/********************************************************************************
* ReactPhysics3D physics library, http://code.google.com/p/reactphysics3d/      *
* Copyright (c) 2010-2012 Daniel Chappuis                                       *
*********************************************************************************
*                                                                               *
* This software is provided 'as-is', without any express or implied warranty.   *
* In no event will the authors be held liable for any damages arising from the  *
* use of this software.                                                         *
*                                                                               *
* Permission is granted to anyone to use this software for any purpose,         *
* including commercial applications, and to alter it and redistribute it        *
* freely, subject to the following restrictions:                                *
*                                                                               *
* 1. The origin of this software must not be misrepresented; you must not claim *
*    that you wrote the original software. If you use this software in a        *
*    product, an acknowledgment in the product documentation would be           *
*    appreciated but is not required.                                           *
*                                                                               *
* 2. Altered source versions must be plainly marked as such, and must not be    *
*    misrepresented as being the original software.                             *
*                                                                               *
* 3. This notice may not be removed or altered from any source distribution.    *
*                                                                               *
********************************************************************************/

#ifndef VECTOR3_H
#define VECTOR3_H

// Libraries
#include <cmath>
#include <cassert>
#include "mathematics_functions.h"
#include "../decimal.h"


// ReactPhysics3D namespace
namespace reactphysics3d {

/*  -------------------------------------------------------------------
    Structure Vector3 :
        This class represents a 3D vector.
    -------------------------------------------------------------------
*/
struct Vector3 {

    public:

        // -------------------- Attributes -------------------- //

        // Values of the 3D vector
        decimal x, y, z;

        // -------------------- Methods -------------------- //

        // Constructor of the class Vector3D
        Vector3();

        // Constructor with arguments
        Vector3(decimal newX, decimal newY, decimal newZ);

        // Copy-constructor
        Vector3(const Vector3& vector);

        // Destructor
        ~Vector3();

        // Set all the values of the vector
        void setAllValues(decimal newX, decimal newY, decimal newZ);

        // Return the lenght of the vector
        decimal length() const;

        // Return the square of the length of the vector
        decimal lengthSquare() const;

        // Return the corresponding unit vector
        Vector3 getUnit() const;

        // Return one unit orthogonal vector of the current vector
        Vector3 getOneUnitOrthogonalVector() const;

        // Return true if the vector is unit and false otherwise
        bool isUnit() const;

        // Return true if the current vector is the zero vector
        bool isZero() const;

        // Dot product of two vectors
        decimal dot(const Vector3& vector) const;

        // Cross product of two vectors
        Vector3 cross(const Vector3& vector) const;

        // Normalize the vector
        void normalize();

        // Return the corresponding absolute value vector
        Vector3 getAbsoluteVector() const;

        // Return the axis with the minimal value
        int getMinAxis() const;

        // Return the axis with the maximal value
        int getMaxAxis() const;

        // Return true if two vectors are parallel
        bool isParallelWith(const Vector3& vector) const;

        // Overloaded operator for the equality condition
        bool operator== (const Vector3& vector) const;

        // Overloaded operator for the is different condition
        bool operator!= (const Vector3& vector) const;

        // Overloaded operator for addition with assignment
        Vector3& operator+=(const Vector3& vector);

        // Overloaded operator for substraction with assignment
        Vector3& operator-=(const Vector3& vector);

        // Overloaded operator for multiplication with a number with assignment
        Vector3& operator*=(decimal number);

        // Overloaded operator for division by a number with assignment
        Vector3& operator/=(decimal number);

        // Overloaded operator for value access
        decimal& operator[] (int index);

        // Overloaded operator for value access
        const decimal& operator[] (int index) const;

        // Overloaded operator
        Vector3& operator=(const Vector3& vector);

        // -------------------- Friends -------------------- //

        friend Vector3 operator+(const Vector3& vector1, const Vector3& vector2);
        friend Vector3 operator-(const Vector3& vector1, const Vector3& vector2);
        friend Vector3 operator-(const Vector3& vector);
        friend Vector3 operator*(const Vector3& vector, decimal number);
        friend Vector3 operator*(decimal number, const Vector3& vector);
        friend Vector3 operator/(const Vector3& vector, decimal number);
};

// Set all the values of the vector
inline void Vector3::setAllValues(decimal newX, decimal newY, decimal newZ) {
    x = newX;
    y = newY;
    z = newZ;
}

// Return the length of the vector
inline decimal Vector3::length() const {
    return sqrt(x*x + y*y + z*z);
}

// Return the square of the length of the vector
inline decimal Vector3::lengthSquare() const {
    return x*x + y*y + z*z;
}

// Scalar product of two vectors (inline)
inline decimal Vector3::dot(const Vector3& vector) const {
    return (x*vector.x + y*vector.y + z*vector.z);
}

// Cross product of two vectors (inline)
inline Vector3 Vector3::cross(const Vector3& vector) const {
    return Vector3(y * vector.z - z * vector.y,
                   z * vector.x - x * vector.z,
                   x * vector.y - y * vector.x);
}

// Normalize the vector
inline void Vector3::normalize() {
    decimal l = length();
    assert(l > std::numeric_limits<decimal>::epsilon());
    x /= l;
    y /= l;
    z /= l;
}

// Return the corresponding absolute value vector
inline Vector3 Vector3::getAbsoluteVector() const {
    return Vector3(std::abs(x), std::abs(y), std::abs(z));
}       

// Return true if two vectors are parallel
inline bool Vector3::isParallelWith(const Vector3& vector) const {
    decimal scalarProd = this->dot(vector);
    return approxEqual(std::abs(scalarProd), length() * vector.length());
}    


// Return the axis with the minimal value
inline int Vector3::getMinAxis() const {
    return (x < y ? (x < z ? 0 : 2) : (y < z ? 1 : 2));
}

// Return the axis with the maximal value
inline int Vector3::getMaxAxis() const {
    return (x < y ? (y < z ? 2 : 1) : (x < z ? 2 : 0));
}

// Return true if the vector is unit and false otherwise
inline bool Vector3::isUnit() const {
    return approxEqual(lengthSquare(), 1.0);
}

// Return true if the vector is the zero vector
inline bool Vector3::isZero() const {
    return approxEqual(lengthSquare(), 0.0);
}

// Overloaded operator for the equality condition
inline bool Vector3::operator== (const Vector3& vector) const {
    return (x == vector.x && y == vector.y && z == vector.z);
}

// Overloaded operator for the is different condition
inline bool Vector3::operator!= (const Vector3& vector) const {
    return !(*this == vector);
}

// Overloaded operator for addition with assignment
inline Vector3& Vector3::operator+=(const Vector3& vector) {
    x += vector.x;
    y += vector.y;
    z += vector.z;
    return *this;
}

// Overloaded operator for substraction with assignment
inline Vector3& Vector3::operator-=(const Vector3& vector) {
    x -= vector.x;
    y -= vector.y;
    z -= vector.z;
    return *this;
}

// Overloaded operator for multiplication with a number with assignment
inline Vector3& Vector3::operator*=(decimal number) {
    x *= number;
    y *= number;
    z *= number;
    return *this;
}

// Overloaded operator for division by a number with assignment
inline Vector3& Vector3::operator/=(decimal number) {
    assert(number > std::numeric_limits<decimal>::epsilon());
    x /= number;
    y /= number;
    z /= number;
    return *this;
}

// Overloaded operator for value access
inline decimal& Vector3::operator[] (int index) {
    return (&x)[index];
}

// Overloaded operator for value access
inline const decimal& Vector3::operator[] (int index) const {
    return (&x)[index];
}

// Overloaded operator for addition
inline Vector3 operator+(const Vector3& vector1, const Vector3& vector2) {
    return Vector3(vector1.x + vector2.x, vector1.y + vector2.y, vector1.z + vector2.z);
}

// Overloaded operator for substraction
inline Vector3 operator-(const Vector3& vector1, const Vector3& vector2) {
    return Vector3(vector1.x - vector2.x, vector1.y - vector2.y, vector1.z - vector2.z);
}

// Overloaded operator for the negative of a vector
inline Vector3 operator-(const Vector3& vector) {
    return Vector3(-vector.x, -vector.y, -vector.z);
}

// Overloaded operator for multiplication with a number
inline Vector3 operator*(const Vector3& vector, decimal number) {
    return Vector3(number * vector.x, number * vector.y, number * vector.z);
}

// Overloaded operator for division by a number
inline Vector3 operator/(const Vector3& vector, decimal number) {
    assert(number > std::numeric_limits<decimal>::epsilon());
    return Vector3(vector.x / number, vector.y / number, vector.z / number);
}

// Overloaded operator for multiplication with a number
inline Vector3 operator*(decimal number, const Vector3& vector) {
    return vector * number;
}

// Assignment operator
inline Vector3& Vector3::operator=(const Vector3& vector) {
    if (&vector != this) {
        x = vector.x;
        y = vector.y;
        z = vector.z;
    }
    return *this;
}

}

#endif