Chris@16: // Boost.Geometry (aka GGL, Generic Geometry Library)
Chris@16: 
Chris@16: // Copyright (c) 2009-2012 Mateusz Loskot, London, UK.
Chris@16: // Copyright (c) 2008-2012 Barend Gehrels, Amsterdam, the Netherlands.
Chris@16: // Copyright (c) 2008-2012 Bruno Lalande, Paris, France.
Chris@16: 
Chris@16: // Use, modification and distribution is subject to the Boost Software License,
Chris@16: // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: #ifndef BOOST_GEOMETRY_ARITHMETIC_DETERMINANT_HPP
Chris@16: #define BOOST_GEOMETRY_ARITHMETIC_DETERMINANT_HPP
Chris@16: 
Chris@16: 
Chris@16: #include <cstddef>
Chris@16: 
Chris@16: #include <boost/geometry/core/access.hpp>
Chris@16: #include <boost/geometry/geometries/concepts/point_concept.hpp>
Chris@16: #include <boost/geometry/util/select_coordinate_type.hpp>
Chris@16: 
Chris@16: namespace boost { namespace geometry
Chris@16: {
Chris@16: 
Chris@16: #ifndef DOXYGEN_NO_DETAIL
Chris@16: namespace detail
Chris@16: {
Chris@16: 
Chris@16: template <typename ReturnType, typename U, typename V>
Chris@16: class calculate_determinant
Chris@16: {
Chris@16:     template <typename T>
Chris@16:     static inline ReturnType rt(T const& v)
Chris@16:     {
Chris@16:         return boost::numeric_cast<ReturnType>(v);
Chris@16:     }
Chris@16: 
Chris@16: public :
Chris@16: 
Chris@16:     static inline ReturnType apply(U const& ux, U const& uy
Chris@16:                                  , V const& vx, V const& vy)
Chris@16:     {
Chris@16:         return rt(ux) * rt(vy) - rt(uy) * rt(vx);
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: template <typename ReturnType, typename U, typename V>
Chris@16: inline ReturnType determinant(U const& ux, U const& uy
Chris@16:                             , V const& vx, V const& vy)
Chris@16: {
Chris@16:     return calculate_determinant
Chris@16:         <
Chris@16:             ReturnType, U, V
Chris@16:         >::apply(ux, uy, vx, vy);
Chris@16: }
Chris@16: 
Chris@16: 
Chris@16: template <typename ReturnType, typename U, typename V>
Chris@16: inline ReturnType determinant(U const& u, V const& v)
Chris@16: {
Chris@16:     BOOST_CONCEPT_ASSERT( (concept::ConstPoint<U>) );
Chris@16:     BOOST_CONCEPT_ASSERT( (concept::ConstPoint<V>) );
Chris@16: 
Chris@16:     return calculate_determinant
Chris@16:         <
Chris@101:             ReturnType,
Chris@16:             typename geometry::coordinate_type<U>::type,
Chris@16:             typename geometry::coordinate_type<V>::type
Chris@16:         >::apply(get<0>(u), get<1>(u), get<0>(v), get<1>(v));
Chris@16: }
Chris@16: 
Chris@16: } // namespace detail
Chris@16: #endif // DOXYGEN_NO_DETAIL
Chris@16: 
Chris@16: }} // namespace boost::geometry
Chris@16: 
Chris@16: #endif // BOOST_GEOMETRY_ARITHMETIC_DETERMINANT_HPP