vtkCellGridToUnstructuredGrid.h

Go to the documentation of this file.

// SPDX-FileCopyrightText: Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
// SPDX-License-Identifier: BSD-3-Clause
 
#ifndef vtkCellGridToUnstructuredGrid_h
#define vtkCellGridToUnstructuredGrid_h
 
#include "vtkCellGrid.h"              // For subclass
#include "vtkCellType.h"              // For initializer
#include "vtkFiltersCellGridModule.h" // For export macro
#include "vtkNew.h"                   // For ivar
#include "vtkStringToken.h"           // For ivars
#include "vtkUnstructuredGridAlgorithm.h"
 
#include <atomic>        // For atomic
#include <unordered_map> // For unordered_map
#include <vector>        // For vector
 
VTK_ABI_NAMESPACE_BEGIN
 
class vtkDoubleArray;
class vtkIdTypeArray;
 
class VTKFILTERSCELLGRID_EXPORT vtkCellGridToUnstructuredGrid : public vtkUnstructuredGridAlgorithm
{
public:
  class Query : public vtkCellGridQuery
  {
  public:
    static Query* New();
    vtkTypeMacro(vtkCellGridToUnstructuredGrid::Query, vtkCellGridQuery);
    void PrintSelf(ostream& os, vtkIndent indent) override;

    struct OutputAllocation
    {
      int CellType{ VTK_EMPTY_CELL };
      vtkIdType NumberOfSamples{ 0 };
      vtkIdType NumberOfCells{ 0 };
      vtkIdType NumberOfConnectivityIds{ 0 };
      vtkIdType SampleOffset{ 0 };
      vtkIdType CellOffset{ 0 };
      vtkIdType ConnOffset{ 0 };
    };

    using OutputAllocations = std::unordered_map<vtkStringToken, OutputAllocation>;

    enum PassType : int
    {
      CountOutputs = 0, 
      GenerateSamples =
        1, 
      GenerateConnectivity =
        2, 
      GeneratePointData = 3 
    };
 
    bool Initialize() override;
    void StartPass() override;
    bool Finalize() override;

    vtkSetClampMacro(SubdivisionLevel, int, 0, VTK_INT_MAX);
    vtkGetMacro(SubdivisionLevel, int);

    vtkSetClampMacro(PointMergeTolerance, double, 0., VTK_DOUBLE_MAX);
    vtkGetMacro(PointMergeTolerance, double);

    bool IsAborted() { return this->Algorithm && this->Algorithm->CheckAbort(); }

    vtkIdType GetSubdivisionCount() const
    {
      constexpr int maxShift = 8 * static_cast<int>(sizeof(vtkIdType)) - 2;
      unsigned shift = static_cast<unsigned>(
        this->SubdivisionLevel > maxShift ? maxShift : this->SubdivisionLevel);
      return static_cast<vtkIdType>(1) << shift;
    }

    bool IsAnotherPassRequired() override { return this->Pass < PassType::GeneratePointData; }

    vtkUnstructuredGrid* GetOutput() const { return this->Output; }
    vtkCellGrid* GetInput() const { return this->Input; }

    OutputAllocations& GetOutputAllocations() { return this->OutputOffsets; }
    const OutputAllocations& GetOutputAllocations() const { return this->OutputOffsets; }

    vtkDataArray* GetOutputArray(vtkCellAttribute* inputAttribute);

    vtkDoubleArray* GetSampleCoordinates() { return this->SampleCoordinates.GetPointer(); }

    vtkIdTypeArray* GetSampleToPoint() { return this->SampleToPoint.GetPointer(); }

    using ConnectivityCountType = std::vector<std::atomic<int>>;

    using ConnectivityWeightType = std::vector<float>;
    ConnectivityWeightType& GetConnectivityWeights() { return this->ConnectivityWeights; }
 
  protected:
    friend class vtkCellGridToUnstructuredGrid;
    Query() = default;
    ~Query() override = default;
 
    vtkCellGrid* Input{ nullptr };
    vtkUnstructuredGrid* Output{ nullptr };

    int SubdivisionLevel{ 0 };
    double PointMergeTolerance{ 1e-12 };
    vtkCellGridToUnstructuredGrid* Algorithm{ nullptr };

    OutputAllocations OutputOffsets;
    // Map input to output attributes:
    std::unordered_map<vtkCellAttribute*, vtkDataArray*> AttributeMap;
    vtkNew<vtkDoubleArray> SampleCoordinates;
    vtkNew<vtkIdTypeArray> SampleToPoint;
    ConnectivityCountType ConnectivityCount;
    ConnectivityWeightType ConnectivityWeights;
    vtkIdType TotalCells{ 0 };
    vtkIdType TotalConnectivityIds{ 0 };
    vtkNew<vtkIdTypeArray> CellArrayOffsets;
    vtkNew<vtkIdTypeArray> CellArrayConnectivity;

    void MergeSamplesIntoPoints();
 
  private:
    Query(const Query&) = delete;
    void operator=(const Query&) = delete;
  };
 
  static vtkCellGridToUnstructuredGrid* New();
  vtkTypeMacro(vtkCellGridToUnstructuredGrid, vtkUnstructuredGridAlgorithm);
  void PrintSelf(ostream& os, vtkIndent indent) override;

  virtual void SetSubdivisionLevel(int level);
  virtual int GetSubdivisionLevel() const;

  virtual void SetPointMergeTolerance(double tolerance);
  virtual double GetPointMergeTolerance() const;
 
protected:
  vtkCellGridToUnstructuredGrid() = default;
  ~vtkCellGridToUnstructuredGrid() override = default;
 
  int FillInputPortInformation(int port, vtkInformation* info) override;
  int RequestData(
    vtkInformation* request, vtkInformationVector** inInfo, vtkInformationVector* ouInfo) override;
 
  vtkNew<Query> Request;
 
private:
  vtkCellGridToUnstructuredGrid(const vtkCellGridToUnstructuredGrid&) = delete;
  void operator=(const vtkCellGridToUnstructuredGrid&) = delete;
};
 
VTK_ABI_NAMESPACE_END
#endif // vtkCellGridToUnstructuredGrid_h