// Boost.Geometry (aka GGL, Generic Geometry Library)

// Copyright (c) 2007-2012 Barend Gehrels, Amsterdam, the Netherlands.

// Use, modification and distribution is subject to 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)

#ifndef BOOST_GEOMETRY_ALGORITHMS_DIFFERENCE_HPP
#define BOOST_GEOMETRY_ALGORITHMS_DIFFERENCE_HPP

#include <algorithm>

#include <boost/geometry/algorithms/detail/overlay/intersection_insert.hpp>
#include <boost/geometry/policies/robustness/get_rescale_policy.hpp>

namespace boost { namespace geometry
{

#ifndef DOXYGEN_NO_DETAIL
namespace detail { namespace difference
{

/*!
\brief_calc2{difference} \brief_strategy
\ingroup difference
\details \details_calc2{difference_insert, spatial set theoretic difference}
    \brief_strategy. \details_inserter{difference}
\tparam GeometryOut output geometry type, must be specified
\tparam Geometry1 \tparam_geometry
\tparam Geometry2 \tparam_geometry
\tparam OutputIterator output iterator
\tparam Strategy \tparam_strategy_overlay
\param geometry1 \param_geometry
\param geometry2 \param_geometry
\param out \param_out{difference}
\param strategy \param_strategy{difference}
\return \return_out

\qbk{distinguish,with strategy}
*/
template
<
    typename GeometryOut,
    typename Geometry1,
    typename Geometry2,
    typename RobustPolicy,
    typename OutputIterator,
    typename Strategy
>
inline OutputIterator difference_insert(Geometry1 const& geometry1,
            Geometry2 const& geometry2,
            RobustPolicy const& robust_policy,
            OutputIterator out,
            Strategy const& strategy)
{
    concept::check<Geometry1 const>();
    concept::check<Geometry2 const>();
    concept::check<GeometryOut>();

    return geometry::dispatch::intersection_insert
        <
            Geometry1, Geometry2,
            GeometryOut,
            overlay_difference,
            geometry::detail::overlay::do_reverse<geometry::point_order<Geometry1>::value>::value,
            geometry::detail::overlay::do_reverse<geometry::point_order<Geometry2>::value, true>::value
        >::apply(geometry1, geometry2, robust_policy, out, strategy);
}

/*!
\brief_calc2{difference}
\ingroup difference
\details \details_calc2{difference_insert, spatial set theoretic difference}.
    \details_insert{difference}
\tparam GeometryOut output geometry type, must be specified
\tparam Geometry1 \tparam_geometry
\tparam Geometry2 \tparam_geometry
\tparam OutputIterator output iterator
\param geometry1 \param_geometry
\param geometry2 \param_geometry
\param out \param_out{difference}
\return \return_out

\qbk{[include reference/algorithms/difference_insert.qbk]}
*/
template
<
    typename GeometryOut,
    typename Geometry1,
    typename Geometry2,
    typename RobustPolicy,
    typename OutputIterator
>
inline OutputIterator difference_insert(Geometry1 const& geometry1,
            Geometry2 const& geometry2,
            RobustPolicy const& robust_policy,
            OutputIterator out)
{
    concept::check<Geometry1 const>();
    concept::check<Geometry2 const>();
    concept::check<GeometryOut>();

    typedef strategy_intersection
        <
            typename cs_tag<GeometryOut>::type,
            Geometry1,
            Geometry2,
            typename geometry::point_type<GeometryOut>::type,
            RobustPolicy
        > strategy;

    return difference_insert<GeometryOut>(geometry1, geometry2,
            robust_policy, out, strategy());
}


}} // namespace detail::difference
#endif // DOXYGEN_NO_DETAIL



/*!
\brief_calc2{difference}
\ingroup difference
\details \details_calc2{difference, spatial set theoretic difference}.
\tparam Geometry1 \tparam_geometry
\tparam Geometry2 \tparam_geometry
\tparam Collection \tparam_output_collection
\param geometry1 \param_geometry
\param geometry2 \param_geometry
\param output_collection the output collection

\qbk{[include reference/algorithms/difference.qbk]}
*/
template
<
    typename Geometry1,
    typename Geometry2,
    typename Collection
>
inline void difference(Geometry1 const& geometry1,
            Geometry2 const& geometry2, Collection& output_collection)
{
    concept::check<Geometry1 const>();
    concept::check<Geometry2 const>();

    typedef typename boost::range_value<Collection>::type geometry_out;
    concept::check<geometry_out>();

    typedef typename geometry::rescale_overlay_policy_type
        <
            Geometry1,
            Geometry2
        >::type rescale_policy_type;

    rescale_policy_type robust_policy
            = geometry::get_rescale_policy<rescale_policy_type>(geometry1, geometry2);

    detail::difference::difference_insert<geometry_out>(
            geometry1, geometry2, robust_policy,
            std::back_inserter(output_collection));
}


}} // namespace boost::geometry


#endif // BOOST_GEOMETRY_ALGORITHMS_DIFFERENCE_HPP