About the DirectDraw Hardware Interface
The DirectDraw hardware interface provides hardware-specific DirectDraw support. It can be an integral part of the display driver or a separate DLL that communicates with the display driver through a private interface defined by the driver’s creator. On Windows NT, a DirectDraw hardware interface must be a 32-bit implementation.
The DirectDraw hardware interface is implemented by the chip manufacturer, board producer, or OEM. The hardware interface should not perform any software validation. If a function is not performed by the hardware, the hardware interface should not report it as a hardware capability. The hardware interface should also never do any parameter validation, as DirectDraw does this before invoking the hardware interface.