DD_WAITFORVERTICALBLANKDATA structure (ddrawint.h)

The DD_WAITFORVERTICALBLANKDATA structure contains information necessary to obtain the monitor's vertical blank information.

Syntax

typedef struct _DD_WAITFORVERTICALBLANKDATA {
  PDD_DIRECTDRAW_GLOBAL lpDD;
  DWORD                 dwFlags;
  DWORD                 bIsInVB;
  ULONG_PTR             hEvent;
  HRESULT               ddRVal;
  VOID                  *WaitForVerticalBlank;
} *PDD_WAITFORVERTICALBLANKDATA, DD_WAITFORVERTICALBLANKDATA;

Members

lpDD

Points to a DD_DIRECTDRAW_GLOBAL structure that describes the driver's device.

dwFlags

Specifies how the driver should wait for the vertical blank. This member can be one of the following values:

Flag	Meaning
DDWAITVB_BLOCKBEGIN	The driver should return when it detects the beginning of the vertical blank interval.
DDWAITVB_BLOCKBEGINEVENT	Set up an event to trigger when the vertical blank begins. This flag is not currently supported.
DDWAITVB_BLOCKEND	The driver should return when it detects the end of the vertical blank interval and display begins.
DDWAITVB_I_TESTVB	The driver should determine whether a vertical blank is currently occurring and return the status in bIsInVB.

bIsInVB

Indicates the status of the vertical blank. A value of TRUE indicates that the device is in a vertical blank; FALSE means that it is not. The driver should return the current vertical blanking status in this member when dwFlags is DDWAITVB_I_TESTVB.

hEvent

Handle for the event that should be triggered when the vertical blank begins. The event is triggered on an interrupt, so if your hardware is able to generate an interrupt on the vertical blank, you should pass this event handle to your HwVidInterrupt function so that the event is triggered when the interrupt fires. This member is currently unsupported and should be ignored by the driver.

ddRVal

Specifies the location in which the driver writes the return value of the DdWaitForVerticalBlank callback. A return code of DD_OK indicates success. For more information, see Return Values for DirectDraw.

WaitForVerticalBlank

Used by the Microsoft DirectDraw API and should not be filled in by the driver.

Requirements

Requirement	Value
Header	ddrawint.h (include Winddi.h, Ddrawi.h)

See also

DdWaitForVerticalBlank