//
//  glgrav - OpenGL N-Body gravity simulator
//
//  Copyright (C) 2003  Ian Cowburn (ianc@noddybox.demon.co.uk)
//
//  This program is free software; you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation; either version 2 of the License, or
//  (at your option) any later version.
//
//  This program 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 General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with this program; if not, write to the Free Software
//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//
//  -------------------------------------------------------------------------
//
//  3D Vector
//
//
static const char id[]="$Id: sparks.cpp 8 2010-08-18 14:38:34Z ianc $";

#include "vec3d.h"

#include <math.h>

Vec3D::Vec3D()
{
    m_dx = 0.0;
    m_dy = 0.0;
    m_dz = 0.0;
}

Vec3D::Vec3D(double dx, double dy, double dz)
{
    m_dx = dx;
    m_dy = dy;
    m_dz = dz;
}

Vec3D::~Vec3D()
{
}

void Vec3D::Set(double dx, double dy ,double dz)
{
    m_dx = dx;
    m_dy = dy;
    m_dz = dz;
}

double Vec3D::dx() const
{
    return m_dx;
}

double Vec3D::dy() const
{
    return m_dy;
}

double Vec3D::dz() const
{
    return m_dz;
}


bool Vec3D::IsNull() const
{
    return m_dx == 0.0 && m_dy == 0.0 && m_dz == 0.0;
}


double Vec3D::Length() const
{
    if (IsNull())
    {
    	return 0.0;
    }
    else
    {
	return sqrt(m_dx * m_dx + m_dy * m_dy + m_dz * m_dz);
    }
}


void Vec3D::Normalise()
{
    double l;

    l = Length();

    m_dx /= l;
    m_dy /= l;
    m_dz /= l;
}

void Vec3D::SetLength(double d)
{
    Normalise();
    Scale(d);
}


void Vec3D::AddScalar(double d)
{
    m_dx += d;
    m_dy += d;
    m_dz += d;
}

void Vec3D::Minus()
{
    m_dx = -m_dx;
    m_dy = -m_dy;
    m_dz = -m_dz;
}

void Vec3D::Scale(double d)
{
    m_dx *= d;
    m_dy *= d;
    m_dz *= d;
}


void Vec3D::Add(const Vec3D& v)
{
    m_dx += v.m_dx;
    m_dy += v.m_dy;
    m_dz += v.m_dz;
}

void Vec3D::Subtract(const Vec3D& v)
{
    m_dx -= v.m_dx;
    m_dy -= v.m_dy;
    m_dz -= v.m_dz;
}

void Vec3D::Scale(const Vec3D& v)
{
    m_dx *= v.m_dx;
    m_dy *= v.m_dy;
    m_dz *= v.m_dz;
}

double Vec3D::DotProduct(const Vec3D& v)
{
    return m_dx*v.m_dx + m_dy*v.m_dy + m_dz*v.m_dz;
}

Vec3D Vec3D::CrossProduct(const Vec3D& v)
{
    return Vec3D(m_dy * v.m_dz - v.m_dy * m_dz,
    		 m_dz * v.m_dx - v.m_dz * m_dx,
		 m_dx * v.m_dy - v.m_dx * m_dy);
}



// END OF FILE //