| // Copyright (C) 2005-2006 The Trustees of Indiana University. |
| |
| // Distributed under the Boost Software License, Version 1.0. |
| // (See accompanying file LICENSE_1_0.txt or copy at |
| // http://www.boost.org/LICENSE_1_0.txt) |
| |
| // Authors: Jeremiah Willcock |
| // Douglas Gregor |
| // Andrew Lumsdaine |
| |
| // Two bit per color property map |
| |
| #ifndef BOOST_TWO_BIT_COLOR_MAP_HPP |
| #define BOOST_TWO_BIT_COLOR_MAP_HPP |
| |
| #include <boost/property_map/property_map.hpp> |
| #include <boost/graph/properties.hpp> |
| #include <boost/shared_array.hpp> |
| #include <boost/config.hpp> |
| #include <boost/assert.hpp> |
| #include <algorithm> |
| #include <limits> |
| |
| namespace boost { |
| |
| enum two_bit_color_type { |
| two_bit_white = 0, |
| two_bit_gray = 1, |
| two_bit_green = 2, |
| two_bit_black = 3 |
| }; |
| |
| template <> |
| struct color_traits<two_bit_color_type> |
| { |
| static two_bit_color_type white() { return two_bit_white; } |
| static two_bit_color_type gray() { return two_bit_gray; } |
| static two_bit_color_type green() { return two_bit_green; } |
| static two_bit_color_type black() { return two_bit_black; } |
| }; |
| |
| |
| template<typename IndexMap = identity_property_map> |
| struct two_bit_color_map |
| { |
| std::size_t n; |
| IndexMap index; |
| shared_array<unsigned char> data; |
| |
| BOOST_STATIC_CONSTANT(int, bits_per_char = std::numeric_limits<unsigned char>::digits); |
| BOOST_STATIC_CONSTANT(int, elements_per_char = bits_per_char / 2); |
| typedef typename property_traits<IndexMap>::key_type key_type; |
| typedef two_bit_color_type value_type; |
| typedef void reference; |
| typedef read_write_property_map_tag category; |
| |
| explicit two_bit_color_map(std::size_t n, const IndexMap& index = IndexMap()) |
| : n(n), index(index), data(new unsigned char[(n + elements_per_char - 1) / elements_per_char]) |
| { |
| // Fill to white |
| std::fill(data.get(), data.get() + (n + elements_per_char - 1) / elements_per_char, 0); |
| } |
| }; |
| |
| template<typename IndexMap> |
| inline two_bit_color_type |
| get(const two_bit_color_map<IndexMap>& pm, |
| typename property_traits<IndexMap>::key_type key) |
| { |
| BOOST_STATIC_CONSTANT(int, elements_per_char = two_bit_color_map<IndexMap>::elements_per_char); |
| typename property_traits<IndexMap>::value_type i = get(pm.index, key); |
| BOOST_ASSERT ((std::size_t)i < pm.n); |
| std::size_t byte_num = i / elements_per_char; |
| std::size_t bit_position = ((i % elements_per_char) * 2); |
| return two_bit_color_type((pm.data.get()[byte_num] >> bit_position) & 3); |
| } |
| |
| template<typename IndexMap> |
| inline void |
| put(const two_bit_color_map<IndexMap>& pm, |
| typename property_traits<IndexMap>::key_type key, |
| two_bit_color_type value) |
| { |
| BOOST_STATIC_CONSTANT(int, elements_per_char = two_bit_color_map<IndexMap>::elements_per_char); |
| typename property_traits<IndexMap>::value_type i = get(pm.index, key); |
| BOOST_ASSERT ((std::size_t)i < pm.n); |
| BOOST_ASSERT (value >= 0 && value < 4); |
| std::size_t byte_num = i / elements_per_char; |
| std::size_t bit_position = ((i % elements_per_char) * 2); |
| pm.data.get()[byte_num] = |
| (unsigned char) |
| ((pm.data.get()[byte_num] & ~(3 << bit_position)) |
| | (value << bit_position)); |
| } |
| |
| template<typename IndexMap> |
| inline two_bit_color_map<IndexMap> |
| make_two_bit_color_map(std::size_t n, const IndexMap& index_map) |
| { |
| return two_bit_color_map<IndexMap>(n, index_map); |
| } |
| |
| } // end namespace boost |
| |
| #endif // BOOST_TWO_BIT_COLOR_MAP_HPP |
| |
| #ifdef BOOST_GRAPH_USE_MPI |
| # include <boost/graph/distributed/two_bit_color_map.hpp> |
| #endif |