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PDD_VPORTCB_GETLINE callback function (ddrawint.h)

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The DdVideoPortGetLine callback function returns the current line number of the hardware video port.

Syntax

PDD_VPORTCB_GETLINE PddVportcbGetline;

DWORD PddVportcbGetline(
  PDD_GETVPORTLINEDATA unnamedParam1
)
{...}

Parameters

unnamedParam1

Points to a DD_GETVPORTLINEDATA structure that contains the information required for the driver to determine and return the current line number for the specified hardware video port.

Return value

DdVideoPortGetLine returns one of the following callback codes:

Remarks

Drivers that set the DDVPCAPS_READBACKLINE flag in the dwCaps member of the DDVIDEOPORTCAPS structure must implement DdVideoPortGetLine.

The driver should write the number of the current video line in the dwLine member of the DD_GETVPORTLINEDATA structure at lpGetLine. The returned line number must be zero-based; that is, the first line of video is line 0, the second line of video is line 1, etc.

If the device is in a vertical blank, the driver should set DDERR_VERTICALBLANKINPROGRESS in the ddRVal member of DD_GETVPORTLINEDATA. If the query cannot be performed because the hardware video port is disabled, the driver should set DDERR_VIDEONOTACTIVE in ddRVal. In both of these failed cases, the driver should return DDHAL_DRIVER_HANDLED.

Requirements

Requirement Value
Target Platform Desktop
Header ddrawint.h (include Winddi.h)

See also

DDVIDEOPORTCAPS

DD_GETVPORTLINEDATA