Dynamic HTML in Action

Microsoft incorporated a number of special multimedia ActiveX controls into Microsoft Internet Explorer version 4 that are being carried forward in version 5. They are not currently directly supported by any version of Netscape Navigator. These features were designed to help Web developers create low-bandwidth multimedia that can be controlled both at Web page creation time and when the page is being displayed. Because the effects created with these controls are constructed and directly controllable through script, they allow a level of programming control that is not possible with other similar technologies, such as Macromedia Flash. In this chapter, we will examine the multimedia controls included with Internet Explorer and how they can be used to build exciting, media-rich Web pages.

The DirectAnimation multimedia controls are a set of four ActiveX controls that play different roles in presenting multimedia. They offer several advantages to content developers.

• Unlike most ActiveX controls, the DirectAnimation controls do not have to be downloaded by the user because they are included with Internet Explorer.
• The DirectAnimation controls are windowless—that is, they are not restricted to a particular rectangle in the browser, and they can interact with other elements on the page. For example, an object can be created with transparent areas through which you can see text and other objects on the page.
• The DirectAnimation controls allow integration and animation of vector graphics as well as bitmap images.

The DirectAnimation controls include the Structured Graphics control, the Sequencer control, the Path control, and the Sprite control. More about these controls can be found by going to microsoft.com/directx/dxm and choosing the DirectAnimation link. Let's begin by looking at how to use the Structured Graphics control.