/*=========================================================================

  Program:   Visualization Toolkit
  Module:    vtkClipVolume.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   vtkClipVolume
 * @brief   clip volume data with user-specified implicit function or input scalar data
 *
 * vtkClipVolume is a filter that clips volume data (i.e., vtkImageData)
 * using either: any subclass of vtkImplicitFunction or the input scalar
 * data. The clipping operation cuts through the cells of the
 * dataset--converting 3D image data into a 3D unstructured grid--returning
 * everything inside of the specified implicit function (or greater than the
 * scalar value). During the clipping the filter will produce pieces of a
 * cell. (Compare this with vtkExtractGeometry or vtkGeometryFilter, which
 * produces entire, uncut cells.) The output of this filter is a 3D
 * unstructured grid (e.g., tetrahedra or other 3D cell types).
 *
 * To use this filter, you must decide if you will be clipping with an
 * implicit function, or whether you will be using the input scalar data.  If
 * you want to clip with an implicit function, you must first define and then
 * set the implicit function with the SetClipFunction() method. Otherwise,
 * you must make sure input scalar data is available. You can also specify a
 * scalar value, which is used to decide what is inside and outside of the
 * implicit function. You can also reverse the sense of what inside/outside
 * is by setting the InsideOut instance variable. (The cutting algorithm
 * proceeds by computing an implicit function value or using the input scalar
 * data for each point in the dataset. This is compared to the scalar value
 * to determine inside/outside.)
 *
 * This filter can be configured to compute a second output. The
 * second output is the portion of the volume that is clipped away. Set the
 * GenerateClippedData boolean on if you wish to access this output data.
 *
 * The filter will produce an unstructured grid of entirely tetrahedra or a
 * mixed grid of tetrahedra and other 3D cell types (e.g., wedges). Control
 * this behavior by setting the Mixed3DCellGeneration. By default the
 * Mixed3DCellGeneration is on and a combination of cell types will be
 * produced. Note that producing mixed cell types is a faster than producing
 * only tetrahedra.
 *
 * @warning
 * This filter is designed to function with 3D structured points. Clipping
 * 2D images should be done by converting the image to polygonal data
 * and using vtkClipPolyData,
 *
 * @sa
 * vtkImplicitFunction vtkClipPolyData vtkGeometryFilter vtkExtractGeometry
 */

#ifndef vtkClipVolume_h
#define vtkClipVolume_h

#include "vtkFiltersGeneralModule.h" // For export macro
#include "vtkUnstructuredGridAlgorithm.h"

class vtkCellData;
class vtkDataArray;
class vtkIdList;
class vtkImplicitFunction;
class vtkMergePoints;
class vtkOrderedTriangulator;
class vtkPointData;
class vtkIncrementalPointLocator;
class vtkPoints;
class vtkUnstructuredGrid;
class vtkCell;
class vtkTetra;
class vtkCellArray;
class vtkIdTypeArray;
class vtkUnsignedCharArray;

class VTKFILTERSGENERAL_EXPORT vtkClipVolume : public vtkUnstructuredGridAlgorithm
{
public:
  vtkTypeMacro(vtkClipVolume, vtkUnstructuredGridAlgorithm);
  void PrintSelf(ostream& os, vtkIndent indent) override;

  /**
   * Construct with user-specified implicit function; InsideOut turned off;
   * value set to 0.0; and generate clip scalars turned off.
   */
  static vtkClipVolume* New();

  ///@{
  /**
   * Set the clipping value of the implicit function (if clipping with
   * implicit function) or scalar value (if clipping with scalars). The
   * default value is 0.0.
   */
  vtkSetMacro(Value, double);
  vtkGetMacro(Value, double);
  ///@}

  ///@{
  /**
   * Set/Get the InsideOut flag. When off, a vertex is considered inside the
   * implicit function if its value is greater than the Value ivar. When
   * InsideOutside is turned on, a vertex is considered inside the implicit
   * function if its implicit function value is less than or equal to the
   * Value ivar.  InsideOut is off by default.
   */
  vtkSetMacro(InsideOut, vtkTypeBool);
  vtkGetMacro(InsideOut, vtkTypeBool);
  vtkBooleanMacro(InsideOut, vtkTypeBool);
  ///@}

  ///@{
  /**
   * Specify the implicit function with which to perform the clipping. If you
   * do not define an implicit function, then the input scalar data will be
   * used for clipping.
   */
  virtual void SetClipFunction(vtkImplicitFunction*);
  vtkGetObjectMacro(ClipFunction, vtkImplicitFunction);
  ///@}

  ///@{
  /**
   * If this flag is enabled, then the output scalar values will be
   * interpolated from the implicit function values, and not the
   * input scalar data. If you enable this flag but do not provide an
   * implicit function an error will be reported.
   */
  vtkSetMacro(GenerateClipScalars, vtkTypeBool);
  vtkGetMacro(GenerateClipScalars, vtkTypeBool);
  vtkBooleanMacro(GenerateClipScalars, vtkTypeBool);
  ///@}

  ///@{
  /**
   * Control whether a second output is generated. The second output
   * contains the unstructured grid that's been clipped away.
   */
  vtkSetMacro(GenerateClippedOutput, vtkTypeBool);
  vtkGetMacro(GenerateClippedOutput, vtkTypeBool);
  vtkBooleanMacro(GenerateClippedOutput, vtkTypeBool);
  ///@}

  /**
   * Return the clipped output.
   */
  vtkUnstructuredGrid* GetClippedOutput();

  ///@{
  /**
   * Control whether the filter produces a mix of 3D cell types on output, or
   * whether the output cells are all tetrahedra. By default, a mixed set of
   * cells (e.g., tetrahedra and wedges) is produced. (Note: mixed type
   * generation is faster and less overall data is generated.)
   */
  vtkSetMacro(Mixed3DCellGeneration, vtkTypeBool);
  vtkGetMacro(Mixed3DCellGeneration, vtkTypeBool);
  vtkBooleanMacro(Mixed3DCellGeneration, vtkTypeBool);
  ///@}

  ///@{
  /**
   * Set the tolerance for merging clip intersection points that are near
   * the corners of voxels. This tolerance is used to prevent the generation
   * of degenerate tetrahedra.
   */
  vtkSetClampMacro(MergeTolerance, double, 0.0001, 0.25);
  vtkGetMacro(MergeTolerance, double);
  ///@}

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

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

  /**
   * Return the mtime also considering the locator and clip function.
   */
  vtkMTimeType GetMTime() override;

protected:
  vtkClipVolume(vtkImplicitFunction* cf = nullptr);
  ~vtkClipVolume() override;

  void ReportReferences(vtkGarbageCollector*) override;

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

  void ClipTets(double value, vtkTetra* clipTetra, vtkDataArray* clipScalars,
    vtkDataArray* cellScalars, vtkIdList* tetraIds, vtkPoints* tetraPts, vtkPointData* inPD,
    vtkPointData* outPD, vtkCellData* inCD, vtkIdType cellId, vtkCellData* outCD,
    vtkCellData* clippedCD, int insideOut);
  void ClipVoxel(double value, vtkDataArray* cellScalars, int flip, double origin[3],
    double spacing[3], vtkIdList* cellIds, vtkPoints* cellPts, vtkPointData* inPD,
    vtkPointData* outPD, vtkCellData* inCD, vtkIdType cellId, vtkCellData* outCD,
    vtkCellData* clippedCD);

  vtkImplicitFunction* ClipFunction;
  vtkIncrementalPointLocator* Locator;
  vtkTypeBool InsideOut;
  double Value;
  vtkTypeBool GenerateClipScalars;
  double MergeTolerance;
  vtkTypeBool Mixed3DCellGeneration;
  vtkTypeBool GenerateClippedOutput;
  vtkUnstructuredGrid* ClippedOutput;

private:
  vtkOrderedTriangulator* Triangulator;

  // Used temporarily to pass data around
  vtkIdType NumberOfCells;
  vtkCellArray* Connectivity;
  vtkUnsignedCharArray* Types;
  vtkIdType NumberOfClippedCells;
  vtkCellArray* ClippedConnectivity;
  vtkUnsignedCharArray* ClippedTypes;

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

#endif
