vtkArrayExtents.h

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

  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.

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

/**
 * @class   vtkArrayExtents
 * @brief   Stores the number of dimensions and valid
 * coordinate ranges along each dimension for vtkArray.
 *
 *
 * 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.
 *
 * @sa
 * vtkArray, vtkArrayRange, vtkArrayCoordinates
 *
 * @par Thanks:
 * Developed by Timothy M. Shead (tshead@sandia.gov) at Sandia National
 * Laboratories.
 */

#ifndef vtkArrayExtents_h
#define vtkArrayExtents_h

#include "vtkArrayRange.h"
#include "vtkCommonCoreModule.h" // For export macro
#include "vtkSystemIncludes.h"
#include <vector> // STL Header

class VTKCOMMONCORE_EXPORT vtkArrayExtents
{
public:
  typedef vtkArrayCoordinates::DimensionT DimensionT;
  typedef vtkArrayCoordinates::CoordinateT CoordinateT;
  typedef vtkTypeUInt64 SizeT;

  /**
   * Create zero-dimensional extents.
   */
  vtkArrayExtents();

  /**
   * Create zero-based one-dimensional extents.  This constructor is shorthand for
   * vtkArrayExtents(vtkArrayRange(0, i)).
   */
  explicit vtkArrayExtents(const CoordinateT i);
  /**
   * Create one-dimensional extents.
   */
  explicit vtkArrayExtents(const vtkArrayRange& i);

  /**
   * Create zero-based two-dimensional extents.  This constructor is shorthand for
   * vtkArrayExtents(vtkArrayRange(0, i), vtkArrayRange(0, j)).
   */
  vtkArrayExtents(const CoordinateT i, const CoordinateT j);
  /**
   * Create two-dimensional extents.
   */
  vtkArrayExtents(const vtkArrayRange& i, const vtkArrayRange& j);

  /**
   * Create zero-based three-dimensional extents.  This constructor is shorthand for
   * vtkArrayExtents(vtkArrayRange(0, i), vtkArrayRange(0, j),
   * vtkArrayRange(0, k)).
   */
  vtkArrayExtents(const CoordinateT i, const CoordinateT j, const CoordinateT k);
  /**
   * Create three-dimensional extents.
   */
  vtkArrayExtents(const vtkArrayRange& i, const vtkArrayRange& j, const vtkArrayRange& k);

  /**
   * Create n-dimensional extents with extent [0, m) along each dimension.
   * This is useful for creating e.g: a square matrix.
   */
  static vtkArrayExtents Uniform(DimensionT n, CoordinateT m);

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

  /**
   * Return the current number of dimensions.
   */
  DimensionT GetDimensions() const;

  /**
   * 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.
   */
  SizeT GetSize() const;

  /**
   * 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(DimensionT dimensions);

  /**
   * Accesses the extent of the i-th dimension.
   */
  vtkArrayRange& operator[](DimensionT i);

  /**
   * Accesses the extent of the i-th dimension.
   */
  const vtkArrayRange& operator[](DimensionT i) const;

  /**
   * Get the extent of the i-th dimension.
   */
  vtkArrayRange GetExtent(DimensionT i) const;

  /**
   * Set the extent of the i-th dimension.
   */
  void SetExtent(DimensionT i, const vtkArrayRange&);

  /**
   * Equality comparison
   */
  bool operator==(const vtkArrayExtents& rhs) const;

  /**
   * Inequality comparison
   */
  bool operator!=(const vtkArrayExtents& rhs) const;

  /**
   * 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;

  /**
   * 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;

  /**
   * 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.  This 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(SizeT n, vtkArrayCoordinates& coordinates) const;

  /**
   * 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.  This 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(SizeT n, vtkArrayCoordinates& coordinates) const;

  /**
   * 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;

  /**
   * 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;

  VTKCOMMONCORE_EXPORT friend ostream& operator<<(ostream& stream, const vtkArrayExtents& rhs);

private:
  std::vector<vtkArrayRange> Storage;
};

#endif
// VTK-HeaderTest-Exclude: vtkArrayExtents.h