///////////////////////////////////////////////////////////////////////////////////
/// OpenGL Mathematics (glm.g-truc.net)
///
/// Copyright (c) 2005 - 2015 G-Truc Creation (www.g-truc.net)
/// Permission is hereby granted, free of charge, to any person obtaining a copy
/// of this software and associated documentation files (the "Software"), to deal
/// in the Software without restriction, including without limitation the rights
/// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
/// copies of the Software, and to permit persons to whom the Software is
/// furnished to do so, subject to the following conditions:
/// 
/// The above copyright notice and this permission notice shall be included in
/// all copies or substantial portions of the Software.
/// 
/// Restrictions:
///             By making use of the Software for military purposes, you choose to make
///             a Bunny unhappy.
/// 
/// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
/// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
/// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
/// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
/// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
/// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
/// THE SOFTWARE.
///
/// @ref gtc_round
/// @file glm/gtc/round.inl
/// @date 2014-11-03 / 2014-11-03
/// @author Christophe Riccio
///////////////////////////////////////////////////////////////////////////////////

namespace glm
{
namespace detail
{
        template <typename T, precision P, template <typename, precision> class vecType, bool compute = false>
        struct compute_ceilShift
        {
                GLM_FUNC_QUALIFIER static vecType<T, P> call(vecType<T, P> const & v, T)
                {
                        return v;
                }
        };

        template <typename T, precision P, template <typename, precision> class vecType>
        struct compute_ceilShift<T, P, vecType, true>
        {
                GLM_FUNC_QUALIFIER static vecType<T, P> call(vecType<T, P> const & v, T Shift)
                {
                        return v | (v >> Shift);
                }
        };

        template <typename T, precision P, template <typename, precision> class vecType, bool isSigned = true>
        struct compute_ceilPowerOfTwo
        {
                GLM_FUNC_QUALIFIER static vecType<T, P> call(vecType<T, P> const & x)
                {
                        GLM_STATIC_ASSERT(!std::numeric_limits<T>::is_iec559, "'ceilPowerOfTwo' only accept integer scalar or vector inputs");

                        vecType<T, P> const Sign(sign(x));

                        vecType<T, P> v(abs(x));

                        v = v - static_cast<T>(1);
                        v = v | (v >> static_cast<T>(1));
                        v = v | (v >> static_cast<T>(2));
                        v = v | (v >> static_cast<T>(4));
                        v = compute_ceilShift<T, P, vecType, sizeof(T) >= 2>::call(v, 8);
                        v = compute_ceilShift<T, P, vecType, sizeof(T) >= 4>::call(v, 16);
                        v = compute_ceilShift<T, P, vecType, sizeof(T) >= 8>::call(v, 32);
                        return (v + static_cast<T>(1)) * Sign;
                }
        };

        template <typename T, precision P, template <typename, precision> class vecType>
        struct compute_ceilPowerOfTwo<T, P, vecType, false>
        {
                GLM_FUNC_QUALIFIER static vecType<T, P> call(vecType<T, P> const & x)
                {
                        GLM_STATIC_ASSERT(!std::numeric_limits<T>::is_iec559, "'ceilPowerOfTwo' only accept integer scalar or vector inputs");

                        vecType<T, P> v(x);

                        v = v - static_cast<T>(1);
                        v = v | (v >> static_cast<T>(1));
                        v = v | (v >> static_cast<T>(2));
                        v = v | (v >> static_cast<T>(4));
                        v = compute_ceilShift<T, P, vecType, sizeof(T) >= 2>::call(v, 8);
                        v = compute_ceilShift<T, P, vecType, sizeof(T) >= 4>::call(v, 16);
                        v = compute_ceilShift<T, P, vecType, sizeof(T) >= 8>::call(v, 32);
                        return v + static_cast<T>(1);
                }
        };

        template <bool is_float, bool is_signed>
        struct compute_ceilMultiple{};

        template <>
        struct compute_ceilMultiple<true, true>
        {
                template <typename genType>
                GLM_FUNC_QUALIFIER static genType call(genType Source, genType Multiple)
                {
                        if(Source > genType(0))
                        {
                                genType Tmp = Source - genType(1);
                                return Tmp + (Multiple - std::fmod(Tmp, Multiple));
                        }
                        else
                                return Source + std::fmod(-Source, Multiple);
                }
        };

        template <>
        struct compute_ceilMultiple<false, false>
        {
                template <typename genType>
                GLM_FUNC_QUALIFIER static genType call(genType Source, genType Multiple)
                {
                        genType Tmp = Source - genType(1);
                        return Tmp + (Multiple - (Tmp % Multiple));
                }
        };

        template <>
        struct compute_ceilMultiple<false, true>
        {
                template <typename genType>
                GLM_FUNC_QUALIFIER static genType call(genType Source, genType Multiple)
                {
                        if(Source > genType(0))
                        {
                                genType Tmp = Source - genType(1);
                                return Tmp + (Multiple - (Tmp % Multiple));
                        }
                        else
                                return Source + (-Source % Multiple);
                }
        };

        template <bool is_float, bool is_signed>
        struct compute_floorMultiple{};

        template <>
        struct compute_floorMultiple<true, true>
        {
                template <typename genType>
                GLM_FUNC_QUALIFIER static genType call(genType Source, genType Multiple)
                {
                        if(Source >= genType(0))
                                return Source - std::fmod(Source, Multiple);
                        else
                        {
                                genType Tmp = Source + genType(1);
                                return Tmp - std::fmod(Tmp, Multiple) - Multiple;
                        }
                }
        };

        template <>
        struct compute_floorMultiple<false, false>
        {
                template <typename genType>
                GLM_FUNC_QUALIFIER static genType call(genType Source, genType Multiple)
                {
                        if(Source >= genType(0))
                                return Source - Source % Multiple;
                        else
                        {
                                genType Tmp = Source + genType(1);
                                return Tmp - Tmp % Multiple - Multiple;
                        }
                }
        };

        template <>
        struct compute_floorMultiple<false, true>
        {
                template <typename genType>
                GLM_FUNC_QUALIFIER static genType call(genType Source, genType Multiple)
                {
                        if(Source >= genType(0))
                                return Source - Source % Multiple;
                        else
                        {
                                genType Tmp = Source + genType(1);
                                return Tmp - Tmp % Multiple - Multiple;
                        }
                }
        };

        template <bool is_float, bool is_signed>
        struct compute_roundMultiple{};

        template <>
        struct compute_roundMultiple<true, true>
        {
                template <typename genType>
                GLM_FUNC_QUALIFIER static genType call(genType Source, genType Multiple)
                {
                        if(Source >= genType(0))
                                return Source - std::fmod(Source, Multiple);
                        else
                        {
                                genType Tmp = Source + genType(1);
                                return Tmp - std::fmod(Tmp, Multiple) - Multiple;
                        }
                }
        };

        template <>
        struct compute_roundMultiple<false, false>
        {
                template <typename genType>
                GLM_FUNC_QUALIFIER static genType call(genType Source, genType Multiple)
                {
                        if(Source >= genType(0))
                                return Source - Source % Multiple;
                        else
                        {
                                genType Tmp = Source + genType(1);
                                return Tmp - Tmp % Multiple - Multiple;
                        }
                }
        };

        template <>
        struct compute_roundMultiple<false, true>
        {
                template <typename genType>
                GLM_FUNC_QUALIFIER static genType call(genType Source, genType Multiple)
                {
                        if(Source >= genType(0))
                                return Source - Source % Multiple;
                        else
                        {
                                genType Tmp = Source + genType(1);
                                return Tmp - Tmp % Multiple - Multiple;
                        }
                }
        };
}//namespace detail

        ////////////////
        // isPowerOfTwo

        template <typename genType>
        GLM_FUNC_QUALIFIER bool isPowerOfTwo(genType Value)
        {
                genType const Result = glm::abs(Value);
                return !(Result & (Result - 1));
        }

        template <typename T, precision P, template <typename, precision> class vecType>
        GLM_FUNC_QUALIFIER vecType<bool, P> isPowerOfTwo(vecType<T, P> const & Value)
        {
                vecType<T, P> const Result(abs(Value));
                return equal(Result & (Result - 1), vecType<T, P>(0));
        }

        //////////////////
        // ceilPowerOfTwo

        template <typename genType>
        GLM_FUNC_QUALIFIER genType ceilPowerOfTwo(genType value)
        {
                return detail::compute_ceilPowerOfTwo<genType, defaultp, tvec1, std::numeric_limits<genType>::is_signed>::call(tvec1<genType, defaultp>(value)).x;
        }

        template <typename T, precision P, template <typename, precision> class vecType>
        GLM_FUNC_QUALIFIER vecType<T, P> ceilPowerOfTwo(vecType<T, P> const & v)
        {
                return detail::compute_ceilPowerOfTwo<T, P, vecType, std::numeric_limits<T>::is_signed>::call(v);
        }

        ///////////////////
        // floorPowerOfTwo

        template <typename genType>
        GLM_FUNC_QUALIFIER genType floorPowerOfTwo(genType value)
        {
                return isPowerOfTwo(value) ? value : highestBitValue(value);
        }

        template <typename T, precision P, template <typename, precision> class vecType>
        GLM_FUNC_QUALIFIER vecType<T, P> floorPowerOfTwo(vecType<T, P> const & v)
        {
                return detail::functor1<T, T, P, vecType>::call(floorPowerOfTwo, v);
        }

        ///////////////////
        // roundPowerOfTwo

        template <typename genIUType>
        GLM_FUNC_QUALIFIER genIUType roundPowerOfTwo(genIUType value)
        {
                if(isPowerOfTwo(value))
                        return value;

                genIUType const prev = highestBitValue(value);
                genIUType const next = prev << 1;
                return (next - value) < (value - prev) ? next : prev;
        }

        template <typename T, precision P, template <typename, precision> class vecType>
        GLM_FUNC_QUALIFIER vecType<T, P> roundPowerOfTwo(vecType<T, P> const & v)
        {
                return detail::functor1<T, T, P, vecType>::call(roundPowerOfTwo, v);
        }

        ////////////////
        // isMultiple

        template <typename genType>
        GLM_FUNC_QUALIFIER bool isMultiple(genType Value, genType Multiple)
        {
                return isMultiple(tvec1<genType>(Value), tvec1<genType>(Multiple)).x;
        }

        template <typename T, precision P, template <typename, precision> class vecType>
        GLM_FUNC_QUALIFIER vecType<bool, P> isMultiple(vecType<T, P> const & Value, T Multiple)
        {
                return (Value % Multiple) == vecType<T, P>(0);
        }

        template <typename T, precision P, template <typename, precision> class vecType>
        GLM_FUNC_QUALIFIER vecType<bool, P> isMultiple(vecType<T, P> const & Value, vecType<T, P> const & Multiple)
        {
                return (Value % Multiple) == vecType<T, P>(0);
        }

        //////////////////////
        // ceilMultiple

        template <typename genType>
        GLM_FUNC_QUALIFIER genType ceilMultiple(genType Source, genType Multiple)
        {
                return detail::compute_ceilMultiple<std::numeric_limits<genType>::is_iec559, std::numeric_limits<genType>::is_signed>::call(Source, Multiple);
        }

        template <typename T, precision P, template <typename, precision> class vecType>
        GLM_FUNC_QUALIFIER vecType<T, P> ceilMultiple(vecType<T, P> const & Source, vecType<T, P> const & Multiple)
        {
                return detail::functor2<T, P, vecType>::call(ceilMultiple, Source, Multiple);
        }

        //////////////////////
        // floorMultiple

        template <typename genType>
        GLM_FUNC_QUALIFIER genType floorMultiple(genType Source, genType Multiple)
        {
                return detail::compute_floorMultiple<std::numeric_limits<genType>::is_iec559, std::numeric_limits<genType>::is_signed>::call(Source, Multiple);
        }

        template <typename T, precision P, template <typename, precision> class vecType>
        GLM_FUNC_QUALIFIER vecType<T, P> floorMultiple(vecType<T, P> const & Source, vecType<T, P> const & Multiple)
        {
                return detail::functor2<T, P, vecType>::call(floorMultiple, Source, Multiple);
        }

        //////////////////////
        // roundMultiple

        template <typename genType>
        GLM_FUNC_QUALIFIER genType roundMultiple(genType Source, genType Multiple)
        {
                return detail::compute_roundMultiple<std::numeric_limits<genType>::is_iec559, std::numeric_limits<genType>::is_signed>::call(Source, Multiple);
        }

        template <typename T, precision P, template <typename, precision> class vecType>
        GLM_FUNC_QUALIFIER vecType<T, P> roundMultiple(vecType<T, P> const & Source, vecType<T, P> const & Multiple)
        {
                return detail::functor2<T, P, vecType>::call(roundMultiple, Source, Multiple);
        }
}//namespace glm