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/*=========================================================================
Program: Visualization Toolkit
Module: vtkSimpleCellTessellator.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 vtkSimpleCellTessellator
* @brief helper class to perform cell tessellation
*
* vtkSimpleCellTessellator is a helper class to perform adaptive tessellation
* of particular cell topologies. The major purpose for this class is to
* transform higher-order cell types (e.g., higher-order finite elements)
* into linear cells that can then be easily visualized by VTK. This class
* works in conjunction with the vtkGenericDataSet and vtkGenericAdaptorCell
* classes.
*
* This algorithm is based on edge subdivision. An error metric along each
* edge is evaluated, and if the error is greater than some tolerance, the
* edge is subdivided (as well as all connected 2D and 3D cells). The process
* repeats until the error metric is satisfied. Since the algorithm is based
* on edge subdivision it inherently avoid T-junctions.
*
* A significant issue addressed by this algorithm is to insure face
* compatibility across neighboring cells. That is, diagonals due to face
* triangulation must match to insure that the mesh is compatible. The
* algorithm employs a precomputed table to accelerate the tessellation
* process. The table was generated with the help of vtkOrderedTriangulator
* the basic idea is that the choice of diagonal is made only by considering the
* relative value of the point ids.
*
* @sa
* vtkGenericCellTessellator vtkGenericSubdivisionErrorMetric vtkAttributesErrorMetric
* vtkGeometricErrorMetric vtkViewDependentErrorMetric
*/
#ifndef vtkSimpleCellTessellator_h
#define vtkSimpleCellTessellator_h
#include "vtkCommonDataModelModule.h" // For export macro
#include "vtkGenericCellTessellator.h"
class vtkTriangleTile;
class vtkTetraTile;
class vtkCellArray;
class vtkDoubleArray;
class vtkGenericEdgeTable;
class vtkGenericSubdivisionErrorMetric;
class vtkGenericAttributeCollection;
class vtkGenericAdaptorCell;
class vtkGenericCellIterator;
class vtkPointData;
class vtkOrderedTriangulator;
class vtkPolygon;
class vtkIdList;
//-----------------------------------------------------------------------------
//
// The tessellation object
class VTKCOMMONDATAMODEL_EXPORT vtkSimpleCellTessellator : public vtkGenericCellTessellator
{
public:
static vtkSimpleCellTessellator* New();
vtkTypeMacro(vtkSimpleCellTessellator, vtkGenericCellTessellator);
void PrintSelf(ostream& os, vtkIndent indent) override;
//@{
/**
* Get the higher order cell in order to access the evaluation function.
*/
vtkGetObjectMacro(GenericCell, vtkGenericAdaptorCell);
//@}
/**
* Tessellate a face of a 3D `cell'. The face is specified by the
* index value.
* The result is a set of smaller linear triangles in `cellArray' with
* `points' and point data `internalPd'.
* \pre cell_exists: cell!=0
* \pre valid_dimension: cell->GetDimension()==3
* \pre valid_index_range: (index>=0) && (index<cell->GetNumberOfBoundaries(2))
* \pre att_exists: att!=0
* \pre points_exists: points!=0
* \pre cellArray_exists: cellArray!=0
* \pre internalPd_exists: internalPd!=0
*/
void TessellateFace(vtkGenericAdaptorCell* cell, vtkGenericAttributeCollection* att,
vtkIdType index, vtkDoubleArray* points, vtkCellArray* cellArray,
vtkPointData* internalPd) override;
/**
* Tessellate a 3D `cell'. The result is a set of smaller linear
* tetrahedra in `cellArray' with `points' and point data `internalPd'.
* \pre cell_exists: cell!=0
* \pre valid_dimension: cell->GetDimension()==3
* \pre att_exists: att!=0
* \pre points_exists: points!=0
* \pre cellArray_exists: cellArray!=0
* \pre internalPd_exists: internalPd!=0
*/
void Tessellate(vtkGenericAdaptorCell* cell, vtkGenericAttributeCollection* att,
vtkDoubleArray* points, vtkCellArray* cellArray, vtkPointData* internalPd) override;
/**
* Triangulate a 2D `cell'. The result is a set of smaller linear triangles
* in `cellArray' with `points' and point data `internalPd'.
* \pre cell_exists: cell!=0
* \pre valid_dimension: cell->GetDimension()==2
* \pre att_exists: att!=0
* \pre points_exists: points!=0
* \pre cellArray_exists: cellArray!=0
* \pre internalPd_exists: internalPd!=0
*/
void Triangulate(vtkGenericAdaptorCell* cell, vtkGenericAttributeCollection* att,
vtkDoubleArray* points, vtkCellArray* cellArray, vtkPointData* internalPd) override;
/**
* Reset the output for repeated use of this class.
*/
void Reset();
/**
* Initialize the tessellator with a data set `ds'.
*/
void Initialize(vtkGenericDataSet* ds) override;
/**
* Return the number of fixed subdivisions. It is used to prevent from
* infinite loop in degenerated cases. For order 3 or higher, if the
* inflection point is exactly on the mid-point, error metric will not
* detect that a subdivision is required. 0 means no fixed subdivision:
* there will be only adaptive subdivisions.
* The algorithm first performs `GetFixedSubdivisions' non adaptive
* subdivisions followed by at most `GetMaxAdaptiveSubdivisions' adaptive
* subdivisions. Hence, there are at most `GetMaxSubdivisionLevel'
* subdivisions.
* \post positive_result: result>=0 && result<=GetMaxSubdivisionLevel()
*/
int GetFixedSubdivisions();
/**
* Return the maximum level of subdivision. It is used to prevent from
* infinite loop in degenerated cases. For order 3 or higher, if the
* inflection point is exactly on the mid-point, error metric will not
* detect that a subdivision is required. 0 means no subdivision,
* neither fixed nor adaptive.
* \post positive_result: result>=GetFixedSubdivisions()
*/
int GetMaxSubdivisionLevel();
/**
* Return the maximum number of adaptive subdivisions.
* \post valid_result: result==GetMaxSubdivisionLevel()-GetFixedSubdivisions()
*/
int GetMaxAdaptiveSubdivisions();
/**
* Set the number of fixed subdivisions. See GetFixedSubdivisions() for
* more explanations.
* \pre positive_level: level>=0 && level<=GetMaxSubdivisionLevel()
* \post is_set: GetFixedSubdivisions()==level
*/
void SetFixedSubdivisions(int level);
/**
* Set the maximum level of subdivision. See GetMaxSubdivisionLevel() for
* more explanations.
* \pre positive_level: level>=GetFixedSubdivisions()
* \post is_set: level==GetMaxSubdivisionLevel()
*/
void SetMaxSubdivisionLevel(int level);
/**
* Set both the number of fixed subdivisions and the maximum level of
* subdivisions. See GetFixedSubdivisions(), GetMaxSubdivisionLevel() and
* GetMaxAdaptiveSubdivisions() for more explanations.
* \pre positive_fixed: fixed>=0
* \pre valid_range: fixed<=maxLevel
* \post fixed_is_set: fixed==GetFixedSubdivisions()
* \post maxLevel_is_set: maxLevel==GetMaxSubdivisionLevel()
*/
void SetSubdivisionLevels(int fixed, int maxLevel);
protected:
vtkSimpleCellTessellator();
~vtkSimpleCellTessellator() override;
/**
* Extract point `pointId' from the edge table to the output point and output
* point data.
*/
void CopyPoint(vtkIdType pointId);
/**
* HashTable instead of vtkPointLocator
*/
vtkGenericEdgeTable* EdgeTable;
void InsertEdgesIntoEdgeTable(vtkTriangleTile& tri);
void RemoveEdgesFromEdgeTable(vtkTriangleTile& tri);
void InsertPointsIntoEdgeTable(vtkTriangleTile& tri);
void InsertEdgesIntoEdgeTable(vtkTetraTile& tetra);
void RemoveEdgesFromEdgeTable(vtkTetraTile& tetra);
/**
* Initialize `root' with the sub-tetra defined by the `localIds' points on
* the complex cell, `ids' are the global ids over the mesh of those points.
* The sub-tetra is also defined by the ids of its edges and of its faces
* relative to the complex cell. -1 means that the edge or the face of the
* sub-tetra is not an original edge or face of the complex cell.
* \pre cell_exists: this->GenericCell!=0
* \pre localIds_exists: localIds!=0
* \pre localIds_size: sizeof(localIds)==4
* \pre ids_exists: ids!=0
* \pre ids_size: sizeof(ids)==4
* \pre edgeIds_exists: edgeIds!=0
* \pre edgeIds_size: sizeof(edgeIds)==6
* \pre faceIds_exists: faceIds!=0
* \pre faceIds_size: sizeof(faceIds)==4
*/
void InitTetraTile(
vtkTetraTile& root, const vtkIdType* localIds, vtkIdType* ids, int* edgeIds, int* faceIds);
/**
* Triangulate a triangle of `cell'. This triangle can be the top-level
* triangle if the cell is a triangle or a toplevel sub-triangle is the cell
* is a polygon, or a triangular face of a 3D cell or a top-level
* sub-triangle of a face of a 3D cell if the face is not a triangle.
* Arguments `localIds', `ids' and `edgeIds' have the same meaning than
* for InitTetraTile.
* \pre cell_exists: cell!=0
* \pre localIds_exists: localIds!=0
* \pre localIds_size: sizeof(localIds)==3
* \pre ids_exists: ids!=0
* \pre ids_size: sizeof(ids)==3
* \pre edgeIds_exists: edgeIds!=0
* \pre edgeIds_size: sizeof(edgeIds)==3
*
* @note Parameter edgeIds's type changed to match new vtkCell API.
* This API change could not be smoothly done by deprecation.
*/
void TriangulateTriangle(vtkGenericAdaptorCell* cell, vtkIdType* localIds, vtkIdType* ids,
const vtkIdType* edgeIds, vtkGenericAttributeCollection* att, vtkDoubleArray* points,
vtkCellArray* cellArray, vtkPointData* internalPd);
/**
* To access the higher order cell from third party library
*/
vtkGenericAdaptorCell* GenericCell;
/**
* Allocate some memory if Scalars does not exists or is smaller than size.
* \pre positive_size: size>0
*/
void AllocateScalars(int size);
/**
* Scalar buffer used to save the interpolate values of the attributes
* The capacity is at least the number of components of the attribute
* collection ot the current cell.
*/
// Scalar buffer that stores the global coordinates, parametric coordinates,
// attributes at left, mid and right point. The format is:
// lxlylz lrlslt [lalb lcldle...] mxmymz mrmsmt [mamb mcmdme...]
// rxryrz rrrsrt [rarb rcrdre...]
// The ScalarsCapacity>=(6+attributeCollection->GetNumberOfComponents())*3
double* Scalars;
int ScalarsCapacity;
/**
* Number of double value to skip to go to the next point into Scalars array
* It is 6+attributeCollection->GetNumberOfComponents()
*/
int PointOffset;
/**
* Used to iterate over edges boundaries in GetNumberOfCellsUsingEdges()
*/
vtkGenericCellIterator* CellIterator;
/**
* To access the higher order field from third party library
*/
vtkGenericAttributeCollection* AttributeCollection;
//@{
/**
* To avoid New/Delete
*/
vtkDoubleArray* TessellatePoints; // Allow to use GetPointer
vtkCellArray* TessellateCellArray;
vtkPointData* TessellatePointData;
//@}
int FindEdgeReferenceCount(double p1[3], double p2[3], vtkIdType& e1, vtkIdType& e2);
int GetNumberOfCellsUsingFace(int faceId);
int GetNumberOfCellsUsingEdge(int edgeId);
/**
* Is the edge defined by vertices (`p1',`p2') in parametric coordinates on
* some edge of the original tetrahedron? If yes return on which edge it is,
* else return -1.
* \pre p1!=p2
* \pre p1 and p2 are in bounding box (0,0,0) (1,1,1)
* \post valid_result: (result==-1) || ( result>=0 && result<=5 )
*/
int IsEdgeOnFace(double p1[3], double p2[3]);
/**
* Return 1 if the parent of edge defined by vertices (`p1',`p2') in
* parametric coordinates, is an edge; 3 if there is no parent (the edge is
* inside). If the parent is an edge, return its id in `localId'.
* \pre p1!=p2
* \pre p1 and p2 are in bounding box (0,0,0) (1,1,1)
* \post valid_result: (result==1)||(result==3)
*/
int FindEdgeParent2D(double p1[3], double p2[3], int& localId);
/**
* Return 1 if the parent of edge defined by vertices (`p1',`p2') in
* parametric coordinates, is an edge; 2 if the parent is a face, 3 if there
* is no parent (the edge is inside). If the parent is an edge or a face,
* return its id in `localId'.
* \pre p1!=p2
* \pre p1 and p2 are in bounding box (0,0,0) (1,1,1)
* \post valid_result: result>=1 && result<=3
*/
int FindEdgeParent(double p1[3], double p2[3], int& localId);
/**
* Allocate some memory if PointIds does not exist or is smaller than size.
* \pre positive_size: size>0
*/
void AllocatePointIds(int size);
/**
* Are the faces `originalFace' and `face' equal?
* The result is independent from any order or orientation.
* \pre originalFace_exists: originalFace!=0
*
* @note Parameter originalFace and face types changed to match new vtkCell API.
* This API change could not be smoothly done by deprecation.
*/
int FacesAreEqual(const vtkIdType* originalFace, const vtkIdType face[3]);
/**
* Number of points in the dataset to be tessellated.
*/
vtkIdType NumberOfPoints;
int FixedSubdivisions;
int MaxSubdivisionLevel;
int CurrentSubdivisionLevel;
/**
* For each edge (6) of the sub-tetra, there is the id of the original edge
* or -1 if the edge is not an original edge
*/
const vtkIdType* EdgeIds;
/**
* For each face (4) of the sub-tetra, there is the id of the original face
* or -1 if the face is not an original face
*/
const vtkIdType* FaceIds;
// The following variables are for complex cells.
// Used to create tetra from more complex cells, because the tessellator
// is supposed to deal with simplices only.
vtkOrderedTriangulator* Triangulator;
// Used to store the sub-tetra during the tessellation of complex
// cells.
vtkCellArray* Connectivity;
// Used to create triangles from a face of a complex cell.
vtkPolygon* Polygon;
// Used to store the sub-triangles during the tessellation of complex cells.
vtkIdList* TriangleIds;
vtkIdType* PointIds;
int PointIdsCapacity;
private:
vtkSimpleCellTessellator(const vtkSimpleCellTessellator&) = delete;
void operator=(const vtkSimpleCellTessellator&) = delete;
friend class vtkTetraTile;
friend class vtkTriangleTile;
};
#endif