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:

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[Embed(source="channelscrambler.pbj",mimeType="application/octet-stream")]
var ChannelScramblerKernel:Class;

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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>

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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:

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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 ];
}

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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