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

  Program:   Visualization Toolkit
  Module:    vtkIncrementalPointLocator.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.

=========================================================================*/
// .NAME vtkIncrementalPointLocator - Abstract class in support of both
//  point location and point insertion.
// 
// .SECTION Description
//  Compared to a static point locator for pure location functionalities 
//  through some search structure established from a fixed set of points,
//  an incremental point locator allows for, in addition, point insertion
//  capabilities, with the search structure maintaining a dynamically
//  increasing number of points. There are two incremental point locators,
//  i.e., vtkPointLocator and vtkIncrementalOctreePointLocator. As opposed
//  to the uniform bin-based search structure (adopted in vtkPointLocator)
//  with a fixed spatial resolution, an octree mechanism (employed in
//  vtkIncrementalOctreePointlocator) resorts to a hierarchy of tree-like
//  sub-division of the 3D data domain. Thus it enables data-aware multi-
//  resolution and accordingly accelerated point location as well as point
//  insertion, particularly when handling a radically imbalanced layout of
//  points as not uncommon in datasets defined on adaptive meshes. In other
//  words, vtkIncrementalOctreePointLocator is an octree-based accelerated
//  implementation of all functionalities of vtkPointLocator. 
//  
// .SECTION See Also
//  vtkLocator, vtkIncrementalOctreePointLocator, vtkPointLocator, 
//  vtkMergePoints

#ifndef __vtkIncrementalPointLocator_h
#define __vtkIncrementalPointLocator_h

#include "vtkAbstractPointLocator.h"

class vtkPoints;
class vtkIdList;

class VTK_FILTERING_EXPORT vtkIncrementalPointLocator : public vtkAbstractPointLocator
{
public:

  vtkTypeMacro( vtkIncrementalPointLocator, vtkAbstractPointLocator );
  void PrintSelf( ostream & os, vtkIndent indent );
  
  // Description:
  // Delete the search structure.
  virtual void Initialize() = 0;
  
  // Description:
  // Given a point x assumed to be covered by the search structure, return the
  // index of the closest point (already inserted to the search structure) 
  // regardless of the associated minimum squared distance relative to the 
  // squared insertion-tolerance distance. This method is used when performing
  // incremental point insertion. Note -1 indicates that no point is found. 
  // InitPointInsertion() should have been called in advance.
  virtual vtkIdType FindClosestInsertedPoint( const double x[3] ) = 0;
 
  // -------------------------------------------------------------------------
  // ---------------------------- Point  Location ----------------------------
  // ---- All virtual functions related to point location are declared by ---- 
  // --------------- the parent class  vtkAbstractPointLocator ---------------
  // -------------------------------------------------------------------------
                                   
  // -------------------------------------------------------------------------
  // ---------------------------- Point Insertion ----------------------------
  // -------------------------------------------------------------------------

  // Description:
  // Initialize the point insertion process. newPts is an object, storing 3D
  // point coordinates, to which incremental point insertion puts coordinates.
  // It is created and provided by an external VTK class. Argument bounds
  // represents the spatial bounding box, into which the points fall.
  virtual int InitPointInsertion( vtkPoints * newPts, const double bounds[6] ) = 0;
    
  // Description:
  // Initialize the point insertion process. newPts is an object, storing 3D
  // point coordinates, to which incremental point insertion puts coordinates.
  // It is created and provided by an external VTK class. Argument bounds
  // represents the spatial bounding box, into which the points fall.
  virtual int InitPointInsertion( vtkPoints * newPts, const double bounds[6], 
                                  vtkIdType estSize ) = 0;
                                  
  // Description:
  // Determine whether or not a given point has been inserted. Return the id of 
  // the already inserted point if true, else return -1. InitPointInsertion()
  // should have been called in advance.
  virtual vtkIdType IsInsertedPoint( double x, double  y, double z ) = 0;
    
  // Description:
  // Determine whether or not a given point has been inserted. Return the id of 
  // the already inserted point if true, else return -1. InitPointInsertion()
  // should have been called in advance.
  virtual vtkIdType IsInsertedPoint( const double x[3] ) = 0;
  
  // Description:
  // Insert a point unless there has been a duplciate in the search structure. 
  // This method is not thread safe.
  virtual int InsertUniquePoint( const double x[3], vtkIdType & ptId ) = 0;
  
  // Description:
  // Insert a given point with a specified point index ptId. InitPointInsertion()
  // should have been called prior to this function. Also, IsInsertedPoint()
  // should have been called in advance to ensure that the given point has not 
  // been inserted unless point duplication is allowed.
  virtual void InsertPoint( vtkIdType ptId, const double x[3] ) = 0;
  
  // Description:
  // Insert a given point and return the point index. InitPointInsertion()
  // should have been called prior to this function. Also, IsInsertedPoint() 
  // should have been called in advance to ensure that the given point has not
  // been inserted unless point duplication is allowed.
  virtual vtkIdType InsertNextPoint( const double x[3] ) = 0;
  
protected:
  vtkIncrementalPointLocator();
  virtual ~vtkIncrementalPointLocator();
  
private:
  vtkIncrementalPointLocator( const vtkIncrementalPointLocator & );  // Not implemented.
  void operator = ( const vtkIncrementalPointLocator & );            // Not implemented.
};

#endif
