IDXSurfacePick Interface

IID_IDXSurfacePick

{30A5FB79-E11F-11d1-9064-00C04FD9189D}

The IDXSurfacePick interface enables picking, which is the process of identifying which of the transform inputs contributed to the output at a given point.

Remarks

The pick point often corresponds to the location where the user clicked the mouse on the output image; the pick point is handed by the container to the transform through this interface. This operation is also known as hit testing.

If multiple inputs contribute to the output at the specified point, the transform chooses only one of the inputs as the picked surface. The criteria for selecting a picked surface depend on the transform. This interface inherits from the IUnknown interface.

To use the IDXSurfacePick interface, call QueryInterface on the selected transform interface with IID_IDXSurfacePick as the interface identifier (ID).

ComPtr<IDXSurfacePick> cpPick;
m_cpDXTransform->QueryInterface(IID_IDXSurfacePick, (void **)&cpPick)))

You must override the CDXBaseNTo1::OnSurfacePick or CDXBaseNTo1::OnGetSurfacePickOrder member functions of the CDXBaseNTo1 class to use picking.
 

Methods in VTable order

IUnknown Methods

Description

QueryInterface

Returns pointers to supported interfaces.

AddRef

Increments reference count.

Release

Decrements reference count.

IDXSurfacePick Members

Description

PointPick

Performs a surface pick at the specified output point.

PointPick

FUNCTION IDXSurfacePick_PointPick ( _
  BYVAL pthis AS DWORD PTR _
, BYREF pPoint AS DXVEC _
, BYREF pulInputSurfaceIndex AS DWORD _
, BYREF pInputPoint AS DXVEC _
  ) AS LONG

  LOCAL HRESULT AS LONG
  CALL DWORD @@pthis[3] USING IDXSurfacePick_PointPick (pthis, pPoint, pulInputSurfaceIndex, pInputPoint) TO HRESULT
  FUNCTION = HRESULT
 

END FUNCTION