IDXBaseObject Interface

IID_IDXBaseObject

{17B59B2B-9CC8-11D1-9053-00C04FD9189D}

The IDXBaseObject interface manages the generation identifier (ID) of an object.

Remarks

Every time an operation changes the state of an object, the generation ID is incremented. The following are examples of operations that change the generation IDs of objects.

• Locking a surface with a read/write pointer.

• Setting up a transform.

• Changing the properties of a transform.

• Changing the properties of a procedural surface.

 

When calling the IDXBaseObject::GetGenerationId method for a transform, the transform examines the generation IDs of all inputs. If they have changed, the transform's generation ID changes. If the ID has not changed since the last time a transform was executed or a surface was used, this indicates that the data has not changed. It is then possible to skip execution of a transform Setup or the copying of a surface.

The IDXBaseObject interface is exposed on DXSurface objects and DXTransform objects.

Methods in VTable order

IUnknown Methods

Description

QueryInterface

Returns pointers to supported interfaces.

AddRef

Increments reference count.

Release

Decrements reference count.

IDXBaseObject Members

Description

GetGenerationId

Retrieves the current generation ID for the object.

IncrementGenerationId

Manually increments the object generation ID.

GetObjectSize

Retrieves the size, in bytes, of the data object (for example, a surface or buffer).

GetGenerationId

FUNCTION IDXBaseObject_GetGenerationId ( _
  BYVAL pthis AS DWORD PTR _

, BYREF pID AS DWORD _

  ) AS LONG

  LOCAL HRESULT AS LONG
  CALL DWORD @@pthis[3] USING IDXBaseObject_GetGenerationId (pthis, pID) TO HRESULT
  FUNCTION = HRESULT

END FUNCTION
 

IncrementGenerationId

FUNCTION IDXBaseObject_IncrementGenerationId ( _
  BYVAL pthis AS DWORD PTR _

, BYVAL bRefresh AS LONG _

  ) AS LONG

  LOCAL HRESULT AS LONG
  CALL DWORD @@pthis[4] USING IDXBaseObject_IncrementGenerationId (pthis, bRefresh) TO HRESULT
  FUNCTION = HRESULT

END FUNCTION
 

GetObjectSize

FUNCTION IDXBaseObject_GetObjectSize ( _
  BYVAL pthis AS DWORD PTR _

, BYREF pcbSize AS DWORD _

  ) AS LONG

  LOCAL HRESULT AS LONG
  CALL DWORD @@pthis[5] USING IDXBaseObject_GetObjectSize (pthis, pcbSize) TO HRESULT
  FUNCTION = HRESULT

END FUNCTION