ActionScript™ 3.0 Bible

Chapter 33. Drawing Bitmap Graphics Programmatically

Introduction

In this chapter

• Understanding bitmap data

• Copying bitmap data by pixels, color channels, and other methods

• Applying fills

• Using color transforms

• Working with bitmap effects

• Using noise

• Applying filters

Flash Player 9 contains an API for working with bitmaps. The flash.display.BitmapData class is the main focus with regard to bitmaps, and it has methods for getting and setting pixels, applying pixel dissolves, setting threshold settings, applying filters, and more. In this chapter, you look at how to work with the new API to achieve a variety of effects.

Creating a BitmapData Object

There are several ways to construct or retrieve a new BitmapData object in ActionScript:

• You can use the constructor to make a new, blank BitmapData object with specific dimensions and background.

• If you have an embedded asset (embedded with the [Embed] tag in Flex Builder or with a library symbol in Flash authoring) you can construct a new Bitmap or BitmapAsset instance using the class name you assigned to the embedded asset, and retrieve the bitmapData property from it.

In the following sections, you look at how to use those ways to construct or retrieve BitmapData objects. No matter how you want to work with bitmaps via ActionScript, you'll need to use at least one of those ways to create and retrieve a reference to the object.

Using the constructor method

You can construct a new BitmapData object using the constructor method as part of a new statement. ...