Called by the base class to cause a transform to produce its output.
HRESULT retVal = object.OnExecute(pRequestID, pClipBnds, pPlacement);
Type: const GUID
Pointer to the ID passed into the IDXTransform::Execute method by the caller. This ID should be passed to the task manager if CDXBaseNTo1::OnExecute schedules any asynchronous work through the task manager. Otherwise, this parameter should be ignored.
Type: const DXBNDS
Pointer to the portion of the transform output space that should be rendered. If NULL, the entire output space is rendered. If a transform can't produce the specified region of the result, the transform should mask off the DXTMF_BOUNDS_SUPPORTED flag from the m_dwMiscFlags data member in the Active Template Library (ATL) CComObjectRootEx::FinalConstruct constructor method. Image transforms must be able to render regions of their output.
Type: const DXVEC
Pointer to the position to place the result in the output coordinate space. If the transform does not support this capability, it should mask off the DXTMF_PLACEMENT_SUPPORTED flag from the m_dwMiscFlags data member in the FinalConstruct constructor method.