/**
 * @file v4math.h
 * @brief LLVector4 class header file.
 *
 * $LicenseInfo:firstyear=2000&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2010, Linden Research, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License only.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */

#ifndef LL_V4MATH_H
#define LL_V4MATH_H

#include "llerror.h"
#include "llmath.h"
#include "v3math.h"
#include "v2math.h"

class LLMatrix3;
class LLMatrix4;
class LLQuaternion;

//  LLVector4 = |x y z w|

static constexpr U32 LENGTHOFVECTOR4 = 4;

class LLVector4
{
    public:
        F32 mV[LENGTHOFVECTOR4];
        LLVector4();                        // Initializes LLVector4 to (0, 0, 0, 1)
        explicit LLVector4(const F32 *vec);         // Initializes LLVector4 to (vec[0]. vec[1], vec[2], vec[3])
        explicit LLVector4(const F64 *vec);         // Initialized LLVector4 to ((F32) vec[0], (F32) vec[1], (F32) vec[3], (F32) vec[4]);
        explicit LLVector4(const LLVector2 &vec);
        explicit LLVector4(const LLVector2 &vec, F32 z, F32 w);
        explicit LLVector4(const LLVector3 &vec);           // Initializes LLVector4 to (vec, 1)
        explicit LLVector4(const LLVector3 &vec, F32 w);    // Initializes LLVector4 to (vec, w)
        explicit LLVector4(const LLSD &sd);
        LLVector4(F32 x, F32 y, F32 z);     // Initializes LLVector4 to (x. y, z, 1)
        LLVector4(F32 x, F32 y, F32 z, F32 w);

        LLSD getValue() const
        {
            LLSD ret;
            ret[0] = mV[VX];
            ret[1] = mV[VY];
            ret[2] = mV[VZ];
            ret[3] = mV[VW];
            return ret;
        }

        void setValue(const LLSD& sd)
        {
            mV[VX] = (F32)sd[0].asReal();
            mV[VY] = (F32)sd[1].asReal();
            mV[VZ] = (F32)sd[2].asReal();
            mV[VW] = (F32)sd[3].asReal();
        }


        inline bool isFinite() const;                                   // checks to see if all values of LLVector3 are finite

        inline void clear();        // Clears LLVector4 to (0, 0, 0, 1)
        inline void clearVec();     // deprecated
        inline void zeroVec();      // deprecated

        inline void set(F32 x, F32 y, F32 z);           // Sets LLVector4 to (x, y, z, 1)
        inline void set(F32 x, F32 y, F32 z, F32 w);    // Sets LLVector4 to (x, y, z, w)
        inline void set(const LLVector4 &vec);          // Sets LLVector4 to vec
        inline void set(const LLVector3 &vec, F32 w = 1.f); // Sets LLVector4 to LLVector3 vec
        inline void set(const F32 *vec);                // Sets LLVector4 to vec

        inline void setVec(F32 x, F32 y, F32 z);        // deprecated
        inline void setVec(F32 x, F32 y, F32 z, F32 w); // deprecated
        inline void setVec(const LLVector4 &vec);       // deprecated
        inline void setVec(const LLVector3 &vec, F32 w = 1.f); // deprecated
        inline void setVec(const F32 *vec);             // deprecated

        F32 length() const;             // Returns magnitude of LLVector4
        F32 lengthSquared() const;      // Returns magnitude squared of LLVector4
        F32 normalize();                // Normalizes and returns the magnitude of LLVector4

        F32         magVec() const;             // deprecated
        F32         magVecSquared() const;      // deprecated
        F32         normVec();                  // deprecated

        // Sets all values to absolute value of their original values
        // Returns true if data changed
        bool abs();

        bool isExactlyClear() const     { return (mV[VW] == 1.0f) && !mV[VX] && !mV[VY] && !mV[VZ]; }
        bool isExactlyZero() const      { return !mV[VW] && !mV[VX] && !mV[VY] && !mV[VZ]; }

        const LLVector4&    rotVec(const LLMatrix4 &mat);               // Rotates by MAT4 mat
        const LLVector4&    rotVec(const LLQuaternion &q);              // Rotates by QUAT q

        const LLVector4&    scaleVec(const LLVector4& vec); // Scales component-wise by vec

        F32 operator[](int idx) const { return mV[idx]; }
        F32 &operator[](int idx) { return mV[idx]; }

        friend std::ostream&     operator<<(std::ostream& s, const LLVector4 &a);       // Print a
        friend LLVector4 operator+(const LLVector4 &a, const LLVector4 &b); // Return vector a + b
        friend LLVector4 operator-(const LLVector4 &a, const LLVector4 &b); // Return vector a minus b
        friend F32  operator*(const LLVector4 &a, const LLVector4 &b);      // Return a dot b
        friend LLVector4 operator%(const LLVector4 &a, const LLVector4 &b); // Return a cross b
        friend LLVector4 operator/(const LLVector4 &a, F32 k);              // Return a divided by scaler k
        friend LLVector4 operator*(const LLVector4 &a, F32 k);              // Return a times scaler k
        friend LLVector4 operator*(F32 k, const LLVector4 &a);              // Return a times scaler k
        friend bool operator==(const LLVector4 &a, const LLVector4 &b);     // Return a == b
        friend bool operator!=(const LLVector4 &a, const LLVector4 &b);     // Return a != b

        friend const LLVector4& operator+=(LLVector4 &a, const LLVector4 &b);   // Return vector a + b
        friend const LLVector4& operator-=(LLVector4 &a, const LLVector4 &b);   // Return vector a minus b
        friend const LLVector4& operator%=(LLVector4 &a, const LLVector4 &b);   // Return a cross b
        friend const LLVector4& operator*=(LLVector4 &a, F32 k);                // Return a times scaler k
        friend const LLVector4& operator/=(LLVector4 &a, F32 k);                // Return a divided by scaler k

        friend LLVector4 operator-(const LLVector4 &a);                 // Return vector -a
};

// Non-member functions
F32 angle_between(const LLVector4 &a, const LLVector4 &b);      // Returns angle (radians) between a and b
bool are_parallel(const LLVector4 &a, const LLVector4 &b, F32 epsilon = F_APPROXIMATELY_ZERO);      // Returns true if a and b are very close to parallel
F32 dist_vec(const LLVector4 &a, const LLVector4 &b);           // Returns distance between a and b
F32 dist_vec_squared(const LLVector4 &a, const LLVector4 &b);   // Returns distance squared between a and b
LLVector3   vec4to3(const LLVector4 &vec);
LLVector4   vec3to4(const LLVector3 &vec);
LLVector4 lerp(const LLVector4 &a, const LLVector4 &b, F32 u); // Returns a vector that is a linear interpolation between a and b

// Constructors

inline LLVector4::LLVector4(void)
{
    mV[VX] = 0.f;
    mV[VY] = 0.f;
    mV[VZ] = 0.f;
    mV[VW] = 1.f;
}

inline LLVector4::LLVector4(F32 x, F32 y, F32 z)
{
    mV[VX] = x;
    mV[VY] = y;
    mV[VZ] = z;
    mV[VW] = 1.f;
}

inline LLVector4::LLVector4(F32 x, F32 y, F32 z, F32 w)
{
    mV[VX] = x;
    mV[VY] = y;
    mV[VZ] = z;
    mV[VW] = w;
}

inline LLVector4::LLVector4(const F32 *vec)
{
    mV[VX] = vec[VX];
    mV[VY] = vec[VY];
    mV[VZ] = vec[VZ];
    mV[VW] = vec[VW];
}

inline LLVector4::LLVector4(const F64 *vec)
{
    mV[VX] = (F32) vec[VX];
    mV[VY] = (F32) vec[VY];
    mV[VZ] = (F32) vec[VZ];
    mV[VW] = (F32) vec[VW];
}

inline LLVector4::LLVector4(const LLVector2 &vec)
{
    mV[VX] = vec[VX];
    mV[VY] = vec[VY];
    mV[VZ] = 0.f;
    mV[VW] = 0.f;
}

inline LLVector4::LLVector4(const LLVector2 &vec, F32 z, F32 w)
{
    mV[VX] = vec[VX];
    mV[VY] = vec[VY];
    mV[VZ] = z;
    mV[VW] = w;
}

inline LLVector4::LLVector4(const LLVector3 &vec)
{
    mV[VX] = vec.mV[VX];
    mV[VY] = vec.mV[VY];
    mV[VZ] = vec.mV[VZ];
    mV[VW] = 1.f;
}

inline LLVector4::LLVector4(const LLVector3 &vec, F32 w)
{
    mV[VX] = vec.mV[VX];
    mV[VY] = vec.mV[VY];
    mV[VZ] = vec.mV[VZ];
    mV[VW] = w;
}

inline LLVector4::LLVector4(const LLSD &sd)
{
    setValue(sd);
}


inline bool LLVector4::isFinite() const
{
    return (llfinite(mV[VX]) && llfinite(mV[VY]) && llfinite(mV[VZ]) && llfinite(mV[VW]));
}

// Clear and Assignment Functions

inline void LLVector4::clear()
{
    mV[VX] = 0.f;
    mV[VY] = 0.f;
    mV[VZ] = 0.f;
    mV[VW] = 1.f;
}

// deprecated
inline void LLVector4::clearVec()
{
    mV[VX] = 0.f;
    mV[VY] = 0.f;
    mV[VZ] = 0.f;
    mV[VW] = 1.f;
}

// deprecated
inline void LLVector4::zeroVec()
{
    mV[VX] = 0.f;
    mV[VY] = 0.f;
    mV[VZ] = 0.f;
    mV[VW] = 0.f;
}

inline void LLVector4::set(F32 x, F32 y, F32 z)
{
    mV[VX] = x;
    mV[VY] = y;
    mV[VZ] = z;
    mV[VW] = 1.f;
}

inline void LLVector4::set(F32 x, F32 y, F32 z, F32 w)
{
    mV[VX] = x;
    mV[VY] = y;
    mV[VZ] = z;
    mV[VW] = w;
}

inline void LLVector4::set(const LLVector4& vec)
{
    mV[VX] = vec.mV[VX];
    mV[VY] = vec.mV[VY];
    mV[VZ] = vec.mV[VZ];
    mV[VW] = vec.mV[VW];
}

inline void LLVector4::set(const LLVector3& vec, F32 w)
{
    mV[VX] = vec.mV[VX];
    mV[VY] = vec.mV[VY];
    mV[VZ] = vec.mV[VZ];
    mV[VW] = w;
}

inline void LLVector4::set(const F32* vec)
{
    mV[VX] = vec[VX];
    mV[VY] = vec[VY];
    mV[VZ] = vec[VZ];
    mV[VW] = vec[VW];
}


// deprecated
inline void LLVector4::setVec(F32 x, F32 y, F32 z)
{
    mV[VX] = x;
    mV[VY] = y;
    mV[VZ] = z;
    mV[VW] = 1.f;
}

// deprecated
inline void LLVector4::setVec(F32 x, F32 y, F32 z, F32 w)
{
    mV[VX] = x;
    mV[VY] = y;
    mV[VZ] = z;
    mV[VW] = w;
}

// deprecated
inline void LLVector4::setVec(const LLVector4& vec)
{
    mV[VX] = vec.mV[VX];
    mV[VY] = vec.mV[VY];
    mV[VZ] = vec.mV[VZ];
    mV[VW] = vec.mV[VW];
}

// deprecated
inline void LLVector4::setVec(const LLVector3& vec, F32 w)
{
    mV[VX] = vec.mV[VX];
    mV[VY] = vec.mV[VY];
    mV[VZ] = vec.mV[VZ];
    mV[VW] = w;
}

// deprecated
inline void LLVector4::setVec(const F32* vec)
{
    mV[VX] = vec[VX];
    mV[VY] = vec[VY];
    mV[VZ] = vec[VZ];
    mV[VW] = vec[VW];
}

// LLVector4 Magnitude and Normalization Functions

inline F32      LLVector4::length() const
{
    return sqrt(mV[VX]*mV[VX] + mV[VY]*mV[VY] + mV[VZ]*mV[VZ]);
}

inline F32      LLVector4::lengthSquared() const
{
    return mV[VX]*mV[VX] + mV[VY]*mV[VY] + mV[VZ]*mV[VZ];
}

inline F32      LLVector4::magVec() const
{
    return sqrt(mV[VX]*mV[VX] + mV[VY]*mV[VY] + mV[VZ]*mV[VZ]);
}

inline F32      LLVector4::magVecSquared() const
{
    return mV[VX]*mV[VX] + mV[VY]*mV[VY] + mV[VZ]*mV[VZ];
}

// LLVector4 Operators

inline LLVector4 operator+(const LLVector4& a, const LLVector4& b)
{
    LLVector4 c(a);
    return c += b;
}

inline LLVector4 operator-(const LLVector4& a, const LLVector4& b)
{
    LLVector4 c(a);
    return c -= b;
}

inline F32  operator*(const LLVector4& a, const LLVector4& b)
{
    return (a.mV[VX]*b.mV[VX] + a.mV[VY]*b.mV[VY] + a.mV[VZ]*b.mV[VZ]);
}

inline LLVector4 operator%(const LLVector4& a, const LLVector4& b)
{
    return LLVector4(a.mV[VY]*b.mV[VZ] - b.mV[VY]*a.mV[VZ], a.mV[VZ]*b.mV[VX] - b.mV[VZ]*a.mV[VX], a.mV[VX]*b.mV[VY] - b.mV[VX]*a.mV[VY]);
}

inline LLVector4 operator/(const LLVector4& a, F32 k)
{
    F32 t = 1.f / k;
    return LLVector4( a.mV[VX] * t, a.mV[VY] * t, a.mV[VZ] * t );
}


inline LLVector4 operator*(const LLVector4& a, F32 k)
{
    return LLVector4( a.mV[VX] * k, a.mV[VY] * k, a.mV[VZ] * k );
}

inline LLVector4 operator*(F32 k, const LLVector4& a)
{
    return LLVector4( a.mV[VX] * k, a.mV[VY] * k, a.mV[VZ] * k );
}

inline bool operator==(const LLVector4& a, const LLVector4& b)
{
    return (  (a.mV[VX] == b.mV[VX])
            &&(a.mV[VY] == b.mV[VY])
            &&(a.mV[VZ] == b.mV[VZ]));
}

inline bool operator!=(const LLVector4& a, const LLVector4& b)
{
    return (  (a.mV[VX] != b.mV[VX])
            ||(a.mV[VY] != b.mV[VY])
            ||(a.mV[VZ] != b.mV[VZ])
            ||(a.mV[VW] != b.mV[VW]) );
}

inline const LLVector4& operator+=(LLVector4& a, const LLVector4& b)
{
    a.mV[VX] += b.mV[VX];
    a.mV[VY] += b.mV[VY];
    a.mV[VZ] += b.mV[VZ];
    return a;
}

inline const LLVector4& operator-=(LLVector4& a, const LLVector4& b)
{
    a.mV[VX] -= b.mV[VX];
    a.mV[VY] -= b.mV[VY];
    a.mV[VZ] -= b.mV[VZ];
    return a;
}

inline const LLVector4& operator%=(LLVector4& a, const LLVector4& b)
{
    LLVector4 ret(a.mV[VY]*b.mV[VZ] - b.mV[VY]*a.mV[VZ], a.mV[VZ]*b.mV[VX] - b.mV[VZ]*a.mV[VX], a.mV[VX]*b.mV[VY] - b.mV[VX]*a.mV[VY]);
    a = ret;
    return a;
}

inline const LLVector4& operator*=(LLVector4& a, F32 k)
{
    a.mV[VX] *= k;
    a.mV[VY] *= k;
    a.mV[VZ] *= k;
    return a;
}

inline const LLVector4& operator/=(LLVector4& a, F32 k)
{
    F32 t = 1.f / k;
    a.mV[VX] *= t;
    a.mV[VY] *= t;
    a.mV[VZ] *= t;
    return a;
}

inline LLVector4 operator-(const LLVector4& a)
{
    return LLVector4( -a.mV[VX], -a.mV[VY], -a.mV[VZ] );
}

inline F32  dist_vec(const LLVector4& a, const LLVector4& b)
{
    LLVector4 vec = a - b;
    return (vec.length());
}

inline F32  dist_vec_squared(const LLVector4& a, const LLVector4& b)
{
    LLVector4 vec = a - b;
    return (vec.lengthSquared());
}

inline LLVector4 lerp(const LLVector4& a, const LLVector4& b, F32 u)
{
    return LLVector4(
        a.mV[VX] + (b.mV[VX] - a.mV[VX]) * u,
        a.mV[VY] + (b.mV[VY] - a.mV[VY]) * u,
        a.mV[VZ] + (b.mV[VZ] - a.mV[VZ]) * u,
        a.mV[VW] + (b.mV[VW] - a.mV[VW]) * u);
}

inline F32      LLVector4::normalize()
{
    F32 mag = sqrt(mV[VX]*mV[VX] + mV[VY]*mV[VY] + mV[VZ]*mV[VZ]);
    F32 oomag;

    if (mag > FP_MAG_THRESHOLD)
    {
        oomag = 1.f/mag;
        mV[VX] *= oomag;
        mV[VY] *= oomag;
        mV[VZ] *= oomag;
    }
    else
    {
        mV[VX] = 0.f;
        mV[VY] = 0.f;
        mV[VZ] = 0.f;
        mag = 0.f;
    }
    return (mag);
}

// deprecated
inline F32      LLVector4::normVec()
{
    F32 mag = sqrt(mV[VX]*mV[VX] + mV[VY]*mV[VY] + mV[VZ]*mV[VZ]);
    F32 oomag;

    if (mag > FP_MAG_THRESHOLD)
    {
        oomag = 1.f/mag;
        mV[VX] *= oomag;
        mV[VY] *= oomag;
        mV[VZ] *= oomag;
    }
    else
    {
        mV[VX] = 0.f;
        mV[VY] = 0.f;
        mV[VZ] = 0.f;
        mag = 0.f;
    }
    return (mag);
}

// Because apparently some parts of the viewer use this for color info.
inline const LLVector4 srgbVector4(const LLVector4& a)
{
    LLVector4 srgbColor;

    srgbColor.mV[VX] = linearTosRGB(a.mV[VX]);
    srgbColor.mV[VY] = linearTosRGB(a.mV[VY]);
    srgbColor.mV[VZ] = linearTosRGB(a.mV[VZ]);
    srgbColor.mV[VW] = a.mV[VW];

    return srgbColor;
}


#endif