Setting a veiwing range for a AI character

I've been trying to make some kind of AI for a flash game, now I'm trying to make it attack when I get within a sertant range of it.
I got one problem, when I use the formula written below, I can get closer when closing up from behind than if I'm going from the front. This might sound like a good idea, but since the coordinates doesn't really change when the enemy turns around it's not good at all.

How can I stop this from happening?

-------------------
How I've done it now:


XG, XR, YG, YR and distance are all variables.
XG and YG are the _y and _x coordinates for a green circle.
XR and YR are the _y and _x coordinates for a red circle.
And distance is the range where it will react when you get close.
The "_root.gotoAndPlay("1")" is just something I've used to test if it does react when I get within that range.

if (Math.sqrt((XG-XR)*(XG-XR)+(YG-YR)*(YG-YR))<distance) {
_root.gotoAndPlay("1");
}

Man, this is the first post ever, which I could not answer in the flash forum. Sorry, you really have me stuck on this one...lol

Well, that's something Anyone who think they have the answer?
You think it might help if I add my messy FLA file?

Attached Files

AI.zip (14.1 KB, 36 views)

I will take a look at it, and point some of the other flash guru's over to this forum...We shall see!!

Alright, it's seems I got the answer.
There was nothing wrong with the actionscript, but both the green and the red circle weren't didn't have their... I don't know what to call it, point zero? at the center. in other words where the Y and X coordinates were calculated from was in the corner of the symbols, not center....

Oh...yeah, I was really amazed, I am an ActionScript guru, and saw nothing wrong with that. Glad you found you answer, I would never of thought of that.

When I tried make it move I used:

if (_root.attack >= 2)
{
if(YG<=YR&&XG>=XR){
this._x-=fart;
this._y+=fart;
}
else if (YG>=YR&&XG>=XR){
this._x-=fart;
this._y-=fart;
}
else if (YG<=YR&&XG<=XR){
this._x+=fart;
this._y+=fart;
}
else if (YG>=YR&&XG<=XR){
this._x+=fart;
this._y-=fart;
}

This will make the Green circle (YG and XG (YG = Green circle's _y value, XG = Green circle's _x value)) close in on the red circle (XR and YR (same deal as with the Green circle)).
The problem I'm having is that when it does finaly reach this point, it start shaking. I can't get it to stop completely, it looks like it moves a bit too far forward, then realize this and move too far backward then repeat this forever. How can I correct this?

Oh, I see the problem...you are doing gaming in flash...hehehe, I know nothing about gaming in flash...lol, maybe someone else can answer this for you!!