Use vtkObjectBase’s Function Delete To Free Object

Use vtkObjectBase’s Function Delete To Free Object

Explore what will happen when we use delete on vtkSmartPointer object.

// An highlighted block
vtkSmartPointer<vtkActor> leftActor =
            vtkSmartPointer<vtkActor>::New();
    leftActor->SetMapper( mapper );
//...
    void *ptr = leftActor.Get();
    leftActor->GetProperty()->SetColor( 1, 0, 0 );
    rightActor->GetProperty()->SetColor( 0, 1, 0 );
    leftActor->Delete();
    cout << "leftActor: " << (void *)leftActor.Get() << endl;
    cout << "leftActor reference count: " << leftActor->GetReferenceCount() << endl;
    if( ptr && leftActor->GetReferenceCount() > 0 )
    {
    
    
        leftRenderer->AddActor( leftActor );
    }
    if( rightActor )
    {
    
    
        rightRenderer->AddActor( rightActor );
    }

output:

leftActor: 0x7ff976417b00
leftActor reference count: -1073741824
17:07:04: The program has unexpectedly finished.
17:07:04: The process was ended forcefully.

Remove vtkSmartPointer In the code snippet:

 vtkActor *leftActor = vtkActor::New();
    //...
    leftActor->GetProperty()->SetColor( 1, 0, 0 );
    rightActor->GetProperty()->SetColor( 0, 1, 0 );
    while( leftActor->GetReferenceCount() > 0 )
    {
    
    
        leftActor->Delete();
    }
    leftActor = nullptr;
    cout << "leftActor: " << (void *)leftActor << endl;
    if( nullptr != leftActor && leftActor->GetReferenceCount() > 0 )
    {
    
    
        cout << "leftActor reference count: " << leftActor->GetReferenceCount() << endl;
        leftRenderer->AddActor( leftActor );
    }

output:

leftActor: 0x0