///////////////////////////////////////////////////////////////////////////////////
/// 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_random
/// @file glm/gtc/random.inl
/// @date 2011-09-19 / 2012-04-07
/// @author Christophe Riccio
///////////////////////////////////////////////////////////////////////////////////

#include "../geometric.hpp"
#include "../exponential.hpp"
#include <cstdlib>
#include <ctime>
#include <cassert>

namespace glm{
namespace detail
{
        template <typename T, precision P, template <class, precision> class vecType>
        struct compute_rand
        {
                GLM_FUNC_QUALIFIER static vecType<T, P> call();
        };

        template <precision P>
        struct compute_rand<uint8, P, tvec1>
        {
                GLM_FUNC_QUALIFIER static tvec1<uint8, P> call()
                {
                        return tvec1<uint8, P>(
                                std::rand()) % std::numeric_limits<uint8>::max();
                }
        };

        template <precision P>
        struct compute_rand<uint8, P, tvec2>
        {
                GLM_FUNC_QUALIFIER static tvec2<uint8, P> call()
                {
                        return tvec2<uint8, P>(
                                std::rand(),
                                std::rand()) % std::numeric_limits<uint8>::max();
                }
        };

        template <precision P>
        struct compute_rand<uint8, P, tvec3>
        {
                GLM_FUNC_QUALIFIER static tvec3<uint8, P> call()
                {
                        return tvec3<uint8, P>(
                                std::rand(),
                                std::rand(),
                                std::rand()) % std::numeric_limits<uint8>::max();
                }
        };

        template <precision P>
        struct compute_rand<uint8, P, tvec4>
        {
                GLM_FUNC_QUALIFIER static tvec4<uint8, P> call()
                {
                        return tvec4<uint8, P>(
                                std::rand(),
                                std::rand(),
                                std::rand(),
                                std::rand()) % std::numeric_limits<uint8>::max();
                }
        };

        template <precision P, template <class, precision> class vecType>
        struct compute_rand<uint16, P, vecType>
        {
                GLM_FUNC_QUALIFIER static vecType<uint16, P> call()
                {
                        return
                                (vecType<uint16, P>(compute_rand<uint8, P, vecType>::call()) << static_cast<uint16>(8)) |
                                (vecType<uint16, P>(compute_rand<uint8, P, vecType>::call()) << static_cast<uint16>(0));
                }
        };

        template <precision P, template <class, precision> class vecType>
        struct compute_rand<uint32, P, vecType>
        {
                GLM_FUNC_QUALIFIER static vecType<uint32, P> call()
                {
                        return
                                (vecType<uint32, P>(compute_rand<uint16, P, vecType>::call()) << static_cast<uint32>(16)) |
                                (vecType<uint32, P>(compute_rand<uint16, P, vecType>::call()) << static_cast<uint32>(0));
                }
        };

        template <precision P, template <class, precision> class vecType>
        struct compute_rand<uint64, P, vecType>
        {
                GLM_FUNC_QUALIFIER static vecType<uint64, P> call()
                {
                        return
                                (vecType<uint64, P>(compute_rand<uint32, P, vecType>::call()) << static_cast<uint64>(32)) |
                                (vecType<uint64, P>(compute_rand<uint32, P, vecType>::call()) << static_cast<uint64>(0));
                }
        };

        template <typename T, precision P, template <class, precision> class vecType>
        struct compute_linearRand
        {
                GLM_FUNC_QUALIFIER static vecType<T, P> call(vecType<T, P> const & Min, vecType<T, P> const & Max);
        };

        template <precision P, template <class, precision> class vecType>
        struct compute_linearRand<int8, P, vecType>
        {
                GLM_FUNC_QUALIFIER static vecType<int8, P> call(vecType<int8, P> const & Min, vecType<int8, P> const & Max)
                {
                        return (vecType<int8, P>(compute_rand<uint8, P, vecType>::call() % vecType<uint8, P>(Max + static_cast<int8>(1) - Min))) + Min;
                }
        };

        template <precision P, template <class, precision> class vecType>
        struct compute_linearRand<uint8, P, vecType>
        {
                GLM_FUNC_QUALIFIER static vecType<uint8, P> call(vecType<uint8, P> const & Min, vecType<uint8, P> const & Max)
                {
                        return (compute_rand<uint8, P, vecType>::call() % (Max + static_cast<uint8>(1) - Min)) + Min;
                }
        };

        template <precision P, template <class, precision> class vecType>
        struct compute_linearRand<int16, P, vecType>
        {
                GLM_FUNC_QUALIFIER static vecType<int16, P> call(vecType<int16, P> const & Min, vecType<int16, P> const & Max)
                {
                        return (vecType<int16, P>(compute_rand<uint16, P, vecType>::call() % vecType<uint16, P>(Max + static_cast<int16>(1) - Min))) + Min;
                }
        };

        template <precision P, template <class, precision> class vecType>
        struct compute_linearRand<uint16, P, vecType>
        {
                GLM_FUNC_QUALIFIER static vecType<uint16, P> call(vecType<uint16, P> const & Min, vecType<uint16, P> const & Max)
                {
                        return (compute_rand<uint16, P, vecType>::call() % (Max + static_cast<uint16>(1) - Min)) + Min;
                }
        };

        template <precision P, template <class, precision> class vecType>
        struct compute_linearRand<int32, P, vecType>
        {
                GLM_FUNC_QUALIFIER static vecType<int32, P> call(vecType<int32, P> const & Min, vecType<int32, P> const & Max)
                {
                        return (vecType<int32, P>(compute_rand<uint32, P, vecType>::call() % vecType<uint32, P>(Max + static_cast<int32>(1) - Min))) + Min;
                }
        };

        template <precision P, template <class, precision> class vecType>
        struct compute_linearRand<uint32, P, vecType>
        {
                GLM_FUNC_QUALIFIER static vecType<uint32, P> call(vecType<uint32, P> const & Min, vecType<uint32, P> const & Max)
                {
                        return (compute_rand<uint32, P, vecType>::call() % (Max + static_cast<uint32>(1) - Min)) + Min;
                }
        };

        template <precision P, template <class, precision> class vecType>
        struct compute_linearRand<int64, P, vecType>
        {
                GLM_FUNC_QUALIFIER static vecType<int64, P> call(vecType<int64, P> const & Min, vecType<int64, P> const & Max)
                {
                        return (vecType<int64, P>(compute_rand<uint64, P, vecType>::call() % vecType<uint64, P>(Max + static_cast<int64>(1) - Min))) + Min;
                }
        };

        template <precision P, template <class, precision> class vecType>
        struct compute_linearRand<uint64, P, vecType>
        {
                GLM_FUNC_QUALIFIER static vecType<uint64, P> call(vecType<uint64, P> const & Min, vecType<uint64, P> const & Max)
                {
                        return (compute_rand<uint64, P, vecType>::call() % (Max + static_cast<uint64>(1) - Min)) + Min;
                }
        };

        template <template <class, precision> class vecType>
        struct compute_linearRand<float, lowp, vecType>
        {
                GLM_FUNC_QUALIFIER static vecType<float, lowp> call(vecType<float, lowp> const & Min, vecType<float, lowp> const & Max)
                {
                        return vecType<float, lowp>(compute_rand<uint8, lowp, vecType>::call()) / static_cast<float>(std::numeric_limits<uint8>::max()) * (Max - Min) + Min;
                }
        };

        template <template <class, precision> class vecType>
        struct compute_linearRand<float, mediump, vecType>
        {
                GLM_FUNC_QUALIFIER static vecType<float, mediump> call(vecType<float, mediump> const & Min, vecType<float, mediump> const & Max)
                {
                        return vecType<float, mediump>(compute_rand<uint16, mediump, vecType>::call()) / static_cast<float>(std::numeric_limits<uint16>::max()) * (Max - Min) + Min;
                }
        };

        template <template <class, precision> class vecType>
        struct compute_linearRand<float, highp, vecType>
        {
                GLM_FUNC_QUALIFIER static vecType<float, highp> call(vecType<float, highp> const & Min, vecType<float, highp> const & Max)
                {
                        return vecType<float, highp>(compute_rand<uint32, highp, vecType>::call()) / static_cast<float>(std::numeric_limits<uint32>::max()) * (Max - Min) + Min;
                }
        };

        template <template <class, precision> class vecType>
        struct compute_linearRand<double, lowp, vecType>
        {
                GLM_FUNC_QUALIFIER static vecType<double, lowp> call(vecType<double, lowp> const & Min, vecType<double, lowp> const & Max)
                {
                        return vecType<double, lowp>(compute_rand<uint16, lowp, vecType>::call()) / static_cast<double>(std::numeric_limits<uint16>::max()) * (Max - Min) + Min;
                }
        };

        template <template <class, precision> class vecType>
        struct compute_linearRand<double, mediump, vecType>
        {
                GLM_FUNC_QUALIFIER static vecType<double, mediump> call(vecType<double, mediump> const & Min, vecType<double, mediump> const & Max)
                {
                        return vecType<double, mediump>(compute_rand<uint32, mediump, vecType>::call()) / static_cast<double>(std::numeric_limits<uint32>::max()) * (Max - Min) + Min;
                }
        };

        template <template <class, precision> class vecType>
        struct compute_linearRand<double, highp, vecType>
        {
                GLM_FUNC_QUALIFIER static vecType<double, highp> call(vecType<double, highp> const & Min, vecType<double, highp> const & Max)
                {
                        return vecType<double, highp>(compute_rand<uint64, highp, vecType>::call()) / static_cast<double>(std::numeric_limits<uint64>::max()) * (Max - Min) + Min;
                }
        };

        template <template <class, precision> class vecType>
        struct compute_linearRand<long double, lowp, vecType>
        {
                GLM_FUNC_QUALIFIER static vecType<long double, lowp> call(vecType<long double, lowp> const & Min, vecType<long double, lowp> const & Max)
                {
                        return vecType<long double, lowp>(compute_rand<uint32, lowp, vecType>::call()) / static_cast<long double>(std::numeric_limits<uint32>::max()) * (Max - Min) + Min;
                }
        };

        template <template <class, precision> class vecType>
        struct compute_linearRand<long double, mediump, vecType>
        {
                GLM_FUNC_QUALIFIER static vecType<long double, mediump> call(vecType<long double, mediump> const & Min, vecType<long double, mediump> const & Max)
                {
                        return vecType<long double, mediump>(compute_rand<uint64, mediump, vecType>::call()) / static_cast<long double>(std::numeric_limits<uint64>::max()) * (Max - Min) + Min;
                }
        };

        template <template <class, precision> class vecType>
        struct compute_linearRand<long double, highp, vecType>
        {
                GLM_FUNC_QUALIFIER static vecType<long double, highp> call(vecType<long double, highp> const & Min, vecType<long double, highp> const & Max)
                {
                        return vecType<long double, highp>(compute_rand<uint64, highp, vecType>::call()) / static_cast<long double>(std::numeric_limits<uint64>::max()) * (Max - Min) + Min;
                }
        };
}//namespace detail

        template <typename genType>
        GLM_FUNC_QUALIFIER genType linearRand(genType Min, genType Max)
        {
                return detail::compute_linearRand<genType, highp, tvec1>::call(
                        tvec1<genType, highp>(Min),
                        tvec1<genType, highp>(Max)).x;
        }

        template <typename T, precision P, template <typename, precision> class vecType>
        GLM_FUNC_QUALIFIER vecType<T, P> linearRand(vecType<T, P> const & Min, vecType<T, P> const & Max)
        {
                return detail::compute_linearRand<T, P, vecType>::call(Min, Max);
        }

        template <typename genType>
        GLM_FUNC_QUALIFIER genType gaussRand(genType Mean, genType Deviation)
        {
                genType w, x1, x2;
        
                do
                {
                        x1 = linearRand(genType(-1), genType(1));
                        x2 = linearRand(genType(-1), genType(1));
                
                        w = x1 * x1 + x2 * x2;
                } while(w > genType(1));
        
                return x2 * Deviation * Deviation * sqrt((genType(-2) * log(w)) / w) + Mean;
        }

        template <typename T, precision P, template <typename, precision> class vecType>
        GLM_FUNC_QUALIFIER vecType<T, P> gaussRand(vecType<T, P> const & Mean, vecType<T, P> const & Deviation)
        {
                return detail::functor2<T, P, vecType>::call(gaussRand, Mean, Deviation);
        }

        template <typename T>
        GLM_FUNC_QUALIFIER tvec2<T, defaultp> diskRand(T Radius)
        {               
                tvec2<T, defaultp> Result(T(0));
                T LenRadius(T(0));
                
                do
                {
                        Result = linearRand(
                                tvec2<T, defaultp>(-Radius),
                                tvec2<T, defaultp>(Radius));
                        LenRadius = length(Result);
                }
                while(LenRadius > Radius);
                
                return Result;
        }
        
        template <typename T>
        GLM_FUNC_QUALIFIER tvec3<T, defaultp> ballRand(T Radius)
        {               
                tvec3<T, defaultp> Result(T(0));
                T LenRadius(T(0));
                
                do
                {
                        Result = linearRand(
                                tvec3<T, defaultp>(-Radius),
                                tvec3<T, defaultp>(Radius));
                        LenRadius = length(Result);
                }
                while(LenRadius > Radius);
                
                return Result;
        }
        
        template <typename T>
        GLM_FUNC_QUALIFIER tvec2<T, defaultp> circularRand(T Radius)
        {
                T a = linearRand(T(0), T(6.283185307179586476925286766559f));
                return tvec2<T, defaultp>(cos(a), sin(a)) * Radius;             
        }
        
        template <typename T>
        GLM_FUNC_QUALIFIER tvec3<T, defaultp> sphericalRand(T Radius)
        {
                T z = linearRand(T(-1), T(1));
                T a = linearRand(T(0), T(6.283185307179586476925286766559f));
        
                T r = sqrt(T(1) - z * z);
        
                T x = r * cos(a);
                T y = r * sin(a);
        
                return tvec3<T, defaultp>(x, y, z) * Radius;    
        }
}//namespace glm