DXGKDDI_VIDPNTOPOLOGY_GETNUMPATHSFROMSOURCE callback function

The pfnGetNumPathsFromSource function returns the number of video present paths that contain a specified video present source.

Syntax

DXGKDDI_VIDPNTOPOLOGY_GETNUMPATHSFROMSOURCE DxgkddiVidpntopologyGetnumpathsfromsource;

NTSTATUS DxgkddiVidpntopologyGetnumpathsfromsource(
  IN_CONST_D3DKMDT_HVIDPNTOPOLOGY hVidPnTopology,
  IN_CONST_D3DDDI_VIDEO_PRESENT_SOURCE_ID VidPnSourceId,
  OUT_PSIZE_T pNumPathsFromSource
)
{...}

Parameters

hVidPnTopology

[in] A handle to a VidPN topology object. The display miniport driver previously obtained this handle by calling the pfnGetTopology function of the DXGK_VIDPN_INTERFACE interface.

VidPnSourceId

[in] An integer that identifies a particular video present source.

pNumPathsFromSource

[out] A pointer to a SIZE_T-typed variable that receives the number of paths that contain the specified source.

Return Value

The pfnGetNumPathsFromSource function returns one of the following values:

Return code Description
STATUS_SUCCESS
The function succeeded.
STATUS_GRAPHICS_INVALID_VIDPN_TOPOLOGY
The handle supplied in hVidPnTopology was invalid.
STATUS_INVALID_PARAMETER
The pointer supplied in pNumPathsFromSource was in valid.

Remarks

A topology is a collection paths, each of which contains a (source, target) pair. It is possible for a particular source to appear in more than one path. For example, one source can be paired with two distinct targets in the case of a clone view.

VidPN source identifiers are assigned by the operating system. DxgkDdiStartDevice, implemented by the display miniport driver, returns the number N of video present sources supported by the display adapter. Then the operating system assigns identifiers 0, 1, 2, ... N - 1.

The D3DKMDT_HVIDPNTOPOLOGY data type is defined in D3dkmdt.h.

The D3DDDI_VIDEO_PRESENT_SOURCE_ID data type is defined in D3dukmdt.h.

Requirements

   
Windows version Available in Windows Vista and later versions of the Windows operating systems.
Target Platform Desktop
Header d3dkmddi.h (include D3dkmddi.h)
IRQL PASSIVE_LEVEL

See Also

pfnGetNumPaths