Ok, been googling my but off over this. I have a package that extends my sound class that I want to also control the alpha of an existing symbol on my stage. I have read that this would be ideally done through some sort of event listener but I can’t find a way to do it. Basically, my package generates a wavelength that I want to control the alpha of an existing library symbol. I have gotten examples to work the way I wish but can’t seem to get my package to access the main .swf’s library.
Here’s the code:
package { import flash.events.SampleDataEvent;
import flash.media.Sound;
/**
* A dynamically generated binaural beat carrier wave Sound with frequency easing.
*/
public class Binaural extends Sound {
// Frequency-easing parameters
private var carrier:Number; // Scaled frequency of carrier wave
private var binStart:Number; // Starting scaled binaural difference
private var binDif:Number; // Ending scaled binaural difference
private var endPos:int; // Total samples in sound
private var easing:Function;
private var lPhase:Number = 0, rPhase:Number = 0; // Current angular positions
/**
* Creates a Binaural instance with the specified behavior.
* @param carrier Carrier wave frequency
* @param binStart initial binaural frequency
* @param binEnd final binaural frequency
* @param time Length of sound in seconds
* @param easing Easing function for the frequency shift. Default is linear.
*/
public function Binaural(carrier:Number, binStart:Number, binEnd:Number, time:Number, easing:Function = null) {
var scale:Number = 2 * Math.PI / 44100;
this.carrier = scale * carrier;
this.binStart = scale * binStart;
binDif = scale * (binEnd - binStart);
endPos = time * 44100;
this.easing = easing || defaultEasing;
addEventListener(SampleDataEvent.SAMPLE_DATA, onSampleData);
}
// Standard linear ease
public function defaultEasing(position:Number, frequency:Number, totalchange:Number, totaltime:Number):Number {
return frequency + totalchange * position / totaltime;
}
// Generator
private function onSampleData(e:SampleDataEvent):void {
var maxPos:int = e.position + 8192;
if (maxPos >= endPos) maxPos = endPos;
for (var position:int = e.position; position < maxPos; position++) {
var halfDiff:Number = easing(position, binStart, binDif, endPos);
e.data.writeFloat(Math.sin(lPhase += carrier + (halfDiff/2)));
e.data.writeFloat(Math.sin(rPhase += carrier - (halfDiff/2)));
// LibraryObject.alpha = (halfDiff+1)/2;
}
}
}
}
The
// LibraryObject.alpha = (halfDiff+1)/2;
is what worked in the main .swf when I was testing the basic concept.
Thanks,
Pete