EngQueryDeviceAttribute function (winddi.h)

The EngQueryDeviceAttribute function allows the driver to query the system about particular attributes of the device.

Syntax

ENGAPI BOOL EngQueryDeviceAttribute(
  [in]  HDEV                 hdev,
  [in]  ENG_DEVICE_ATTRIBUTE devAttr,
  [in]  VOID                 *pvIn,
  [in]  ULONG                ulInSize,
  [out] VOID                 *pvOut,
  [out] ULONG                ulOutSize
);

Parameters

[in] hdev

Handle to the device. This parameter is the GDI handle received by the driver's DrvCompletePDEV function.

[in] devAttr

Specifies the attribute for which GDI should return information. This parameter must be QDA_ACCELERATION_LEVEL, which queries the driver accelerations that GDI currently allows.

[in] pvIn

Reserved for system use. This parameter is currently ignored by GDI.

[in] ulInSize

Reserved for system use. This parameter is currently ignored by GDI.

[out] pvOut

Pointer to a buffer of ulOutSize bytes in which GDI writes information about the attribute being queried. When devAttr is QDA_ACCELERATION_LEVEL, GDI writes in the buffer a DWORD value from 0 through 5 that indicates the current acceleration level. See Display Driver Testing Tools for a description of the acceleration levels.

[out] ulOutSize

Specifies the size, in bytes, of the buffer to which pvOut points.

Return value

EngQueryDeviceAttribute returns TRUE upon success; otherwise, it returns FALSE.

Remarks

The video card's acceleration level can be dynamically set through the Display program in Control Panel. EngQueryDeviceAttribute allows the driver to determine the acceleration level currently set.

Requirements

See also

DrvNotify