Performs a surface pick at the specified output point.
HRESULT retVal = object.PointPick(pPoint, pulInputSurfaceIndex, pInputPoint);
Type: const [DXVEC](aa753434(v=vs.85).md)
Pointer to a location on the output surface to use in the pick operation.
Type: unsigned long
Pointer to an indexed value of the input surface given by the surface pick.
Pointer to the location on the input surface that was selected by the surface pick. Because the transformed input might be inverted or rotated relative to its original orientation, pPoint and pInputPoint are not necessarily the same. The point returned is in the input surface's coordinate frame.
If an image transform has no input data or cannot map the pick event back to one of the inputs, IDXSurfacePick::PointPick returns DXT_S_HITOUTPUT, if the pick point intersects the output surface. For example, this is the case for any procedural surface, such as the gradient surface.