DDHAL Customization (Windows CE 5.0)
Once you implement a basic display driver with DirectDraw support, you might want to customize it to take full advantage of the hardware you are using. Before you try to extend your new DDHAL implementation, familiarize yourself with the DirectDraw hardware abstraction layer specification that is part of the DirectDraw driver documentation.
The basic DDHAL implementation has no internal hardware acceleration. All hardware acceleration is performed through extensions you make to DDGPE. While acceleration accomplished in this way is acceptable, copying some or all of the acceleration into the DDHAL can make your driver faster.
Once you identify a function that you want to accelerate, decide whether you want to implement acceleration in your DDGPE, in your DDHAL, or in both. The DDGPE implementation and sample code allow you to perform HAL acceleration in your DDGPE-based class. The DDGPE model also allows you to move many acceleration functions, excluding acceleration of some line drawing functions, into the DDHAL and to use these DDHAL functions from within your DDGPE class.
You can add new functionality to your DDHAL implementation by modifying the device capabilities and callback structures, and by implementing new callbacks.
See Also
DirectDraw Driver Extension | DirectDraw Display Driver Creation | DDHAL Functionality Implementation
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