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DRVFN structure (winddi.h)

  • Article

The DRVFN structure is used by graphics drivers to provide GDI with pointers to the graphics DDI functions defined by the driver.

Syntax

typedef struct _DRVFN {
  ULONG iFunc;
  PFN   pfn;
} DRVFN, *PDRVFN;

Members

iFunc

Is the function index that identifies a graphics DDI function implemented by the driver. The index name reflects the name of the related graphics DDI function; for example, an index value of INDEX_DrvEnablePDEV specifies the DrvEnablePDEV function. See the header file, winddi.h, for a complete list of index values.

pfn

Specifies the address of the driver-defined graphics DDI function associated with the index supplied for iFunc. This function has the following prototype:

LONG_PTR  (APIENTRY * PFN) ();

Remarks

A graphics driver must allocate an array of DRVFN structures, with an array element for each graphics DDI function implemented in the driver. The driver returns the array's address to GDI in the DRVENABLEDATA structure whose pointer is passed to the driver's DrvEnableDriver function during driver initialization.

Graphics DDI function addresses can be placed in the DRVFN array in any order.

Requirements

Requirement Value
Header winddi.h (include Winddi.h)

See also

DrvEnableDriver