Flash CS3 Documentation

Learning ActionScript 2.0 in Adobe Flash > Animation, Filters, and Drawings > Working with filters using ActionScript

Working with filters using ActionScript

The flash.filters package contains classes for the bitmap filter effects in Flash Player 8 and later. Filters let you use ActionScript to apply rich visual effects, such as blur, bevel, glow, and drop shadow, to text, movie clip, and button instances. You can also use the Flash authoring tool to apply filter effects to objects such as text, images, and video. Flash has nine filter effects, although only seven are accessible by using the user interface. The ConvolutionFilter and DisplacementMapFilter filters are only available by using ActionScript code.

The following procedure loads a semitransparent PNG image, and applies a GlowFilter effect to the nontransparent portion of the image.

To apply filters to semitransparent images:

1. Create a new Flash document and save it as transparentImg.fla.
2. Add the following ActionScript to Frame 1 of the Timeline:

   import flash.filters.GlowFilter;
   System.security.allowDomain("http://www.helpexamples.com");
   var mclListener:Object = new Object();
   mclListener.onLoadInit = function(target_mc:MovieClip) {
       target_mc._x = (Stage.width - target_mc._width) / 2;
       target_mc._y = (Stage.height - target_mc._height) / 2;
       var glow:GlowFilter = new GlowFilter();
       target_mc.filters = [glow];
   };
   this.createEmptyMovieClip("img_mc", 10);
   var img_mcl:MovieClipLoader = new MovieClipLoader();
   img_mcl.addListener(mclListener);
   img_mcl.loadClip("http://www.helpexamples.com/flash/images/logo.png", img_mc);
   

   This code uses a movie clip loader instance to load a semi-transparent PNG image. After the image finishes loading, the image moves to the center of the Stage and a glow filter is applied.

3. Select Control > Test Movie to test the document.

   The glow filter effect is only applied to the opaque (nontransparent) area of the PNG image.

The following sections describe how to use the filters:

• Using the blur filter
• Using the drop shadow filter
• Using the glow filter
• Creating gradient glows
• Using the bevel filter
• Applying a gradient bevel filter
• Using the color matrix filter
• Using the convolution filter
• Using the displacement map filter

For a source sample of using ActionScript to apply filters, Filters.fla, see the Flash Samples page at www.adobe.com/go/learn_fl_samples. Download the Samples zip file and navigate to the ActionScript2.0/Filters folder to access this sample.

Flash CS3