///////////////////////////////////////////////////////////////////////////////////
/// 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_packing
/// @file glm/gtc/packing.inl
/// @date 2013-08-08 / 2013-08-08
/// @author Christophe Riccio
///////////////////////////////////////////////////////////////////////////////////

#include "../common.hpp"
#include "../vec2.hpp"
#include "../vec3.hpp"
#include "../vec4.hpp"
#include "../detail/type_half.hpp"
#include <cstring>

namespace glm{
namespace detail
{
        GLM_FUNC_QUALIFIER glm::uint16 float2half(glm::uint32 f)
        {
                // 10 bits    =>                         EE EEEFFFFF
                // 11 bits    =>                        EEE EEFFFFFF
                // Half bits  =>                   SEEEEEFF FFFFFFFF
                // Float bits => SEEEEEEE EFFFFFFF FFFFFFFF FFFFFFFF

                // 0x00007c00 => 00000000 00000000 01111100 00000000
                // 0x000003ff => 00000000 00000000 00000011 11111111
                // 0x38000000 => 00111000 00000000 00000000 00000000
                // 0x7f800000 => 01111111 10000000 00000000 00000000
                // 0x00008000 => 00000000 00000000 10000000 00000000
                return
                        ((f >> 16) & 0x8000) | // sign
                        ((((f & 0x7f800000) - 0x38000000) >> 13) & 0x7c00) | // exponential
                        ((f >> 13) & 0x03ff); // Mantissa
        }

        GLM_FUNC_QUALIFIER glm::uint32 float2packed11(glm::uint32 f)
        {
                // 10 bits    =>                         EE EEEFFFFF
                // 11 bits    =>                        EEE EEFFFFFF
                // Half bits  =>                   SEEEEEFF FFFFFFFF
                // Float bits => SEEEEEEE EFFFFFFF FFFFFFFF FFFFFFFF

                // 0x000007c0 => 00000000 00000000 00000111 11000000
                // 0x00007c00 => 00000000 00000000 01111100 00000000
                // 0x000003ff => 00000000 00000000 00000011 11111111
                // 0x38000000 => 00111000 00000000 00000000 00000000
                // 0x7f800000 => 01111111 10000000 00000000 00000000
                // 0x00008000 => 00000000 00000000 10000000 00000000
                return
                        ((((f & 0x7f800000) - 0x38000000) >> 17) & 0x07c0) | // exponential
                        ((f >> 17) & 0x003f); // Mantissa
        }

        GLM_FUNC_QUALIFIER glm::uint32 packed11ToFloat(glm::uint32 p)
        {
                // 10 bits    =>                         EE EEEFFFFF
                // 11 bits    =>                        EEE EEFFFFFF
                // Half bits  =>                   SEEEEEFF FFFFFFFF
                // Float bits => SEEEEEEE EFFFFFFF FFFFFFFF FFFFFFFF

                // 0x000007c0 => 00000000 00000000 00000111 11000000
                // 0x00007c00 => 00000000 00000000 01111100 00000000
                // 0x000003ff => 00000000 00000000 00000011 11111111
                // 0x38000000 => 00111000 00000000 00000000 00000000
                // 0x7f800000 => 01111111 10000000 00000000 00000000
                // 0x00008000 => 00000000 00000000 10000000 00000000
                return
                        ((((p & 0x07c0) << 17) + 0x38000000) & 0x7f800000) | // exponential
                        ((p & 0x003f) << 17); // Mantissa
        }

        GLM_FUNC_QUALIFIER glm::uint32 float2packed10(glm::uint32 f)
        {
                // 10 bits    =>                         EE EEEFFFFF
                // 11 bits    =>                        EEE EEFFFFFF
                // Half bits  =>                   SEEEEEFF FFFFFFFF
                // Float bits => SEEEEEEE EFFFFFFF FFFFFFFF FFFFFFFF

                // 0x0000001F => 00000000 00000000 00000000 00011111
                // 0x0000003F => 00000000 00000000 00000000 00111111
                // 0x000003E0 => 00000000 00000000 00000011 11100000
                // 0x000007C0 => 00000000 00000000 00000111 11000000
                // 0x00007C00 => 00000000 00000000 01111100 00000000
                // 0x000003FF => 00000000 00000000 00000011 11111111
                // 0x38000000 => 00111000 00000000 00000000 00000000
                // 0x7f800000 => 01111111 10000000 00000000 00000000
                // 0x00008000 => 00000000 00000000 10000000 00000000
                return
                        ((((f & 0x7f800000) - 0x38000000) >> 18) & 0x03E0) | // exponential
                        ((f >> 18) & 0x001f); // Mantissa
        }

        GLM_FUNC_QUALIFIER glm::uint32 packed10ToFloat(glm::uint32 p)
        {
                // 10 bits    =>                         EE EEEFFFFF
                // 11 bits    =>                        EEE EEFFFFFF
                // Half bits  =>                   SEEEEEFF FFFFFFFF
                // Float bits => SEEEEEEE EFFFFFFF FFFFFFFF FFFFFFFF

                // 0x0000001F => 00000000 00000000 00000000 00011111
                // 0x0000003F => 00000000 00000000 00000000 00111111
                // 0x000003E0 => 00000000 00000000 00000011 11100000
                // 0x000007C0 => 00000000 00000000 00000111 11000000
                // 0x00007C00 => 00000000 00000000 01111100 00000000
                // 0x000003FF => 00000000 00000000 00000011 11111111
                // 0x38000000 => 00111000 00000000 00000000 00000000
                // 0x7f800000 => 01111111 10000000 00000000 00000000
                // 0x00008000 => 00000000 00000000 10000000 00000000
                return
                        ((((p & 0x03E0) << 18) + 0x38000000) & 0x7f800000) | // exponential
                        ((p & 0x001f) << 18); // Mantissa
        }

        GLM_FUNC_QUALIFIER glm::uint half2float(glm::uint h)
        {
                return ((h & 0x8000) << 16) | ((( h & 0x7c00) + 0x1C000) << 13) | ((h & 0x03FF) << 13);
        }

        GLM_FUNC_QUALIFIER glm::uint floatTo11bit(float x)
        {
                if(x == 0.0f)
                        return 0;
                else if(glm::isnan(x))
                        return ~0;
                else if(glm::isinf(x))
                        return 0x1f << 6;

#               if(GLM_COMPILER & GLM_COMPILER_GCC || GLM_COMPILER & (GLM_COMPILER_APPLE_CLANG | GLM_COMPILER_LLVM))
                        uint Pack = 0;
                        memcpy(&Pack, &x, sizeof(Pack));
#               else    
                        uint Pack = reinterpret_cast<uint&>(x);
#               endif

                return float2packed11(Pack);
        }

        GLM_FUNC_QUALIFIER float packed11bitToFloat(glm::uint x)
        {
                if(x == 0)
                        return 0.0f;
                else if(x == ((1 << 11) - 1))
                        return ~0;//NaN
                else if(x == (0x1f << 6))
                        return ~0;//Inf

                uint Result = packed11ToFloat(x);

#               if(GLM_COMPILER & GLM_COMPILER_GCC || GLM_COMPILER & (GLM_COMPILER_APPLE_CLANG | GLM_COMPILER_LLVM))
                        float Temp = 0;
                        memcpy(&Temp, &Result, sizeof(Temp));
                        return Temp;
#               else    
                        return reinterpret_cast<float&>(Result);
#               endif
        }

        GLM_FUNC_QUALIFIER glm::uint floatTo10bit(float x)
        {
                if(x == 0.0f)
                        return 0;
                else if(glm::isnan(x))
                        return ~0;
                else if(glm::isinf(x))
                        return 0x1f << 5;

#               if(GLM_COMPILER & GLM_COMPILER_GCC || GLM_COMPILER & (GLM_COMPILER_APPLE_CLANG | GLM_COMPILER_LLVM))
                        uint Pack = 0;
                        memcpy(&Pack, &x, sizeof(Pack));
#               else    
                        uint Pack = reinterpret_cast<uint&>(x);
#               endif

                return float2packed10(Pack);
        }

        GLM_FUNC_QUALIFIER float packed10bitToFloat(glm::uint x)
        {
                if(x == 0)
                        return 0.0f;
                else if(x == ((1 << 10) - 1))
                        return ~0;//NaN
                else if(x == (0x1f << 5))
                        return ~0;//Inf

                uint Result = packed10ToFloat(x);

#               if(GLM_COMPILER & GLM_COMPILER_GCC || GLM_COMPILER & (GLM_COMPILER_APPLE_CLANG | GLM_COMPILER_LLVM))
                        float Temp = 0;
                        memcpy(&Temp, &Result, sizeof(Temp));
                        return Temp;
#               else    
                        return reinterpret_cast<float&>(Result);
#               endif
        }

//      GLM_FUNC_QUALIFIER glm::uint f11_f11_f10(float x, float y, float z)
//      {
//              return ((floatTo11bit(x) & ((1 << 11) - 1)) << 0) |  ((floatTo11bit(y) & ((1 << 11) - 1)) << 11) | ((floatTo10bit(z) & ((1 << 10) - 1)) << 22);
//      }

        union u10u10u10u2
        {
                struct
                {
                        uint x : 10;
                        uint y : 10;
                        uint z : 10;
                        uint w : 2;
                } data;
                uint32 pack;
        };

        union i10i10i10i2
        {
                struct
                {
                        int x : 10;
                        int y : 10;
                        int z : 10;
                        int w : 2;
                } data;
                uint32 pack;
        };

}//namespace detail

        GLM_FUNC_QUALIFIER uint8 packUnorm1x8(float v)
        {
                return static_cast<uint8>(round(clamp(v, 0.0f, 1.0f) * 255.0f));
        }
        
        GLM_FUNC_QUALIFIER float unpackUnorm1x8(uint8 p)
        {
                float Unpack(static_cast<float>(p));
                return Unpack * static_cast<float>(0.0039215686274509803921568627451); // 1 / 255
        }
        
        GLM_FUNC_QUALIFIER uint16 packUnorm2x8(vec2 const & v)
        {
                u8vec2 Topack(round(clamp(v, 0.0f, 1.0f) * 255.0f));
                uint16* Packed = reinterpret_cast<uint16*>(&Topack);
                return *Packed;
        }
        
        GLM_FUNC_QUALIFIER vec2 unpackUnorm2x8(uint16 p)
        {
                u8vec2* Unpacked = reinterpret_cast<u8vec2*>(const_cast<uint16*>(&p));
                return vec2(*Unpacked) * float(0.0039215686274509803921568627451); // 1 / 255
        }

        GLM_FUNC_QUALIFIER uint8 packSnorm1x8(float v)
        {
                int8 Topack(static_cast<int8>(round(clamp(v ,-1.0f, 1.0f) * 127.0f)));
                uint8* Packed = reinterpret_cast<uint8*>(&Topack);
                return *Packed;
        }
        
        GLM_FUNC_QUALIFIER float unpackSnorm1x8(uint8 p)
        {
                float Unpack(static_cast<float>(*const_cast<uint8*>(&p)));
                return clamp(
                        Unpack * 0.00787401574803149606299212598425f, // 1.0f / 127.0f
                        -1.0f, 1.0f);
        }
        
        GLM_FUNC_QUALIFIER uint16 packSnorm2x8(vec2 const & v)
        {
                i8vec2 Topack(round(clamp(v ,-1.0f, 1.0f) * 127.0f));
                uint16* Packed = reinterpret_cast<uint16*>(&Topack);
                return *Packed;
        }
        
        GLM_FUNC_QUALIFIER vec2 unpackSnorm2x8(uint16 p)
        {
                i8vec2* Unpack = reinterpret_cast<i8vec2*>(const_cast<uint16*>(&p));
                return clamp(
                        vec2(*Unpack) * 0.00787401574803149606299212598425f, // 1.0f / 127.0f
                        -1.0f, 1.0f);
        }
        
        GLM_FUNC_QUALIFIER uint16 packUnorm1x16(float s)
        {
                return static_cast<uint16>(round(clamp(s, 0.0f, 1.0f) * 65535.0f));
        }

        GLM_FUNC_QUALIFIER float unpackUnorm1x16(uint16 p)
        {
                float Unpack = static_cast<float>(*const_cast<uint16*>(&p));
                return Unpack * 1.5259021896696421759365224689097e-5f; // 1.0 / 65535.0
        }

        GLM_FUNC_QUALIFIER uint64 packUnorm4x16(vec4 const & v)
        {
                u16vec4 Topack(round(clamp(v , 0.0f, 1.0f) * 65535.0f));
                uint64* Packed = reinterpret_cast<uint64*>(&Topack);
                return *Packed;
        }

        GLM_FUNC_QUALIFIER vec4 unpackUnorm4x16(uint64 p)
        {
                u16vec4* Unpack = reinterpret_cast<u16vec4*>(const_cast<uint64*>(&p));
                return vec4(*Unpack) * 1.5259021896696421759365224689097e-5f; // 1.0 / 65535.0
        }

        GLM_FUNC_QUALIFIER uint16 packSnorm1x16(float v)
        {
                int16 Topack = static_cast<int16>(round(clamp(v ,-1.0f, 1.0f) * 32767.0f));
                uint16* Packed = reinterpret_cast<uint16*>(&Topack);
                return *Packed;
        }

        GLM_FUNC_QUALIFIER float unpackSnorm1x16(uint16 p)
        {
                float Unpack = static_cast<float>(*const_cast<uint16*>(&p));
                return clamp(
                        Unpack * 3.0518509475997192297128208258309e-5f, //1.0f / 32767.0f, 
                        -1.0f, 1.0f);
        }

        GLM_FUNC_QUALIFIER uint64 packSnorm4x16(vec4 const & v)
        {
                i16vec4 Topack = static_cast<i16vec4>(round(clamp(v ,-1.0f, 1.0f) * 32767.0f));
                uint64* Packed = reinterpret_cast<uint64*>(&Topack);
                return *Packed;
        }

        GLM_FUNC_QUALIFIER vec4 unpackSnorm4x16(uint64 p)
        {
                i16vec4* Unpack(reinterpret_cast<i16vec4*>(const_cast<uint64*>(&p)));
                return clamp(
                        vec4(*Unpack) * 3.0518509475997192297128208258309e-5f, //1.0f / 32767.0f,
                        -1.0f, 1.0f);
        }

        GLM_FUNC_QUALIFIER uint16 packHalf1x16(float v)
        {
                int16 Topack = detail::toFloat16(v);
                uint16* Packed = reinterpret_cast<uint16*>(&Topack);
                return *Packed;
        }

        GLM_FUNC_QUALIFIER float unpackHalf1x16(uint16 v)
        {
                int16* Unpack = reinterpret_cast<int16*>(const_cast<uint16*>(&v));
                return detail::toFloat32(*Unpack);
        }

        GLM_FUNC_QUALIFIER uint64 packHalf4x16(glm::vec4 const & v)
        {
                i16vec4 Unpack(
                        detail::toFloat16(v.x),
                        detail::toFloat16(v.y),
                        detail::toFloat16(v.z),
                        detail::toFloat16(v.w));

                uint64* Packed = reinterpret_cast<uint64*>(&Unpack);
                return *Packed;
        }

        GLM_FUNC_QUALIFIER glm::vec4 unpackHalf4x16(uint64 v)
        {
                i16vec4* p = reinterpret_cast<i16vec4*>(const_cast<uint64*>(&v));
                i16vec4 Unpack(*p);
        
                return vec4(
                        detail::toFloat32(Unpack.x), 
                        detail::toFloat32(Unpack.y), 
                        detail::toFloat32(Unpack.z), 
                        detail::toFloat32(Unpack.w));
        }

        GLM_FUNC_QUALIFIER uint32 packI3x10_1x2(ivec4 const & v)
        {
                detail::i10i10i10i2 Result;
                Result.data.x = v.x;
                Result.data.y = v.y;
                Result.data.z = v.z;
                Result.data.w = v.w;
                return Result.pack; 
        }

        GLM_FUNC_QUALIFIER ivec4 unpackI3x10_1x2(uint32 v)
        {
                detail::i10i10i10i2 Unpack;
                Unpack.pack = v;
                return ivec4(
                        Unpack.data.x,
                        Unpack.data.y,
                        Unpack.data.z,
                        Unpack.data.w);
        }

        GLM_FUNC_QUALIFIER uint32 packU3x10_1x2(uvec4 const & v)
        {
                detail::u10u10u10u2 Result;
                Result.data.x = v.x;
                Result.data.y = v.y;
                Result.data.z = v.z;
                Result.data.w = v.w;
                return Result.pack; 
        }

        GLM_FUNC_QUALIFIER uvec4 unpackU3x10_1x2(uint32 v)
        {
                detail::u10u10u10u2 Unpack;
                Unpack.pack = v;
                return uvec4(
                        Unpack.data.x,
                        Unpack.data.y,
                        Unpack.data.z,
                        Unpack.data.w);
        }

        GLM_FUNC_QUALIFIER uint32 packSnorm3x10_1x2(vec4 const & v)
        {
                detail::i10i10i10i2 Result;
                Result.data.x = int(round(clamp(v.x,-1.0f, 1.0f) * 511.f));
                Result.data.y = int(round(clamp(v.y,-1.0f, 1.0f) * 511.f));
                Result.data.z = int(round(clamp(v.z,-1.0f, 1.0f) * 511.f));
                Result.data.w = int(round(clamp(v.w,-1.0f, 1.0f) *   1.f));
                return Result.pack;
        }

        GLM_FUNC_QUALIFIER vec4 unpackSnorm3x10_1x2(uint32 v)
        {
                detail::i10i10i10i2 Unpack;
                Unpack.pack = v;
                vec4 Result;
                Result.x = clamp(float(Unpack.data.x) / 511.f, -1.0f, 1.0f);
                Result.y = clamp(float(Unpack.data.y) / 511.f, -1.0f, 1.0f);
                Result.z = clamp(float(Unpack.data.z) / 511.f, -1.0f, 1.0f);
                Result.w = clamp(float(Unpack.data.w) /   1.f, -1.0f, 1.0f);
                return Result;
        }

        GLM_FUNC_QUALIFIER uint32 packUnorm3x10_1x2(vec4 const & v)
        {
                detail::i10i10i10i2 Result;
                Result.data.x = int(round(clamp(v.x, 0.0f, 1.0f) * 1023.f));
                Result.data.y = int(round(clamp(v.y, 0.0f, 1.0f) * 1023.f));
                Result.data.z = int(round(clamp(v.z, 0.0f, 1.0f) * 1023.f));
                Result.data.w = int(round(clamp(v.w, 0.0f, 1.0f) *    3.f));
                return Result.pack;
        }

        GLM_FUNC_QUALIFIER vec4 unpackUnorm3x10_1x2(uint32 v)
        {
                detail::i10i10i10i2 Unpack;
                Unpack.pack = v;
                vec4 Result;
                Result.x = float(Unpack.data.x) / 1023.f;
                Result.y = float(Unpack.data.y) / 1023.f;
                Result.z = float(Unpack.data.z) / 1023.f;
                Result.w = float(Unpack.data.w) /   3.f;
                return Result;
        }

        GLM_FUNC_QUALIFIER uint32 packF2x11_1x10(vec3 const & v)
        {
                return 
                        ((detail::floatTo11bit(v.x) & ((1 << 11) - 1)) <<  0) |
                        ((detail::floatTo11bit(v.y) & ((1 << 11) - 1)) << 11) |
                        ((detail::floatTo10bit(v.z) & ((1 << 10) - 1)) << 22);
        }

        GLM_FUNC_QUALIFIER vec3 unpackF2x11_1x10(uint32 v)
        {
                return vec3(
                        detail::packed11bitToFloat(v >> 0), 
                        detail::packed11bitToFloat(v >> 11), 
                        detail::packed10bitToFloat(v >> 22));
        }

}//namespace glm