Pan And Volume Depending on Movieclip's rela - actionscript-3

Question

I am creating a simple 2d platformer in as3, and am starting to implement sounds.
I have a dog that follows you around the level, and plays an ambient sound everywhere.
I am just wondering if there is a way to change the volume and pan of the sound channel, depending on the distance between two movieclips?
So far I am checking if the dog movieclips's x is greater or less than the player's x and soundTransforming it from there, but it is not at all smooth.
I really can't think of any math to do it at the moment, and any help is appreciated!
Thanks!

Answer 1

Here is an example. This assumes you have the following vars:
var player:Sprite;
var dog:Sprite;
var mySoundChannel:SoundChannel;//assigned when you play a sound
var myVolume:SoundTransform = new SoundTransform(); //sound transform to hold the current volume and pan settings
var currentDistance:Number; //the distance between dog and player
var currentDistanceX:Number; //the x distance between dog and player for panning
var minSound:Number = 0.1; //10% is the quietesst it can get;
var minDistance:Number = 500; //500 pixels away is when it should reach the min sound value
var distanceGrace:Number = 10; //if within 10 pixels, keep the volume at 100%
//you'll probably want run the code below in an enter frame handler
function enterFrameHandler(e:Event):void {
//populate the distance vars
currentDistance = Point.distance(new Point(dog.x, dog.y), new Point(player.x, player.y)); //for volume
currentDistanceX = Point.distance(new Point(dog.x, 0), new Point(player.x, 0)); //for panning
myVolume.volume = Math.max(minSound, 1 - Math.abs(currentDistance - distanceGrace) / minDistance);
myVolume.pan = ((currentDistanceX + 1) / minDistance);//only adding 1 to the distance so we don't ever divide by 0
if (dog.x < player.x) myVolume.pan *= -1;
mySoundChannel.soundTransform = myVolume;
}