漸層光暈濾鏡

GradientGlowFilter 類別可讓您對顯示物件或 BitmapData 物件套用增強的光暈特效。此效果可讓您更容易掌控光暈顏色，進而產生更真實的光暈效果。此外，漸層光暈濾鏡可讓您將漸層光暈套用至物件的邊緣內部、外部，或邊緣上方。

下列範例會在「舞台」上繪製一個圓形，並將漸層光暈濾鏡套用至此圓形。當您將滑鼠移至右側並接著往下移時，模糊量就會分別往水平及垂直方向增加。此外，任何時候，只要您在「舞台」上按一下，就可增加模糊的強度。

import flash.events.MouseEvent; 
import flash.filters.BitmapFilterQuality; 
import flash.filters.BitmapFilterType; 
import flash.filters.GradientGlowFilter; 
 
// Create a new Shape instance. 
var shape:Shape = new Shape(); 
 
// Draw the shape. 
shape.graphics.beginFill(0xFF0000, 100); 
shape.graphics.moveTo(0, 0); 
shape.graphics.lineTo(100, 0); 
shape.graphics.lineTo(100, 100); 
shape.graphics.lineTo(0, 100); 
shape.graphics.lineTo(0, 0); 
shape.graphics.endFill(); 
 
// Position the shape on the Stage. 
addChild(shape); 
shape.x = 100; 
shape.y = 100; 
 
// Define a gradient glow. 
var gradientGlow:GradientGlowFilter = new GradientGlowFilter(); 
gradientGlow.distance = 0; 
gradientGlow.angle = 45; 
gradientGlow.colors = [0x000000, 0xFF0000]; 
gradientGlow.alphas = [0, 1]; 
gradientGlow.ratios = [0, 255]; 
gradientGlow.blurX = 10; 
gradientGlow.blurY = 10; 
gradientGlow.strength = 2; 
gradientGlow.quality = BitmapFilterQuality.HIGH; 
gradientGlow.type = BitmapFilterType.OUTER; 
 
// Define functions to listen for two events. 
function onClick(event:MouseEvent):void 
{ 
    gradientGlow.strength++; 
    shape.filters = [gradientGlow]; 
} 
 
function onMouseMove(event:MouseEvent):void 
{ 
    gradientGlow.blurX = (stage.mouseX / stage.stageWidth) * 255; 
    gradientGlow.blurY = (stage.mouseY / stage.stageHeight) * 255; 
    shape.filters = [gradientGlow]; 
} 
stage.addEventListener(MouseEvent.CLICK, onClick); 
stage.addEventListener(MouseEvent.MOUSE_MOVE, onMouseMove);