crawl-ref/source/bitary.cc

   1 /*
   2  *  File:         bitary.cc
   3  *  Summary:      Bit array data type.
   4  *  Created by:   Robert Vollmert
   5  */
   6
   7 #include "AppHdr.h"
   8
   9 #include "bitary.h"
  10
  11 #include "debug.h"
  12
  13 #define LONGSIZE (sizeof(unsigned long)*8)
  14
  15 bit_array::bit_array(unsigned long s)
  16     : size(s)
  17 {
  18     nwords = static_cast<int>((size + LONGSIZE - 1) / LONGSIZE);
  19     data = new unsigned long[nwords];
  20     reset();
  21 }
  22
  23 bit_array::~bit_array()
  24 {
  25     delete[] data;
  26 }
  27
  28 void bit_array::reset()
  29 {
  30     for (int w = 0; w < nwords; ++w)
  31         data[w] = 0;
  32 }
  33
  34 bool bit_array::get(unsigned long index) const
  35 {
  36     ASSERT(index < size);
  37     int w = index / LONGSIZE;
  38     int b = index % LONGSIZE;
  39     return (data[w] & (1UL << b));
  40 }
  41
  42 void bit_array::set(unsigned long index, bool value)
  43 {
  44     ASSERT(index < size);
  45     int w = index / LONGSIZE;
  46     int b = index % LONGSIZE;
  47     if (value)
  48         data[w] |= (1UL << b);
  49     else
  50         data[w] &= ~(1UL << b);
  51 }
  52
  53 bit_array& bit_array::operator |= (const bit_array& other)
  54 {
  55     ASSERT(size == other.size);
  56     for (int w = 0; w < nwords; ++w)
  57         data[w] |= other.data[w];
  58     return (*this);
  59 }
  60
  61 bit_array& bit_array::operator &= (const bit_array& other)
  62 {
  63     ASSERT(size == other.size);
  64     for (int w = 0; w < nwords; ++w)
  65         data[w] &= other.data[w];
  66     return (*this);
  67 }
  68
  69 bit_array bit_array::operator & (const bit_array& other) const
  70 {
  71     ASSERT(size == other.size);
  72     bit_array res = bit_array(size);
  73     for (int w = 0; w < nwords; ++w)
  74         res.data[w] = data[w] & other.data[w];
  75     return (res);
  76 }