Method UpdateWidgetFromTensor

Interaction/Widgets/vtkTensorRepresentation.cxx:1346–1387

------------------------------------------------------------------------------ Update the tensor ellipsoid, and associated widget/representation from the current tensor specification. We'll use the current position.

// Update the tensor ellipsoid, and associated widget/representation from the
// current tensor specification. We'll use the current position.
void vtkTensorRepresentation::UpdateWidgetFromTensor()
{
  // We are using the current tensor position
  double* pts = static_cast<vtkDoubleArray*>(this->Points->GetData())->GetPointer(0);
  double* center = pts + 3 * 14;

  // We'll reset the points to be axis aligned, (-1,1,-1,1,-1,1) box.
  // The feed the eigenvectors into a transformation matrix and
  // transform the eight corner points.
  this->Points->SetPoint(0, -1, -1, -1);
  this->Points->SetPoint(1, 1, -1, -1);
  this->Points->SetPoint(2, 1, 1, -1);
  this->Points->SetPoint(3, -1, 1, -1);
  this->Points->SetPoint(4, -1, -1, 1);
  this->Points->SetPoint(5, 1, -1, 1);
  this->Points->SetPoint(6, 1, 1, 1);
  this->Points->SetPoint(7, -1, 1, 1);

  this->EllipsoidTransform->Identity();
  this->EllipsoidTransform->Translate(center[0], center[1], center[2]);
  this->EllipsoidTransform->Scale(this->Eigenvalues);

  for (auto j = 0; j < 3; ++j)
  {
    for (auto i = 0; i < 3; ++i)
    {
      this->EllipsoidMatrix->Element[i][j] = this->Eigenvectors[i][j];
    }
  }
  this->EllipsoidTransform->Concatenate(this->EllipsoidMatrix);
  this->EllipsoidTransform->Translate(-center[0], -center[1], -center[2]);

  // Transform the 8 corner points
  this->TmpPoints->Reset();
  this->EllipsoidTransform->TransformPoints(this->Points, this->TmpPoints);
  for (auto i = 0; i < 8; i++)
  {
    this->Points->SetPoint(i, this->TmpPoints->GetPoint(i));
  }

  this->PositionHandles();
}

//------------------------------------------------------------------------------
int vtkTensorRepresentation::ComputeInteractionState(int X, int Y, int modify)