knockout (GlowFilter.knockout property) -- Version 8

Specifies whether the object has a knockout effect. A value of true makes the object's fill transparent and reveals the background color of the document. The default is false (no knockout effect).

Example

The following example changes the knockout property on an existing movie clip when a user clicks it.

import flash.filters.GlowFilter;

var mc:MovieClip = createGlowFilterRectangle("GlowFilterKnockout");
mc.onRelease = function() {
    var filter:GlowFilter = this.filters[0];
    filter.knockout = true;
    this.filters = new Array(filter);
}

function createGlowFilterRectangle(name:String):MovieClip {
    var rect:MovieClip = this.createEmptyMovieClip(name, this.getNextHighestDepth());
    var w:Number = 100;
    var h:Number = 100;
    rect.beginFill(0x003366);
    rect.lineTo(w, 0);
    rect.lineTo(w, h);
    rect.lineTo(0, h);
    rect.lineTo(0, 0);
    rect._x = 20;
    rect._y = 20;

    var filter:GlowFilter = new GlowFilter(0x000000, .8, 16, 16, 1, 3, false, false);
    var filterArray:Array = new Array();
    filterArray.push(filter);
    rect.filters = filterArray;
    return rect;
}