/Src/Dependencies/Boost/boost/graph/one_bit_color_map.hpp

  1// Copyright (C) 2005-2010 The Trustees of Indiana University.
  2
  3// Distributed under the Boost Software License, Version 1.0.
  4// (See accompanying file LICENSE_1_0.txt or copy at
  5// http://www.boost.org/LICENSE_1_0.txt)
  6
  7//  Authors: Jeremiah Willcock
  8//           Douglas Gregor
  9//           Andrew Lumsdaine
 10
 11// One bit per color property map (gray and black are the same, green is not
 12// supported)
 13
 14#ifndef BOOST_ONE_BIT_COLOR_MAP_HPP
 15#define BOOST_ONE_BIT_COLOR_MAP_HPP
 16
 17#include <boost/property_map/property_map.hpp>
 18#include <boost/graph/properties.hpp>
 19#include <boost/shared_array.hpp>
 20#include <boost/config.hpp>
 21#include <boost/assert.hpp>
 22#include <algorithm>
 23#include <limits>
 24
 25namespace boost {
 26
 27enum one_bit_color_type { 
 28  one_bit_white     = 0, 
 29  one_bit_not_white  = 1
 30};
 31
 32template <>
 33struct color_traits<one_bit_color_type>
 34{
 35  static one_bit_color_type white() { return one_bit_white; }
 36  static one_bit_color_type gray()  { return one_bit_not_white; }
 37  static one_bit_color_type black() { return one_bit_not_white; }
 38};
 39
 40
 41template<typename IndexMap = identity_property_map>
 42struct one_bit_color_map 
 43{
 44  BOOST_STATIC_CONSTANT(int, bits_per_char = std::numeric_limits<unsigned char>::digits);
 45  std::size_t n;
 46  IndexMap index;
 47  shared_array<unsigned char> data;
 48
 49  typedef typename property_traits<IndexMap>::key_type key_type;
 50  typedef one_bit_color_type value_type;
 51  typedef void reference;
 52  typedef read_write_property_map_tag category;
 53
 54  explicit one_bit_color_map(std::size_t n, const IndexMap& index = IndexMap())
 55    : n(n), index(index), data(new unsigned char[(n + bits_per_char - 1) / bits_per_char])
 56  {
 57    // Fill to white
 58    std::fill(data.get(), data.get() + (n + bits_per_char - 1) / bits_per_char, 0);
 59  }
 60};
 61
 62template<typename IndexMap>
 63inline one_bit_color_type
 64get(const one_bit_color_map<IndexMap>& pm, 
 65    typename property_traits<IndexMap>::key_type key) 
 66{
 67  BOOST_STATIC_CONSTANT(int, bits_per_char = one_bit_color_map<IndexMap>::bits_per_char);
 68  typename property_traits<IndexMap>::value_type i = get(pm.index, key);
 69  BOOST_ASSERT ((std::size_t)i < pm.n);
 70  return one_bit_color_type((pm.data.get()[i / bits_per_char] >> (i % bits_per_char)) & 1);
 71}
 72
 73template<typename IndexMap>
 74inline void
 75put(const one_bit_color_map<IndexMap>& pm, 
 76    typename property_traits<IndexMap>::key_type key,
 77    one_bit_color_type value)
 78{
 79  BOOST_STATIC_CONSTANT(int, bits_per_char = one_bit_color_map<IndexMap>::bits_per_char);
 80  typename property_traits<IndexMap>::value_type i = get(pm.index, key);
 81  BOOST_ASSERT ((std::size_t)i < pm.n);
 82  BOOST_ASSERT (value >= 0 && value < 2);
 83  std::size_t byte_num = i / bits_per_char;
 84  std::size_t bit_position = (i % bits_per_char);
 85    pm.data.get()[byte_num] =
 86      (unsigned char)
 87        ((pm.data.get()[byte_num] & ~(1 << bit_position))
 88         | (value << bit_position));
 89}
 90
 91template<typename IndexMap>
 92inline one_bit_color_map<IndexMap>
 93make_one_bit_color_map(std::size_t n, const IndexMap& index_map)
 94{
 95  return one_bit_color_map<IndexMap>(n, index_map);
 96}
 97
 98} // end namespace boost
 99
100#endif // BOOST_ONE_BIT_COLOR_MAP_HPP
101
102#ifdef BOOST_GRAPH_USE_MPI
103#  include <boost/graph/distributed/one_bit_color_map.hpp>
104#endif