/***************************************************************************
                          vector.cpp  -  A 3D vector class
                             -------------------
    begin                : Tue Apr 23 2002
    copyright            : (C) 2002 by CJP
    email                : cornware-cjp@users.sourceforge.net
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   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.                                   *
 *                                                                         *
 ***************************************************************************/
#include <cmath>

#include "vector.h"
#include "matrix.h"

CVector::CVector()
{x=0; y=0; z=0;}

CVector::CVector( float xa, float ya, float za)
{
    x = xa;
    y = ya;
    z = za;
}

CVector const &CVector::operator*=(CMatrix const &val)
{
	float xt = x, yt = y, zt = z;

	x = val.Element(0,0)*xt + val.Element(1,0)*yt + val.Element(2,0)*zt;
	y = val.Element(0,1)*xt + val.Element(1,1)*yt + val.Element(2,1)*zt;
	z = val.Element(0,2)*xt + val.Element(1,2)*yt + val.Element(2,2)*zt;

	return (*this);
}

/*
CVector const CVector::operator*(CMatrix const &val) const
{
	CVector ret(x,y,z);
	ret *= val;
	return ret;
}
*/

CVector const &CVector::operator/=(CMatrix const &val)
{
	float xt = x, yt = y, zt = z;

	x = val.Element(0,0)*xt + val.Element(0,1)*yt + val.Element(0,2)*zt;
	y = val.Element(1,0)*xt + val.Element(1,1)*yt + val.Element(1,2)*zt;
	z = val.Element(2,0)*xt + val.Element(2,1)*yt + val.Element(2,2)*zt;

	return (*this);
}

/*
CVector const CVector::operator/(CMatrix const &val) const
{
	CVector ret(x,y,z);
	ret /= val;
	return ret;
}
*/

CVector const CVector::operator*(float const &val) const
	{return CVector(x*val,y*val,z*val);}

CVector const &CVector::operator*=(float const &val)
{
	x *= val;
	y *= val;
	z *= val;
	return (*this);
}

CVector const operator*(float const &val1, CVector const &val2)
	{return CVector(val2.x*val1,val2.y*val1,val2.z*val1);}

CVector const CVector::operator/(float const &val) const
	{return CVector(x/val, y/val, z/val);}

CVector const &CVector::operator/=(float const &val)
{
	x /= val;
	y /= val;
	z /= val;
	return (*this);
}

CVector const CVector::operator+(CVector const &val) const
{
	float xt = x+val.x, yt = y+val.y, zt = z+val.z;

	CVector ret(xt,yt,zt);

	return ret;
}

CVector const CVector::operator-(CVector const &val) const
{
	float xt = x-val.x, yt = y-val.y, zt = z-val.z;

	CVector ret(xt,yt,zt);

	return ret;
}

CVector const CVector::operator-() const
{return CVector(-x,-y,-z);}

CVector const &CVector::operator+=(CVector const &val)
{
	x += val.x;
	y += val.y;
	z += val.z;

	return (*this);
}

CVector const &CVector::operator-=(CVector const &val)
{
	x -= val.x;
	y -= val.y;
	z -= val.z;

	return (*this);
}

float const CVector::operator*(CVector const &val) const
{
	return dotProduct(val);
}

float CVector::dotProduct(CVector const &val) const
{
	return x*val.x + y*val.y + z*val.z;
}

CVector CVector::crossProduct(CVector const &val) const
{
	CVector ret;
	ret.x = y*val.z - z*val.y;
	ret.y = z*val.x - x*val.z;
	ret.z = x*val.y - y*val.x;
	return ret;
}

float CVector::abs() const
{return sqrt(abs2());}

float CVector::abs2() const
{return x*x+y*y+z*z;}

void CVector::normalise()
{
	float a = abs();
	if(a > 0.0)
	{
		x /= a;
		y /= a;
		z /= a;
	}
	else //very small vector->badly defined direction->setting to +x
	{
		x = 1.0;
	}
}

CVector CVector::normal() const
{
	CVector ret;
	float a = abs();
	if(a > 0.0)
	{
		ret.x = x / a;
		ret.y = y / a;
		ret.z = z / a;
	}
	else //very small vector->badly defined direction->setting to +x
	{
		ret.x = 1.0;
	}
	return ret;
}

CVector CVector::component(CVector const &val) const
{
	CVector ret;
	float comp = x*val.x + y*val.y + z*val.z;
	ret.x = val.x * comp;
	ret.y = val.y * comp;
	ret.z = val.z * comp;
	return ret;
}