// Copyright 2013 Dolphin Emulator Project / 2014 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.

#include <cstring>
#include <numeric> // Necessary on OS X, but not Linux

#include "common/common_types.h"
#include "common/math_util.h"

namespace MathUtil
{

u32 ClassifyDouble(double dvalue)
{
    // TODO: Optimize the below to be as fast as possible.
    IntDouble value;
    value.d = dvalue;
    u64 sign = value.i & DOUBLE_SIGN;
    u64 exp  = value.i & DOUBLE_EXP;
    if (exp > DOUBLE_ZERO && exp < DOUBLE_EXP)
    {
        // Nice normalized number.
        return sign ? PPC_FPCLASS_NN : PPC_FPCLASS_PN;
    }
    else
    {
        u64 mantissa = value.i & DOUBLE_FRAC;
        if (mantissa)
        {
            if (exp)
            {
                return PPC_FPCLASS_QNAN;
            }
            else
            {
                // Denormalized number.
                return sign ? PPC_FPCLASS_ND : PPC_FPCLASS_PD;
            }
        }
        else if (exp)
        {
            //Infinite
            return sign ? PPC_FPCLASS_NINF : PPC_FPCLASS_PINF;
        }
        else
        {
            //Zero
            return sign ? PPC_FPCLASS_NZ : PPC_FPCLASS_PZ;
        }
    }
}

u32 ClassifyFloat(float fvalue)
{
    // TODO: Optimize the below to be as fast as possible.
    IntFloat value;
    value.f = fvalue;
    u32 sign = value.i & FLOAT_SIGN;
    u32 exp  = value.i & FLOAT_EXP;
    if (exp > FLOAT_ZERO && exp < FLOAT_EXP)
    {
        // Nice normalized number.
        return sign ? PPC_FPCLASS_NN : PPC_FPCLASS_PN;
    }
    else
    {
        u32 mantissa = value.i & FLOAT_FRAC;
        if (mantissa)
        {
            if (exp)
            {
                return PPC_FPCLASS_QNAN; // Quiet NAN
            }
            else
            {
                // Denormalized number.
                return sign ? PPC_FPCLASS_ND : PPC_FPCLASS_PD;
            }
        }
        else if (exp)
        {
            // Infinite
            return sign ? PPC_FPCLASS_NINF : PPC_FPCLASS_PINF;
        }
        else
        {
            //Zero
            return sign ? PPC_FPCLASS_NZ : PPC_FPCLASS_PZ;
        }
    }
}


}  // namespace

inline void MatrixMul(int n, const float *a, const float *b, float *result)
{
    for (int i = 0; i < n; ++i)
    {
        for (int j = 0; j < n; ++j)
        {
            float temp = 0;
            for (int k = 0; k < n; ++k)
            {
                temp += a[i * n + k] * b[k * n + j];
            }
            result[i * n + j] = temp;
        }
    }
}

// Calculate sum of a float list
float MathFloatVectorSum(const std::vector<float>& Vec)
{
    return std::accumulate(Vec.begin(), Vec.end(), 0.0f);
}

void Matrix33::LoadIdentity(Matrix33 &mtx)
{
    memset(mtx.data, 0, sizeof(mtx.data));
    mtx.data[0] = 1.0f;
    mtx.data[4] = 1.0f;
    mtx.data[8] = 1.0f;
}

void Matrix33::RotateX(Matrix33 &mtx, float rad)
{
    float s = sin(rad);
    float c = cos(rad);
    memset(mtx.data, 0, sizeof(mtx.data));
    mtx.data[0] = 1;
    mtx.data[4] = c;
    mtx.data[5] = -s;
    mtx.data[7] = s;
    mtx.data[8] = c;
}
void Matrix33::RotateY(Matrix33 &mtx, float rad)
{
    float s = sin(rad);
    float c = cos(rad);
    memset(mtx.data, 0, sizeof(mtx.data));
    mtx.data[0] = c;
    mtx.data[2] = s;
    mtx.data[4] = 1;
    mtx.data[6] = -s;
    mtx.data[8] = c;
}

void Matrix33::Multiply(const Matrix33 &a, const Matrix33 &b, Matrix33 &result)
{
    MatrixMul(3, a.data, b.data, result.data);
}

void Matrix33::Multiply(const Matrix33 &a, const float vec[3], float result[3])
{
    for (int i = 0; i < 3; ++i) {
        result[i] = 0;
        for (int k = 0; k < 3; ++k) {
            result[i] += a.data[i * 3 + k] * vec[k];
        }
    }
}

void Matrix44::LoadIdentity(Matrix44 &mtx)
{
    memset(mtx.data, 0, sizeof(mtx.data));
    mtx.data[0] = 1.0f;
    mtx.data[5] = 1.0f;
    mtx.data[10] = 1.0f;
    mtx.data[15] = 1.0f;
}

void Matrix44::LoadMatrix33(Matrix44 &mtx, const Matrix33 &m33)
{
    for (int i = 0; i < 3; ++i)
    {
        for (int j = 0; j < 3; ++j)
        {
            mtx.data[i * 4 + j] = m33.data[i * 3 + j];
        }
    }

    for (int i = 0; i < 3; ++i)
    {
        mtx.data[i * 4 + 3] = 0;
        mtx.data[i + 12] = 0;
    }
    mtx.data[15] = 1.0f;
}

void Matrix44::Set(Matrix44 &mtx, const float mtxArray[16])
{
    for(int i = 0; i < 16; ++i) {
        mtx.data[i] = mtxArray[i];
    }
}

void Matrix44::Translate(Matrix44 &mtx, const float vec[3])
{
    LoadIdentity(mtx);
    mtx.data[3] = vec[0];
    mtx.data[7] = vec[1];
    mtx.data[11] = vec[2];
}

void Matrix44::Multiply(const Matrix44 &a, const Matrix44 &b, Matrix44 &result)
{
    MatrixMul(4, a.data, b.data, result.data);
}