Pixel Bender 之 Flex 特效使用

Embed 标记指示 ActionScript 编译器在它创建 SWF 文件时嵌入 Pixel Bender 内核即pbj格式文件。



您必须包含 MIME 类型声明, 如以下示例所示:



[Embed(source="channelscrambler.pbj", mimeType="application/octet-stream")]

var ChannelScramblerKernel:Class;



要使用内核, 创建一个类实例, 本例中为 ChannelScramblerFilter。以下代码使用一个嵌入的内核新建 Shader 和 ShaderFilter 对象, 它们被应用于一个 Image 实例:



<?xml version="1.0" encoding="utf-8"?>

<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="vertical" applicationComplete="applyFilter()"

    width="476" height="281" backgroundGradientAlphas="[1.0, 1.0]" backgroundGradientColors="[#FFFFFF, #FFFFFF]">

    <mx:Script>

        <![CDATA[

            //Embed the PixelBender kernel in the output SWF

            [Embed(source="kernels/channelscrambler.pbj", mimeType="application/octet-stream")]

            private var ChannelScramblerKernel:Class;

           

            private function applyFilter():void

            {               

                var shader:Shader = new Shader(new ChannelScramblerKernel() );

                var shaderFilter:ShaderFilter = new ShaderFilter( shader );

                camellia.filters = [ shaderFilter ];               

            }

        ]]>

    </mx:Script>

    <mx:HBox width="410" height="100%">

        <mx:VBox height="100%">

            <mx:Image source="images/camellia.jpg" scaleContent="false" autoLoad="true"/>

            <mx:Label text="Original" width="200" textAlign="center"/>

        </mx:VBox>

        <mx:VBox height="100%">

            <mx:Image source="images/camellia.jpg" id="camellia" scaleContent="false" autoLoad="true"/>

            <mx:Label text="Channel Scrambler" width="199" textAlign="center"/>

        </mx:VBox>

    </mx:HBox>

</mx:Application>



使用 Embed 标记通常是载入 Pixel Bender 内核最简单的方法, 但您也可以在运行时载入内核。以下示例说明如何使用 URLLoader 类载入内核:



function loadFilter()

{

    var urlRequest:URLRequest = new URLRequest( "channelscrambler.pbj" );

    var urlLoader:URLLoader = new URLLoader();

    urlLoader.dataFormat = URLLoaderDataFormat.BINARY;

    urlLoader.addEventListener( Event.COMPLETE, applyFilter );

    urlLoader.load( urlRequest );

}



function applyFilter( event:Event ):void

{

    trace("apply");

    urlLoader.removeEventListener( Event.COMPLETE, applyFilter );

    var shader:Shader = new Shader( event.target.data );

    var shaderFilter:ShaderFilter = new ShaderFilter( shader );

    camellia.filters = [ shaderFilter ];

}



如果需要动态设置加载的内核的值可以在加载pbj文件时断点调试查看即可