if(Key.isDown(Key.RIGHT))

{

this._y+=0;

}

else if(Key.isDown(Key.LEFT))

{

this._y-=0;

}

		hideAllAnimations();

		this.videlblockingup._visible = true;

		wasDown = false;

		wasUp = true;

		wasRight = false;

		wasLeft = false;

	}

	else if(Key.isDown(Key.UP))

	{

		this._y-=3;

if(Key.isDown(Key.RIGHT))

{

this._y+=3;

}

else if(Key.isDown(Key.LEFT))

{

this._y-=3;

}

		hideAllAnimations();

		this.videlwalkingup._visible = true;

		wasDown = false;

		wasUp = true;

		wasRight = false;

		wasLeft = false;

	}

	else if (Key.isDown(Key.DOWN) && Key.isDown(Key.SPACE))

	{

		this._y+=0;

if(Key.isDown(Key.RIGHT))

{

this._y+=0;

}

else if(Key.isDown(Key.LEFT))

{

this._y-=0;

}

		hideAllAnimations();

		this.videlblockingdown._visible = true;

		wasDown = true;

		wasUp = false;

		wasRight = false;

		wasLeft = false;

	}

	else if(Key.isDown(Key.DOWN))

	{

		this._y+=3;

if(Key.isDown(Key.RIGHT))

{

this._y+=3;

}

else if(Key.isDown(Key.LEFT))

{

this._y-=3;

}

		hideAllAnimations();

		this.videlwalkingdown._visible = true;

		wasDown = true;

		wasUp = false;

		wasRight = false;

		wasLeft = false;

	}

	else if( wasDown )

	{

		hideAllAnimations();

		this.videlstandingdown._visible = true;

	}

	else if( wasUp )

	{

		hideAllAnimations();

		this.videlstandingup._visible = true;

	}

	else if( wasRight )

	{

		hideAllAnimations();

		this.videlstandingr._visible = true;

	}

	else if( wasLeft )

	{

		hideAllAnimations();

		this.videlstandingl._visible = true;

	}

}



function hideAllAnimations()

{

	this.videlstandingr._visible = false;

	this.videlwalkr._visible = false;

	this.videlblockr._visible = false;

	this.videlpunchr._visible = false;

    this.videlkir._visible = false;

    this.videlkickr._visible = false;



	this.videlstandingl._visible = false;

	this.videlwalkingl._visible = false;

	this.videlblockingl._visible = false;

    this.videlpunchingl._visible = false;

    this.videlkil._visible = false;

    this.videlkickingl._visible = false;

	

	this.videlstandingup._visible = false;

	this.videlwalkingup._visible = false;

	this.videlblockingup._visible = false;

    this.videlpunchup._visible = false;

	this.videlkiup._visible = false;

    this.videlkickup._visible = false;



	this.videlstandingdown._visible = false;

	this.videlwalkingdown._visible = false;

	this.videlblockingdown._visible = false;

    this.videlpunchdown._visible = false;

    this.videlkidown._visible = false;

    this.videlkickdown._visible = false;

}



initialize();

---

but since theres 2 scripts for movement the character just slows down and continues through it and with the current wall code when you hold space and an arrow key your supposed to stop and block but that doesnt work till you come in contact with the wall so if someone could help me out a bit I would be VERY grateful. I'll include the .fla for even more reference, it's in Flash MX format

Say if I had a man that could walk but I wanted him to walk up or down hills, if it can be done, how would I approach doing this using the hitTest method so its easy to understand??

Okay, I have a BIG problem:

I'm making an object move up the screen (object 1). When Object one syncs up EXACTLY with another object (object 2), the player will have to push a hey (Up directional button).

When the Up directional button is pushed, it performs a hitTest. if both objects are at sync exactly, it will say "GOOD". if it hasn't passed object 2 yet, it won't do anything. But if it HAS passed object 2 (and the player didn't push the updirectional button), it will say "BAD"

How am I supposed to do this?

Here's what I have so far:

// locks the UP arrow's Y cord
onClipEvent (enterFrame) {
this._y -= 11;
if(this._x<0 || this._x>Stage.width || this._y < 0)
{
this.removeMovieClip();
}
}
// when UP KEY is pushed, performs collision detection analysis and tells weather it is good or bad
// if uparrow syncs up with deadline coord, displays GOOD
// if uparrow passes deadline coord, displays BAD
onClipEvent (keyUp) {
if (Key.isDown(Key.UP)) {
if(this.hitTest(45.9, 20, true)) {


After that, I'm lost.

BTW, "this" is referring to object 1.And 45.9 and 20 are objects 2's exact coordinates ;)

i have a game that the 2 obejcts moves "the goodguy and the wall"
how could i make the hitTest Works for that.


one movie clip move to the right the other to the left.

Quote:

---

Originally posted by Progranimator
I'm making an object move up the screen (object 1). When Object one syncs up EXACTLY with another object (object 2), the player will have to push a hey (Up directional button).

When the Up directional button is pushed, it performs a hitTest. if both objects are at sync exactly, it will say "GOOD". if it hasn't passed object 2 yet, it won't do anything. But if it HAS passed object 2 (and the player didn't push the updirectional button), it will say "BAD"

How am I supposed to do this?

---

code:

---

onClipEvent (enterFrame) {

	this._y -= 11;

	if(this._x<0 || this._x>Stage.width || this._y < 0){

		this.removeMovieClip();

	}

	if(this._y<20) {

		trace("bad");

	}

}

onClipEvent (keyDown) {

	if (Key.isDown(Key.UP)) {

	if(this.hitTest(45.9, 20, true)) {

		trace("good");

	}

}

---

Quote:

---

Originally posted by GodAngel
i have a game that the 2 obejcts moves "the goodguy and the wall"
how could i make the hitTest Works for that.

---

if(!_root.goodguy.hitTest(_root.wall)){
//move
}

Okay, I've tried your code, and it glitched a little. I've modified it here:

onClipEvent (enterFrame) {
this._y -= 11;
if(this._x<0 || this._x>Stage.width || this._y < 0) {
this.removeMovieClip();
}
}
onClipEvent (keyDown) {
if (Key.isDown(Key.UP)) {
if(this.hitTest(45.9, 20, true)) {
trace("GOOD!!"); }
else {
trace("BAD"); }
}
}

The thing is that I want to make the hitTest area bigger, and not limited to just one point. I've tried the other hitTest format:

if(object1.hitTest(object2)) {

But I can't seem to get it right.

Just another question. Sorry!! But when the player pushes the Up Directional button, it will show either one of two images that were hidden, depending on weather he got GOOD or BAD. How do I do this?

Thanks for your help!!

P.S. I'm putting all this code in the actionscript window of Object1, and don't yet have any code for object 2. this is getting me a little worried. I'm putting object 2 on a seperate layer than object 1. I hope I'm not confuzing you.:D

Quote:

---

Originally posted by Progranimator
The thing is that I want to make the hitTest area bigger, and not limited to just one point. I've tried the other hitTest format:

if(object1.hitTest(object2)) {

But I can't seem to get it right.

---

Your other movie clip has to have instance name set to "object2", then you can use code in the object1:
if(this.hitTest(_root.object2)) {
This will return true if any part of bounding boxes of the 2 objects overlap.

Quote:

---

Originally posted by Progranimator
Just another question. Sorry!! But when the player pushes the Up Directional button, it will show either one of two images that were hidden, depending on weather he got GOOD or BAD. How do I do this?

---

Create movie clip. Make 3 keyframes inside it. Delete all the graphics from frame 1 and place stop() statement in frame 1. Place image of "Good" in frame 2 and image of "Bad" in frame 3. Give this movie lcip instance name "images" and instead of trace use:

_root.images.gotoAndStop(2);
for good and
_root.images.gotoAndStop(3);
for bad.