public class Client extends MovieClip {
    public var emitter:StarEmitter;
    public var cloudEmitter:CloudEmitter;
    public var renderer:DisplayObjectRenderer;
    
    public var loginPane:MovieClip;
    
    public var starBg:StarBackground;
    
    public function Client() {
        stage.scaleMode = StageScaleMode.NO_SCALE; 
        stage.align = StageAlign.TOP_LEFT;

        emitter = new StarEmitter(stage.stageWidth, stage.stageHeight);
        renderer = new DisplayObjectRenderer();
        renderer.addEmitter(emitter);

        addChild(renderer);
	stage.addEventListener(Event.RESIZE, this.onResizeStage);
    }

//...

    private function onResizeStage(e:Event):void {
        renderer.removeEmitter(emitter);
        
        trace("Stage Width: " + stage.stageWidth + ". Stage Height: " + stage.stageHeight + ".");
        
        emitter = new StarEmitter(stage.stageWidth, stage.stageHeight);
        
        renderer.addEmitter(emitter);
    }

//...

public class StarEmitter extends Emitter2D {
    private var position:Position;
    public static const STARS:Number = 1000;

    public function StarEmitter(w:Number, h:Number) {
        counter = new Blast(STARS);
        addInitializer( new ImageClass( RadialDot, [2] ) );
        position = new Position( new RectangleZone(0, 0, w, h));
        addInitializer( position );
        this.start();
    }
}

Stage Width: 1676. Stage Height: 963. (this was while it was large)
Stage Width: 892. Stage Height: 592. (this was back to small again)