Efficient cell iterator for vtkDataSet topologies. More...

#include <vtkCellIterator.h>

Inheritance diagram for vtkCellIterator:

Collaboration diagram for vtkCellIterator:

Public Member Functions
void	PrintSelf (ostream &os, vtkIndent indent) override
	Methods invoked by print to print information about the object including superclasses.

	vtkAbstractTypeMacro (vtkCellIterator, vtkObject)

void	InitTraversal ()
	Reset to the first cell.

void	GoToNextCell ()
	Increment to next cell.

virtual bool	IsDoneWithTraversal ()=0
	Returns false while the iterator is valid.

int	GetCellType ()
	Get the current cell type (e.g.

int	GetCellDimension ()
	Get the current cell dimension (0, 1, 2, or 3).

virtual vtkIdType	GetCellId ()=0
	Get the id of the current cell.

vtkIdList *	GetPointIds ()
	Get the ids of the points in the current cell.

vtkPoints *	GetPoints ()
	Get the points in the current cell.

vtkIdList *	GetFaces ()
	Get the faces for a polyhedral cell.

void	GetCell (vtkGenericCell *cell)
	Write the current full cell information into the argument.

vtkIdType	GetNumberOfPoints ()
	Return the number of points in the current cell.

vtkIdType	GetNumberOfFaces ()
	Return the number of faces in the current cell.

Public Member Functions inherited from vtkObject
	vtkBaseTypeMacro (vtkObject, vtkObjectBase)

virtual void	DebugOn ()
	Turn debugging output on.

virtual void	DebugOff ()
	Turn debugging output off.

bool	GetDebug ()
	Get the value of the debug flag.

void	SetDebug (bool debugFlag)
	Set the value of the debug flag.

virtual void	Modified ()
	Update the modification time for this object.

virtual vtkMTimeType	GetMTime ()
	Return this object's modified time.

void	PrintSelf (ostream &os, vtkIndent indent) override
	Methods invoked by print to print information about the object including superclasses.

void	RemoveObserver (unsigned long tag)

void	RemoveObservers (unsigned long event)

void	RemoveObservers (const char *event)

void	RemoveAllObservers ()

vtkTypeBool	HasObserver (unsigned long event)

vtkTypeBool	HasObserver (const char *event)

int	InvokeEvent (unsigned long event)

int	InvokeEvent (const char *event)

unsigned long	AddObserver (unsigned long event, vtkCommand *, float priority=0.0f)
	Allow people to add/remove/invoke observers (callbacks) to any VTK object.

unsigned long	AddObserver (const char event, vtkCommand , float priority=0.0f)
	Allow people to add/remove/invoke observers (callbacks) to any VTK object.

vtkCommand *	GetCommand (unsigned long tag)
	Allow people to add/remove/invoke observers (callbacks) to any VTK object.

void	RemoveObserver (vtkCommand *)
	Allow people to add/remove/invoke observers (callbacks) to any VTK object.

void	RemoveObservers (unsigned long event, vtkCommand *)
	Allow people to add/remove/invoke observers (callbacks) to any VTK object.

void	RemoveObservers (const char event, vtkCommand )
	Allow people to add/remove/invoke observers (callbacks) to any VTK object.

vtkTypeBool	HasObserver (unsigned long event, vtkCommand *)
	Allow people to add/remove/invoke observers (callbacks) to any VTK object.

vtkTypeBool	HasObserver (const char event, vtkCommand )
	Allow people to add/remove/invoke observers (callbacks) to any VTK object.

template<class U , class T >
unsigned long	AddObserver (unsigned long event, U observer, void(T::*callback)(), float priority=0.0f)
	Overloads to AddObserver that allow developers to add class member functions as callbacks for events.

template<class U , class T >
unsigned long	AddObserver (unsigned long event, U observer, void(T::callback)(vtkObject , unsigned long, void *), float priority=0.0f)
	Overloads to AddObserver that allow developers to add class member functions as callbacks for events.

template<class U , class T >
unsigned long	AddObserver (unsigned long event, U observer, bool(T::callback)(vtkObject , unsigned long, void *), float priority=0.0f)
	Allow user to set the AbortFlagOn() with the return value of the callback method.

int	InvokeEvent (unsigned long event, void *callData)
	This method invokes an event and return whether the event was aborted or not.

int	InvokeEvent (const char event, void callData)
	This method invokes an event and return whether the event was aborted or not.

Public Member Functions inherited from vtkObjectBase
const char *	GetClassName () const
	Return the class name as a string.

virtual vtkTypeBool	IsA (const char *name)
	Return 1 if this class is the same type of (or a subclass of) the named class.

virtual vtkIdType	GetNumberOfGenerationsFromBase (const char *name)
	Given the name of a base class of this class type, return the distance of inheritance between this class type and the named class (how many generations of inheritance are there between this class and the named class).

virtual void	Delete ()
	Delete a VTK object.

virtual void	FastDelete ()
	Delete a reference to this object.

void	InitializeObjectBase ()

void	Print (ostream &os)
	Print an object to an ostream.

virtual void	Register (vtkObjectBase *o)
	Increase the reference count (mark as used by another object).

virtual void	UnRegister (vtkObjectBase *o)
	Decrease the reference count (release by another object).

int	GetReferenceCount ()
	Return the current reference count of this object.

void	SetReferenceCount (int)
	Sets the reference count.

bool	GetIsInMemkind () const
	A local state flag that remembers whether this object lives in the normal or extended memory space.

virtual void	PrintHeader (ostream &os, vtkIndent indent)
	Methods invoked by print to print information about the object including superclasses.

virtual void	PrintTrailer (ostream &os, vtkIndent indent)
	Methods invoked by print to print information about the object including superclasses.

Protected Member Functions
	vtkCellIterator ()

	~vtkCellIterator () override

virtual void	ResetToFirstCell ()=0
	Update internal state to point to the first cell.

virtual void	IncrementToNextCell ()=0
	Update internal state to point to the next cell.

virtual void	FetchCellType ()=0
	Lookup the cell type in the data set and store it in this->CellType.

virtual void	FetchPointIds ()=0
	Lookup the cell point ids in the data set and store them in this->PointIds.

virtual void	FetchPoints ()=0
	Lookup the cell points in the data set and store them in this->Points.

virtual void	FetchFaces ()
	Lookup the cell faces in the data set and store them in this->Faces.

Protected Member Functions inherited from vtkObject
	vtkObject ()

	~vtkObject () override

void	RegisterInternal (vtkObjectBase *, vtkTypeBool check) override

void	UnRegisterInternal (vtkObjectBase *, vtkTypeBool check) override

void	InternalGrabFocus (vtkCommand mouseEvents, vtkCommand keypressEvents=nullptr)
	These methods allow a command to exclusively grab all events.

void	InternalReleaseFocus ()
	These methods allow a command to exclusively grab all events.

Protected Member Functions inherited from vtkObjectBase
	vtkObjectBase ()

virtual	~vtkObjectBase ()

virtual void	RegisterInternal (vtkObjectBase *, vtkTypeBool check)

virtual void	UnRegisterInternal (vtkObjectBase *, vtkTypeBool check)

virtual void	ReportReferences (vtkGarbageCollector *)

	vtkObjectBase (const vtkObjectBase &)

void	operator= (const vtkObjectBase &)

Protected Attributes
int	CellType

vtkPoints *	Points

vtkIdList *	PointIds

vtkIdList *	Faces

Protected Attributes inherited from vtkObject
bool	Debug

vtkTimeStamp	MTime

vtkSubjectHelper *	SubjectHelper

Protected Attributes inherited from vtkObjectBase
std::atomic< int32_t >	ReferenceCount

vtkWeakPointerBase **	WeakPointers

Additional Inherited Members
Static Public Member Functions inherited from vtkObject
static vtkObject *	New ()
	Create an object with Debug turned off, modified time initialized to zero, and reference counting on.

static void	BreakOnError ()
	This method is called when vtkErrorMacro executes.

static void	SetGlobalWarningDisplay (int val)
	This is a global flag that controls whether any debug, warning or error messages are displayed.

static void	GlobalWarningDisplayOn ()
	This is a global flag that controls whether any debug, warning or error messages are displayed.

static void	GlobalWarningDisplayOff ()
	This is a global flag that controls whether any debug, warning or error messages are displayed.

static int	GetGlobalWarningDisplay ()
	This is a global flag that controls whether any debug, warning or error messages are displayed.

Static Public Member Functions inherited from vtkObjectBase
static vtkTypeBool	IsTypeOf (const char *name)
	Return 1 if this class type is the same type of (or a subclass of) the named class.

static vtkIdType	GetNumberOfGenerationsFromBaseType (const char *name)
	Given a the name of a base class of this class type, return the distance of inheritance between this class type and the named class (how many generations of inheritance are there between this class and the named class).

static vtkObjectBase *	New ()
	Create an object with Debug turned off, modified time initialized to zero, and reference counting on.

static void	SetMemkindDirectory (const char *directoryname)
	The name of a directory, ideally mounted -o dax, to memory map an extended memory space within.

static bool	GetUsingMemkind ()
	A global state flag that controls whether vtkObjects are constructed in the usual way (the default) or within the extended memory space.

Static Protected Member Functions inherited from vtkObjectBase
static vtkMallocingFunction	GetCurrentMallocFunction ()

static vtkReallocingFunction	GetCurrentReallocFunction ()

static vtkFreeingFunction	GetCurrentFreeFunction ()

static vtkFreeingFunction	GetAlternateFreeFunction ()

Detailed Description

Efficient cell iterator for vtkDataSet topologies.

vtkCellIterator provides a method for traversing cells in a data set. Call the vtkDataSet::NewCellIterator() method to use this class.

The cell is represented as a set of three pieces of information: The cell type, the ids of the points constituting the cell, and the points themselves. This iterator fetches these as needed. If only the cell type is used, the type is not looked up until GetCellType is called, and the point information is left uninitialized. This allows efficient screening of cells, since expensive point lookups may be skipped depending on the cell type/etc.

An example usage of this class:

void myWorkerFunction(vtkDataSet *ds)
{
  vtkCellIterator *it = ds->NewCellIterator();
  for (it->InitTraversal(); !it->IsDoneWithTraversal(); it->GoToNextCell())
    {
    if (it->GetCellType() != VTK_TETRA)
      {
      continue; // Skip non-tetrahedral cells
      }
 
    vtkIdList *pointIds = it->GetPointIds();
    // Do screening on the point ids, maybe figure out scalar range and skip
       cells that do not lie in a certain range?
 
    vtkPoints *points = it->GetPoints();
    // Do work using the cell points, or ...
 
    vtkGenericCell *cell = ...;
    it->GetCell(cell);
    // ... do work with a vtkCell.
    }
  it->Delete();
}

The example above pulls in bits of information as needed to filter out cells that aren't relevant. The least expensive lookups are performed first (cell type, then point ids, then points/full cell) to prevent wasted cycles fetching unnecessary data. Also note that at the end of the loop, the iterator must be deleted as these iterators are vtkObject subclasses.

Online Examples:

QuadraticHexahedronDemo

QuadraticTetraDemo

ReadLegacyUnstructuredGrid

Definition at line 176 of file vtkCellIterator.h.

Constructor & Destructor Documentation

◆ vtkCellIterator()

vtkCellIterator::vtkCellIterator ( )

protected

◆ ~vtkCellIterator()

vtkCellIterator::~vtkCellIterator ( )

overrideprotected

Member Function Documentation

◆ PrintSelf()

void vtkCellIterator::PrintSelf	(	ostream &	os,
		vtkIndent	indent
	)

overridevirtual

Methods invoked by print to print information about the object including superclasses.

Typically not called by the user (use Print() instead) but used in the hierarchical print process to combine the output of several classes.

Reimplemented from vtkObject.

Reimplemented in vtkCPExodusIIElementBlockCellIterator, vtkDataSetCellIterator, vtkMappedUnstructuredGridCellIterator< Implementation >, vtkPointSetCellIterator, and vtkUnstructuredGridCellIterator.

◆ vtkAbstractTypeMacro()

vtkCellIterator::vtkAbstractTypeMacro	(	vtkCellIterator	,
		vtkObject
	)

◆ InitTraversal()

void vtkCellIterator::InitTraversal ( )

inline

Reset to the first cell.

Definition at line 324 of file vtkCellIterator.h.

◆ GoToNextCell()

void vtkCellIterator::GoToNextCell ( )

inline

Increment to next cell.

Always safe to call.

Definition at line 331 of file vtkCellIterator.h.

◆ IsDoneWithTraversal()

virtual bool vtkCellIterator::IsDoneWithTraversal ( )

pure virtual

Returns false while the iterator is valid.

Always safe to call.

Implemented in vtkDataSetCellIterator, vtkMappedUnstructuredGridCellIterator< Implementation >, vtkPointSetCellIterator, and vtkUnstructuredGridCellIterator.

◆ GetCellType()

int vtkCellIterator::GetCellType ( )

inline

Get the current cell type (e.g.

VTK_LINE, VTK_VERTEX, VTK_TETRA, etc). This should only be called when IsDoneWithTraversal() returns false.

Definition at line 338 of file vtkCellIterator.h.

◆ GetCellDimension()

int vtkCellIterator::GetCellDimension ( )

Get the current cell dimension (0, 1, 2, or 3).

This should only be called when IsDoneWithTraversal() returns false.

◆ GetCellId()

virtual vtkIdType vtkCellIterator::GetCellId ( )

pure virtual

Get the id of the current cell.

Implemented in vtkCPExodusIIElementBlockCellIterator, vtkDataSetCellIterator, vtkMappedUnstructuredGridCellIterator< Implementation >, vtkPointSetCellIterator, and vtkUnstructuredGridCellIterator.

◆ GetPointIds()

vtkIdList * vtkCellIterator::GetPointIds ( )

inline

Get the ids of the points in the current cell.

This should only be called when IsDoneWithTraversal() returns false.

Definition at line 349 of file vtkCellIterator.h.

◆ GetPoints()

vtkPoints * vtkCellIterator::GetPoints ( )

inline

Get the points in the current cell.

This is usually a very expensive call, and should be avoided when possible. This should only be called when IsDoneWithTraversal() returns false.

Definition at line 360 of file vtkCellIterator.h.

◆ GetFaces()

vtkIdList * vtkCellIterator::GetFaces ( )

inline

Get the faces for a polyhedral cell.

This is only valid when CellType is VTK_POLYHEDRON.

Definition at line 371 of file vtkCellIterator.h.

◆ GetCell()

void vtkCellIterator::GetCell ( vtkGenericCell * cell )

Write the current full cell information into the argument.

This is usually a very expensive call, and should be avoided when possible. This should only be called when IsDoneWithTraversal() returns false.

◆ GetNumberOfPoints()

vtkIdType vtkCellIterator::GetNumberOfPoints ( )

inline

Return the number of points in the current cell.

This should only be called when IsDoneWithTraversal() returns false.

Definition at line 382 of file vtkCellIterator.h.

◆ GetNumberOfFaces()

vtkIdType vtkCellIterator::GetNumberOfFaces ( )

inline

Return the number of faces in the current cell.

This should only be called when IsDoneWithTraversal() returns false.

Definition at line 393 of file vtkCellIterator.h.

◆ ResetToFirstCell()

virtual void vtkCellIterator::ResetToFirstCell ( )

protectedpure virtual

Update internal state to point to the first cell.

Implemented in vtkCPExodusIIElementBlockCellIterator, vtkDataSetCellIterator, vtkMappedUnstructuredGridCellIterator< Implementation >, vtkPointSetCellIterator, and vtkUnstructuredGridCellIterator.

◆ IncrementToNextCell()

virtual void vtkCellIterator::IncrementToNextCell ( )

protectedpure virtual

Update internal state to point to the next cell.

Implemented in vtkCPExodusIIElementBlockCellIterator, vtkDataSetCellIterator, vtkMappedUnstructuredGridCellIterator< Implementation >, vtkPointSetCellIterator, and vtkUnstructuredGridCellIterator.

◆ FetchCellType()

virtual void vtkCellIterator::FetchCellType ( )

protectedpure virtual

Lookup the cell type in the data set and store it in this->CellType.

Implemented in vtkCPExodusIIElementBlockCellIterator, vtkDataSetCellIterator, vtkMappedUnstructuredGridCellIterator< Implementation >, vtkPointSetCellIterator, and vtkUnstructuredGridCellIterator.

◆ FetchPointIds()

virtual void vtkCellIterator::FetchPointIds ( )

protectedpure virtual

Lookup the cell point ids in the data set and store them in this->PointIds.

Implemented in vtkCPExodusIIElementBlockCellIterator, vtkDataSetCellIterator, vtkMappedUnstructuredGridCellIterator< Implementation >, vtkPointSetCellIterator, and vtkUnstructuredGridCellIterator.

◆ FetchPoints()

virtual void vtkCellIterator::FetchPoints ( )

protectedpure virtual

Lookup the cell points in the data set and store them in this->Points.

Implemented in vtkCPExodusIIElementBlockCellIterator, vtkDataSetCellIterator, vtkMappedUnstructuredGridCellIterator< Implementation >, vtkPointSetCellIterator, and vtkUnstructuredGridCellIterator.

◆ FetchFaces()

virtual void vtkCellIterator::FetchFaces ( )

inlineprotectedvirtual

Lookup the cell faces in the data set and store them in this->Faces.

Few data sets support faces, so this method has a no-op default implementation. See vtkUnstructuredGrid::GetFaceStream for a description of the layout that Faces should have.

Reimplemented in vtkUnstructuredGridCellIterator.

Definition at line 287 of file vtkCellIterator.h.

Member Data Documentation

◆ CellType

int vtkCellIterator::CellType

protected

Definition at line 289 of file vtkCellIterator.h.

◆ Points

vtkPoints* vtkCellIterator::Points

protected

Definition at line 290 of file vtkCellIterator.h.

◆ PointIds

vtkIdList* vtkCellIterator::PointIds

protected

Definition at line 291 of file vtkCellIterator.h.

◆ Faces

vtkIdList* vtkCellIterator::Faces

protected

Definition at line 292 of file vtkCellIterator.h.

The documentation for this class was generated from the following file:

Common/DataModel/vtkCellIterator.h

Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ vtkCellIterator()

◆ ~vtkCellIterator()

Member Function Documentation

◆ PrintSelf()

◆ vtkAbstractTypeMacro()

◆ InitTraversal()

◆ GoToNextCell()

◆ IsDoneWithTraversal()

◆ GetCellType()

◆ GetCellDimension()

◆ GetCellId()

◆ GetPointIds()

◆ GetPoints()

◆ GetFaces()

◆ GetCell()

◆ GetNumberOfPoints()

◆ GetNumberOfFaces()

◆ ResetToFirstCell()

◆ IncrementToNextCell()

◆ FetchCellType()

◆ FetchPointIds()

◆ FetchPoints()

◆ FetchFaces()

Member Data Documentation

◆ CellType

◆ Points

◆ PointIds

◆ Faces