Add vtkAppendLocationAttributes filter

This filter appends (optionally) cell centers as a cell data array and
point locations as a point data array. Added a test for the filter as
well.

Filters/General/CMakeLists.txt

 set(classes
   vtkAnnotationLink
+  vtkAppendLocationAttributes
   vtkAppendPoints
   vtkApproximatingSubdivisionFilter
   vtkAreaContourSpectrumFilter

Filters/General/Testing/Cxx/CMakeLists.txt

@@ -7,6 +7,7 @@ vtk_add_test_cxx(vtkFiltersGeneralCxxTests tests
   ArrayMatricizeArray.cxx,NO_VALID
   ArrayNormalizeMatrixVectors.cxx,NO_VALID
   CellTreeLocator.cxx,NO_VALID
+  TestAppendLocationAttributes.cxx,NO_VALID
   TestPassArrays.cxx,NO_VALID
   TestPassSelectedArrays.cxx,NO_VALID
   TestPassThrough.cxx,NO_VALID

Filters/General/Testing/Cxx/TestAppendLocationAttributes.cxx

+/*=========================================================================
+
+  Program:   Visualization Toolkit
+  Module:    TestAppendLocationAttributes.cxx
+
+  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
+  All rights reserved.
+  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.
+
+     This software is distributed WITHOUT ANY WARRANTY; without even
+     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+     PURPOSE.  See the above copyright notice for more information.
+
+=========================================================================*/
+#include <vtkAppendLocationAttributes.h>
+
+#include <vtkCellCenters.h>
+#include <vtkCellData.h>
+#include <vtkCellTypeSource.h>
+#include <vtkNew.h>
+#include <vtkPointData.h>
+#include <vtkUnstructuredGrid.h>
+
+#include <cstdlib>
+
+
+int TestAppendLocationAttributes(int, char*[])
+{
+  // Reference dataset
+  vtkNew<vtkCellTypeSource> cellTypeSource;
+  cellTypeSource->SetBlocksDimensions(10, 10, 10);
+  cellTypeSource->Update();
+  vtkUnstructuredGrid* inputUG = cellTypeSource->GetOutput();
+
+  // Create a vtkCellCenters object and use it to test the cell centers calculation in
+  // vtkAppendLocationAttributes.
+  vtkNew<vtkCellCenters> cellCenters;
+  cellCenters->SetInputConnection(cellTypeSource->GetOutputPort());
+  cellCenters->Update();
+
+  vtkPointSet* cellCentersOutput = cellCenters->GetOutput();
+
+  vtkNew<vtkAppendLocationAttributes> locationAttributes;
+  locationAttributes->SetInputConnection(cellTypeSource->GetOutputPort());
+  locationAttributes->Update();
+
+  vtkPointSet* appendLocationOutput = locationAttributes->GetOutput();
+
+  vtkIdType numCells = appendLocationOutput->GetNumberOfCells();
+  vtkIdType numPoints = appendLocationOutput->GetNumberOfPoints();
+  if (numCells != inputUG->GetNumberOfCells())
+  {
+    std::cerr << "Output number of cells is incorrect" << std::endl;
+    return EXIT_FAILURE;
+  }
+
+  if (numPoints != inputUG->GetNumberOfPoints())
+  {
+    std::cerr << "Output number of points is incorrect" << std::endl;
+    return EXIT_FAILURE;
+  }
+
+  vtkPoints* cellCenterPoints = cellCentersOutput->GetPoints();
+  vtkDataArray* cellCentersArray = appendLocationOutput->GetCellData()->GetArray("CellCenters");
+  vtkDataArray* pointLocationsArray = appendLocationOutput->GetPointData()->GetArray("PointLocations");
+
+  for (vtkIdType i = 0; i < numCells; ++i)
+  {
+    double cellCenter[3];
+    cellCenterPoints->GetPoint(i, cellCenter);
+
+    double appendLocationCenter[3];
+    cellCentersArray->GetTuple(i, appendLocationCenter);
+
+    double dist2 = vtkMath::Distance2BetweenPoints(cellCenter, appendLocationCenter);
+    if (dist2 > 1e-9)
+    {
+      std::cerr << "Cell center mismatch for cell " << i << std::endl;
+      return EXIT_FAILURE;
+    }
+  }
+
+  for (vtkIdType i = 0; i < numPoints; ++i)
+  {
+    double inputPoint[3];
+    inputUG->GetPoints()->GetPoint(i, inputPoint);
+
+    double appendLocationPoint[3];
+    pointLocationsArray->GetTuple(i, appendLocationPoint);
+
+    double dist2 = vtkMath::Distance2BetweenPoints(inputPoint, appendLocationPoint);
+    if (dist2 > 1e-9)
+    {
+      std::cerr << "Point location mismatch for point " << i << std::endl;
+      return EXIT_FAILURE;
+    }
+  }
+
+  return EXIT_SUCCESS;
+}

Filters/General/vtkAppendLocationAttributes.cxx

+/*=========================================================================
+
+  Program:   Visualization Toolkit
+  Module:    vtkAppendLocationAttributes.cxx
+
+  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
+  All rights reserved.
+  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.
+
+     This software is distributed WITHOUT ANY WARRANTY; without even
+     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+     PURPOSE.  See the above copyright notice for more information.
+
+=========================================================================*/
+#include "vtkAppendLocationAttributes.h"
+
+#include "vtkCell.h"
+#include "vtkCellArray.h"
+#include "vtkCellCenters.h"
+#include "vtkCellData.h"
+#include "vtkDataSet.h"
+#include "vtkDoubleArray.h"
+#include "vtkInformation.h"
+#include "vtkInformationVector.h"
+#include "vtkObjectFactory.h"
+#include "vtkPointData.h"
+#include "vtkPoints.h"
+#include "vtkPolyData.h"
+
+vtkStandardNewMacro(vtkAppendLocationAttributes);
+
+//----------------------------------------------------------------------------
+// Generate points
+int vtkAppendLocationAttributes::RequestData(vtkInformation* vtkNotUsed(request),
+  vtkInformationVector** inputVector, vtkInformationVector* outputVector)
+{
+  // get the input and output
+  vtkPointSet* input = vtkPointSet::GetData(inputVector[0]);
+  vtkPointSet* output = vtkPointSet::GetData(outputVector);
+
+  output->ShallowCopy(input);
+
+  vtkTypeBool abort = 0;
+
+  // Create cell centers array
+  vtkNew<vtkDoubleArray> cellCenterArray;
+  if (this->AppendCellCenters)
+  {
+    vtkIdType numCells = input->GetNumberOfCells();
+    cellCenterArray->SetName("CellCenters");
+    cellCenterArray->SetNumberOfComponents(3);
+    cellCenterArray->SetNumberOfTuples(numCells);
+
+    vtkCellCenters::ComputeCellCenters(input, cellCenterArray);
+  }
+
+  if (abort)
+  {
+    vtkWarningMacro(<< "Aborting execution");
+    return 0;
+  }
+
+  if (this->AppendPointLocations)
+  {
+    vtkPointData* outPD = output->GetPointData();
+    vtkDataArray* pointArray = output->GetPoints()->GetData();
+    vtkSmartPointer<vtkDataArray> arrayCopy;
+    arrayCopy.TakeReference(pointArray->NewInstance());
+    arrayCopy->ShallowCopy(pointArray);
+    arrayCopy->SetName("PointLocations");
+    outPD->AddArray(arrayCopy);
+  }
+
+  if (this->AppendCellCenters)
+  {
+    vtkCellData* outCD = output->GetCellData();
+    outCD->AddArray(cellCenterArray);
+  }
+
+  this->UpdateProgress(1.0);
+  return 1;
+}
+
+//----------------------------------------------------------------------------
+int vtkAppendLocationAttributes::FillInputPortInformation(int, vtkInformation* info)
+{
+  info->Set(vtkAlgorithm::INPUT_REQUIRED_DATA_TYPE(), "vtkPointSet");
+  return 1;
+}
+
+//----------------------------------------------------------------------------
+void vtkAppendLocationAttributes::PrintSelf(ostream& os, vtkIndent indent)
+{
+  this->Superclass::PrintSelf(os, indent);
+  os << indent << "AppendPointLocations: " << (this->AppendPointLocations ? "On\n" : "Off\n");
+  os << indent << "AppendCellCenters: " << (this->AppendCellCenters ? "On" : "Off") << endl;
+}

Filters/General/vtkAppendLocationAttributes.h

+/*=========================================================================
+
+  Program:   Visualization Toolkit
+  Module:    vtkAppendLocationAttributes.h
+
+  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
+  All rights reserved.
+  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.
+
+     This software is distributed WITHOUT ANY WARRANTY; without even
+     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+     PURPOSE.  See the above copyright notice for more information.
+
+=========================================================================*/
+/**
+ * @class   vtkAppendLocationAttributes
+ * @brief   add point locations to point data and/or cell centers cell data, respectively
+ *
+ * vtkAppendLocationAttributes is a filter that takes as input any dataset and
+ * optionally adds points as point data and optionally adds cell center locations as
+ * cell data in the output. The center of a cell is its parametric center, not necessarily
+ * the geometric or bounding box center. Point and cell attributes in the input can optionally
+ * be copied to the output.
+ *
+ * @note
+ * Empty cells will have their center set to (0, 0, 0).
+ *
+ * @sa
+ * vtkCellCenters
+ */
+
+#ifndef vtkAppendLocationAttributes_h
+#define vtkAppendLocationAttributes_h
+
+#include "vtkFiltersGeneralModule.h" // For export macro
+#include "vtkPointSetAlgorithm.h"
+
+class VTKFILTERSGENERAL_EXPORT vtkAppendLocationAttributes : public vtkPointSetAlgorithm
+{
+public:
+  static vtkAppendLocationAttributes* New();
+  vtkTypeMacro(vtkAppendLocationAttributes, vtkPointSetAlgorithm);
+  void PrintSelf(ostream& os, vtkIndent indent) override;
+
+  /**
+   * Enable/disable whether input point locations should be saved as a point data array.
+   * Default is `true` i.e. the points will be propagated as a point data array named
+   * "PointLocations".
+   */
+  vtkSetMacro(AppendPointLocations, bool);
+  vtkGetMacro(AppendPointLocations, bool);
+  vtkBooleanMacro(AppendPointLocations, bool);
+  //@}
+
+  //@{
+  /**
+   * Enable/disable whether input cell center locations should be saved as a cell data array.
+   * Default is `true` i.e. the cell centers will be propagated as a cell data array named
+   * "CellCenters".
+   */
+  vtkSetMacro(AppendCellCenters, bool);
+  vtkGetMacro(AppendCellCenters, bool);
+  vtkBooleanMacro(AppendCellCenters, bool);
+  //@}
+
+protected:
+  vtkAppendLocationAttributes() = default;
+  ~vtkAppendLocationAttributes() = default;
+
+  int RequestData(vtkInformation*, vtkInformationVector**, vtkInformationVector*) override;
+  int FillInputPortInformation(int port, vtkInformation* info) override;
+
+  bool AppendPointLocations = true;
+  bool AppendCellCenters = true;
+
+private:
+  vtkAppendLocationAttributes(const vtkAppendLocationAttributes&) = delete;
+  void operator=(const vtkAppendLocationAttributes&) = delete;
+};
+
+#endif