/**
 * @file v4math.cpp
 * @brief LLVector4 class implementation.
 *
 * $LicenseInfo:firstyear=2000&license=viewerlgpl$
 * 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
 * $/LicenseInfo$
 */

#include "linden_common.h"

#include "v3math.h"
#include "v4math.h"
#include "m4math.h"
#include "m3math.h"
#include "llquaternion.h"

// LLVector4

// Axis-Angle rotations
const LLVector4&    LLVector4::rotVec(const LLMatrix4& mat)
{
    *this = *this * mat;
    return *this;
}

const LLVector4&    LLVector4::rotVec(const LLQuaternion& q)
{
    *this = *this * q;
    return *this;
}

const LLVector4&    LLVector4::scaleVec(const LLVector4& vec)
{
    mV[VX] *= vec.mV[VX];
    mV[VY] *= vec.mV[VY];
    mV[VZ] *= vec.mV[VZ];
    mV[VW] *= vec.mV[VW];

    return *this;
}

// Sets all values to absolute value of their original values
// Returns true if data changed
bool LLVector4::abs()
{
    bool ret{ false };

    if (mV[VX] < 0.f) { mV[VX] = -mV[VX]; ret = true; }
    if (mV[VY] < 0.f) { mV[VY] = -mV[VY]; ret = true; }
    if (mV[VZ] < 0.f) { mV[VZ] = -mV[VZ]; ret = true; }
    if (mV[VW] < 0.f) { mV[VW] = -mV[VW]; ret = true; }

    return ret;
}


std::ostream& operator<<(std::ostream& s, const LLVector4& a)
{
    s << "{ " << a.mV[VX] << ", " << a.mV[VY] << ", " << a.mV[VZ] << ", " << a.mV[VW] << " }";
    return s;
}


// Non-member functions

F32 angle_between( const LLVector4& a, const LLVector4& b )
{
    LLVector4 an = a;
    LLVector4 bn = b;
    an.normalize();
    bn.normalize();
    F32 cosine = an * bn;
    F32 angle = (cosine >= 1.0f) ? 0.0f :
        (cosine <= -1.0f) ? F_PI :
        acos(cosine);
    return angle;
}

bool are_parallel(const LLVector4 &a, const LLVector4 &b, F32 epsilon)
{
    LLVector4 an = a;
    LLVector4 bn = b;
    an.normalize();
    bn.normalize();
    F32 dot = an * bn;
    if ( (1.0f - fabs(dot)) < epsilon)
        return true;
    return false;
}


LLVector3 vec4to3(const LLVector4& vec)
{
    return LLVector3( vec.mV[VX], vec.mV[VY], vec.mV[VZ] );
}

LLVector4 vec3to4(const LLVector3& vec)
{
    return LLVector4(vec.mV[VX], vec.mV[VY], vec.mV[VZ]);
}