DirectX

DirectX

Disclaimer

This software and accompanying documentation are provided "as is" and without warranties as to performance or merchantability or any other warranties whether expressed or implied. Because of the various hardware and software environments into which this application may be used, no warranty of fitness for a particular purpose is offered. The user must assume the entire risk of using this software. In no case shall any of the contributors to this project be liable for any incidental, special or consequential damages or loss, including, without limitation, lost profits or the inability to use equipment or access data. This is true even if we are advised of the possibility of such damages. We also don't have any obligation of' fix eventual bugs or to add new features.

DirectX is a set of low-level application programming interfaces (APIs) for creating games and other high-performance multimedia applications. It includes support for high-performance 2-D and 3-D graphics, sound, and input.

Microsoft DirectX 9.0 is made up of the following components.

DirectX Graphics combines the Microsoft DirectDraw and Microsoft Direct3D components of previous DirectX versions into a single application programming interface (API) that you can use for all graphics programming. The component includes the Direct3D extensions (D3DX) utility library, which simplifies many graphics programming tasks.
Microsoft DirectInput provides support for a variety of input devices, including full support for force-feedback technology.
Microsoft DirectSound can be used in the development of high-performance audio applications that play and capture waveform audio.

Handling Multiple Users

Windows XP allows multiple users to be logged on to one computer at the same time. If your application cannot run multiple instances simultaneously, you should check to see if another instance is running before starting a new instance. You cannot use FindWindow across desktop sessions. FindWindow only works within the current session.

To see if an instance of the application is already running, use a global mutex. If an instance is running, you can use FindWindow to see if the instance is in the current session and restore the window. Otherwise, notify users that they cannot use the application.

Fast User Switching

Fast User Switching allows users to switch between sessions. Users do not have to terminate their applications or log out for another user to start a session. Instead, they use Fast User Switching, which enables another user to log on and work on the computer.

DirectX applications should be prepared to handle this situation. Windows will send out a WM_WTSSESSION_CHANGE message when a user session changes. In order to receive this message, your application must register its window handle by calling WTSRegisterSessionNotification.