// SPDX-FileCopyrightText: Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
// SPDX-License-Identifier: BSD-3-Clause
/**
 * @class   vtkContourGrid
 * @brief   generate isosurfaces/isolines from scalar values (specialized for unstructured grids)
 *
 * vtkContourGrid is a filter that takes as input datasets of type
 * vtkUnstructuredGrid and generates on output isosurfaces and/or
 * isolines. The exact form of the output depends upon the dimensionality of
 * the input data.  Data consisting of 3D cells will generate isosurfaces,
 * data consisting of 2D cells will generate isolines, and data with 1D or 0D
 * cells will generate isopoints. Combinations of output type are possible if
 * the input dimension is mixed.
 *
 * To use this filter you must specify one or more contour values.
 * You can either use the method SetValue() to specify each contour
 * value, or use GenerateValues() to generate a series of evenly
 * spaced contours. It is also possible to accelerate the operation of
 * this filter (at the cost of extra memory) by using a
 * vtkScalarTree. A scalar tree is used to quickly locate cells that
 * contain a contour surface. This is especially effective if multiple
 * contours are being extracted. If you want to use a scalar tree,
 * invoke the method UseScalarTreeOn().
 *
 * @warning
 * If the input vtkUnstructuredGrid contains 3D linear cells, the class
 * vtkContour3DLinearGrid is much faster and may be preferred in certain
 * applications.
 *
 * @warning
 * For unstructured data or structured grids, normals and gradients
 * are not computed. Use vtkPolyDataNormals to compute the surface
 * normals of the resulting isosurface.
 *
 * @sa
 * vtkContour3DLinearGrid vtkContourFilter vtkMarchingContourFilter
 * vtkFlyingEdges3D vtkMarchingCubes vtkSliceCubes vtkDividingCubes
 * vtkMarchingSquares vtkImageMarchingCubes
 */

#ifndef vtkContourGrid_h
#define vtkContourGrid_h

#include "vtkFiltersCoreModule.h" // For export macro
#include "vtkPolyDataAlgorithm.h"

#include "vtkContourValues.h" // Needed for inline methods

VTK_ABI_NAMESPACE_BEGIN
class vtkEdgeTable;
class vtkScalarTree;
class vtkIncrementalPointLocator;

class VTKFILTERSCORE_EXPORT vtkContourGrid : public vtkPolyDataAlgorithm
{
public:
  vtkTypeMacro(vtkContourGrid, vtkPolyDataAlgorithm);
  void PrintSelf(ostream& os, vtkIndent indent) override;

  /**
   * Construct object with initial range (0,1) and single contour value
   * of 0.0.
   */
  static vtkContourGrid* New();

  ///@{
  /**
   * Methods to set / get contour values.
   */
  void SetValue(int i, double value);
  double GetValue(int i);
  double* GetValues();
  void GetValues(double* contourValues);
  void SetNumberOfContours(int number);
  vtkIdType GetNumberOfContours();
  void GenerateValues(int numContours, double range[2]);
  void GenerateValues(int numContours, double rangeStart, double rangeEnd);
  ///@}

  /**
   * Modified GetMTime Because we delegate to vtkContourValues
   */
  vtkMTimeType GetMTime() override;

  ///@{
  /**
   * Set/Get the computation of normals. Normal computation is fairly
   * expensive in both time and storage. If the output data will be
   * processed by filters that modify topology or geometry, it may be
   * wise to turn Normals and Gradients off.
   */
  vtkSetMacro(ComputeNormals, vtkTypeBool);
  vtkGetMacro(ComputeNormals, vtkTypeBool);
  vtkBooleanMacro(ComputeNormals, vtkTypeBool);
  ///@}

  ///@{
  /**
   * Set/Get the computation of scalars.
   */
  vtkSetMacro(ComputeScalars, vtkTypeBool);
  vtkGetMacro(ComputeScalars, vtkTypeBool);
  vtkBooleanMacro(ComputeScalars, vtkTypeBool);
  ///@}

  ///@{
  /**
   * Enable the use of a scalar tree to accelerate contour extraction.
   */
  vtkSetMacro(UseScalarTree, vtkTypeBool);
  vtkGetMacro(UseScalarTree, vtkTypeBool);
  vtkBooleanMacro(UseScalarTree, vtkTypeBool);
  ///@}

  ///@{
  /**
   * Specify the instance of vtkScalarTree to use. If not specified
   * and UseScalarTree is enabled, then a vtkSimpleScalarTree will be used.
   */
  void SetScalarTree(vtkScalarTree* sTree);
  vtkGetObjectMacro(ScalarTree, vtkScalarTree);
  ///@}

  ///@{
  /**
   * Set / get a spatial locator for merging points. By default,
   * an instance of vtkMergePoints is used.
   */
  void SetLocator(vtkIncrementalPointLocator* locator);
  vtkGetObjectMacro(Locator, vtkIncrementalPointLocator);
  ///@}

  ///@{
  /**
   * If this is enabled (by default), the output will be triangles otherwise,
   * the output may be represented by one or more polygons. WARNING: if the
   * resulting isocontour is not planar, and GenerateTriangles is false, the
   * output may consist of some 3D polygons (i.e., which may be non-planar) -
   * which might be nice to look at but hard to compute with downstream.
   */
  vtkSetMacro(GenerateTriangles, vtkTypeBool);
  vtkGetMacro(GenerateTriangles, vtkTypeBool);
  vtkBooleanMacro(GenerateTriangles, vtkTypeBool);
  ///@}

  /**
   * Create default locator. Used to create one when none is
   * specified. The locator is used to merge coincident points.
   */
  void CreateDefaultLocator();

  ///@{
  /**
   * Set/get the desired precision for the output types. See the documentation
   * for the vtkAlgorithm::DesiredOutputPrecision enum for an explanation of
   * the available precision settings.
   */
  void SetOutputPointsPrecision(int precision);
  int GetOutputPointsPrecision() const;
  ///@}

protected:
  vtkContourGrid();
  ~vtkContourGrid() override;

  int RequestData(vtkInformation*, vtkInformationVector**, vtkInformationVector*) override;
  int FillInputPortInformation(int port, vtkInformation* info) override;

  vtkContourValues* ContourValues;
  vtkTypeBool ComputeNormals;
  vtkTypeBool ComputeScalars;
  vtkTypeBool GenerateTriangles;

  vtkIncrementalPointLocator* Locator;

  vtkTypeBool UseScalarTree;
  vtkScalarTree* ScalarTree;

  int OutputPointsPrecision;
  vtkEdgeTable* EdgeTable;

private:
  vtkContourGrid(const vtkContourGrid&) = delete;
  void operator=(const vtkContourGrid&) = delete;
};

/**
 * Set a particular contour value at contour number i. The index i ranges
 * between 0<=i<NumberOfContours.
 */
inline void vtkContourGrid::SetValue(int i, double value)
{
  this->ContourValues->SetValue(i, value);
}

/**
 * Get the ith contour value.
 */
inline double vtkContourGrid::GetValue(int i)
{
  return this->ContourValues->GetValue(i);
}

/**
 * Get a pointer to an array of contour values. There will be
 * GetNumberOfContours() values in the list.
 */
inline double* vtkContourGrid::GetValues()
{
  return this->ContourValues->GetValues();
}

/**
 * Fill a supplied list with contour values. There will be
 * GetNumberOfContours() values in the list. Make sure you allocate
 * enough memory to hold the list.
 */
inline void vtkContourGrid::GetValues(double* contourValues)
{
  this->ContourValues->GetValues(contourValues);
}

/**
 * Set the number of contours to place into the list. You only really
 * need to use this method to reduce list size. The method SetValue()
 * will automatically increase list size as needed.
 */
inline void vtkContourGrid::SetNumberOfContours(int number)
{
  this->ContourValues->SetNumberOfContours(number);
}

/**
 * Get the number of contours in the list of contour values.
 */
inline vtkIdType vtkContourGrid::GetNumberOfContours()
{
  return this->ContourValues->GetNumberOfContours();
}

/**
 * Generate numContours equally spaced contour values between specified
 * range. Contour values will include min/max range values.
 */
inline void vtkContourGrid::GenerateValues(int numContours, double range[2])
{
  this->ContourValues->GenerateValues(numContours, range);
}

/**
 * Generate numContours equally spaced contour values between specified
 * range. Contour values will include min/max range values.
 */
inline void vtkContourGrid::GenerateValues(int numContours, double rangeStart, double rangeEnd)
{
  this->ContourValues->GenerateValues(numContours, rangeStart, rangeEnd);
}

VTK_ABI_NAMESPACE_END
#endif