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

  Program:   Visualization Toolkit
  Module:    vtkBitArray.h
  Language:  C++
  Date:      $Date$
  Version:   $Revision$


Copyright (c) 1993-1998 Ken Martin, Will Schroeder, Bill Lorensen.

This software is copyrighted by Ken Martin, Will Schroeder and Bill Lorensen.
The following terms apply to all files associated with the software unless
explicitly disclaimed in individual files. This copyright specifically does
not apply to the related textbook "The Visualization Toolkit" ISBN
013199837-4 published by Prentice Hall which is covered by its own copyright.

The authors hereby grant permission to use, copy, and distribute this
software and its documentation for any purpose, provided that existing
copyright notices are retained in all copies and that this notice is included
verbatim in any distributions. Additionally, the authors grant permission to
modify this software and its documentation for any purpose, provided that
such modifications are not distributed without the explicit consent of the
authors and that existing copyright notices are retained in all copies. Some
of the algorithms implemented by this software are patented, observe all
applicable patent law.

IN NO EVENT SHALL THE AUTHORS OR DISTRIBUTORS BE LIABLE TO ANY PARTY FOR
DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT
OF THE USE OF THIS SOFTWARE, ITS DOCUMENTATION, OR ANY DERIVATIVES THEREOF,
EVEN IF THE AUTHORS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

THE AUTHORS AND DISTRIBUTORS SPECIFICALLY DISCLAIM ANY WARRANTIES, INCLUDING,
BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
PARTICULAR PURPOSE, AND NON-INFRINGEMENT.  THIS SOFTWARE IS PROVIDED ON AN
"AS IS" BASIS, AND THE AUTHORS AND DISTRIBUTORS HAVE NO OBLIGATION TO PROVIDE
MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.


=========================================================================*/
// .NAME vtkBitArray - dynamic, self-adjusting array of bits
// .SECTION Description
// vtkBitArray is an array of bits (0/1 data value). The array is packed 
// so that each byte stores eight bits. vtkBitArray provides methods
// for insertion and retrieval of bits, and will automatically resize 
// itself to hold new data.

#ifndef __vtkBitArray_h
#define __vtkBitArray_h

#include "vtkObject.h"

class VTK_EXPORT vtkBitArray : public vtkObject 
{
public:
  vtkBitArray():Array(NULL),Size(0),MaxId(-1),Extend(1000) {};
  int Allocate(const int sz, const int ext=1000);
  void Initialize();
  vtkBitArray(const int sz, const int ext=1000);
  vtkBitArray(const vtkBitArray& ia);
  ~vtkBitArray();
  static vtkBitArray *New() {return new vtkBitArray;};
  virtual const char *GetClassName() {return "vtkBitArray";};
  void PrintSelf(ostream& os, vtkIndent indent);

  // access/insertion methods
  int GetValue(const int id);
  void SetNumberOfValues(const int number);
  void SetValue(const int id, const int value);
  vtkBitArray &InsertValue(const int id, const int i);
  int InsertNextValue(const int i);
  unsigned char *GetPointer(const int id);
  unsigned char *WritePointer(const int id, const int number);

  // special operators
  vtkBitArray &operator=(const vtkBitArray& ia);
  vtkBitArray &operator+=(const vtkBitArray& ia);
  void operator+=(const char i);

  // miscellaneous methods
  void Squeeze();
  int GetSize();
  int GetMaxId();
  void Reset();

private:
  unsigned char *Array;   // pointer to data
  int Size;       // allocated size of data
  int MaxId;     // maximum index inserted thus iar
  int Extend;     // grow array by this point
  unsigned char *Resize(const int sz);  // function to resize data
};

// Description:
// Get the address of a particular data index.
inline unsigned char *vtkBitArray::GetPointer(const int id)
{
  return this->Array + id/8;
};

// Description:
// Get the address of a particular data index. Make sure data is allocated
// for the number of items requested. Set MaxId according to the number of
// data values requested.
inline unsigned char *vtkBitArray::WritePointer(const int id, const int number)
{
  int newSize=id+number;
  if ( newSize > this->Size ) this->Resize(newSize);
  if ( (--newSize) > this->MaxId ) this->MaxId = newSize;
  return this->Array + id/8;
}

// Description:
// Specify the number of values for this object to hold. Does an
// allocation as well as setting the MaxId ivar. Used in conjunction with
// SetValue() method for fast insertion.
inline void vtkBitArray::SetNumberOfValues(const int number) 
{
  this->Allocate(number);
  this->MaxId = number - 1;
}

// Description:
// Set the data at a particular index. Does not do range checking. Make sure
// you use the method SetNumberOfValues() before inserting data.
inline void vtkBitArray::SetValue(const int id, const int value) 
{
  if (value) this->Array[id/8] |= (0x80 >> id%8);
  else this->Array[id/8] &= (~(0x80 >> id%8));
}

// Description:
// Insert data at a specified position in the array.
inline vtkBitArray& vtkBitArray::InsertValue(const int id, const int i)
{
  if ( id >= this->Size ) this->Resize(id+1);
  if (i) this->Array[id/8] |= (0x80 >> id%8);
  else this->Array[id/8] &= (~(0x80 >> id%8));
  if ( id > this->MaxId ) this->MaxId = id;
  return *this;
}

// Description:
// Insert data at the end of the array. Return its location in the array.
inline int vtkBitArray::InsertNextValue(const int i)
{
  this->InsertValue (++this->MaxId,i); return this->MaxId;
}
inline void vtkBitArray::operator+=(const char i) 
{
  this->InsertNextValue(i);
}

// Description:
// Resize object to just fit data requirement. Reclaims extra memory.
inline void vtkBitArray::Squeeze() {this->Resize (this->MaxId+1);}

// Description:
// Get the allocated size of the object in terms of number of data items.
inline int vtkBitArray::GetSize() {return this->Size;}

// Description:
// Returning the maximum index of data inserted so far.
inline int vtkBitArray::GetMaxId() {return this->MaxId;}

// Description:
// Reuse the memory allocated by this object. Object appears as if
// no data has been previously inserted.
inline void vtkBitArray::Reset() {this->MaxId = -1;}

#endif

