Method BuildBackdrop

Interaction/Widgets/vtkCompassRepresentation.cxx:126–170

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//------------------------------------------------------------------------------
void vtkCompassRepresentation::BuildBackdrop()
{
  vtkPolyData* backdropPolyData = vtkPolyData::New();
  vtkPoints* pts = vtkPoints::New();
  pts->SetNumberOfPoints(4);
  pts->SetPoint(0, 0, 0, 0);
  pts->SetPoint(1, 1, 0, 0);
  pts->SetPoint(2, 1, 1, 0);
  pts->SetPoint(3, 0, 1, 0);
  backdropPolyData->SetPoints(pts);
  pts->Delete();

  vtkCellArray* backdrop = vtkCellArray::New();
  backdrop->InsertNextCell(4);
  backdrop->InsertCellPoint(0);
  backdrop->InsertCellPoint(1);
  backdrop->InsertCellPoint(2);
  backdrop->InsertCellPoint(3);
  backdropPolyData->SetPolys(backdrop);
  backdrop->Delete();

  vtkSmartPointer<vtkUnsignedCharArray> colors = vtkSmartPointer<vtkUnsignedCharArray>::New();
  colors->SetNumberOfComponents(4);
  colors->SetNumberOfTuples(4);
  unsigned char color[4];
  color[0] = 0;
  color[1] = 0;
  color[2] = 0;
  color[3] = 0;
  colors->SetTypedTuple(0, color);
  colors->SetTypedTuple(3, color);
  color[3] = 80;
  colors->SetTypedTuple(1, color);
  colors->SetTypedTuple(2, color);
  backdropPolyData->GetPointData()->SetScalars(colors);

  this->BackdropMapper = vtkPolyDataMapper2D::New();
  this->BackdropMapper->SetInputData(backdropPolyData);
  this->BackdropMapper->ScalarVisibilityOn();
  backdropPolyData->Delete();

  this->Backdrop = vtkActor2D::New();
  this->Backdrop->SetMapper(this->BackdropMapper);
  this->Backdrop->GetProperty()->SetColor(0, 0, 0);
}

//------------------------------------------------------------------------------
void vtkCompassRepresentation::BuildRing()