tesseract/cutil/bitvec.cpp
2007-03-07 20:03:40 +00:00

123 lines
4.4 KiB
C++

/******************************************************************************
** 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 "emalloc.h"
#include "freelist.h"
#include "callcpp.h"
#include <stdio.h>
/**----------------------------------------------------------------------------
Global Data Definitions and Declarations
----------------------------------------------------------------------------**/
static int BitVectorCount = 0;
/**----------------------------------------------------------------------------
Public Code
----------------------------------------------------------------------------**/
/*---------------------------------------------------------------------------*/
BIT_VECTOR ExpandBitVector(BIT_VECTOR Vector, int NewNumBits) {
/*
** Parameters:
** Vector bit vector to be expanded
** NewNumBits new size of bit vector
** Globals: none
** Operation: This routine uses realloc to increase the size of
** the specified bit vector.
** Return: New expanded bit vector.
** Exceptions: none
** History: Fri Nov 16 10:11:16 1990, DSJ, Created.
*/
return ((BIT_VECTOR) Erealloc (Vector,
sizeof (unsigned long) *
WordsInVectorOfSize (NewNumBits)));
} /* ExpandBitVector */
/*---------------------------------------------------------------------------*/
void FreeBitVector(BIT_VECTOR BitVector) {
/*
** Parameters:
** BitVector bit vector to be freed
** Globals:
** BitVectorCount count of number of bit vectors allocated
** Operation: This routine frees a bit vector. It also decrements
** the global counter that keeps track of the number of
** bit vectors allocated. If BitVector is NULL, then
** the count is printed to stderr.
** Return: none
** Exceptions: none
** History: Tue Oct 23 16:46:09 1990, DSJ, Created.
*/
if (BitVector) {
memfree(BitVector);
BitVectorCount--;
}
else {
cprintf ("%6d BITVECTOR elements in use\n", BitVectorCount);
}
} /* FreeBitVector */
/*hamming_distance(array1,array2,length) computes the hamming distance
between two bit strings */
/*--------------------------------------------------------------------------*/
int hamming_distance( /*arrays to match */
register unsigned long *array1,
register unsigned long *array2,
register int length) { /*length of arrays */
register unsigned long 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) {
/*
** Parameters:
** NumBits number of bits in new bit vector
** Globals:
** BitVectorCount number of bit vectors allocated
** Operation: Allocate and return a new bit vector large enough to
** hold the specified number of bits.
** Return: New bit vector.
** Exceptions: none
** History: Tue Oct 23 16:51:27 1990, DSJ, Created.
*/
BitVectorCount++;
return ((BIT_VECTOR) Emalloc (sizeof (unsigned long) *
WordsInVectorOfSize (NumBits)));
} /* NewBitVector */