[ActionScript 3.0] AS3实现滤镜叠加效果

import flash.display.BitmapData;

import flash.filters.BlurFilter;

import flash.geom.ColorTransform;

import flash.geom.Matrix;

addChild(new Bitmap(overlapFilter(new 元件1(),5,1)));

function overlapFilter(obj:DisplayObject, dist:Number, qual:Number):BitmapData

{

    var width0:Number = obj.width+(dist*0.05*obj.width)+4;

    var height0:Number = obj.height+(dist*0.05*obj.height)+4;

    var out:BitmapData = new BitmapData(width0,height0,true,0x00000000);

    var buffer:BitmapData = new BitmapData(width0,height0,true,0x00000000);

    var blur:BlurFilter = new BlurFilter(3,3,qual);

    var cmat:ColorTransform = new ColorTransform(1,1,1,0.2,0,0,0,0);

    var mat:Matrix = new Matrix();

    var step:Number;

    for (var i:Number = dist+20; i>1; i--) {

        step = 0.05 * i;

        mat.identity();

        mat.scale(step,step);

        mat.translate(width0/2-obj.width*step/2,height0/2-obj.height*step/2);

        buffer.fillRect(buffer.rect,0x00000000);

        buffer.draw(obj,mat);

        buffer.applyFilter(buffer,buffer.rect,new Point,blur);

        mat.identity();

        out.draw(buffer,mat,cmat);

    }

    mat.identity();

    mat.translate(dist*0.05*obj.width/2+2,dist*0.05*obj.height/2+2);

    cmat.alphaMultiplier = 0.3;

    buffer.dispose();

    out.draw(obj,mat,cmat,null,null,true);

    return out;

}