The GlowFilter class lets you apply a glow effect to display objects. You have several options for the style of the glow, including inner or outer glow and knockout mode. The glow filter is similar to the drop shadow filter with the distance and angle properties of the drop shadow filter set to 0. You can apply the filter to any display object(that is, objects that inherit from the DisplayObject class), such as MovieClip, SimpleButton, TextField, and Video objects, as well as to BitmapData objects.

The use of filters depends on the object to which you apply the filter:

  • To apply filters to display objects, use the filters property(inherited from DisplayObject). Setting the filters property of an object does not modify the object, and you can remove the filter by clearing the filters property.
  • To apply filters to BitmapData objects, use the BitmapData.applyFilter() method. Calling applyFilter() on a BitmapData object takes the source BitmapData object and the filter object and generates a filtered image as a result.

If you apply a filter to a display object, the cacheAsBitmap property of the display object is set to true. If you clear all filters, the original value of cacheAsBitmap is restored.

This filter supports Stage scaling. However, it does not support general scaling, rotation, and skewing. If the object itself is scaled(if scaleX and scaleY are set to a value other than 1.0), the filter is not scaled. It is scaled only when the user zooms in on the Stage.

A filter is not applied if the resulting image exceeds the maximum dimensions. In AIR 1.5 and Flash Player 10, the maximum is 8,191 pixels in width or height, and the total number of pixels cannot exceed 16,777,215 pixels.(So, if an image is 8,191 pixels wide, it can only be 2,048 pixels high.) In Flash Player 9 and earlier and AIR 1.1 and earlier, the limitation is 2,880 pixels in height and 2,880 pixels in width. For example, if you zoom in on a large movie clip with a filter applied, the filter is turned off if the resulting image exceeds the maximum dimensions.

Constructor

new (color:Int = 0xFF0000, alpha:Float = 1, blurX:Float = 6, blurY:Float = 6, strength:Float = 2, quality:Int = 1, inner:Bool = false, knockout:Bool = false)

Initializes a new GlowFilter instance with the specified parameters.

Parameters:

color

The color of the glow, in the hexadecimal format 0xRRGGBB. The default value is 0xFF0000.

alpha

The alpha transparency value for the color. Valid values are 0 to 1. For example, .25 sets a transparency value of 25%.

blurX

The amount of horizontal blur. Valid values are 0 to 255 (floating point). Values that are a power of 2(such as 2, 4, 8, 16 and 32) are optimized to render more quickly than other values.

blurY

The amount of vertical blur. Valid values are 0 to 255 (floating point). Values that are a power of 2(such as 2, 4, 8, 16 and 32) are optimized to render more quickly than other values.

strength

The strength of the imprint or spread. The higher the value, the more color is imprinted and the stronger the contrast between the glow and the background. Valid values are 0 to 255.

quality

The number of times to apply the filter. Use the BitmapFilterQuality constants:

  • BitmapFilterQuality.LOW
  • BitmapFilterQuality.MEDIUM
  • BitmapFilterQuality.HIGH

For more information, see the description of the quality property.

inner

Specifies whether the glow is an inner glow. The value true specifies an inner glow. The value false specifies an outer glow(a glow around the outer edges of the object).

knockout

Specifies whether the object has a knockout effect. The value true makes the object's fill transparent and reveals the background color of the document.

Variables

alpha:Float

The alpha transparency value for the color. Valid values are 0 to 1. For example, .25 sets a transparency value of 25%. The default value is 1.

blurX:Float

The amount of horizontal blur. Valid values are 0 to 255(floating point). The default value is 6. Values that are a power of 2(such as 2, 4, 8, 16, and 32) are optimized to render more quickly than other values.

blurY:Float

The amount of vertical blur. Valid values are 0 to 255(floating point). The default value is 6. Values that are a power of 2(such as 2, 4, 8, 16, and 32) are optimized to render more quickly than other values.

color:Int

The color of the glow. Valid values are in the hexadecimal format 0xRRGGBB. The default value is 0xFF0000.

inner:Bool

Specifies whether the glow is an inner glow. The value true indicates an inner glow. The default is false, an outer glow (a glow around the outer edges of the object).

knockout:Bool

Specifies whether the object has a knockout effect. A value of true makes the object's fill transparent and reveals the background color of the document. The default value is false (no knockout effect).

quality:Int

The number of times to apply the filter. The default value is BitmapFilterQuality.LOW, which is equivalent to applying the filter once. The value BitmapFilterQuality.MEDIUM applies the filter twice; the value BitmapFilterQuality.HIGH applies it three times. Filters with lower values are rendered more quickly.

For most applications, a quality value of low, medium, or high is sufficient. Although you can use additional numeric values up to 15 to achieve different effects, higher values are rendered more slowly. Instead of increasing the value of quality, you can often get a similar effect, and with faster rendering, by simply increasing the values of the blurX and blurY properties.

strength:Float

The strength of the imprint or spread. The higher the value, the more color is imprinted and the stronger the contrast between the glow and the background. Valid values are 0 to 255. The default is 2.

Methods

Inherited Variables

Inherited Methods