User Guide

BitmapData (flash.display.BitmapData) 311
generateFilterRect (BitmapData.generateFilterRect
method)
public generateFilterRect(sourceRect:Rectangle, filter:BitmapFilter) :
Rectangle
Determines the destination rectangle that the applyFilter() method call affects, given a
BitmapData object, a source rectangle, and a filter object.
For example, a blur filter normally affects an area larger than the size of the original image. A
100 x 200 pixel image that is being filtered by a default BlurFilter instance, where
blurX =
blurY = 4
generates a destination rectangle of (-2,-2,104,204). The
generateFilterRect() method lets you find out the size of this destination rectangle in
advance so that you can size the destination image appropriately before performing a filter
operation.
Some filters clip their destination rectangle based on the source image size. For example, an
inner
DropShadow does not generate a larger result than its source image. In this API, the
BitmapData object is used as the source bounds and not the source
rect parameter.
Availability: ActionScript 1.0; Flash Player 8
Parameters
sourceRect:flash.geom.Rectangle - A rectangle defining the area of the source image to
use as input.
filter:flash.filters.BitmapFilter - A filter object that you use to calculate the
destination rectangle.
Returns
flash.geom.Rectangle - A destination rectangle computed by using an image, the
sourceRect parameter, and a filter.
Example
The following example shows how to determine the destination rectangle that the
applyfilter() method affects:
import flash.display.BitmapData;
import flash.filters.BevelFilter;
import flash.geom.Rectangle;
var myBitmapData:BitmapData = new BitmapData(100, 80, true, 0xCCCCCCCC);
var filter:BevelFilter = new BevelFilter(5, 45, 0xFFFF00, .8, 0x0000FF, .8,
20, 20, 1, 3, "outter", false);