/*

    Copyright 2005-2007 Adobe Systems Incorporated

   

    Use, modification and distribution are 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).



    See http://opensource.adobe.com/gil for most recent version including documentation.

*/



/*************************************************************************************************/



#ifndef GIL_APPLY_OPERATION_BASE_HPP

#define GIL_APPLY_OPERATION_BASE_HPP



#include "../../gil_config.hpp"

#include "../../utilities.hpp"

#include <boost/mpl/begin.hpp>

#include <boost/mpl/next.hpp>

#include <boost/mpl/deref.hpp>

#include <boost/mpl/size.hpp>

#include <boost/preprocessor/repeat.hpp> 



////////////////////////////////////////////////////////////////////////////////////////

/// \file               

/// \brief Given an object with run-time specified type (denoted as an array of Bits, dynamic index, and a static set of Types) and a generic operation, 

///        casts the object to its appropriate type and applies the operation

/// \author Lubomir Bourdev and Hailin Jin \n

///         Adobe Systems Incorporated

/// \date 2005-2007 \n Last updated on November 6, 2007

///

////////////////////////////////////////////////////////////////////////////////////////



namespace boost { namespace gil {



/*

GENERATE_APPLY_FWD_OPS generates for every N functions that look like this (for N==2):



    template <> struct apply_operation_fwd_fn<3> {

        template <typename Types, typename Bits, typename UnaryOp>

        typename UnaryOp::result_type apply(Bits& bits, std::size_t index, UnaryOp op) const {

            typedef typename mpl::begin<Types>::type T0;

            typedef typename mpl::next<T0>::type T1;

            typedef typename mpl::next<T1>::type T2;

            switch (index) {

                case 0: return op(reinterpret_cast<typename mpl::deref<T0>::type&>(bits));

                case 1: return op(reinterpret_cast<typename mpl::deref<T1>::type&>(bits));

                case 2: return op(reinterpret_cast<typename mpl::deref<T2>::type&>(bits));

            }

            throw;

        }



        template <typename Types, typename Bits, typename UnaryOp>

        typename UnaryOp::result_type applyc(const Bits& bits, std::size_t index, UnaryOp op) const {

            typedef typename mpl::begin<Types>::type T0;

            typedef typename mpl::next<T0>::type T1;

            typedef typename mpl::next<T1>::type T2;

            switch (index) {

                case 0: return op(reinterpret_cast<const typename mpl::deref<T0>::type&>(bits));

                case 1: return op(reinterpret_cast<const typename mpl::deref<T1>::type&>(bits));

                case 2: return op(reinterpret_cast<const typename mpl::deref<T2>::type&>(bits));

            }

            throw;

        }

    };

*/



#define GIL_FWD_TYPEDEFS(z, N, text)   T##N; typedef typename mpl::next<T##N>::type 

#define GIL_FWD_CASE(z, N, SUM)       case N: return op(*gil_reinterpret_cast<typename mpl::deref<T##N>::type*>(&bits));

#define GIL_FWD_CONST_CASE(z, N, SUM) case N: return op(*gil_reinterpret_cast_c<const typename mpl::deref<T##N>::type*>(&bits));



#define GIL_APPLY_FWD_OP(z, N, text)                                                                        \

    template <> struct apply_operation_fwd_fn<BOOST_PP_ADD(N,1)> {                                      \

        template <typename Types, typename Bits, typename UnaryOp>                                     \

        typename UnaryOp::result_type apply(Bits& bits, std::size_t index, UnaryOp op) const {        \

            typedef typename mpl::begin<Types>::type                                             \

            BOOST_PP_REPEAT(N, GIL_FWD_TYPEDEFS, BOOST_PP_EMPTY)                                            \

            T##N;                                                                                       \

            switch (index) {                                                                            \

                BOOST_PP_REPEAT(BOOST_PP_ADD(N,1), GIL_FWD_CASE, BOOST_PP_EMPTY)                            \

            }                                                                                           \

            throw;                                                                                      \

        }                                                                                               \

        template <typename Types, typename Bits, typename UnaryOp>                                     \

        typename UnaryOp::result_type applyc(const Bits& bits, std::size_t index, UnaryOp op) const { \

            typedef typename mpl::begin<Types>::type                                             \

            BOOST_PP_REPEAT(N, GIL_FWD_TYPEDEFS, BOOST_PP_EMPTY)                                            \

            T##N;                                                                                       \

            switch (index) {                                                                            \

                BOOST_PP_REPEAT(BOOST_PP_ADD(N,1), GIL_FWD_CONST_CASE,BOOST_PP_EMPTY)                       \

            }                                                                                           \

            throw;                                                                                      \

        }                                                                                               \

    };



#define GIL_GENERATE_APPLY_FWD_OPS(N) BOOST_PP_REPEAT(N, GIL_APPLY_FWD_OP, BOOST_PP_EMPTY)



namespace detail {

template <std::size_t N> struct apply_operation_fwd_fn {};



// Create specializations of apply_operation_fn for each N 0..100

GIL_GENERATE_APPLY_FWD_OPS(99)

} // namespace detail



// unary application

template <typename Types, typename Bits, typename Op> 

typename Op::result_type GIL_FORCEINLINE apply_operation_basec(const Bits& bits, std::size_t index, Op op) {

    return detail::apply_operation_fwd_fn<mpl::size<Types>::value>().template applyc<Types>(bits,index,op);

}



// unary application

template <typename Types, typename Bits, typename Op> 

typename Op::result_type GIL_FORCEINLINE apply_operation_base(      Bits& bits, std::size_t index, Op op) {

    return detail::apply_operation_fwd_fn<mpl::size<Types>::value>().template apply<Types>(bits,index,op);

}



namespace detail {

    template <typename T2, typename Op>

    struct reduce_bind1 {

        const T2& _t2;

        mutable Op&  _op;



        typedef typename Op::result_type result_type;



        reduce_bind1(const T2& t2, Op& op) : _t2(t2), _op(op) {}



        template <typename T1> GIL_FORCEINLINE result_type operator()(const T1& t1) { return _op(t1, _t2); }

    };



    template <typename Types1, typename Bits1, typename Op>

    struct reduce_bind2 {

        const Bits1& _bits1;

        std::size_t _index1;

        mutable Op&  _op;



        typedef typename Op::result_type result_type;



        reduce_bind2(const Bits1& bits1, std::size_t index1, Op& op) : _bits1(bits1), _index1(index1), _op(op) {}



        template <typename T2> GIL_FORCEINLINE result_type operator()(const T2& t2) { 

            return apply_operation_basec<Types1>(_bits1, _index1, reduce_bind1<T2,Op>(t2, _op));

        }

    };

} // namespace detail



// Binary application by applying on each dimension separately

template <typename Types1, typename Types2, typename Bits1, typename Bits2, typename Op>

static typename Op::result_type GIL_FORCEINLINE apply_operation_base(const Bits1& bits1, std::size_t index1, const Bits2& bits2, std::size_t index2, Op op) {

    return apply_operation_basec<Types2>(bits2,index2,detail::reduce_bind2<Types1,Bits1,Op>(bits1,index1,op));

}



#undef GIL_FWD_TYPEDEFS

#undef GIL_FWD_CASE

#undef GIL_FWD_CONST_CASE

#undef GIL_APPLY_FWD_OP

#undef GIL_GENERATE_APPLY_FWD_OPS

#undef BHS



} }  // namespace boost::gil





#endif

