Multiple Monitor Systems

Windows 98 and Windows NT 5.0 support multiple display devices and monitors on a single system. The multiple monitor architecture (casually referred to as "MultiMon") enables the operating system to use the display area from two or more display devices and monitors to create a single logical desktop. For example, in a MultiMon system with two monitors, the user could display applications on either monitor, or even drag windows from one monitor to another. DirectDraw supports this architecture, allowing applications to directly access and leverage hardware acceleration on multiple display devices in a MultiMon system.

This section contains information about using DirectDraw on systems with multiple monitor support. The following topics are discussed:

·Enumerating Devices on MultiMon Systems

·Focus and Device Windows

·Setting Focus and Device Windows

·Default Device Windows

·Devices and Acceleration in MultiMon Systems

The DirectX SDK contains files in the \Samples\Misc directory that provide helper functions for working with multiple monitor systems. The Multimon.h header file makes it possible for code written around Windows 98 multiple monitor functions to compile and run successfully on a machine that uses Windows 95. Additionally, the Ddmm.cpp and Ddmm.h files provide helper functions that allow you to create or retrieve DirectDraw objects from a window handle or device string.