tesseract-ocr/cutil/bitvec.cpp

Go to the documentation of this file.

/******************************************************************************
 **     Filename:    bitvec.c
 **     Purpose:     Routines for manipulating bit vectors
 **     Author:      Dan Johnson
 **     History:     Thu Mar 15 10:37:27 1990, DSJ, Created.
 **
 **     (c) Copyright Hewlett-Packard Company, 1988.
 ** Licensed under the Apache License, Version 2.0 (the "License");
 ** you may not use this file except in compliance with the License.
 ** You may obtain a copy of the License at
 ** http://www.apache.org/licenses/LICENSE-2.0
 ** Unless required by applicable law or agreed to in writing, software
 ** distributed under the License is distributed on an "AS IS" BASIS,
 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 ** See the License for the specific language governing permissions and
 ** limitations under the License.
 ******************************************************************************/

/*-----------------------------------------------------------------------------
          Include Files and Type Defines
-----------------------------------------------------------------------------*/
#include "bitvec.h"

#include <stdio.h>

#include "emalloc.h"
#include "freelist.h"
#include "tprintf.h"

/*-----------------------------------------------------------------------------
              Public Code
-----------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
BIT_VECTOR ExpandBitVector(BIT_VECTOR Vector, int NewNumBits) {
  return ((BIT_VECTOR) Erealloc(Vector,
    sizeof(Vector[0]) * WordsInVectorOfSize(NewNumBits)));
}                                /* ExpandBitVector */


/*---------------------------------------------------------------------------*/
void FreeBitVector(BIT_VECTOR BitVector) {
  if (BitVector) {
    Efree(BitVector);
  }
}                                /* FreeBitVector */


/*--------------------------------------------------------------------------*/
int hamming_distance(uinT32* array1, uinT32* array2, int length) {
  register uinT32 diff;   /*bit difference */
  register int dist;             /*total distance */

  dist = 0;
  for (; length > 0; length--) {
    diff = *array1++ ^ *array2++;/*different bits */
    while (diff) {
      diff &= diff - 1;          /*lose a bit */
      dist++;
    }
  }
  return dist;                   /*total distance */
}


/*---------------------------------------------------------------------------*/
BIT_VECTOR NewBitVector(int NumBits) {
  return ((BIT_VECTOR) Emalloc(sizeof(uinT32) *
    WordsInVectorOfSize(NumBits)));
}                                /* NewBitVector */