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

  Program:   Visualization Toolkit
  Module:    vtkArrayExtents.h
  
-------------------------------------------------------------------------
  Copyright 2008 Sandia Corporation.
  Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
  the U.S. Government retains certain rights in this software.
-------------------------------------------------------------------------

  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 vtkArrayExtents - Stores the number of dimensions and valid coordinate
// ranges along each dimension for vtkArray.
//
// .SECTION Description
// vtkArrayExtents describes the number of dimensions and coordinate ranges
//  along each dimension of an N-way collection of values.  It is used to
// retrieve and update the extents of a vtkArray object.
//
// Conceptually, vtkArrayExtents is a collection of vtkArrayRange objects,
// one per dimension, that store the half-open range of valid coordinates
// (the "extent") for that dimension.  Because each extent is stored as a
// range rather than a size, you can: create arrays that use one-based
// coordinates for consistency with mathematics and tools such as MATLAB;
// easily represent arbitrary subsets of an array; and easily store and
// manipulate distributed arrays using "global" coordinates.
//
// Convenience constructors are provided for creating extents along one, two,
// and three dimensions.  For higher dimensions, you can:
//
// Use the static Uniform() factory method to create extents that have the same
// size along an arbitrary number of dimensions.
//
// Use the default constructor and the Append() method to "grow" your extents
// to the correct number of dimensions.
// 
// Use the default constructuor, SetDimensions() and operator[] to assign a
// size along each dimension.
//
// .SECTION See Also
// vtkArray, vtkArrayRange, vtkArrayCoordinates
//
// .SECTION Thanks
// Developed by Timothy M. Shead (tshead@sandia.gov) at Sandia National Laboratories.

#ifndef __vtkArrayExtents_h
#define __vtkArrayExtents_h

#include "vtkSystemIncludes.h"
#include "vtkArrayRange.h"
#include <vtksys/stl/vector> // STL Header

class vtkArrayCoordinates;

class VTK_COMMON_EXPORT vtkArrayExtents
{
public:
  // Description:
  // Create zero-dimensional extents.
  vtkArrayExtents();
  
  // Description:
  // Create one-dimensional extents.  This constructor is shorthand for
  // vtkArrayExtents(vtkArrayRange(0, i)).
  explicit vtkArrayExtents(const vtkIdType i);
  // Description:
  // Create one-dimensional extents. 
  explicit vtkArrayExtents(const vtkArrayRange& i);
  
  // Description:
  // Create two-dimensional extents.  This constructor is shorthand for
  // vtkArrayExtents(vtkArrayRange(0, i), vtkArrayRange(0, j)).
  vtkArrayExtents(const vtkIdType i, const vtkIdType j);
  // Description:
  // Create two-dimensional extents.
  vtkArrayExtents(const vtkArrayRange& i, const vtkArrayRange& j);
  
  // Description:
  // Create three-dimensional extents.  This constructor is shorthand for
  // vtkArrayExtents(vtkArrayRange(0, i), vtkArrayRange(0, j), vtkArrayRange(0, k)).
  vtkArrayExtents(const vtkIdType i, const vtkIdType j, const vtkIdType k);
  // Description:
  // Create two-dimensional extents.
  vtkArrayExtents(const vtkArrayRange& i, const vtkArrayRange& j, const vtkArrayRange& k);
  
  // Description:
  // Create n-dimensional extents with extent [0, m) along each dimension.  This
  // is useful for creating e.g: a square matrix.
  static const vtkArrayExtents Uniform(vtkIdType n, vtkIdType m);

  // Description:
  // Grow the number of dimensions by one, specifying the extent
  // of the new dimension.
  void Append(const vtkArrayRange& extent);

  // Description:
  // Return the current number of dimensions.
  vtkIdType GetDimensions() const;
  
  // Description:
  // Return the number of values that *could* be stored using the
  // current extents.  This is equal to the product of the size of the
  // extent along each dimension.
  vtkIdType GetSize() const;

  // Description:
  // Set the current number of dimensions.  Note that this method
  // resets the extent along each dimension to an empty range, so you
  // must assign each dimension's extent explicitly using operator[]
  // after calling SetDimensions().
  void SetDimensions(vtkIdType dimensions);
  
  // Description:
  // Accesses the extent of the i-th dimension.
  vtkArrayRange& operator[](vtkIdType i);
  
  // Description:
  // Accesses the extent of the i-th dimension.
  const vtkArrayRange& operator[](vtkIdType i) const;
  
  // Description:
  // Equality comparison
  bool operator==(const vtkArrayExtents& rhs) const;
  
  // Description:
  // Inequality comparison
  bool operator!=(const vtkArrayExtents& rhs) const;

  // Description:
  // Returns true iff every range in the current extents is zero-based.
  // This is useful as a precondition test for legacy filters / operations
  // that predate the switch to range-based extents and assume that all extents
  // are zero-based.  In general, new code should be written to work with
  // arbitrary range extents, so won't need to perform this check.
  bool ZeroBased() const;

  // Description:
  // Returns true iff the given extents have the same number of dimensions
  // and size along each dimension.  Note that the ranges along each dimension
  // may have different values, so long as their sizes match.
  bool SameShape(const vtkArrayExtents& rhs) const;

  // Description:
  // Returns coordinates that reference the n-th value in the extents, where
  // n is in the range [0, GetSize()).  The returned coordinates will be ordered
  // so that the left-most indices vary fastest.  The is equivalent to column-major
  // ordering for matrices, and corresponds to the order in which consecutive array
  // values would be stored in languages such as Fortran, MATLAB, Octave, and R.
  void GetLeftToRightCoordinatesN(vtkIdType n, vtkArrayCoordinates& coordinates) const;
  // Description:
  // Returns coordinates that reference the n-th value in the extents, where
  // n is in the range [0, GetSize()).  The returned coordinates will be ordered
  // so that the right-most indices vary fastest.  The is equivalent to row-major
  // ordering for matrices, and corresponds to the order in which consecutive array
  // values would be stored in languages including C and C++.
  void GetRightToLeftCoordinatesN(vtkIdType n, vtkArrayCoordinates& coordinates) const;

  // Description:
  // Returns true if the given extents are a non-overlapping subset of the
  // current extents.  Returns false if any of the given extents fall outside
  // the current extents, or there is a mismatch in the number of dimensions.
  bool Contains(const vtkArrayExtents& extents) const;

  // Description:
  // Returns true if the given array coordinates are completely contained
  // by the current extents (i.e. extent begin <= coordinate and coordinate < extent end
  // along every dimension).  Returns false if the array coordinates are outside
  // the current extents, or contain a different number of dimensions.
  bool Contains(const vtkArrayCoordinates& coordinates) const;

  VTK_COMMON_EXPORT friend ostream& operator<<(
    ostream& stream, const vtkArrayExtents& rhs);
  
private:
  vtksys_stl::vector<vtkArrayRange> Storage;
};

#endif

