// SPDX-FileCopyrightText: Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
// SPDX-License-Identifier: BSD-3-Clause
/**
 * @class   vtkHexahedron
 * @brief   a cell that represents a linear 3D hexahedron
 *
 * vtkHexahedron is a concrete implementation of vtkCell to represent a
 * linear, 3D rectangular hexahedron (e.g., "brick" topology). vtkHexahedron
 * uses the standard isoparametric shape functions for a linear
 * hexahedron. The hexahedron is defined by the eight points (0-7) where
 * (0,1,2,3) is the base of the hexahedron which, using the right hand rule,
 * forms a quadrilaterial whose normal points in the direction of the
 * opposite face (4,5,6,7).
 *
 * @sa
 * vtkConvexPointSet vtkPyramid vtkTetra vtkVoxel vtkWedge
 */

#ifndef vtkHexahedron_h
#define vtkHexahedron_h

#include "vtkCell3D.h"
#include "vtkCommonDataModelModule.h" // For export macro

VTK_ABI_NAMESPACE_BEGIN
class vtkLine;
class vtkQuad;
class vtkIncrementalPointLocator;

class VTKCOMMONDATAMODEL_EXPORT vtkHexahedron : public vtkCell3D
{
public:
  static vtkHexahedron* New();
  vtkTypeMacro(vtkHexahedron, vtkCell3D);
  void PrintSelf(ostream& os, vtkIndent indent) override;

  ///@{
  /**
   * See vtkCell3D API for description of these methods.
   */
  void GetEdgePoints(vtkIdType edgeId, const vtkIdType*& pts) override;
  vtkIdType GetFacePoints(vtkIdType faceId, const vtkIdType*& pts) override;
  void GetEdgeToAdjacentFaces(vtkIdType edgeId, const vtkIdType*& pts) override;
  vtkIdType GetFaceToAdjacentFaces(vtkIdType faceId, const vtkIdType*& faceIds) override;
  vtkIdType GetPointToIncidentEdges(vtkIdType pointId, const vtkIdType*& edgeIds) override;
  vtkIdType GetPointToIncidentFaces(vtkIdType pointId, const vtkIdType*& faceIds) override;
  vtkIdType GetPointToOneRingPoints(vtkIdType pointId, const vtkIdType*& pts) override;
  bool GetCentroid(double centroid[3]) const override;
  ///@}

  /**
   * static constexpr handle on the number of points.
   */
  static constexpr vtkIdType NumberOfPoints = 8;

  /**
   * static contexpr handle on the number of faces.
   */
  static constexpr vtkIdType NumberOfEdges = 12;

  /**
   * static contexpr handle on the number of edges.
   */
  static constexpr vtkIdType NumberOfFaces = 6;

  /**
   * static contexpr handle on the maximum face size. It can also be used
   * to know the number of faces adjacent to one face.
   */
  static constexpr vtkIdType MaximumFaceSize = 4;

  /**
   * static constexpr handle on the maximum valence of this cell.
   * The valence of a vertex is the number of incident edges (or equivalently faces)
   * to this vertex. It is also equal to the size of a one ring neighborhood of a vertex.
   */
  static constexpr vtkIdType MaximumValence = 3;

  ///@{
  /**
   * See the vtkCell API for descriptions of these methods.
   */
  int GetCellType() override { return VTK_HEXAHEDRON; }
  int GetNumberOfEdges() override { return 12; }
  int GetNumberOfFaces() override { return 6; }
  vtkCell* GetEdge(int edgeId) override;
  vtkCell* GetFace(int faceId) override;
  int CellBoundary(int subId, const double pcoords[3], vtkIdList* pts) override;
  void Contour(double value, vtkDataArray* cellScalars, vtkIncrementalPointLocator* locator,
    vtkCellArray* verts, vtkCellArray* lines, vtkCellArray* polys, vtkPointData* inPd,
    vtkPointData* outPd, vtkCellData* inCd, vtkIdType cellId, vtkCellData* outCd) override;
  ///@}

  int EvaluatePosition(const double x[3], double closestPoint[3], int& subId, double pcoords[3],
    double& dist2, double weights[]) override;
  void EvaluateLocation(int& subId, const double pcoords[3], double x[3], double* weights) override;
  int IntersectWithLine(const double p1[3], const double p2[3], double tol, double& t, double x[3],
    double pcoords[3], int& subId) override;
  int Triangulate(int index, vtkIdList* ptIds, vtkPoints* pts) override;
  void Derivatives(
    int subId, const double pcoords[3], const double* values, int dim, double* derivs) override;
  double* GetParametricCoords() override;

  /**
   * Return the case table for table-based isocontouring (aka marching cubes
   * style implementations). A linear 3D cell with N vertices will have 2**N
   * cases. The returned case array lists three edges in order to produce one
   * output triangle which may be repeated to generate multiple triangles. The
   * list of cases terminates with a -1 entry.
   */
  static int* GetTriangleCases(int caseId);

  static void InterpolationFunctions(const double pcoords[3], double weights[8]);
  static void InterpolationDerivs(const double pcoords[3], double derivs[24]);
  ///@{
  /**
   * Compute the interpolation functions/derivatives
   * (aka shape functions/derivatives)
   */
  void InterpolateFunctions(const double pcoords[3], double weights[8]) override
  {
    vtkHexahedron::InterpolationFunctions(pcoords, weights);
  }
  void InterpolateDerivs(const double pcoords[3], double derivs[24]) override
  {
    vtkHexahedron::InterpolationDerivs(pcoords, derivs);
  }
  ///@}

  ///@{
  /**
   * Return the ids of the vertices defining edge/face (`edgeId`/`faceId').
   * Ids are related to the cell, not to the dataset.
   *
   * @note The return type changed. It used to be int*, it is now const vtkIdType*.
   * This is so ids are unified between vtkCell and vtkPoints, and so vtkCell ids
   * can be used as inputs in algorithms such as vtkPolygon::ComputeNormal.
   */
  static const vtkIdType* GetEdgeArray(vtkIdType edgeId) VTK_SIZEHINT(2);
  static const vtkIdType* GetFaceArray(vtkIdType faceId) VTK_SIZEHINT(4);
  ///@}

  /**
   * Static method version of GetEdgeToAdjacentFaces.
   */
  static const vtkIdType* GetEdgeToAdjacentFacesArray(vtkIdType edgeId) VTK_SIZEHINT(2);

  /**
   * Static method version of GetFaceToAdjacentFaces.
   */
  static const vtkIdType* GetFaceToAdjacentFacesArray(vtkIdType faceId) VTK_SIZEHINT(4);

  /**
   * Static method version of GetPointToIncidentEdgesArray.
   */
  static const vtkIdType* GetPointToIncidentEdgesArray(vtkIdType pointId) VTK_SIZEHINT(3);

  /**
   * Static method version of GetPointToIncidentFacesArray.
   */
  static const vtkIdType* GetPointToIncidentFacesArray(vtkIdType pointId) VTK_SIZEHINT(3);

  /**
   * Static method version of GetPointToOneRingPoints.
   */
  static const vtkIdType* GetPointToOneRingPointsArray(vtkIdType pointId) VTK_SIZEHINT(3);

  /**
   * Static method version of GetCentroid.
   */
  static bool ComputeCentroid(vtkPoints* points, const vtkIdType* pointIds, double centroid[3]);

  /**
   * Given parametric coordinates compute inverse Jacobian transformation
   * matrix. Returns 9 elements of 3x3 inverse Jacobian plus interpolation
   * function derivatives.
   */
  void JacobianInverse(const double pcoords[3], double** inverse, double derivs[24]);

protected:
  vtkHexahedron();
  ~vtkHexahedron() override;

  vtkLine* Line;
  vtkQuad* Quad;

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

VTK_ABI_NAMESPACE_END
#endif