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

  Program:   Visualization Toolkit
  Module:    vtkTableBasedClipDataSet.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.

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


/*****************************************************************************
*
* Copyright (c) 2000 - 2009, Lawrence Livermore National Security, LLC
* Produced at the Lawrence Livermore National Laboratory
* LLNL-CODE-400124
* All rights reserved.
*
* This file was adapted from the VisIt clipper (vtkVisItClipper). For  details,
* see https://visit.llnl.gov/.  The full copyright notice is contained in the
* file COPYRIGHT located at the root of the VisIt distribution or at 
* http://www.llnl.gov/visit/copyright.html.
*
*****************************************************************************/


// .NAME vtkTableBasedClipDataSet - Clip any dataset with a user-specified 
//  implicit function or an input scalar point data array. 
//
// .SECTION Description
//  vtkTableBasedClipDataSet is a filter that clips any type of dataset using 
//  either any subclass of vtkImplicitFunction or an input scalar point data 
//  array. Clipping means that it actually "cuts" through the cells of the 
//  dataset, returning everything outside the specified implicit function (or 
//  greater than the scalar value) including "pieces" of a cell (Note to compare 
//  this with vtkExtractGeometry, which pulls out entire, uncut cells). The 
//  output of this filter is a vtkUnstructuredGrid data.
//
//  To use this filter, you need to decide whether an implicit function or an 
//  input scalar point data array is used for clipping. For the former case, 
//  1) define an implicit function
//  2) provide it to this filter via SetClipFunction()
//  If a clipping function is not specified, or GenerateClipScalars is off( the 
//  default), the input scalar point data array is then employed for clipping.
//
//  You can also specify a scalar (iso-)value, which is used to decide what is
//  inside and outside the implicit function. You can also reverse the sense of 
//  what inside/outside is by setting IVAR InsideOut. The clipping algorithm 
//  proceeds by computing an implicit function value or using the input scalar 
//  point data value for each point in the dataset. This is compared against the 
//  scalar (iso-)value to determine the inside/outside status.
//
//  Although this filter sometimes (but rarely) may resort to the sibling class
//  vtkClipDataSet for handling some special grids (such as cylinders or cones 
//  with capping faces in the form of a vtkPolyData), it itself is able to deal
//  with most grids. It is worth mentioning that vtkTableBasedClipDataSet is 
//  capable of addressing the artifacts that may occur with vtkClipDataSet due 
//  to the possibly inconsistent triagulation modes between neighboring cells. 
//  In addition, the former is much faster than the latter. Furthermore, the 
//  former produces less cells (with ratio usually being 5~6) than by the latter 
//  in the output. In other words, this filter retains the original cells (i.e., 
//  without triangulation / tetrahedralization) wherever possible. All these 
//  advantages are gained by adopting the unique clipping and triangulation tables
//  proposed by VisIt.
//
// .SECTION Caveats
//  vtkTableBasedClipDataSet makes use of a hash table (that is provided by class
//  maintained by internal class vtkTableBasedClipperDataSetFromVolume) to achieve
//  rapid removal of duplicate points. The hash-based mechanism simply compares the
//  point Ids, without considering the actual inter-point distance (vtkClipDataSet 
//  adopts vtkMergePoints that though considers the inter-point distance for robust 
//  points merging ). As a result, some duplicate points may be present in the output. 
//  This problem occurs when some boundary (cut-through cells) happen to have faces 
//  EXACTLY aligned with the clipping plane (such as Plane, Box, or other implicit 
//  functions with planar shapes). The occurrence (though very rare) of duplicate 
//  points produces degenerate cells, which can be fixed by post-processing the 
//  output with a filter like vtkCleanGrid.
//
// .SECTION Thanks
//  This filter was adapted from the VisIt clipper (vtkVisItClipper).
//
// .SECTION See Also
//  vtkClipDataSet vtkClipVolume vtkClipPolyData vtkCutter vtkImplicitFunction


#ifndef __vtkTableBasedClipDataSet_h
#define __vtkTableBasedClipDataSet_h

#include "vtkUnstructuredGridAlgorithm.h"

class vtkCallbackCommand;
class vtkImplicitFunction;
class vtkIncrementalPointLocator;

class VTK_GRAPHICS_EXPORT vtkTableBasedClipDataSet : public vtkUnstructuredGridAlgorithm
{
public:
  vtkTypeMacro( vtkTableBasedClipDataSet, vtkUnstructuredGridAlgorithm );
  void PrintSelf( ostream & os, vtkIndent indent );

  // Description:
  // Create an instance with a user-specified implicit function, turning off
  // IVARs InsideOut and GenerateClipScalars and setting IVAR Value to 0.0.
  static vtkTableBasedClipDataSet * New();
  
  // Description:
  // Get the MTime for which the point locator and clip function are consdiered.
  unsigned long GetMTime();
  
  // Description:
  // Set/Get the InsideOut flag. With this flag off, a vertex is considered
  // inside (the implicit function or the isosurface) if the (function or scalar)
  // value is greater than IVAR Value. With this flag on, a vertex is considered
  // inside (the implicit function or the isosurface) if the (function or scalar)
  // value is less than or equal to IVAR Value. This flag is off by default.
  vtkSetMacro( InsideOut, int );
  vtkGetMacro( InsideOut, int );
  vtkBooleanMacro( InsideOut, int );

  // Description:
  // Set/Get the clipping value of the implicit function (if an implicit function
  // is applied) or scalar data array (if a scalar data array is used), with 0.0
  // as the default value. This value is ignored if flag UseValueAsOffset is true
  // AND a clip function is defined.
  vtkSetMacro( Value, double );
  vtkGetMacro( Value, double );
  
  // Description:
  // Set/Get flag UseValueAsOffset, with true as the default value. With this flag
  // on, IVAR Value is used as an offset parameter to the implicit function. Value 
  // is used only when clipping using a scalar array.
  vtkSetMacro( UseValueAsOffset, bool );
  vtkGetMacro( UseValueAsOffset, bool );
  vtkBooleanMacro( UseValueAsOffset, bool );

  // Description
  // Set/Get the implicit function with which to perform the clipping operation. 
  // Unless an implicit function is defined, the specified input scalar data will
  // be used for clipping.
  virtual void SetClipFunction( vtkImplicitFunction * );
  vtkGetObjectMacro( ClipFunction, vtkImplicitFunction );

  // Description:
  // Set/Get flag GenerateClipScalars, with 0 as the default value. With this
  // flag on, the scalar point data values obtained by evaluating the implicit
  // function will be exported to the output. Note that this flag requries that
  // an implicit function be provided.
  vtkSetMacro( GenerateClipScalars, int );
  vtkGetMacro( GenerateClipScalars, int );
  vtkBooleanMacro( GenerateClipScalars, int );

  // Description:
  // Set/Get a point locator locator for merging duplicate points. By default, 
  // an instance of vtkMergePoints is used. Note that this IVAR is provided
  // in this class only because this filter may resort to its sibling class
  // vtkClipDataSet when processing some special grids (such as cylinders or
  // cones with capping faces in the form of a vtkPolyData) while the latter
  // requires a point locator. This filter itself does not need a locator.
  void SetLocator( vtkIncrementalPointLocator * locator );
  vtkGetObjectMacro( Locator, vtkIncrementalPointLocator );
  
  // Description:
  // Set/Get the tolerance used for merging duplicate points near the clipping 
  // intersection cells. This tolerance may prevent the generation of degenerate
  // primitives. Note that only 3D cells actually use this IVAR.
  vtkSetClampMacro( MergeTolerance, double, 0.0001, 0.25 );
  vtkGetMacro( MergeTolerance, double );
  
  // Description:
  // Create a default point locator when none is specified. The point locator is
  // used to merge coincident points.
  void CreateDefaultLocator();
  
  // Description:
  // Set/Get whether a second output is generated. The second output contains the
  // polygonal data that is clipped away by the iso-surface.
  vtkSetMacro( GenerateClippedOutput, int );
  vtkGetMacro( GenerateClippedOutput, int );
  vtkBooleanMacro( GenerateClippedOutput, int );
  
  // Description:
  // Return the clipped output.
  vtkUnstructuredGrid * GetClippedOutput();

protected:
  vtkTableBasedClipDataSet( vtkImplicitFunction * cf = NULL );
  ~vtkTableBasedClipDataSet();

  // Description:
  // Overridden to process REQUEST_UPDATE_EXTENT_INFORMATION.
  virtual int ProcessRequest( vtkInformation *,
                              vtkInformationVector **,
                              vtkInformationVector  *);
  virtual int RequestData( vtkInformation *, 
                           vtkInformationVector **, vtkInformationVector * );
  virtual int FillInputPortInformation( int port, vtkInformation * info );
  
  // Description:
  // This function resorts to the sibling class vtkClipDataSet to handle
  // special grids (such as cylinders or cones with capping faces in the 
  // form a vtkPolyData).
  void ClipDataSet( vtkDataSet * pDataSet, 
                    vtkDataArray * clipAray, vtkUnstructuredGrid * unstruct );
  
  // Description:
  // This function takes a vtkImageData as a vtkRectilinearGrid, which is then
  // clipped by ClipRectilinearGridData(......).
  void ClipImageData( vtkDataSet * inputGrd, vtkDataArray * clipAray, 
                     double isoValue, vtkUnstructuredGrid * outputUG ); 
  
  // Description:
  // This function clips a vtkPolyData object based on a specified iso-value
  // (isoValue) using a scalar point data array (clipAray) that is either just an
  // input scalar point data array or the result of evaluating an implicit function
  // (provided via SetClipFunction()). The clipping result is exported to outputUG.
  void ClipPolyData( vtkDataSet * inputGrd, vtkDataArray * clipAray, 
                     double isoValue, vtkUnstructuredGrid * outputUG ); 
                     
  // Description:
  // This function clips a vtkRectilinearGrid based on a specified iso-value
  // (isoValue) using a scalar point data array (clipAray) that is either just an
  // input scalar point data array or the result of evaluating an implicit function
  // (provided via SetClipFunction()). The clipping result is exported to outputUG.
  void ClipRectilinearGridData( vtkDataSet * inputGrd, vtkDataArray * clipAray, 
                                double isoValue, vtkUnstructuredGrid * outputUG );
                                
  // Description:
  // This function clips a vtkStructuredGrid based on a specified iso-value
  // (isoValue) using a scalar point data array (clipAray) that is either just an
  // input scalar point data array or the result of evaluating an implicit function
  // (provided via SetClipFunction()). The clipping result is exported to outputUG.
  void ClipStructuredGridData( vtkDataSet * inputGrd, vtkDataArray * clipAray, 
                               double isoValue, vtkUnstructuredGrid * outputUG );
                               
  // Description:
  // This function clips a vtkUnstructuredGrid based on a specified iso-value
  // (isoValue) using a scalar point data array (clipAray) that is either just an
  // input scalar point data array or the result of evaluating an implicit function
  // (provided via SetClipFunction()). The clipping result is exported to outputUG.
  void ClipUnstructuredGridData( vtkDataSet * inputGrd, vtkDataArray * clipAray, 
                                 double isoValue, vtkUnstructuredGrid * outputUG );
       
  
  // Description:
  // Register a callback function with the InternalProgressObserver.
  static void InternalProgressCallbackFunction( vtkObject *, unsigned long,
                                                void * clientdata, void * );
  
  // Description:
  // The actual operation executed by the callback function.
  void InternalProgressCallback( vtkAlgorithm * algorithm );
  
  
  int    InsideOut;
  int    GenerateClipScalars;
  int    GenerateClippedOutput;
  bool   UseValueAsOffset;
  double Value;
  double MergeTolerance;
  vtkCallbackCommand         * InternalProgressObserver;
  vtkImplicitFunction        * ClipFunction;
  vtkIncrementalPointLocator * Locator;

private:
  vtkTableBasedClipDataSet( const vtkTableBasedClipDataSet &); // Not implemented.
  void operator= ( const vtkTableBasedClipDataSet & );         // Not implemented.
};

#endif
