IDirectDraw7::GetScanLine method (ddraw.h)

Retrieves the scan line that is currently being drawn on the monitor.

Syntax

HRESULT GetScanLine(
  [out] LPDWORD unnamedParam1
);

Parameters

[out] unnamedParam1

A pointer to a variable that receives the scan line that the display is currently drawing.

Return value

If the method succeeds, the return value is DD_OK.

If it fails, the method can return one of the following error values:

  • DDERR_INVALIDOBJECT
  • DDERR_INVALIDPARAMS
  • DDERR_UNSUPPORTED
  • DDERR_VERTICALBLANKINPROGRESS

Remarks

Scan lines are reported as zero-based integers. The returned scan line value is in the range from 0 through n, where 0 is the first visible scan line on the screen and n is the last visible scan line, plus any scan lines that occur during the vertical blank period. So, in a case where an application is running at a resolution of 640×480 and there are 12 scan lines during vblank, the values returned by this method range from 0 through 491.

Requirements

Requirement Value
Target Platform Windows
Header ddraw.h
Library Ddraw.lib
DLL Ddraw.dll

See also

IDirectDraw7