The GradientGlowFilter class lets you apply an enhanced glow
effect to display objects or BitmapData objects. The effect gives
you greater color control of the glow, and in turn produces a more
realistic glow effect. Additionally, the gradient glow filter allows
you to apply a gradient glow to the inner, outer, or upper edges of
an object.
The following example draws a circle on the Stage, and applies
a gradient glow filter to it. As you move the mouse further to the
right and down, the amount of blur increases in the horizontal and
vertical directions respectively. In addition, any time you click
on the Stage, the strength of the blur increases.
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);