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

  Program:   Visualization Toolkit
  Module:    $RCSfile: vtkHyperOctreeCursor.h,v $

  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 vtkHyperOctreeCursor - Objects that can traverse hyperoctree nodes.
// .SECTION Description
// Objects that can traverse hyperoctree nodes. It is an abstract class.
// Cursors are created by the hyperoctree.
// .SECTION See Also
// vtkDataObject vtkFieldData vtkHyperOctreeAlgorithm

#ifndef __vtkHyperOctreeCursor_h
#define __vtkHyperOctreeCursor_h

#include "vtkObject.h"

enum
{
  VTK_OCTREE_CHILD_ZMIN_YMIN_XMIN=0,
  VTK_OCTREE_CHILD_ZMIN_YMIN_XMAX,
  VTK_OCTREE_CHILD_ZMIN_YMAX_XMIN,
  VTK_OCTREE_CHILD_ZMIN_YMAX_XMAX,
  VTK_OCTREE_CHILD_ZMAX_YMIN_XMIN,
  VTK_OCTREE_CHILD_ZMAX_YMIN_XMAX,
  VTK_OCTREE_CHILD_ZMAX_YMAX_XMIN,
  VTK_OCTREE_CHILD_ZMAX_YMAX_XMAX
};

const int VTK_QUADTREE_CHILD_SW=VTK_OCTREE_CHILD_ZMIN_YMIN_XMIN;
const int VTK_QUADTREE_CHILD_SE=VTK_OCTREE_CHILD_ZMIN_YMIN_XMAX;
const int VTK_QUADTREE_CHILD_NW=VTK_OCTREE_CHILD_ZMIN_YMAX_XMIN;
const int VTK_QUADTREE_CHILD_NE=VTK_OCTREE_CHILD_ZMIN_YMAX_XMAX;

const int VTK_BINARY_TREE_CHILD_LEFT=VTK_QUADTREE_CHILD_SW;
const int VTK_BINARY_TREE_CHILD_RIGHT=VTK_QUADTREE_CHILD_SE;

class VTK_FILTERING_EXPORT vtkHyperOctreeCursor : public vtkObject
{
public:
  vtkTypeRevisionMacro(vtkHyperOctreeCursor,vtkObject);
  void PrintSelf(ostream& os, vtkIndent indent);
  
  // Description:
  // Return the index of the current leaf in the data arrays.
  // \pre is_leaf: CurrentIsLeaf()
  virtual int GetLeafId()=0;
  
  // Description:
  // Is the node pointed by the cursor a leaf?
  virtual int CurrentIsLeaf()=0;
  
  // Description:
  // Is the node pointed by the cursor the root?
  virtual int CurrentIsRoot()=0;
  
  // Description:
  // Return the level of the node pointed by the cursor.
  // \post positive_result: result>=0
  virtual int GetCurrentLevel()=0;
  
  // Description:
  // Return the child number of the current node relative to its parent.
  // \pre not_root: !CurrentIsRoot().
  // \post valid_range: result>=0 && result<GetNumberOfChildren()
  virtual int GetChildIndex()=0;
  
  // Are the children of the current node all leaves?
  // This query can be called also on a leaf node.
  // \post compatible: result implies !CurrentIsLeaf()
  virtual int CurrentIsTerminalNode()=0;
  
  // Description:
  // Move the cursor the root node.
  // \pre can be root
  // \post is_root: CurrentIsRoot()
  virtual void ToRoot()=0;
  
  // Description:
  // Move the cursor to the parent of the current node.
  // \pre not_root: !CurrentIsRoot()
  virtual void ToParent()=0;
  
  // Description:
  // Move the cursor to child `child' of the current node.
  // \pre not_leaf: !CurrentIsLeaf()
  // \pre valid_child: child>=0 && child<this->GetNumberOfChildren()
  virtual void ToChild(int child)=0;
  
  // Description:
  // Move the cursor to the same node pointed by `other'.
  // \pre other_exists: other!=0
  // \pre same_hyperoctree: this->SameTree(other);
  // \post equal: this->IsEqual(other)
  virtual void ToSameNode(vtkHyperOctreeCursor *other)=0;
 
  // Description:
  // Is `this' equal to `other'?
  // \pre other_exists: other!=0
  // \pre same_hyperoctree: this->SameTree(other);
  virtual int IsEqual(vtkHyperOctreeCursor *other)=0;
  
  // Description:
  // Create a copy of `this'.
  // \post results_exists:result!=0
  // \post same_tree: result->SameTree(this)
  virtual vtkHyperOctreeCursor *Clone()=0;
    
  // Description:
  // Are `this' and `other' pointing on the same hyperoctree?
  // \pre other_exists: other!=0
  virtual int SameTree(vtkHyperOctreeCursor *other)=0;
  
  // Description:
  // Return the index in dimension `d', as if the node was a cell of a
  // uniform grid of 1<<GetCurrentLevel() cells in each dimension.
  // \pre valid_range: d>=0 && d<GetDimension()
  // \post valid_result: result>=0 && result<(1<<GetCurrentLevel())
  virtual int GetIndex(int d)=0;
  
  // Description:
  // Return the number of children for each node of the tree.
  // \post positive_number: result>0
  virtual int GetNumberOfChildren()=0;
  
  // Description:
  // Return the dimension of the tree.
  // \post positive_result: result>0
  virtual int GetDimension()=0;
  
  // Description:
  // Move to the node described by its indices in each dimension and
  // at a given level. If there is actually a node or a leaf at this
  // location, Found() returns true. Otherwise, Found() returns false and the
  // cursor moves to the closest parent of the query. It can be the root in the
  // worst case.
  // \pre indices_exists: indices!=0
  // \pre valid_size: sizeof(indices)==GetDimension()
  // \pre valid_level: level>=0
  virtual void MoveToNode(int *indices,
                          int level)=0;
  
  // Description
  // Did the last call to MoveToNode succeed?
  virtual int Found()=0;
  
protected:
  // Constructor.
  vtkHyperOctreeCursor();
  virtual ~vtkHyperOctreeCursor();
private:
  vtkHyperOctreeCursor(const vtkHyperOctreeCursor&);  // Not implemented.
  void operator=(const vtkHyperOctreeCursor&);    // Not implemented.
};
#endif
