/********************************************************************************
* OpenGL-Framework															  *
* Copyright (c) 2013 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 OPENGLFRAMEWORK_VECTOR3_H
#define OPENGLFRAMEWORK_VECTOR3_H

// Libraries
#include <cmath>
#include <cassert>
#include <limits>

namespace openglframework {

// Class vec3
// This class represents a 3D vector.
class vec3 {

	public:

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

		// Components of the vector
		float x, y, z;

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

		// Constructor
		vec3(float x=0, float y=0, float z=0) : x(x), y(y), z(z) {}

		// Constructor
		vec3(const vec3& vector) : x(vector.x()), y(vector.y()), z(vector.z()) {}

		// Constructor
		~vec3() {}

		// = operator
		vec3& operator=(const vec3& vector) {
			if (&vector != this) {
				x = vector.x();
				y = vector.y();
				z = vector.z();
			}
			return *this;
		}

		// + operator
		vec3 operator+(const vec3 &v) const {
			return vec3(x + v.x(), y + v.y(), z + v.z());
		}

		// += operator
		vec3& operator+=(const vec3 &v) {
			x += v.x(); y += v.y(); z += v.z();
			return *this;
		}

		// - operator
		vec3 operator-(const vec3 &v) const {
			return vec3(x - v.x(), y - v.y(), z - v.z());
		}

		// -= operator
		vec3& operator-=(const vec3 &v) {
			x -= v.x(); y -= v.y(); z -= v.z();
			return *this;
		}

		// == operator
		bool operator==(const vec3 &v) const {
			return x == v.x() && y == v.y() && z == v.z();
		}

		// != operator
		bool operator!=(const vec3 &v) const {
		  return !( *this == v );
		}

		// * operator
		vec3 operator*(float f) const {
			return vec3(f*x, f*y, f*z);
		}

		// *= operator
		vec3 &operator*=(float f) {
			x *= f; y *= f; z *= f;
			return *this;
		}

		// / operator
		vec3 operator/(float f) const {
			assert(f > std::numeric_limits<float>::epsilon() );
			float inv = 1.f / f;
			return vec3(x * inv, y * inv, z * inv);
		}

		// /= operator
		vec3 &operator/=(float f) {
			assert(f > std::numeric_limits<float>::epsilon());
			float inv = 1.f / f;
			x *= inv; y *= inv; z *= inv;
			return *this;
		}

		// - operator
		vec3 operator-() const {
			return vec3(-x, -y, -z);
		}

		// [] operator
		float &operator[](int32_t i) {
			assert(i >= 0 && i <= 2);
			switch (i) {
			case 0: return x;
			case 1: return y;
			case 2: return z;
			}
			return z;
		}

		// [] operator
		const float &operator[](int32_t i) const {
			assert(i >= 0 && i <= 2);
			switch (i) {
			case 0: return x;
			case 1: return y;
			case 2: return z;
			}
			return z;
		}

		// Cross product operator
		vec3 cross(const vec3 &v) const{
			return vec3(y * v.z() - z * v.y(), z * v.x() - x * v.z, x * v.y - y * v.x);
		}

		// Dot product operator
		float dot(const vec3 &v) const{
			return x * v.x() + y * v.y() + z * v.z();
		}

		// Normalize the vector and return it
		vec3 normalize() {
			float l = length();
			if(l < std::numeric_limits<float>::epsilon() ) {
			  return *this;
			  }
			x /= l;
			y /= l;
			z /= l;
			return *this;
		}

		bool isNull() const {
		  return( x == 0. && y == 0. && z == 0. );
		}

		// Clamp the values between 0 and 1
		vec3 clamp01() {
			if (x>1.f) x=1.f;
			else if (x<0.f) x=0.f;
			if (y>1.f) y=1.f;
			else if (y<0.f) y=0.f;
			if (z>1.f) z=1.f;
			else if (z<0.f) z=0.f;
			return *this;
		}

		// Return the squared length of the vector
		float length2d() const { return x*x + y*y + z*z; }

		// Return the length of the vector
		float length() const { return sqrt(length2d()); }
};

inline vec3 operator*(float f, const vec3 & o) {
  return o*f;
}

}

#endif